Hybrid data plane for a containerized router

In general, this disclosure describes techniques for providing a hybrid data plane that can include a kernel-based data plane and a Data Plane Development Kit (DPDK)-based data plane. An example system includes a DPDK-based virtual router configured to send and receive packets via a physical network interface, and a kernel network stack configured to perform tunneling processing for packets destined to a containerized application and received by the DPDK-based virtual router via the physical interface.

TECHNICAL FIELD

The disclosure relates to virtualized computing infrastructure and, more specifically, to a hybrid data plane for containerization platforms.

BACKGROUND

In a typical cloud data center environment, there is a large collection of interconnected servers that provide computing and/or storage capacity to run various applications. For example, a data center may comprise a facility that hosts applications and services for subscribers, i.e., customers of data center. The data center may, for example, host all of the infrastructure equipment, such as networking and storage systems, redundant power supplies, and environmental controls. In a typical data center, clusters of storage systems and application servers are interconnected via high-speed switch fabric provided by one or more tiers of physical network switches and routers. More sophisticated data centers provide infrastructure spread throughout the world with subscriber support equipment located in various physical hosting facilities.

Virtualized data centers are becoming a core foundation of the modern information technology (IT) infrastructure. In particular, modern data centers have extensively utilized virtualized environments in which virtual hosts, also referred to herein as virtual execution elements, such virtual machines or containers, are deployed and executed on an underlying compute platform of physical computing devices.

Virtualization within a data center or any environment that includes one or more servers can provide several advantages. One advantage is that virtualization can provide significant improvements to efficiency. As the underlying physical computing devices (i.e., servers) have become increasingly powerful with the advent of multicore microprocessor architectures with a large number of cores per physical CPU, virtualization becomes easier and more efficient. A second advantage is that virtualization provides significant control over the computing infrastructure. As physical computing resources become fungible resources, such as in a cloud-based computing environment, provisioning and management of the computing infrastructure becomes easier. Thus, enterprise IT staff often prefer virtualized compute clusters in data centers for their management advantages in addition to the efficiency and increased return on investment (ROI) that virtualization provides.

Containerization is a virtualization scheme based on operating system-level virtualization. Containers are light-weight and portable execution elements for applications that are isolated from one another and from the host. Such isolated systems represent containers, such as those provided by the open-source DOCKER Container application or by CoreOS Rkt (“Rocket”). Like a virtual machine, each container is virtualized and may remain isolated from the host machine and other containers. However, unlike a virtual machine, each container may omit an individual operating system and instead provide an application suite and application-specific libraries. In general, a container is executed by the host machine as an isolated user-space instance and may share an operating system and common libraries with other containers executing on the host machine. Thus, containers may require less processing power, storage, and network resources than virtual machines. A group of one or more containers may be configured to share one or more virtual network interfaces for communicating on corresponding virtual networks.

Because containers are not tightly-coupled to the host hardware computing environment, an application can be tied to a container image and executed as a single light-weight package on any host or virtual host that supports the underlying container architecture. As such, containers address the problem of how to make software work in different computing environments. Containers offer the promise of running consistently from one computing environment to another, virtual or physical.

With containers' inherently lightweight nature, a single host can often support many more container instances than traditional virtual machines (VMs). Often short-lived, containers can be created and moved more efficiently than VMs, and they can also be managed as groups of logically-related elements (e.g., containerized workloads, sometimes referred to as “pods” for some orchestration platforms, e.g., Kubernetes). These container characteristics impact the requirements for container networking solutions: the network should be agile and scalable. VMs, containers, and bare metal servers may need to coexist in the same computing environment, with communication enabled among the diverse deployments of applications. The container network should also be agnostic to work with the multiple types of orchestration platforms that are used to deploy containerized applications.

A computing infrastructure that manages deployment and infrastructure for application execution may involve two main roles: (1) orchestration—for automating deployment, scaling, and operations of applications across clusters of hosts and providing computing infrastructure, which may include container-centric computing infrastructure; and (2) network management—for creating virtual networks in the network infrastructure to enable packetized communication among applications running on virtual execution environments, such as containers or VMs, as well as among applications running on legacy (e.g., physical) environments. Software-defined networking contributes to network management.

SUMMARY

In general, this disclosure describes techniques for providing a hybrid data plane for a compute node, the hybrid data plane comprised of two different data planes that each may support different communication protocols. Existing systems typically provide a single data plane, or, if multiple data planes are provided, they are disjoint data planes. A single data plane may not be able to meet the varying needs of containerized applications on a server. For example, some containerized applications—which may be deployed using pods—may require high throughput and low latency that may be provided by a Data Plane Development Kit (DPDK) data plane, while other pods may require encapsulations, services, and/or routing that are not supported by a DPDK data plane. In a disjoint model, a set of the fabric (core facing) interfaces are managed by the kernel data plane and another set are managed by DPDK data plane. In this model, traffic from kernel pod interfaces is intended to be forwarded over kernel core interfaces and traffic from DPDK pods is intended to be forwarded over DPDK fabric interfaces. However, it is very complicated, if not impossible, to achieve this separation for corresponding control plane and routing protocols. Further, there can be no guarantee that inbound or outbound packets will take the interface corresponding to the intended data plane. This can result in inefficient packet handling or even a break down in the data plane. As an example, a compute node implementing a disjoint data plane may have a first port owned by the kernel data plane and a second port owned by the DPDK data plane. Because the compute node cannot typically inform an external node which port to use for communication with pods on the compute node, it is possible for a packet that ought to be processed by the DPDK plane data plane to arrive on an interface that is owned by the kernel (e.g., the first port). When this happens, the kernel must forward the packet to the DPDK data plane, thereby incurring overhead and inefficient processing of the packet. Moreover, the DPDK data plane typically handles network traffic at a much higher rate than the kernel data plane. As a result, the kernel may receive packets meant for the DPDK data plane at a high rate. This can result in significant CPU utilization issues or resource memory issues, which can further result in degradation of overall system performance.

In view of the above, the single data plane or disjoint data planes provided by existing systems may not meet the varying needs of different workloads executed on a server. Further, disjoint data planes can result in inefficient handling of network traffic meant for the DPDK data plane that arrives on the kernel data plane.

The hybrid data plane described herein may support a Cloud Native Router in a manner that provides technical advantages over existing systems. For example, a technical advantage of the hybrid data plane model described herein is that the hybrid data plane can avoid breakdowns or inefficient operation by configuring the DPDK data plane in a compute node to own all of the fabric interfaces. A pod or other workload can be configured to utilize one or both of a kernel data plane and a DPDK data plane that are provided as part of the hybrid data plane. The pod can be configured to use the data plane that is best suited to the pod's communications requirements, i.e., of the containerized applications deployed in that pod. For example, pods that require high throughput and/or low latency can be configured to utilize the DPDK data plane, while pods that require more complex encapsulations not supported by the DPDK data plane can utilize the kernel-based data plane. The kernel data plane can perform the encapsulations, and forward the encapsulated packets to the DPDK data plane for pass through forwarding out an interface owned by the DPDK data plane. Because the DPDK data plane is assigned all of the physical interfaces managed by the Cloud Native Router, incoming packets are received by the DPDK data plane. The DPDK data plane can include logic to determine if an incoming packet is to be processed by the DPDK data plane or transferred to the kernel data plane for decapsulation or other processing not supported by the DPDK data plane.

A hybrid data plane according to the techniques disclosed herein may include a kernel data plane and a DPDK data plane. A pod or other containerized workload may be configured to utilize whichever data plane of the hybrid data plane that best meets its requirements. As an example, a pod requiring high data transfer rates and low latency may be configured to use a DPDK data plane. However, a DPDK data plane does not typically support all of the different types of encapsulations and overlays that a kernel data plane may support, such as IPsec support, SRv6, IP-IP, EVPN-VxLAN, L3VPN over SRv6 etc. Thus, a pod or other container unit that requires such capabilities may be configured to use a kernel data plane. However, it can be difficult for a control plane to efficiently control both a kernel data plane and a DPDK data plane that are on a same compute node.

In some aspects, all of the physical interfaces of a compute node that are managed by a Cloud Native Router are assigned to DPDK virtual routers. Pods that are configured to use DPDK can directly use interfaces provided by the DPDK-enabled virtual routers. Pods that require capabilities that are not supported by the DPDK-enabled virtual routers can be configured to use kernel data plane interfaces. The techniques may involve, in at least some aspects, assigning all of the network interfaces of a server to one or more DPDK-based virtual routers on the server. The DPDK-enabled virtual router can provide data communication and routing functions for pods configured to use DPDK, for example, and pods can benefit from this aspect of the hybrid data plane providing high speed, low latency communication. The techniques may further involve a kernel configured with a network stack to provide capabilities that may be lacking in the DPDK-enabled virtual router. For example, the kernel (or a virtual router configured as a module of the kernel) may provide a data plane that supports IPsec, SRv6, IP-IP, EVPN-VxLAN, L3VPN over SRv6 etc. A pod requiring such support may be configured with a virtual network interface with the kernel to cause the pods to send data to the kernel for processing by the kernel network stack. The kernel is configured to route all traffic to the DPDK-enabled router, which acts as a pass-through for traffic received from the kernel. That is, the DPDK-enabled virtual router performs little to no processing of the packet and transmits the packet through one of the physical interfaces allocated to the DPDK-based virtual router. Thus, the kernel data plane and the DPDK-enabled data plane are combined to form a hybrid data plane.

As noted above, the hybrid data plane may be implemented to support a Cloud Native Router using a container orchestration platform. A container networking interface (CNI) is a networking solution for application containers and is a runtime executable that assists with configuring interfaces between containers and other components of the computing device (“host”) hosting the container, which may be a member of a pod. The computing device may be alternatively referred to as a “compute node” or “server”. The CNI typically assigns the network address (e.g., IP address) to the network interface and may also add routes relevant for the interface, such as routes for the default gateway and one or more nameservers.

A virtual router is the software entity that provides packet routing and forwarding data plane functionality on the compute node. The compute node may be hosting VMs or containers centrally orchestrated and provisioned. The virtual router may work with an SDN controller to create the overlay network by exchanging routes, configurations, and other data. A virtual router can run as either a Linux kernel module or a DPDK-based process. DPDK allows a virtual router to process more packets per second than is possible when running as a kernel module. This virtual router data plane may be containerized. In combination, the containerized cRPD and containerized DPDK-based virtual router may thus be a fully functional containerized router.

The compute node may be used to implement parts of a (5thgeneration) cellular network using cloud-native, Open Radio Access Network (“O-RAN” or “Open RAN”) architecture. The cloud may be built with containers and Kubernetes. The cell-site router functionality may be realized on compute nodes that host Distributed Unit (DU) 5G functionality as containerized applications. That is, DU functionality may be realized as Kubernetes Pods on these compute nodes. At a very high level, the DU functionality will consume RAN traffic, process it, and send it over tunnels to the Control Unit functionality (CU) hosted in a data center.

To meet the routing functionality and forwarding performance requirements that may be involved in 5G network use cases, the compute nodes may be configured to use a Cloud Native Router with a hybrid data plane in which a cRPD running on the compute node operates as the control plane and configures the Cloud Native Router to include both kernel-based routing and a DPDK-based virtual router. The kernel-based routing can process routings and encapsulations that the DPDK-based virtual router is not capable of handling, and the DPDK virtual router provides a fast path data plane for pods that do not require more complex encapsulations.

In an example, a system is described that includes processing circuitry; a containerized application; a physical network interface; a data plane development kit (DPDK)-based virtual router configured to execute on the processing circuitry to send and receive packets via the physical network interface; and a kernel network stack configured to execute on the processing circuitry to perform tunneling processing for packets destined to the containerized application and received by the DPDK-based virtual router via the physical interface.

In another example, a method is described that includes receiving, from a physical interface by a data plane development kit (DPDK)-based virtual router executed by processing circuitry, a first packet destined for a containerized application; determining, by the DPDK-based virtual router whether a kernel network stack executed by the processing circuitry is to perform tunneling processing for the first packet; and in response to determining that the kernel network stack is to perform tunneling processing for the first packet, forwarding, by the DPDK-based virtual router, the first packet to the kernel network stack.

In a further example, a computer-readable storage medium is described that includes computer-executable instructions, that when executed, cause one or more processors that execute a DPDK-based virtual router to perform operations comprising: receive a first packet destined for a containerized application; determine whether a kernel network stack executed by the one or more processors is to perform tunneling processing for the first packet; and in response to a determination that the kernel network stack is to perform tunneling processing for the first packet, forward the first packet to the kernel network stack.

The details of one or more examples of this disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.

Like reference characters denote like elements throughout the description and figures.

DETAILED DESCRIPTION

“Container-based” or “operating system” virtualization refers to the virtualization of an operating system to run multiple isolated systems on a single machine (virtual or physical). Such isolated systems represent containers, such as those provided by Kubernetes Container Runtime Interface-Open Container Initiative (CRI-O), containerd, the open-source Docker Container application or by CoreOS Rkt (“Rocket”). Like a virtual machine, each container is virtualized and may remain isolated from the host machine and other containers. However, unlike a virtual machine, each container may omit an individual operating system and provide only an application suite and application-specific libraries. In general, a container is executed by the host machine (e.g., one of network devices107) as an isolated user-space instance and may share an operating system and common libraries with other containers executing on the host machine. Thus, containers may require less processing power, storage, and network resources than virtual machines. A group of one or more containers may be configured to share one or more virtual network interfaces for communicating on corresponding virtual networks.

In some examples, containers are managed by their host kernel to allow limitation and prioritization of resources (CPU, memory, block I/O, network, etc.) without the need for starting any virtual machines. In some examples, containers may be deployed according to Linux Containers (LXC), an operating-system-level virtualization method for running multiple isolated Linux systems (containers) on a control host using a single Linux kernel.

5G uses a cloud-native approach in which functional blocks are decomposed into microservices. The microservices are deployed as containers on x86 platforms, orchestrated by Kubernetes (abbreviated as “K8s”). This includes 5G core control plane functions such Access and Mobility Management Function (AMF) and Session Management Function (SMF), RAN control plane functions such as CU-CP, service management and orchestration (SMO), Near-Real Time & Non-Real Time Radio Intelligent Controller (MC) and even some data-plane functions such as CU-DP and DU.

Kubernetes networking between pods is via plug-ins called Container Networking Interfaces (CNIs) (also known as Container Network Interface plugins). However, the networking capabilities of typical CNIs are rather rudimentary and not suitable when the containerized network functions the CNI serves play a pivotal role within a telecommunications network. A Cloud Native Router (CNR), as described herein, provides a better fit for these situations. A Cloud Native Router is a containerized router that allows an x86 or ARM based host to be a first-class member of the network routing system, participating in protocols such as Intermediate System to Intermediate System (IS-IS) and Border Gateway Protocol (BGP) and providing Multiprotocol Label Switching/Segment Routing (MPLS/SR) based transport and multi-tenancy. In other words, rather than the platform being an appendage to the network (like a customer edge (CE) router), it may be operating as a provider edge (PE) router.

A Cloud Native Router may have one or more advantages over a conventional router. A router has a control plane and a forwarding plane. The control plane participates in dynamic routing protocols and exchanges routing information with other routers in the network. It downloads the results into a forwarding plane, in the form of prefixes, next-hops and associated SR/MPLS labels. Implementations described herein are modular, in the sense that the control plane is agnostic to the exact details of how the forwarding plane is implemented. In a hardware router, the forwarding plane may be based on custom ASICs. In contrast, the Cloud Native Router is a virtualized router. However, the routing protocol software is functionally similar in both cases. This means the Cloud Native Router benefits from the same highly comprehensive and robust protocol implementation as the hardware-based routers that underpin some of the world's largest networks.

The Cloud Native Router uses a containerized routing protocol daemon (cRPD) Control Plane and a virtual router (virtual router) forwarding plane to deliver high performance networking in a small footprint, software package that is functionally similar to a non-virtual router, a physical network function (PNF). The forwarding plane may be implemented via a choice of DPDK, Linux Kernel or Smart-NIC. The complete integration delivers a K8s CNI-compliant package, deployable within a K8s environment (e.g., Multus-enabled).

A server may be a K8s worker/compute node (or “minion”). A pod can be plumbed into the Cloud Native Router. The pod may require multiple network interfaces, facilitated in some cases by the Multus meta-CNI. Each of these interfaces can be mapped into a different Layer 3 VPN on the Cloud Native Router to support multiple network slices. When triggered by K8s pod events, a CNI can dynamically add or delete interfaces between the pod and the virtual router. The CNI can also dynamically update the cRPD control plane container with host routes for each pod interface and corresponding Layer 3 VPN mappings, in the form of Route Distinguishers and Route Targets. The Layer 3 VPNs may be implemented using virtual routing and forwarding instances (VRFs). In turn, the cRPD control plane programs the virtual router forwarding plane accordingly via a gRPC interface. In this way, the Cloud Native Router is introduced into the data path, supporting the F1 interfaces to the CUs running in edge or regional DC sites. While described primarily with respect to O-RAN applications such as the Distributed Units, the Cloud Native Router techniques are applicable for configuring host-based virtual router for other containerized applications.

As the CNR is itself a cloud-native application, it supports installation using K8s manifests or Helm Charts. These include the initial configuration of the router, including routing protocols and Layer 3 VPNs to support slices. A CNR may be orchestrated and configured, in a matter of seconds, with all of the routing protocol adjacencies with the rest of the network up and running. Ongoing configuration changes during the lifetime of the CNR, for example to add or remove network slices, may be via a choice of CLI, K8s manifests, NetConf or Terraform.

By adopting a K8s CNI framework, the Cloud Native Router may mitigate the traditional operational overhead incurred when using a containerized appliance rather than its physical counterpart. By exposing the appropriate device interfaces, the Cloud Native Router may normalize the operational model of the virtual appliance to the physical appliance, eradicating the barrier to adoption within the operator's network operations environment. The Cloud Native Router may present a familiar routing appliance look-and-feel to any trained operations team. The Cloud Native Router has similar features and capabilities, and a similar operational model as a hardware-based platform. Likewise, a domain-controller can use the protocols that it is uses with any other Junos router to communicate with and control the Cloud Native Router, for example Netconf/OpenConfig, gRPC, Path Computation Element Protocol (PCEP) and Programmable Routing Daemon (pRPD) application program interfaces (APIs).

FIG.1Ais a block diagram illustrating an example mobile network system, in accordance with techniques described in this disclosure. Mobile network system100may be a 5G network that implements 5G standards promulgated by, e.g., the 3rdGeneration Partnership Project (3GPP), the Open Radio Access Network (“O-RAN” or “ORAN”) Alliance, the European Telecommunications Standards Institute (ETSI), the Internet Engineering Task Force (IETF), and the International Telecommunication Union (ITU).

5G networks allow for disaggregation of mobile fronthaul and midhaul networks by building then around cloud native principles. As a result, service providers may avoid becoming locked into particular appliance vendors and may combine effective solutions from different vendors at different layers and locations to build and provision the mobile network system. This can improve the radio access networks (RANs), in particular, by making them more open, resilient, and scalable.

O-RAN-based networks decompose the baseband unit (BBU) found in traditional telco networks into three functional units: a Radio Unit (RU), a Distributed Unit (DU), and a Centralized Unit (CU). Different functions of RUs, DUs, and CUs may be implemented by software executed by x86-based or ARM-based host servers. The CU can be further segregated into distinct control plane (CU-CP) and user plane (CU-UP) functions to further control and user plane separation (CUPS). This decoupling helps bring flexibility to deployment—different combinations of RU, DU, and CU may be deployed at the same location, or at different locations. For example, where latency is critical, RU, DU, and CU can be placed together at the edge. DUs and CUs that conform to O-RAN are often referred to as O-DUs and O-CUs, respectively. Additional data plane elements known as user plane functions (UPFs) operate in mobile core network7to forward traffic between the CU and data network15. Additional control plane elements operate in mobile core network7. These control plane elements include Network Slice Selection Function (NSSF), Policy Control Function (PCF), Authentication Server Function (ASUF), Access and Mobility Management Function (AMF), Network Exposure Function (NEF), Network Function Repository Function (NRF), Application Function (AF), Unified Data Management (UDM), and Session Management Function (SMF).

Mobile network system100includes radio access networks9and mobile core network7. Radio access networks9include RUs14located at various cellular network sites (“cell sites”). Each RU14consists of an LO PHY and a RF transmitter. The LO PHY component may be implemented using specialized hardware for high-performance packet processing.

RUs14connect to DUs22A-22X (collectively, “DUs22”) via the fronthaul network. The fronthaul network connects LO PHY and HI PHY and is used by RUs14and DUs22to implement the F2 interface of 5G. DUs22manage the packet transmission of radio by the RUs14. In some cases, such packet transmission conforms to the Common Packet Radio Interface (CPRI) and/or to the enhanced CPRI (eCPRI) standard, or to IEEE 1914.3. DUs22may implement the Radio Link Control (RLC), Media Access Control (MAC), and the HI PHY layer. DUs22are at least partially controlled by CUs13A-13B (collectively, “CUs13”).

DUs22connect to CUs13via the midhaul network, which may be used by DUs22and CUs13to implement the F1 interface of 5G. CUs13may implement the Radio Resource Control (RRC) and Packet Data Convergence Protocol (PDCP) layers. CUs13connect to mobile core network7via a backhaul network. The midhaul and backhaul networks may each be wide area networks (WANs).

In radio access networks9of mobile network system100, the gNodeB includes one of CUs13and one of DUs22. A CU may support multiple DUs to implement multiple gNodeBs. And one or more RUs may be supported by a single DU. Thus, for example with respect toFIG.1A, CU13A and DU22A and one of RUs14may form one eNodeB, while CU13A and DU22B (of server12B) and another one of RUs14may form another eNodeB.

As shown inFIG.1A, any DU of DUs22may or may not be located at the cell site that includes the RU(s)14supported by the DU. DU22X is located at the cell site, while DUs22A-22N are located at a local data center and collectively support multiple RUs14. Mobile network system100may have radio access networks9that include many thousands of cell sites, each having one or more RUs14sand optionally one or more DUs22. Whether located at a cell site or offsite, a DU is typically within 20 km of the supported RUs. CUs13are shown inFIG.1Aas located at a regional data center, typically within 40 km of the supported DUs22.

Radio access networks9connect to mobile core network7to exchange packets with data network15. Mobile core network7may be a 5G core network, and data network (DN)15may represent, for example, one or more service provider networks and services, the Internet, 3rdparty services, an IP-multimedia subsystem, or other network.

Mobile network system100includes multiple servers12A-12X to execute DUs22. Each of servers12may be a real or virtual server that hosts/executes software that implements DUs22. Such software may include one or more applications deployed as, e.g., virtual machine or containers, to servers12. While not shown inFIG.1A, CUs13may also be executed by servers.

The combination of DUs22, the midhaul network, CUs13, and the backhaul network effectively implement an IP-based transport network between the radio units14and mobile core network7.

Cloud Native Routers20A-20X (“CNRs20A-20X” and collectively, “CNRs20”) provide layer 3 routing functionality between DUs22and CUs13. These CNRs20may be executed on the same server12as one or more DUs22to provide provider edge router functionality to such DUs22. In some examples, any of CNRs20may be deployed to a local data center together with one or more DUs22for which the CNR provides IP services, as shown with respect to CNRs20A-20N, i.e., where the local data center includes servers12that execute DUs22for one or more cell sites. In some examples, a CNR may be deployed at a cell site as shown inFIG.1A. A CNR deployed at a cell site may be referred to as a “virtualized cell site router.”

Each of CNRs20is implemented using one of containerized routing protocol daemons24A-24X (“cRPDs24A-24X” and collectively, “cRPDs24”). More specifically, each of CNRs20uses a corresponding cRPD of cRPDs24as a control plane for implementing a layer 3 router. The cRPD provides control plane routing functions. For example, the cRPD can execute IP (IPv4/IPv6) underlay routing protocols such as Intermediate System-Intermediate System (IS-IS) and Border Gateway Protocol (BGP); advertise reachability of DUs22both inside and outside a cluster, e.g., to CUs13; implement network namespaces (supported using L3VPN and EVPN Type-5 advertisements); implement Access Control Lists (ACLs) and network policies for security, network isolation, and quality of service (QoS); support tunnels and tunneling protocols (e.g., MPLS, SR-MPLS, SRv6, SR-MPLSoIPv6, SR-MPLSoIPv4, VxLAN, IP-in-IP, GRE); support dynamic tunnels signaled using BGP; support encryption for IPSec tunnels; and program a forwarding plane of the CNR of the server with learned and/or configured routing information to provide layer 3 packet forwarding, encapsulation, packet filtering, and/or QoS between one or more of DUs22and one of CUs13.

For example, CNR20A executed by server12A includes cRPD24A and a forwarding plane of server12A (e.g., a SmartNIC, kernel-based forwarding plane, or Data Plane Development Kit (DPDK)-based forwarding plane). cRPD24A provides one or more of the above routing functions to program a forwarding plane of CNR20A in order to, among other tasks, advertise a layer 3 route for DU22A outside of the cluster—including across the midhaul network to CU13A—and forward layer 3 packets between DU22A and CU13A. In this way, the techniques realize cloud-native, containerized cell site routers20executing on the same servers12as containerized DUs22, thus significantly reducing latency on the midhaul between DUs22and CUs13.

CNRs20as containerized routers allow an x86-based or ARM-based host to be a first-class member of the network routing system, participating in protocols such as IS-IS and BGP and providing MPLS/SR-based transport and multi-tenancy. Thus, rather than being appendages to the network (similar to a customer edge (CE) router), CNRs20may operate as provider edge (PE) routers for networks transporting layer 3 packets among DUs22, CUs13, and mobile core network7.

Moreover, in some examples, the integration of cRPDs24and host-based forwarding planes may also deliver a Kubernetes CNI-compliant package that is deployable within a Kubernetes environment. The execution by a single server of a DU22and a CNR20together can avoid a two-box solution with a separate DU and router, potentially reducing costs, power, and space requirements, which is particularly attractive for cell sites. Application workloads can be containerized network functions (CNFs), such as DUs.

Orchestrator50represents a container orchestration platform. “Orchestration,” in the context of a virtualized computing infrastructure generally refers to provisioning, scheduling, and managing virtual execution elements and/or applications and services executing on such virtual execution elements to the host servers available to the orchestration platform. Container orchestration, specifically, permits container coordination and refers to the deployment, management, scaling, and configuration, e.g., of containers to host servers by a container orchestration platform. Example instances of orchestration platforms include Kubernetes, Docker swarm, Mesos/Marathon, OpenShift, OpenStack, VMware, and Amazon ECS. Orchestrator50orchestrates DUs22and at least containerized RPDs24of CNRs20. In some examples, the data plane of CNRs20is also containerized and orchestrated by orchestrator50. The data plane may be DPDK-based data plane, a kernel-based data plane, or a hybrid data plane as described further below.

Containers, including those implementing containerized routing protocol daemons24, may be deployed to a virtualization environment using a cluster-based framework in which a cluster master node of a cluster manages the deployment and operation of containers to one or more cluster minion nodes of the cluster. The terms “master node” and “minion node” used herein encompass different orchestration platform terms for analogous devices that distinguish between primarily management elements of a cluster and primarily virtual execution element hosting devices of a cluster. For example, the Kubernetes platform uses the terms “cluster master node” and “minion nodes,” while the Docker Swarm platform refers to cluster managers and cluster nodes. Servers12or virtual machines thereon may represent cluster nodes.

Orchestrator50and software defined network (SDN) controller70may execute on separate computing devices or execute on the same computing device. Each of orchestrator50and SDN controller70may each be a distributed application that executes on one or more computing devices. Orchestrator50and SDN controller70may implement respective master nodes for one or more clusters each having one or more minion nodes implemented by respective servers12. In general, SDN controller70controls the network configuration of radio access network9to facilitate packetized communications among DUs22, CUs13, and mobile core network7. SDN controller70may distribute routing and configuration information to the control plane elements of radio access networks9, in particular, to cRPDs24. SDN controller70may, for instance, program segment routing headers, configure L3VPNs, configure VRFs in routers of radio access network9(including Cloud Native Routers20). SDN controller70may implement one or more southbound protocols for configuring router, switches, and other networks devices of the midhaul and backhaul networks, as well as for configuring CNRs20. Example southbound protocols may include Path Computation Element Protocol (PCEP), BGP, Netconf, OpenConfig, another protocol for configuring cRPDs24, and so forth. Additional information regarding L3VPNs is found in “BGP/MPLS IP Virtual Private Networks (VPNs),” Request for Comments4364, Network Working Group of Internet Engineering Task Force, February 2006, which is incorporated by reference in its entirety.

SDN controller70may provide a logically and in some cases physically centralized controller. In some examples, SDN controller70may operate in response to configuration input received from orchestrator50and/or an administrator/operator. SDN controller70may program NFV infrastructure (NFVI) such as servers12, network switches/routers, and/or other network infrastructure. In the case of NFVI programming, SDN controller70may configure aspects of the operating system kernel to configure L3 IP routing, Linux bridges, iptables, network namespaces, and/or virtual switches.

Additional information of an example SDN controller70, virtual router, and virtual router agent is found in International Application Number PCT/US2013/044378, filed Jun. 5, 2013, and entitled “PHYSICAL PATH DETERMINATION FOR VIRTUAL NETWORK PACKET FLOWS;” U.S. patent application Ser. No. 14/226,509, filed Mar. 26, 2014, and entitled “Tunneled Packet Aggregation for Virtual Networks;” and in U.S. patent application Ser. No. 17/305,110, filed Jun. 30, 2021, and entitled “Network Controller Horizontal Scaling for Network Device Configurations Session Management;” each of which is incorporated by reference as if fully set forth herein.

In general, orchestrator50controls the deployment, scaling, and operations of containers across clusters of servers12and the providing of computing infrastructure, which may include container-centric computing infrastructure. Orchestrator50and, in some cases, network controller70may implement respective cluster masters for one or more Kubernetes clusters. As an example, Kubernetes is a container management platform that provides portability across public and private clouds, each of which may provide virtualization infrastructure to the container management platform.

FIG.1Bis a block diagram illustrating an example computing infrastructure108in which examples of the techniques described herein may be implemented. In general, data center110provides an operating environment for applications and services for customer sites111(illustrated as “customers111”) having one or more customer networks coupled to the data center by service provider network107. Data center110may be an implementation of the local data center and/or regional data center shown inFIG.1A. Data center110may, for example, host infrastructure equipment, such as networking and storage systems, redundant power supplies, and environmental controls. Service provider network107is coupled to public network115, which may represent one or more networks administered by other providers, and may thus form part of a large-scale public network infrastructure, e.g., the Internet. Public network115may represent, for instance, a local area network (LAN), a wide area network (WAN), the Internet, a virtual LAN (VLAN), an enterprise LAN, a layer 3 virtual private network (VPN), an Internet Protocol (IP) intranet operated by the service provider that operates service provider network107, an enterprise IP network, or some combination thereof. Public network115may be data network15ofFIG.1Aor a network accessible via data network15.

Although customer sites111and public network115are illustrated and described primarily as edge networks of service provider network107, in some examples, one or more of customer sites111and public network115may be tenant networks within data center110or another data center. For example, data center110may host multiple tenants (customers) each associated with one or more virtual private networks (VPNs), each of which may implement one of customer sites111.

Service provider network107offers packet-based connectivity to attached customer sites111, data center110, and public network115. Service provider network107may represent a network that is owned and operated by a service provider to interconnect a plurality of networks. Service provider network107may implement Multi-Protocol Label Switching (MPLS) forwarding and in such instances may be referred to as an MPLS network or MPLS backbone. In some instances, service provider network107represents a plurality of interconnected autonomous systems, such as the Internet, that offers services from one or more service providers. In some aspects, service provider network107may be an implementation of mobile core network7ofFIG.1A.

In some examples, data center110may represent one of many geographically distributed network data centers. As illustrated in the example ofFIG.1B, data center110may be a facility that provides network services for customers. A customer of the service provider may be a collective entity such as enterprises and governments or individuals. For example, a network data center may host web services for several enterprises and end users. Other exemplary services may include data storage, virtual private networks, traffic engineering, file service, data mining, scientific- or super-computing, and so on. Although illustrated as a separate edge network of service provider network107, elements of data center110such as one or more physical network functions (PNFs) or virtualized network functions (VNFs) may be included within the service provider network107core.

In this example, data center110includes storage and/or compute servers (or “nodes”) interconnected via switch fabric114provided by one or more tiers of physical network switches and routers, with servers12depicted as coupled to top-of-rack switches116A-116N. Although only server12A coupled to TOR switch116A is shown in detail inFIG.1B, other servers12may be coupled to other TOR switches116of the data center110.

Switch fabric114in the illustrated example includes interconnected top-of-rack (TOR) (or other “leaf”) switches116A-116N (collectively, “TOR switches116”) coupled to a distribution layer of chassis (or “spine” or “core”) switches118A-118M (collectively, “chassis switches118”). Although not shown, data center110may also include, for example, one or more non-edge switches, routers, hubs, gateways, security devices such as firewalls, intrusion detection, and/or intrusion prevention devices, servers, computer terminals, laptops, printers, databases, wireless mobile devices such as cellular phones or personal digital assistants, wireless access points, bridges, cable modems, application accelerators, or other network devices. Data center110may also include one or more physical network functions (PNFs) such as physical firewalls, load balancers, routers, route reflectors, broadband network gateways (BNGs), mobile core network elements, and other PNFs.

In this example, TOR switches116and chassis switches118provide servers12with redundant (multi-homed) connectivity to IP fabric120and service provider network107. Chassis switches118aggregate traffic flows and provides connectivity between TOR switches116. TOR switches116may be network devices that provide layer 2 (MAC) and/or layer 3 (e.g., IP) routing and/or switching functionality. TOR switches116and chassis switches118may each include one or more processors and a memory and can execute one or more software processes. Chassis switches118are coupled to IP fabric120, which may perform layer 3 routing to route network traffic between data center110and customer sites111by service provider network107. The switching architecture of data center110is merely an example. Other switching architectures may have more or fewer switching layers, for instance. IP fabric120may include one or more gateway routers.

The term “packet flow,” “traffic flow,” or simply “flow” refers to a set of packets originating from a particular source device or endpoint and sent to a particular destination device or endpoint. A single flow of packets may be identified by the 5-tuple: <source network address, destination network address, source port, destination port, protocol>, for example. This 5-tuple generally identifies a packet flow to which a received packet corresponds. An n-tuple refers to any n items drawn from the 5-tuple. For example, a 2-tuple for a packet may refer to the combination of <source network address, destination network address> or <source network address, source port> for the packet.

Servers12may each represent a compute server or storage server. For example, each of servers12may represent a computing device, such as an x86 processor-based server, configured to operate according to techniques described herein. Servers12may provide Network Function Virtualization Infrastructure (NFVI) for an NFV architecture.

Server12may be configured with kernel380. Kernel380may manage operations of server12, including scheduling processes, threads or other executable units and managing devices, file systems, and memory of server12. Kernel380may represent a Linux kernel, other Unix-variant kernel, or other operating system kernel that includes a network stack and is capable of packet forwarding.

Any server of servers12may be configured with virtual execution elements by virtualizing resources of the server to provide an isolation among one or more processes (applications) executing on the server. “Hypervisor-based” or “hardware-level” or “platform” virtualization refers to the creation of virtual machines that each includes a guest operating system for executing one or more processes. In general, a virtual machine provides a virtualized/guest operating system for executing applications in an isolated virtual environment. Because a virtual machine is virtualized from physical hardware of the host server, executing applications are isolated from both the hardware of the host and other virtual machines. Each virtual machine may be configured with one or more virtual network interfaces for communicating on corresponding virtual networks.

Virtual networks are logical constructs implemented on top of the physical networks. Virtual networks may be used to replace VLAN-based isolation and provide multi-tenancy in a virtualized data center, e.g., data center110. Each tenant or an application can have one or more virtual networks. Each virtual network may be isolated from all the other virtual networks unless explicitly allowed by security policy.

Virtual networks can be connected to and extended across physical Multi-Protocol Label Switching (MPLS) Layer 3 Virtual Private Networks (L3VPNs) and Ethernet Virtual Private Networks (EVPNs) networks using a datacenter110gateway router (not shown inFIG.1B). Virtual networks may also be used to implement Network Function Virtualization (NFV) and service chaining.

Virtual networks can be implemented using a variety of mechanisms. For example, each virtual network could be implemented as a Virtual Local Area Network (VLAN), Virtual Private Networks (VPN), etc. A virtual network can also be implemented using two networks—the physical underlay network made up of IP fabric120and switching fabric114and a virtual overlay network. The role of the physical underlay network is to provide an “IP fabric,” which provides unicast IP connectivity from any physical device (server, storage device, router, or switch) to any other physical device. The underlay network may provide uniform low-latency, non-blocking, high-bandwidth connectivity from any point in the network to any other point in the network.

As described further below with respect to virtual router121A, virtual routers running in servers12create a virtual overlay network on top of the physical underlay network using a mesh of dynamic “tunnels” amongst themselves. These overlay tunnels can be MPLS over GRE/UDP tunnels, or VXLAN tunnels, or NVGRE tunnels, for instance. The underlay physical routers and switches may not store any per-tenant state for virtual machines or other virtual execution elements, such as any Media Access Control (MAC) addresses, IP address, or policies. The forwarding tables of the underlay physical routers and switches may, for example, only contain the IP prefixes or MAC addresses of the physical servers12. (Gateway routers or switches that connect a virtual network to a physical network are an exception and may contain tenant MAC or IP addresses.)

Virtual routers121of servers12often contain per-tenant state. For example, they may contain a separate forwarding table (a routing-instance) per virtual network. That forwarding table contains the IP prefixes (in the case of a layer 3 overlays) or the MAC addresses (in the case of layer 2 overlays) of the virtual machines or other virtual execution elements (e.g., pods of containers). No single virtual router121needs to contain all IP prefixes or all MAC addresses for all virtual machines in the entire data center. A given virtual router121only needs to contain those routing instances that are locally present on the server12(i.e., which have at least one virtual execution element present on the server12.)

The control plane protocol between the control plane nodes of the SDN controller70or a physical gateway router (or switch) may be BGP (and may be Netconf for management). This is the same control plane protocol may also be used for MPLS L3VPNs and MPLS EVPNs. The protocol between the SDN controller70and the virtual routers121may be based on XMPP, for instance.

Servers12host virtual network endpoints for one or more virtual networks that operate over the physical network represented here by IP fabric120and switch fabric114. Although described primarily with respect to a data center-based switching network, other physical networks, such as service provider network107, may underlay the one or more virtual networks.

Each of servers12may host one or more virtual execution elements each having at least one virtual network endpoint for one or more virtual networks configured in the physical network. A virtual network endpoint for a virtual network may represent one or more virtual execution elements that share a virtual network interface for the virtual network. For example, a virtual network endpoint may be a virtual machine, a set of one or more containers (e.g., a pod), or another other virtual execution element(s), such as a layer 3 endpoint for a virtual network. The term “virtual execution element” encompasses virtual machines, containers, and other virtualized computing resources that provide an at least partially independent execution environment for applications. The term “virtual execution element” may also encompass a pod of one or more containers. As shown inFIG.1B, server12A hosts virtual network endpoints in the form of pods122A and122B, each having one or more containers. However, a server12may execute as many virtual execution elements as is practical given hardware resource limitations of the server12. Each of the virtual network endpoints may use one or more virtual network interfaces to perform packet I/O or otherwise process a packet. For example, a virtual network endpoint may use one virtual hardware component (e.g., an SR-IOV virtual function) enabled by NIC113A to perform packet I/O and receive/send packets on one or more communication links with TOR switch116A. Other examples of virtual network interfaces are described below.

Servers12each includes at least one network interface card (NIC)113, which each includes at least one interface to exchange packets with TOR switches116over a communication link. For example, server12A includes NIC113A. Any of NICs113may provide one or more virtual hardware components121for virtualized input/output (I/O). A virtual hardware component for I/O maybe a virtualization of the physical NIC (the “physical function”). For example, in Single Root I/O Virtualization (SR-IOV), which is described in the Peripheral Component Interface Special Interest Group SR-My specification, the PCIe Physical Function of the network interface card (or “network adapter”) is virtualized to present one or more virtual network interfaces as “virtual functions” for use by respective endpoints executing on the server12. In this way, the virtual network endpoints may share the same PCIe physical hardware resources and the virtual functions are examples of virtual hardware components121. As another example, one or more servers12may implement virtio, a para-virtualization framework available, e.g., for the Linux Operating System, that provides emulated NIC functionality as a type of virtual hardware component to provide virtual network interfaces to virtual network endpoints. As another example, one or more servers12may implement Open vSwitch to perform distributed virtual multilayer switching between one or more virtual NICs (vNICs) for hosted virtual machines, where such vNICs may also represent a type of virtual hardware component that provide virtual network interfaces to virtual network endpoints. In some instances, the virtual hardware components are virtual I/O (e.g., NIC) components. In some instances, the virtual hardware components are SR-IOV virtual functions. In some examples, any server of servers12may implement a Linux bridge that emulates a hardware bridge and forwards packets among virtual network interfaces of the server or between a virtual network interface of the server and a physical network interface of the server. For Docker implementations of containers hosted by a server, a Linux bridge or other operating system bridge, executing on the server, that switches packets among containers may be referred to as a “Docker bridge.” The term “virtual router” as used herein may encompass a Contrail or Tungsten Fabric virtual router, Open vSwitch (OVS), an OVS bridge, a Linux bridge, Docker bridge, or other device and/or software that is located on a host device and performs switching, bridging, or routing packets among virtual network endpoints of one or more virtual networks, where the virtual network endpoints are hosted by one or more of servers12.

Any of NICs113may include an internal device switch to switch data between virtual hardware components associated with the NIC. For example, for an SR-IOV-capable NIC, the internal device switch may be a Virtual Ethernet Bridge (VEB) to switch between the SR-IOV virtual functions and, correspondingly, between endpoints configured to use the SR-IOV virtual functions, where each endpoint may include a guest operating system. Internal device switches may be alternatively referred to as NIC switches or, for SR-IOV implementations, SR-IOV NIC switches. Virtual hardware components associated with NIC113A may be associated with a layer 2 destination address, which may be assigned by the NIC113A or a software process responsible for configuring NIC113A. The physical hardware component (or “physical function” for SR-IOV implementations) is also associated with a layer 2 destination address.

One or more of servers12may each include a virtual router121that executes one or more routing instances for corresponding virtual networks within data center110to provide virtual network interfaces and route packets among the virtual network endpoints. In some aspects, virtual router121may be incorporated as part of a CNR20. In some aspects, virtual router may be a virtual router that is implemented in kernel space memory of a server12, and may be referred to as a “kernel-based” virtual router. In some aspects, virtual router121may be implemented in user memory space of server12and support DPDK interfaces. Such virtual routers may be referred to as “DPDK” virtual routers.

Each of the routing instances of virtual router121may be associated with a network forwarding table. Each of the routing instances may represent a virtual routing and forwarding instance (VRF) for an Internet Protocol-Virtual Private Network (IP-VPN). Packets received by the virtual router121A of server12A, for instance, from the underlying physical network fabric of data center110(i.e., IP fabric120and switch fabric114) may include an outer header to allow the physical network fabric to tunnel the payload or “inner packet” to a physical network address for a network interface card113A of server12A that executes the virtual router. The outer header may include not only the physical network address of the network interface card113A of the server but also a virtual network identifier such as a VxLAN tag or Multiprotocol Label Switching (MPLS) label that identifies one of the virtual networks as well as the corresponding routing instance executed by the virtual router121A. An inner packet includes an inner header having a destination network address that conforms to the virtual network addressing space for the virtual network identified by the virtual network identifier.

Virtual routers121terminate virtual network overlay tunnels and determine virtual networks for received packets based on tunnel encapsulation headers for the packets, and forwards packets to the appropriate destination virtual network endpoints for the packets. For server12A, for example, for each of the packets outbound from virtual network endpoints hosted by server12A and coupled to virtual router121A (e.g., pod122A), the virtual router121A attaches a tunnel encapsulation header indicating the virtual network for the packet to generate an encapsulated or “tunnel” packet, and virtual router121A outputs the encapsulated packet via overlay tunnels for the virtual networks to a physical destination computing device, such as another one of servers12. As used herein, a virtual router121may execute the operations of a tunnel endpoint to encapsulate inner packets sourced by virtual network endpoints to generate tunnel packets and decapsulate tunnel packets to obtain inner packets for routing to other virtual network endpoints.

In the example ofFIG.1B, virtual router121A is a Data Plane Development Kit (DPDK)-enabled virtual router. That is, virtual router121A uses DPDK as a data plane. In this mode, virtual router121A runs as a user space application that is linked to the DPDK library (not shown). This is a performance version of a virtual router and is commonly used by telecommunications companies, where the VNFs are often DPDK-based applications. The performance of virtual router121A as a DPDK virtual router can achieve much higher throughput than a virtual router operating as a kernel-based virtual router. The physical interface is used by DPDK's poll mode drivers (PMDs) instead of Linux kernel's interrupt-based drivers, thereby eliminating much of the context switching overhead associated with interrupt-based drivers.

A user-I/O (UIO) kernel module, such as vfio or uio_pci_generic, may be used to expose a physical network interface's registers into user space so that they are accessible by the DPDK PMD. When NIC113A is bound to a UIO driver, it is moved from Linux kernel space to user space and therefore no longer managed nor visible by the Linux OS. Consequently, it is the DPDK application (i.e., virtual router121A in this example) that fully manages the NIC113. This includes packets polling, packets processing, and packets forwarding. User packet processing steps may be performed by the virtual router121A DPDK data plane with limited or no participation by the kernel (kernel not shown inFIG.1B). The nature of this “polling mode” makes the virtual router121A DPDK data plane packet processing/forwarding much more efficient as compared to the interrupt mode, particularly when the packet rate is high. There are limited or no interrupts and context switching during packet I/O.

Additional details of an example of a DPDK virtual router are found in “DAY ONE: CONTRAIL DPDK VROUTER,” 2021, Kiran K N et al., Juniper Networks, Inc., which is incorporated by reference herein in its entirety.

Computing infrastructure108implements an automation platform for automating deployment, scaling, and operations of virtual execution elements across servers12to provide virtualized infrastructure for executing application workloads and services. In some examples, the platform may be a container orchestration platform that provides a container-centric infrastructure for automating deployment, scaling, and operations of containers to provide a container-centric infrastructure. “Orchestration,” in the context of a virtualized computing infrastructure generally refers to provisioning, scheduling, and managing virtual execution elements and/or applications and services executing on such virtual execution elements to the host servers available to the orchestration platform. Container orchestration, specifically, permits container coordination and refers to the deployment, management, scaling, and configuration, e.g., of containers to host servers by a container orchestration platform. Example instances of orchestration platforms include Kubernetes, Docker swarm, Mesos/Marathon, OpenShift, OpenStack, VMware, and Amazon ECS.

Elements of the automation platform of computing infrastructure108include at least servers12, orchestrator50, and SDN controller70. Containers may be deployed to a virtualization environment using a cluster-based framework in which a cluster master node of a cluster manages the deployment and operation of containers to one or more cluster minion nodes of the cluster. The terms “master node” and “minion node” used herein encompass different orchestration platform terms for analogous devices that distinguish between primarily management elements of a cluster and primarily container hosting devices of a cluster. For example, the Kubernetes platform uses the terms “cluster master” and “minion nodes,” while the Docker Swarm platform refers to cluster managers and cluster nodes.

Orchestrator50and SDN controller70may execute on separate computing devices, execute on the same computing device. Each of orchestrator50and SDN controller70may be a distributed application that executes on one or more computing devices. Orchestrator50and SDN controller70may implement respective master nodes for one or more clusters each having one or more minion nodes implemented by respective servers12(also referred to as “compute nodes”).

In general, SDN controller70controls the network configuration of the data center110fabric to, e.g., establish one or more virtual networks for packetized communications among virtual network endpoints. SDN controller70provides a logically and in some cases physically centralized controller for facilitating operation of one or more virtual networks within data center110. In some examples, SDN controller70may operate in response to configuration input received from orchestrator50and/or an administrator/operator. Additional information regarding SDN controller70operating in conjunction with other devices of data center110or other software-defined network is found in International Application Number PCT/US2013/044378, filed Jun. 5, 2013, and entitled “PHYSICAL PATH DETERMINATION FOR VIRTUAL NETWORK PACKET FLOWS;” and in U.S. patent application Ser. No. 14/226,509, filed Mar. 26, 2014, and entitled “Tunneled Packet Aggregation for Virtual Networks,” each of which is incorporated by reference as if fully set forth herein.

In general, orchestrator50controls the deployment, scaling, and operations of containers across clusters of servers12and providing computing infrastructure, which may include container-centric computing infrastructure. Orchestrator50and, in some cases, SDN controller70may implement respective cluster masters for one or more Kubernetes clusters. As an example, Kubernetes is a container management platform that provides portability across public and private clouds, each of which may provide virtualization infrastructure to the container management platform. Example components of a Kubernetes orchestration system are described below with respect toFIG.6B.

In one example, pods122A and122B are Kubernetes pods, and are examples of a virtual network endpoint. A pod is a group of one or more logically related containers (not shown inFIG.1B), the shared storage for the containers, and options on how to run the containers. Where instantiated for execution, a pod may alternatively be referred to as a “pod replica.” Each container of pods122A and122B is an example of a virtual execution element. Containers of a pod are always co-located on a single server, co-scheduled, and run in a shared context. The shared context of a pod may be a set of Linux namespaces, cgroups, and other facets of isolation. Within the context of a pod, individual applications might have further sub-isolations applied. Typically, containers within a pod have a common IP address and port space and are able to detect one another via the localhost. Because they have a shared context, containers within a pod are also communicate with one another using inter-process communications (IPC). Examples of IPC include SystemV semaphores or POSIX shared memory. Generally, containers that are members of different pods have different IP addresses and are unable to communicate by IPC in the absence of a configuration for enabling this feature. Containers that are members of different pods instead usually communicate with each other via pod IP addresses.

Server12A includes a container platform119A for running containerized applications, such as those of pods122A and122B. Container platform119A receives requests from orchestrator50to obtain and host, in server12A, containers. Container platform119A obtains and executes the containers.

Container platform119A includes a container network interface (CNI)117A that configures virtual network interfaces for virtual network endpoints. The orchestrator50and container platform119A uses CNI117A to manage networking for pods, including pods122A and122B. For example, the CNI117A creates virtual network interfaces to connect pod122A to virtual router121A and creates virtual network interfaces to connect pod122B to kernel380. CNI117A thereby enables containers of such pods to communicate, via their respective virtual network interfaces, to other virtual network endpoints over the virtual networks. CNI117A may, for example, insert a virtual network interface for a virtual network into the network namespace for containers in pod122A and configure (or request to configure) the virtual network interface for the virtual network in virtual router121A such that the virtual router121A is configured to send packets received from the virtual network via the virtual network interface to containers of pod122A and to send packets received via the virtual network interface from containers of pod122A on the virtual network. CNI117A may assign a network address (e.g., a virtual IP address for the virtual network) and may set up routes for the virtual network interface. In Kubernetes, by default all pods can communicate with all other pods without using network address translation (NAT). In some cases, the orchestrator50and SDN controller70create a service virtual network and a pod virtual network that are shared by all namespaces, from which service and pod network addresses are allocated, respectively. In some cases, all pods in all namespaces that are spawned in the Kubernetes cluster may be able to communicate with one another, and the network addresses for all of the pods may be allocated from a pod subnet that is specified by the orchestrator50. When a user creates an isolated namespace for a pod, orchestrator50and SDN controller70may create a new pod virtual network and new shared service virtual network for the new isolated namespace. Pods in the isolated namespace that are spawned in the Kubernetes cluster draw network addresses from the new pod virtual network, and corresponding services for such pods draw network addresses from the new service virtual network

CNI117A may represent a library, a plugin, a module, a runtime, or other executable code for server12A. CNI117A may conform, at least in part, to the Container Network Interface (CNI) specification or the rkt Networking Proposal. CNI117A may represent a Contrail, OpenContrail, Multus, Calico, cRPD, or other CNI. CNI117A may alternatively be referred to as a network plugin or CNI plugin or CNI instance. Separate CNIs may be invoked by, e.g., a Multus CNI to establish different virtual network interfaces for pod122A.

CNI117A is invoked by orchestrator50. For purposes of the CNI specification, a container can be considered synonymous with a Linux network namespace. What unit this corresponds to depends on a particular container runtime implementation: for example, in implementations of the application container specification such as rkt, each pod runs in a unique network namespace. In Docker, however, network namespaces generally exist for each separate Docker container. For purposes of the CNI specification, a network refers to a group of entities that are uniquely addressable and that can communicate amongst each other. This could be either an individual container, a machine/server (real or virtual), or some other network device (e.g., a router). Containers can be conceptually added to or removed from one or more networks. The CNI specification specifies a number of considerations for a conforming plugin (“CNI plugin”).

In the example ofFIG.1B, pod122A includes a containerized DPDK workload that is designed to use DPDK to accelerate packet processing, e.g., by exchanging data with other components using DPDK libraries. Pod122B is configured to utilize network services and stacks provided by kernel380.

CNI117A may configure, for pods122A and122B, in conjunction with one or more other components shown inFIG.1B, data interfaces126and127. These may be different types of interfaces. Data interface126and data interface127may be referred to herein as virtual network interfaces. Other example types of virtual network interfaces are described below. Any of the containers of the pods122A and122B may utilize, i.e., share, any virtual network interface of their respective pod.

Pod122A is configured with data interface127that is used for high-throughput packet processing, more specifically, for sending and receiving packets with virtual router121A for high-throughput applications. Pod122A and virtual router121A exchange data packets using data interface127. Data interface127may be a DPDK interface. Pod122A and virtual router121A may set up data interface127using vhost. Pod122A may operate according to an aggregation model. Pod122A may use a virtual device, such as a virtio device with a vhost-user adapter, for user space container inter-process communication for data interface127. The workload of pod122A is thus built on DPDK and operates data interface127using DPDK. Pod122A and virtual router121A may bring up DPDK interfaces using vhost. Pod122A may operate as a vhost server in some examples, with virtual router121A as the vhost client, for setting up a DPDK interface. Virtual router121A may operate as a vhost server in some examples, with pod122as the vhost client, for setting up a DPDK interface.

Pod122B is configured with data interface126that is used sending and receiving packets with kernel380. A workload of pod122B may not be configured for high throughput data communication, and may require encapsulations or other network services that vrouter121A is unable to provide.

Network packets sent and received by pods122A and122B may take different paths to and from NIC113A. For example, pod122A exchanges network packets with virtual router121A via data interface127. Virtual router121A sends or receives network packets from NIC113A. Virtual router121A and NIC113A form a DPDK data plane for pod122A.

Pod122B exchanges network packets with kernel380. Kernel380processes network packets sent and received by pod122B, including encapsulating or decapsulating the packets as necessary. In some aspects, kernel380sends and receives packets via virtual router121A using data interface125. In this case, virtual router121A acts as a “pass-through” with respect to kernel380, and does not perform any network processing of packets received from kernel380for transmission via NIC113, or for packets received from NIC113A that have pod122B as a destination. Kernel380, virtual router121A and NIC113A from a kernel data plane.

Virtual router121A and kernel380are configured to interoperate as will be further described below to provide hybrid data plane150. Hybrid data plane150allows pods such as pods122A and122B to be configured to use a DPDK data plane of hybrid data plane150or a kernel data plane of hybrid data plane150.

With respect to pod122B, a virtual network interface may represent a virtual ethernet (“veth”) pair, where each end of the pair is a separate device (e.g., a Linux/Unix device), with one end of the pair assigned to pod122B and one end of the pair assigned to kernel380. The veth pair or an end of a veth pair are sometimes referred to as “ports”. A virtual network interface may represent a macvlan network with media access control (MAC) addresses assigned to the pod122B and to kernel380for communications between containers of pod122B and network stacks of kernel380. Virtual network interfaces may alternatively be referred to as virtual machine interfaces (VMIs), pod interfaces, container network interfaces, tap interfaces, veth interfaces, or simply network interfaces (in specific contexts), for instance.

In the example server12A ofFIG.1B, pods122A and122B are virtual network endpoints in one or more virtual networks. Orchestrator50may store or otherwise manage configuration data for application deployments that specifies a virtual network and specifies that a pod (or the one or more containers therein) is a virtual network endpoint of the virtual network. Orchestrator50may receive the configuration data from a user, operator/administrator, or other machine system, for instance.

As part of the process of creating pod122A or122B, orchestrator50requests that SDN controller70create respective virtual network interfaces for the virtual networks (indicated in the configuration data). A pod may have a different virtual network interface for each virtual network to which it belongs. For example, each of data interface126and data interface127may be a virtual network interface for a particular virtual network. Additional data interfaces may be configured for other virtual networks. SDN controller70processes the request to generate interface configuration data for the virtual network interfaces for the pods122A and122B. Interface configuration data may include a container or pod unique identifier and a list or other data structure specifying, for each of the virtual network interfaces, network configuration data for configuring the virtual network interface. Network configuration data for a virtual network interface may include a network name, assigned virtual network address, MAC address, and/or domain name server values. An example of interface configuration data in JavaScript Object Notation (JSON) format is below.

SDN controller70sends interface configuration data to server12A and, more specifically in some cases, to virtual router121A. To configure a virtual network interface for a pod (e.g., pod122A or pod122B), orchestrator50may invoke CNI117A. CNI117A obtains the interface configuration data from virtual router121A and processes it. CNI117A creates each virtual network interface specified in the interface configuration data.

A conventional CNI plugin is invoked by a container platform/runtime, receives an Add command from the container platform to add a container to a single virtual network, and such a plugin may subsequently be invoked to receive a Del(ete) command from the container/runtime and remove the container from the virtual network. The term “invoke” may refer to the instantiation, as executable code, of a software component or module in memory for execution by processing circuitry.

FIG.2is a block diagram illustrating an example implementation of a part of the network systems ofFIGS.1A and1Bin further detail, in accordance with techniques of this disclosure. System200includes CUs213A-213K, each of which may represent any of CUs13ofFIG.1A. In this example, multiple network slices (e.g., 5G network slices) are implemented using L3VPNs and tunnels231A-231K to connect DU22A to different CUs213A-213K for respective network slices.

A network slice provides a way to segment a mobile network to support a particular type of service or business or even to host service providers (multi-tenancy) who do not own a physical network. Furthermore, each slice can be optimized according to capacity, coverage, connectivity, security and performance characteristics. Since the slices can be isolated from each other, as if they are physically separated both in the control and user planes, the user experience of the network slice will be the same as if it was a separate network. A network slice can span all domains of the network including software applications (both memory and processing) running on network nodes, specific configurations of the core transport network, access network configurations as well as the end devices. The network slicing enables multiple operators to share a mobile network securely but by separating their own users from others, and different applications of a user to use different network slices that provide widely different performance characteristics.

Cloud native router20A includes a virtual router forwarding plane (virtual router)121A configured with VRFs212A-212K (collectively, “VRFs212”) for respective network slices implemented with respective L3VPNs, which CNR20A and routers204A-204B implement using tunnels231A-231K connecting VRFs212to VRFs210A-210K on routers204A-204B. Each of tunnels231A-231K may represent a SR-MPLSoIPv6 or other type of tunnel mentioned above. Each of routers204A-204K may be a gateway router for a data center (e.g., data center100ofFIG.1A) having one or more servers to execute any one or more of CUs213A-213K. The data center may include a data center fabric to switch mobile data traffic between the router and the CU. In some cases, the one or more servers of the data center may also execute a UPF for the mobile network, in which case the data center fabric may also switch mobile data traffic between the CU and the UPF.

Each of the VRFs212A-212K has a corresponding virtual network interface to DU22A. Each of the virtual network interfaces of DU22A may thus be mapped into a different L3VPN in CNR20A in order to, e.g., support a different one of multiple network slices. As described in further detail below, CNI117A of server12A (FIG.1B) when triggered by pod events from orchestrator50, dynamically adds or deletes virtual network interfaces between the pod (here deployed with DU22A) and the virtual router121A, which may also be deployed as container in some examples. CNI117A also dynamically updates cRPD24A (the control plane of CNR20A) with host routes for each DU22A/pod virtual network interface and corresponding Layer 3 VPN mappings, in the form of Route Distinguishers and Route Targets. In turn, cRPD24A programs virtual router121A (the data plane of CNR accordingly, optionally using a gRPC interface. In this way, CNR20A is introduced as a cloud-native router into the data path to, e.g., support the F1 interfaces to CUs213A-213K that may be executing in edge or regional data center sites, for instance. Virtual router121A may represent a SmartNIC-based virtual router, kernel-based virtual router, or DPDK-based virtual router in various examples.

FIG.3is a block diagram illustrating an example server according to techniques of this disclosure. Server300may represent any of servers12ofFIGS.1A and1B. In some cases, servers300is configured to implement both a Cloud Native Router and distributed unit for same-box forwarding of mobile data traffic between DU22A ofFIG.1Aand the data plane of Cloud Native Router of20A ofFIG.1A. Server300may be a bare-metal server or a virtual machine. An example hardware architecture for server300is described inFIGS.6A and6B.

Kernel380may manage operations of server300, including scheduling processes, threads or other executable units and managing devices, file systems, and memory of server300. Kernel380may represent a Linux kernel, other Unix-variant kernel, or other operating system kernel that includes a network stack and is capable of packet forwarding.

Server300includes one or more network interface cards (NICs)321A-321B (collectively, “NICs321”) each having one or more hardware interfaces320and322respectively. In a 5G radio access network deployment, interfaces320of NIC321A may be coupled via physical cabling to RUs. Interfaces320may implement the F2 interface. Interfaces322of NIC321B may be coupled via physical cabling to the midhaul network, for sending/receiving mobile data traffic to/from CUs. Interfaces322may implement the F1 interface. In some examples, server400may have a single NIC with one or more interfaces322.

Server300may host pods328A-328L (collectively, “pods328”). Pods328may be DUs in some cases. Pods328may be implementations of pods122A and122B ofFIG.1B. Pods328A-328L are endpoints from the perspective of virtual router206A, and in particular may represents overlay endpoints for one or more virtual networks that have been programmed into virtual router206A.

At a high level, a DPDK-based virtual router data or forwarding plane (“virtual router”)206A is programmed by virtual router agent314with forwarding information for implementing a packet fast path. Virtual router agent314may be a user space process. Virtual router agent314may have a northbound interface340for receiving configuration and routing information from control plane processes, such as cRPD324. cRPD324may be an example of cRPD24A ofFIGS.1A and1B. Virtual router agent314has a southbound interface341for programming virtual router206A. Reference herein to a “virtual router” may refer to the virtual router forwarding plane specifically, or to a combination of the virtual router forwarding plane (e.g., virtual router206A) and the corresponding virtual router agent (e.g., virtual router agent314).

cRPD324may have a northbound interface for exchanging configuration and routing information with SDN controller70. Containerized networking interface312may be a CNI plugin that configures the interfaces of the container workloads (pods328A to328L in this example) with the DPDK-based virtual router206A. Orchestrator50may orchestrate DPDK-based virtual router206A, cRPD324, and/or pod328workloads on server300via requests sent to orchestration agent310of server300. In some cases, workloads may have multiple interfaces and multiple types of interfaces (e.g., some with virtual router206A and some with NIC321A). Thus, CNI312may represent a combination of CNIs or unified CNI that is capable of configuring a workload with multiple types of interfaces. The multiple CNIs may be controlled by a master CNI such as Multus. Where orchestrator50is a Kubernetes master, CustomResourceDefinitions (CRDs) may be implemented for orchestrator50for supporting multi-tenancy and network isolation.

Orchestrator50orchestrates pods (e.g., pods328A-328L) comprising container workloads via orchestration agent310. CNI312configures virtual interfaces between pods and the data plane, which may be DPDK-based virtual router, a kernel-based virtual router, or a SmartNIC-based virtual router. In the example shown inFIG.3, virtual router206A is a DPDK-based virtual router. In some examples such as that shown inFIG.3, CNI312configures a virtio interface for each pod as a vhost-user interface of the DPDK-based virtual router206A. In some examples, CNI312configures veth pairs for each pod to virtual router206A. In some examples, virtual router206A has a bonded interface to NIC321B, which may be an Intel-based NIC that supports DPDK. Bonded interfaces facilitate packet load balancing among fabric interfaces. Additional description of configuring virtual interfaces may be found in U.S. Pat. No. 10,728,145, issued Jul. 28, 2020, which is incorporated by reference herein in its entirety.

In a Kubernetes deployment, CNI312provides networking for application workloads. This includes, for example, setting up interfaces, IP address management, and access control lists; advertising reachability of workloads within a Kubernetes cluster comprising any of servers300and servers12ofFIGS.1A and1B(e.g., minion nodes); and setting up network namespaces.

cRPD324may incorporate elements of network service mesh architecture (NSM), service discovery, external endpoints, and tunneling. cRPD324may use exterior routing protocols such as Border Gateway Protocol (BGP) to advertise pod reachability both within and outside the Kubernetes cluster. cRPD324may use interior gateway and other routing protocols such as IS-IS, OSPF, Label Distribution Protocol (LDP), etc., to participate in underlay networking. cRPD324may also provide support for advanced L3VPN overlays using protocols/technologies such as MPLS, MPLSoUDP, or MPLSoGRE tunneling; VxLANs; SR-MPLS, SRv6, SRv4, and/or IPSec.

Virtual router206A exposes respective interfaces382A to kernel380for physical interfaces322. That is, for each of physical interfaces, virtual router206A exposes an interface to kernel380. Each of interfaces382A may be a vhost interface and may be terminated at a default VRF381A. Kernel380may therefore send and receive network packets with virtual router206A via interfaces382.

In some examples, cRPD324runs routing protocols and can exchange routing protocol messages with routers external to server300. Moreover, cRPD324can utilize kernel380network stack to obtain network topology information for the underlay network. cRPD324can use this topology information to establish routing protocol adjacencies with the external routers. Interfaces382A provide access for cRPD324, via kernel380and virtual router206A, to physical interfaces322and thus to the underlay networks accessible via physical interfaces322. As examples, such underlay networks may include the midhaul network, a switch fabric for a local data center in which server300is located, and so forth. Virtual router206A can be configured with a route that causes virtual router206A to forward network packets, received at one of physical interfaces322and destined for an IP address of the corresponding one of interfaces382, via that corresponding one of interfaces382A to kernel380.

Kernel380outputs the network packets to cRPD324via interface384. Interface384may represent system call interfaces/APIs exposed by kernel380, a file system, pthread, socket, or other mechanism by which processes such as cRPD324can receive packets from and inject packets into kernel380. cRPD324operates as the control plane for a router implemented by server300and DPDK-based virtual router206A operates as the fast path forwarding plane for the router. In 5G environments such as that shown inFIG.1A, cRPD324operates as the control plane for CNR20A, while virtual router206A and kernel380provide a data or forwarding plane for pods328and/or CNR20A (FIG.1B). CNI312leveraging cRPD324is thus able to facilitate multi-tenancy using L3VPNs, e.g., to implement network slices for different tenants; ACLs and network policies for applications; and IPSec for high security. DPDK-based virtual router206A acts as the data plane or forwarding plane for forwarding data traffic between pods328and physical interfaces322in a way that may exclude the kernel380.

Server300has two data planes for packet forwarding, a first data plane394implemented by kernel380and a second data plane392implemented by virtual router206A. Second data plane392may be an implementation of hybrid data plane150ofFIG.1. DPDK-based virtual router206A is configured with “ownership” of physical interfaces322. In some aspects, DPDK-based virtual routers on server300such as virtual router206A are configured with ownership of all of the physical interfaces of NICs321on server300. Physical interfaces322may be VPN attachment circuits for VRFs212. Physical interfaces322may be associated with respective interfaces of virtual router206A by which virtual router206A sends and receives traffic via physical interfaces322.

First data plane394and second data plane392may store different routes for the underlay network and overlay network, respectively. First data plane394and second data plane392may independently perform forwarding lookups for and forward traffic using the respective, different stored routes. cRPD324is the routing protocol process for processing both underlay routes and overlay routes. Having learned the routes, whether by routing protocols or from SDN controller70, cRPD324can selectively program underlay routes to kernel380and overlay routes to virtual router206A (via virtual router agent314). In some aspects, server300may be configured and operated as described below such that distinct data planes394and392are combined into a hybrid data plane.

FIG.4is a block diagram illustrating an example server with example control and data traffic flows within the server, according to techniques of this disclosure. Server400may be similar to servers described herein such as servers12ofFIGS.1A,1B and2, and server300ofFIG.3. PODs328A-328L may be DUs in some cases. A vhost interface, vhost0 interface382A, is exposed by virtual router206A to kernel380and in some cases by kernel380to virtual router206A. vhost interface382A has an associated underlay host IP address for receiving traffic “at the host”. Thus, kernel380may be a network endpoint of the underlay network that includes server400as a network device, the network endpoint having the IP address of vhost interface382A. The application layer endpoint may be cRPD324or other process managed by kernel380.

Underlay networking refers to the physical infrastructure that provides connectivity between nodes (typically servers) in the network. The underlay network is responsible for delivering packets across the infrastructure. Network devices of the underlay use routing protocols to determine IP connectivity. Typical routing protocols used on the underlay network devices for routing purposes are OSPF, IS-IS, and BGP. Overlay networking refers to the virtual infrastructure that provides connectivity between virtual workloads (typically VMs/pods). This connectivity is built on top of the underlay network and permits the construction of virtual networks. The overlay traffic (i.e., virtual networking) is usually encapsulated in IP/MPLS tunnels or other tunnels, which are routed by the underlay network. Overlay networks can run across all or a subset of the underlay network devices and achieve multi-tenancy via virtualization.

Control traffic402may represent routing protocol traffic for one or more routing protocols executed by cRPD324. In server400, control traffic402may be received over a physical interface322owned by virtual router206A. Virtual router206A is programmed with a route for the vhost0 interface382A host IP address along with a receive next-hop, which causes virtual router206A to send traffic, received at the physical interface322and destined to the vhost0 interface382A host IP address, to kernel380via vhost0 interface382A. From the perspective of cRPD324and kernel380, all such control traffic402would appear to come from vhost0 interface382A. Accordingly, cRPD324routes will specify vhost0 interface382A as the forwarding next-hop for the routes. cRPD324selectively installs some routes to virtual router agent314and the same (or other) routes to kernel380, as described in further detail below. Virtual router agent314will receive a forwarding information base (FIB) update corresponding to some routes received by cRPD324. These routes will point to vHost0 interface382A and virtual router206A may automatically translate or map vHost0 interface382A to a physical interface322.

Routing information programmed by cRPD324can be classified into underlay and overlay. cRPD324will install the underlay routes to kernel380, because cRPD324might need that reachability to establish additional protocols adjacencies/sessions with external routers, e.g., BGP multi-hop sessions over reachability provided by IGPs. cRPD324supports selective filtering of FIB updates to specific data planes, e.g., to kernel380or virtual router206A using routing policy constructs that allow for matching against RIB, routings instance, prefix, or other property.

Control traffic402sent by cRPD324to virtual router206A over vhost0 interface382A may be sent by virtual router206A out the corresponding physical interface322for vhost0 interface382A.

As shown inFIG.4, CNI312can create the virtual network (here, “pod”) interfaces for each of the application pods328A-328L on being notified by the orchestrator50via orchestration agent310. One end of a pod interface terminates in a container included in the pod. CNI312may request virtual router206A to start monitoring the other end of the pod interface, and cRPD324facilitates traffic from the physical interfaces322destined for application containers in DPDK-based pods328A-322L to be forwarded using DPDK, exclusively, and without involving kernel380. The reverse process applies for traffic sourced by pods328A-328L.

However, because DPDK-based virtual router206A manages these the virtual network interfaces for pods328A-328L, the virtual network interfaces are not known to kernel380. Server400may use tunnels exclusive to the DPDK forwarding path to send and receive overlay data traffic404internally among DPDK-based pods328A-328L; virtual router206A; and NIC321B.

As such, in server400, cRPD324interfaces with two data planes: kernel380and the DPDK-based virtual router206A. cRPD324leverages the kernel380networking stack to setup routing exclusively for the DPDK fast path. The routing information cRPD324receives includes underlay routing information and overlay routing information. cRPD324runs routing protocols on vHost interface382A that is visible in kernel380, and cRPD324may install FIB updates corresponding to IGP-learnt routes (underlay routing information) in the kernel380FIB. This may enable establishment of multi-hop iBGP sessions to those destinations indicated in such IGP-learnt routes. Again, the cRPD324routing protocol adjacencies involve kernel380(and vHost interface382A) because kernel380executes the networking stack.

Virtual router agent314for virtual router206A notifies cRPD324A about the application pod interfaces for pods328A-328L. These pod interfaces are created by CNI312and managed exclusively (i.e., without involvement of kernel380) by the virtual router agent314. These pod interfaces are not known to the kernel380. cRPD324may advertise reachability to these pod interfaces to the rest of the network as L3VPN routes including Network Layer Reachability Information (NLRI). In the 5G mobile network context, such L3VPN routes may be stored in VRFs of virtual router206A for different network slices. The corresponding MPLS routes may be programmed by cRPD324only to virtual router206A, via interface340with virtual router agent314, and not to kernel380. That is so because the next-hop of these MPLS labels is a pop-and-forward to a pod interface for one of pods328A-328L; these interfaces are only visible in virtual router206A and not kernel380. Similarly, reachability information received over BGP L3VPN may be selectively programmed by cRPD324to virtual router206A, for such routes are only needed for forwarding traffic generated by pods328A-328L. The above routes programmed to virtual router206A constitute overlay routes for the overlay network.

FIG.5is a conceptual diagram depicting a sequence of operations on a port-add leading to route programming in a virtual router, according to example aspects of this disclosure. The sequence of operations is described with respect to components of server400, but may be performed by components of any server described in this disclosure, e.g., servers12ofFIGS.1A,1B and2, or server400ofFIG.4. CNI312has the IP address block reserved for Pods. Virtual router agent314listens for Port-Add and Port-Delete messages, e.g., on a thrift service, where a “port” corresponds to a virtual network interface. CNI312sends a Port-Add message to virtual router agent314(502). The Port-Add message includes an identifier for the virtual network for the port and an IP address allocated by CNI312for the Pod. (CNI312may separately configure the Pod with the other end of the virtual network interface.) virtual router agent314creates a virtual network interface (referred to here as a virtual machine interface or VMI, which is an example of a virtual network interface) in interfaces540(504). Virtual router agent314configures the virtual network interface in virtual router206A with a default VRF identifier, with a VMI Add message (506). Virtual router agent314subscribes to cRPD324instead of an SDN controller with a VMI Subscribe message that includes the virtual network name and IP address received in the Port Add message (508). cRPD327sends a VMI Config message to virtual router agent314with the correct VRF identifier for virtual network for the virtual network interface (512), optionally adding a VRF to virtual router agent314if needed with a VRF Add message (510). Virtual router agent314send a VMI Update message with the correct VRF identifier to virtual router206A to cause virtual router206A, which attaches the virtual network interface to the correct VRF (514). cRPD324allocates a service label and adds a route and next-hop (e.g., an MPLS route for BGP IP-VPNs) using a Route Add message to virtual router agent314(516). cRPD324also advertises a route for reaching the Pod to its peer routers (518), which may include other cRPDs, routers in the underlay network, or other routers. Virtual router agent314configures virtual router206A with forwarding information for the route received in the Route Add message from cRPD324(520).

FIG.6Ais a block diagram of an example computing device (e.g., host), according to techniques described in this disclosure. Computing device600ofFIG.6Amay represent a real or virtual server and may represent an example instance of any of servers12ofFIGS.1A and1B, server300ofFIG.3or server400ofFIG.4. Computing device600includes in this example, a bus642coupling hardware components of a computing device600hardware environment. Bus642couples network interface card (NIC)630, storage disk646, and one or more microprocessors610(hereinafter, “microprocessor610”). NIC630may be SR-IOV-capable. A front-side bus may in some cases couple microprocessor610and memory device644. In some examples, bus642may couple memory device644, microprocessor610, and NIC630. Bus642may represent a Peripheral Component Interface (PCI) express (PCIe) bus. In some examples, a direct memory access (DMA) controller may control DMA transfers among components coupled to bus642. In some examples, components coupled to bus642control DMA transfers among components coupled to bus642.

Microprocessor610may include one or more processors each including an independent execution unit to perform instructions that conform to an instruction set architecture, the instructions stored to storage media. Execution units may be implemented as separate integrated circuits (ICs) or may be combined within one or more multi-core processors (or “many-core” processors) that are each implemented using a single IC (i.e., a chip multiprocessor).

Disk646represents computer readable storage media that includes volatile and/or non-volatile, removable and/or non-removable media implemented in any method or technology for storage of information such as processor-readable instructions, data structures, program modules, or other data. Computer readable storage media includes, but is not limited to, random access memory (RAM), read-only memory (ROM), EEPROM, Flash memory, CD-ROM, digital versatile discs (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and that can be accessed by microprocessor610.

Memory644includes one or more computer-readable storage media, which may include random-access memory (RAM) such as various forms of dynamic RAM (DRAM), e.g., DDR2/DDR3 SDRAM, or static RAM (SRAM), flash memory, or any other form of fixed or removable storage medium that can be used to carry or store desired program code and program data in the form of instructions or data structures and that can be accessed by a computer. Main memory644provides a physical address space composed of addressable memory locations.

Network interface card (NIC)630includes one or more interfaces632configured to exchange packets using links of an underlying physical network. Interfaces632may include a port interface card having one or more network ports. NIC630may also include an on-card memory to, e.g., store packet data. Direct memory access transfers between the NIC630and other devices coupled to bus642may read/write from/to the NIC memory.

Memory644, NIC630, storage disk646, and microprocessor610may provide an operating environment for a software stack that includes an operating system kernel380executing in kernel space. Kernel380may represent, for example, a Linux, Berkeley Software Distribution (BSD), another Unix-variant kernel, or a Windows server operating system kernel, available from Microsoft Corp. In some instances, the operating system may execute a hypervisor and one or more virtual machines managed by hypervisor. Example hypervisors include Kernel-based Virtual Machine (KVM) for the Linux kernel, Xen, ESXi available from VMware, Windows Hyper-V available from Microsoft, and other open-source and proprietary hypervisors. The term hypervisor can encompass a virtual machine manager (VMM). An operating system that includes kernel380provides an execution environment for one or more processes in user space645.

Kernel380includes a physical driver625to use the network interface card630. Network interface card630may also implement SR-IOV to enable sharing the physical network function (I/O) among one or more virtual execution elements, such as containers629A-629B or one or more virtual machines (not shown inFIG.6A). Shared virtual devices such as virtual functions may provide dedicated resources such that each of the virtual execution elements may access dedicated resources of NIC630, which therefore appears to each of the virtual execution elements as a dedicated NIC. Virtual functions may represent lightweight PCIe functions that share physical resources with a physical function used by physical driver625and with other virtual functions. For an SR-IOV-capable NIC630, NIC630may have thousands of available virtual functions according to the SR-IOV standard, but for I/O-intensive applications the number of configured virtual functions is typically much smaller.

Computing device600may be coupled to a physical network switch fabric that includes an overlay network that extends switch fabric from physical switches to software or “virtual” routers of physical servers coupled to the switch fabric, including virtual routers206A and206B (collectively, “virtual routers206”). Virtual routers may be processes or threads, or a component thereof, executed by the physical servers, e.g., servers12ofFIGS.1A and1B, server300ofFIG.3, and/or server400ofFIG.4, that dynamically create and manage one or more virtual networks usable for communication between virtual network endpoints. In one example, virtual routers implement each virtual network using an overlay network, which provides the capability to decouple an endpoint's virtual address from a physical address (e.g., IP address) of the server on which the endpoint is executing. Each virtual network may use its own addressing and security scheme and may be viewed as orthogonal from the physical network and its addressing scheme. Various techniques may be used to transport packets within and across virtual networks over the physical network. The term “virtual router” as used herein may encompass an Open vSwitch (OVS), an OVS bridge, a Linux bridge, Docker bridge, or other device and/or software that is located on a host device and performs switching, bridging, or routing packets among virtual network endpoints of one or more virtual networks, where the virtual network endpoints are hosted by one or more of servers12. In the example computing device600ofFIG.6A, virtual router206A executes within user space as a DPDK-based virtual router and virtual router206B executes in kernel380space. In some aspects, a virtual router may execute within a hypervisor, a host operating system, a host application, or a virtual machine in various implementations.

Virtual routers206may replace and subsume the virtual routing/bridging functionality of the Linux bridge/OVS module that is commonly used for Kubernetes deployments of pods, including pods602A-602N (collectively, “pods602”). In the example shown inFIG.6A, pod602A includes one or more application containers629A and pod602B includes one or more application containers629B. Pod602N includes an instance of cRPD324.

Virtual routers206may perform bridging (e.g., E-VPN) and routing (e.g., L3VPN, IP-VPNs) for virtual networks. Virtual routers206may perform networking services such as applying security policies, NAT, multicast, mirroring, and load balancing.

In the example shown inFIG.6A, virtual router206A executes as a user space656as DPDK process. Virtual router agent314may also be executing in user space. In the example computing device600ofFIG.2, virtual router206A executes within user space as a DPDK-based virtual router, but virtual router206A may execute within a hypervisor, a host operating system, a host application, or a virtual machine in various implementations. Virtual router agent314has a connection to SDN controller70using a channel, which is used to download configurations and forwarding information. Virtual router agent314programs this forwarding state to the virtual router data (or “forwarding”) plane represented by virtual router206A, and virtual router206B. Virtual router206A and virtual router agent314may be processes.

Virtual routers206may be multi-threaded and execute on one or more processor cores. Virtual router206may include multiple queues. Virtual router206may implement a packet processing pipeline. The pipeline can be stitched by the corresponding virtual router agent314from the simplest to the most complicated manner depending on the operations to be applied to a packet. Virtual routers206may maintain multiple instances of forwarding bases. Virtual routers206may access and update tables (e.g., tables627) using RCU (Read Copy Update) locks.

To send packets to other compute nodes or switches, virtual router206A uses one or more physical interfaces632. In general, a virtual router206exchanges overlay packets with workloads, such as VMs or pods602. A virtual router206may have multiple virtual network interfaces (e.g., vifs). These interfaces may include the kernel interface, vhost0, for exchanging packets with the host operating system; an interface with a corresponding virtual router agent314, pkt0, to obtain forwarding state from the network controller and to send up exception packets. There may be one or more virtual network interfaces corresponding to the one or more physical network interfaces632.

Other virtual network interfaces of virtual router206may be used for exchanging packets with the workloads. Such virtual network interfaces may be any of the aforementioned types of virtual interfaces. In some cases, the virtual network interfaces612may be tap interfaces.

Virtual router206B is a kernel-based virtual router. In this case, virtual router206B is installed as a kernel module inside the operating system. Virtual router206B registers itself with the TCP/IP stack to receive packets from any of the desired operating system interfaces that it wants to. The interfaces can be bond, physical, tap (for VMs), veth (for containers) etc. In the example shown inFIG.6A, virtual router206B has a veth interface with vRF622B of virtual router206B. Virtual router206B in this mode relies on the operating system to send and receive packets from different interfaces. For example, the operating system may expose a tap interface backed by a vhost-net driver to communicate with VMs. Once virtual router206B registers for packets from this tap interface, the TCP/IP stack sends all the packets to it. Virtual router206B sends packets via an operating system interface. In addition, NIC queues (physical or virtual) are handled by the operating system. Packet processing may operate in interrupt mode, which generates interrupts and may lead to frequent context switching. When there is a high packet rate, the overhead attendant with frequent interrupts and context switching may overwhelm the operating system and lead to poor performance.

In a DPDK-based deployment of virtual router206A as shown inFIG.6A, virtual router206A is installed as a user space645application that is linked to a DPDK library. This may lead to faster performance than a kernel-based deployment, particularly in the presence of high packet rates. The physical interfaces632are used by the poll mode drivers (PMDs) of DPDK rather the kernel's interrupt-based drivers. The registers of physical interfaces632may be exposed into user space645in order to be accessible to the PMDs; a physical interface632bound in this way is no longer managed by or visible to the host operating system, and the DPDK-based virtual router206A manages the physical interface632. This includes packet polling, packet processing, and packet forwarding. In other words, user packet processing steps are performed by the virtual router206A DPDK data plane. The nature of this “polling mode” makes the virtual router206A DPDK data plane packet processing/forwarding much more efficient as compared to the interrupt mode when the packet rate is high. There are comparatively few interrupts and context switching during packet I/O, compared to kernel-mode virtual router206A, and interrupt and context switching during packet I/O may in some cases be avoided altogether.

In general, each of pods602may be assigned one or more virtual network addresses for use within respective virtual networks, where each of the virtual networks may be associated with a different virtual subnet provided by a virtual router206. Pod602B may be assigned its own virtual layer three (L3) IP address, for example, for sending and receiving communications but may be unaware of an IP address of the computing device600on which the pod602B executes. The virtual network address may thus differ from the logical address for the underlying, physical computer system, e.g., computing device600.

Virtual router agents314control the overlay of virtual networks for computing device600and that coordinates the routing of data packets within computing device600. In general, virtual router agents314A and314B communicate with SDN controller70(FIGS.1A,1B and2) for the virtualization infrastructure, which generates commands to create virtual networks and configure network virtualization endpoints, such as computing device600and, more specifically, a corresponding virtual router206A and206B, as well as virtual network interfaces612A and612B. By configuring virtual router206A based on information received from SDN controller70, virtual router agent314may support configuring network isolation, policy-based security, a gateway, source network address translation (SNAT), a load-balancer, and service chaining capability for orchestration.

In one example, network packets, e.g., layer three (L3) IP packets or layer two (L2) Ethernet packets generated or consumed by the containers629A within the virtual network domain may be encapsulated in another packet (e.g., another IP or Ethernet packet) that is transported by the physical network. The packet transported in a virtual network may be referred to herein as an “inner packet” while the physical network packet may be referred to herein as an “outer packet” or a “tunnel packet.” Encapsulation and/or de-capsulation of virtual network packets within physical network packets may be performed by virtual router206A. This functionality is referred to herein as tunneling and may be used to create one or more overlay networks. Besides IPinIP, other example tunneling protocols that may be used include IP over Generic Route Encapsulation (GRE), VxLAN, Multiprotocol Label Switching (MPLS) over GRE, MPLS over User Datagram Protocol (UDP), etc. Virtual router206A performs tunnel encapsulation/decapsulation for packets sourced by/destined to any containers of pods602, and virtual router206A exchanges packets with pods602via bus642and/or a bridge of NIC630.

As noted above, a SDN controller70may provide a logically centralized controller for facilitating operation of one or more virtual networks. SDN controller70may, for example, maintain a routing information base, e.g., one or more routing tables that store routing information for the physical network as well as one or more overlay networks. Virtual routers206implement one or more virtual routing and forwarding instances (VRFs)622A-622B for respective virtual networks for which the corresponding virtual router206operates as respective tunnel endpoints. In general, each VRF622stores forwarding information for the corresponding virtual network and identifies where data packets are to be forwarded and whether the packets are to be encapsulated in a tunneling protocol, such as with a tunnel header that may include one or more headers for different layers of the virtual network protocol stack. Each of VRFs622may include a network forwarding table storing routing and forwarding information for the virtual network.

NIC630may receive tunnel packets and forward the tunnel packets to the appropriate virtual router. As an example, virtual router206A processes the tunnel packet to determine, from the tunnel encapsulation header, the virtual network of the source and destination endpoints for the inner packet. Virtual router206A may strip the layer 2 header and the tunnel encapsulation header to internally forward only the inner packet. The tunnel encapsulation header may include a virtual network identifier, such as a VxLAN tag or MPLS label, that indicates a virtual network, e.g., a virtual network corresponding to VRF622A. VRF622A may include forwarding information for the inner packet. For instance, VRF622A may map a destination layer 3 address for the inner packet to virtual network interface212. VRF622A forwards the inner packet via virtual network interface212to POD602A in response.

Pod602A includes one or more application containers629A and pod602B includes one or more application containers629B. Containers such as containers629A or629B may also source inner packets as source virtual network endpoints. Container629A, for instance, may generate a layer 3 inner packet destined for a destination virtual network endpoint that is executed by another computing device (i.e., not computing device600) or for another one of containers. Container629A may sends the layer 3 inner packet to virtual router206A via virtual network interface212attached to VRF622A.

Virtual router206A receives the inner packet and layer 2 header and determines a virtual network for the inner packet. Virtual router206A may determine the virtual network using any of the above-described virtual network interface implementation techniques (e.g., macvlan, veth, etc.). Virtual router206A uses the VRF622A corresponding to the virtual network for the inner packet to generate an outer header for the inner packet, the outer header including an outer IP header for the overlay tunnel and a tunnel encapsulation header identifying the virtual network. Virtual router206A encapsulates the inner packet with the outer header. Virtual router206A may encapsulate the tunnel packet with a new layer 2 header having a destination layer 2 address associated with a device external to the computing device600, e.g., a TOR switch116(FIG.1B) or one of servers12. If external to computing device600, virtual router206A outputs the tunnel packet with the new layer 2 header to NIC630. NIC630outputs the packet on an outbound interface. If the destination is another virtual network endpoint executing on computing device600, virtual router206A routes the packet to the appropriate one of virtual network interfaces212(FIG.2).

In some examples, a controller for computing device600(e.g., SDN controller70) ofFIGS.1A,1B and2) configures a default route in each of pods602to cause the pods to use a virtual router (e.g., virtual routers206A and206B) as an initial next hop for outbound packets.

Container platform604includes container engine608, orchestration agent310, service proxy611, and CNI312. Container engine608includes code executable by microprocessor610. Container runtime608may be one or more computer processes. Container engine608runs containerized applications in the form of containers629A-629B. Container engine608may represent a Dockert, rkt, or other container engine for managing containers. In general, container engine608receives requests and manages objects such as images, containers, networks, and volumes. An image is a template with instructions for creating a container. A container is an executable instance of an image. Based on directives from orchestration agent310, container engine608may obtain images and instantiate them as executable containers in pods602A-602B.

Service proxy611includes code executable by microprocessor610. Service proxy611may be one or more computer processes. Service proxy611monitors for the addition and removal of service and endpoints objects, and it maintains the network configuration of the computing device600to ensure communication among pods and containers, e.g., using services. Service proxy611may also manage iptables to capture traffic to a service's virtual IP address and port and redirect the traffic to the proxy port that proxies a backed pod. Service proxy611may represent a kube-proxy for a minion node of a Kubernetes cluster. In some examples, container platform604does not include a service proxy611or the service proxy611is disabled in favor of configuration of virtual router206A and pods602by CNI312.

Orchestration agent310includes code executable by microprocessor610. Orchestration agent310may be one or more computer processes. Orchestration agent310may represent a kubelet for a minion node of a Kubernetes cluster. Orchestration agent310is an agent of an orchestrator, e.g., orchestrator50ofFIGS.1A,1B and2, that receives container specification data for containers and ensures the containers execute by computing device600. Container specification data may be in the form of a manifest file sent to orchestration agent310from orchestrator50or indirectly received via a command line interface, HTTP endpoint, or HTTP server. Container specification data may be a pod specification (e.g., a PodSpec—a YAML (Yet Another Markup Language) or JSON object that describes a pod) for one of pods602of containers629. Based on the container specification data, orchestration agent310directs container engine608to obtain and instantiate the container images for containers629, for execution of containers629by computing device600.

Orchestration agent310instantiates or otherwise invokes CNI312to configure one or more virtual network interfaces for each of pods602. For example, orchestration agent310receives a container specification data for pod602A and directs container engine608to create the pod602A with containers629A based on the container specification data for pod602A. Orchestration agent310can also receive a container specification data for pod602B and directs container engine608to create the pod602B with containers629B based on the container specification data for pod602B. Orchestration agent310also invokes the CNI312to configure, for pod602A, virtual network interface612A for a virtual network corresponding to VRFs622A, and for pod602B, virtual network interface612B for a virtual network interface corresponding to VRFs622B. In this example, pod602A is a virtual network endpoint for a virtual network corresponding to VRF622A and pod602B is a virtual network endpoint for a virtual network corresponding to VRF622B.

CNI312may obtain interface configuration data for configuring virtual network interfaces for pods602. Virtual router agents314A and314B operate as virtual network control plane modules for enabling SDN controller70to configure virtual routers206A and206B respectively. Unlike the orchestration control plane (including the container platforms604for minion nodes and the master node(s), e.g., orchestrator50), which manages the provisioning, scheduling, and managing virtual execution elements, a virtual network control plane (including SDN controller70and virtual router agents314for minion nodes) manages the configuration of virtual networks implemented in the data plane in part by virtual routers of the minion nodes. Virtual router agents314communicate, to CNI312, interface configuration data for virtual network interfaces to enable an orchestration control plane element (i.e., CNI312) to configure the virtual network interfaces according to the configuration state determined by the SDN controller70, thus bridging the gap between the orchestration control plane and virtual network control plane. In addition, this may enable a CNI312to obtain interface configuration data for multiple virtual network interfaces for a pod and configure the multiple virtual network interfaces, which may reduce communication and resource overhead inherent with invoking a separate CNI312for configuring each virtual network interface.

FIG.6Bis a block diagram of the example computing device ofFIG.6Aoperating as an instance of an orchestrator master node for a cluster for a virtualized computing infrastructure. In this example, computing device600may represent one or more real or virtual servers. As such, computing device600may in some instances implement one or more master nodes for respective clusters. In the example shown inFIG.6B, computing devices includes scheduler652, API server650, network controller manager656, network controller654, network controller manager655, and configuration store658

Scheduler652, API server650, network controller manager656, network controller654, network controller manager655, and configuration store658, although illustrated and described as being executed by a single computing device600, may be distributed among multiple computing devices600that make up a computing system or hardware/server cluster. Each of the multiple computing devices600, in other words, may provide a hardware operating environment for one or more instances of any one or more of scheduler652, API server650, network controller manager656, network controller654, network controller manager655, or configuration store658. Network controller654may represent an example instance of SDN controller70ofFIGS.1A,1B and2. Scheduler652, API server650, controller manager656, and network controller manager655may implement an example instance of orchestrator50. Network controller manager655may represent an example implementation of a Kubernetes cloud controller manager or Kube-manager. Network controller654may represent an example instance of SDN controller70.

API server650, scheduler652, controller manager656, and configuration store may implement a master node for a cluster and be alternatively referred to as “master components.” The cluster may be a Kubernetes cluster and the master node a Kubernetes master node, in which case the master components are Kubernetes master components.

API server650includes code executable by microprocessor610. API server650may be one or more computer processes. API server650validates and configures data for objects, such as virtual execution elements (e.g., pods of containers), services, and replication controllers, for instance. A service may be an abstraction that defines a logical set of pods and the policy used to access the pods. The set of pods implementing a service are selected based on the service definition. A service may be implemented in part as, or otherwise include, a load balancer. API server650may implement a Representational State Transfer (REST) interface to process REST operations and provide the frontend to a corresponding cluster's shared state stored to configuration store658. API server650may authenticate and authorize requests. API server650communicates with other components to instantiate virtual execution elements in the computing infrastructure8. API server650may represent a Kubernetes API server.

Configuration store658is a backing store for all cluster data. Cluster data may include cluster state and configuration data. Configuration data may also provide a backend for service discovery and/or provide a locking service. Configuration store658may be implemented as a key value store. Configuration store658may be a central database or distributed database. Configuration store658may represent an etcd store. Configuration store658may represent a Kubernetes configuration store.

Scheduler652includes code executable by microprocessor610. Scheduler652may be one or more computer processes. Scheduler652monitors for newly created or requested virtual execution elements (e.g., pods of containers) and selects a minion node on which the virtual execution elements are to run. Scheduler652may select a minion node based on resource requirements, hardware constraints, software constraints, policy constraints, locality, etc. Scheduler652may represent a Kubernetes scheduler.

In general, API server650may invoke the scheduler652to schedule a virtual execution element, which may select a minion node and returns an identifier for the selected minion node to API server650, which may write the identifier to the configuration store658in association with the virtual execution element. API server650may invoke the orchestration agent310(FIG.6A) for the selected minion node, which may cause the container engine608(FIG.6A) for the selected minion node to obtain the virtual execution element from a storage server and create the virtual execution element on the minion node. The orchestration agent310for the selected minion node may update the status for the virtual execution element to the API server650, which persists this new state to the configuration store658. In this way, computing device600instantiates new virtual execution elements in the computing infrastructure100,108(FIGS.1A and1B).

Controller manager656includes code executable by microprocessor610. Controller manager656may be one or more computer processes. Controller manager656may embed the core control loops, monitoring a shared state of a cluster by obtaining notifications from API Server650. Controller manager656may attempt to move the state of the cluster toward the desired state. Example controllers (not shown) managed by the controller manager656may include a replication controller, endpoints controller, namespace controller, and service accounts controller. Controller manager656may perform lifecycle functions such as namespace creation and lifecycle, event garbage collection, terminated pod garbage collection, cascading-deletion garbage collection, node garbage collection, etc. Controller manager656may represent a Kubernetes Controller Manager for a Kubernetes cluster.

Network controller654includes code executable by microprocessor610. Network controller654may include one or more computer processes. Network controller654may represent an example instance of SDN controller70ofFIGS.1A and1B. The network controller654may be a logically centralized but physically distributed SDN controller that is responsible for providing the management, control, and analytics functions of a virtualized network. In particular, network controller654may be a logically centralized control plane and management plane of the computing infrastructure100,108and orchestrates virtual routers for one or more minion nodes.

Network controller654may provide cloud networking for a computing architecture operating over a network infrastructure. Cloud networking may include private clouds for enterprise or service providers, infrastructure as a service (IaaS), and virtual private clouds (VPCs) for cloud service providers (CSPs). The private cloud, VPC, and IaaS use cases may involve a multi-tenant virtualized data centers, such as that described with respect toFIG.1. In such cases, multiple tenants in a data center share the same physical resources (physical servers, physical storage, physical network). Each tenant is assigned its own logical resources (virtual machines, containers, or other form of virtual execution elements; virtual storage; virtual networks). These logical resources are isolated from each other, unless specifically allowed by security policies. The virtual networks in the data center may also be interconnected to a physical IP VPN or L2 VPN.

Network controller654may provide network function virtualization (NFV) to networks, such as business edge networks, broadband subscriber management edge networks, and mobile edge networks. NFV involves orchestration and management of networking functions such as a Firewalls, Intrusion Detection or Preventions Systems (IDS/IPS), Deep Packet Inspection (DPI), caching, Wide Area Network (WAN) optimization, etc. in virtual machines, containers, or other virtual execution elements instead of on physical hardware appliances. The main drivers for virtualization of the networking services in this market are time to market and cost optimization.

Network controller654programs network infrastructure elements to create virtual networks and may create interface configurations for virtual network interfaces for the virtual networks.

Additional information regarding an example network controller is found in International Application Number PCT/US2013/044378 and in U.S. patent application Ser. No. 14/226,509, incorporated by reference above.

Network controller manager655includes code executable by microprocessor610. Network controller manager655may be one or more computer processes. Network controller manager655operates as an interface between the orchestration-oriented elements (e.g., scheduler652, API server650, controller manager656, and configuration store658) and network controller654. In general, network controller manager655monitors the cluster for new objects (e.g., pods and services). Network controller manager655may isolate pods in virtual networks and connect pods with services.

Network controller manager655may be executed as a container of the master node for a cluster. In some cases, using network controller manager655enables disabling the service proxies of minion nodes (e.g., the Kubernetes kube-proxy) such that all pod connectivity is implemented using virtual routers, as described herein.

Network controller manager655may use the controller framework for the orchestration platform to listen for (or otherwise monitor for) changes in objects that are defined in the API and to add annotations to some of these objects. The annotations may be labels or other identifiers specifying properties of the objects (e.g., “Virtual Network Green”). Network controller manager655may create a network solution for the application using an interface to network controller654to define network objects such as virtual networks, virtual network interfaces, and access control policies. Network controller654may implement the network solution in the computing infrastructure by, e.g., configuring the one or more virtual network and virtual network interfaces in the virtual routers.

FIG.7is a block diagram of an example computing device (e.g., server) that includes a hybrid data plane, according to techniques described in this disclosure. In the example shown inFIG.7, server700includes network interfaces721A-721N (collectively “network interfaces721”), kernel380, DPDK virtual router206A, CNI312, and cRPD704. Server700may be an implementation of any of servers12,300,400, and600ofFIGS.1A,1B,2,3,4,6A and6B. Additionally, in this example, server700hosts pods722A-722D (collectively, “pods722”). Kernel380, DPDK virtual router206A, CNI312, and cRPD704may be combined in an implementation of Cloud Native Router702.

Cloud native router702includes a hybrid data plane734that incorporates kernel data plane732and DPDK data plane730. Hybrid data plane734may be an implementation of hybrid data plane150ofFIG.1B. Kernel data plane732is implemented by kernel380and network stack712. In some aspects, kernel380may include a virtual router module (not shown inFIG.7) that is part of kernel data plane732. DPDK data plane730is implemented by virtual router206A.

NICs721may be implementations of NICs321(FIGS.3and4) and/or NIC630(FIGS.6A and6B). In some aspects, each of NICs721is assigned to DPDK data plane734, and none of NICs721are assigned to kernel data plane732.

In some aspects, a K8s node on server700is modeled as a PE router, and each pod is modeled as a CE router. cRPD324may be configured to run in “host mode.” Pods722may be linked to hybrid data plane734via one or both of kernel data plane732and DPDK data plane734. In the example illustrated inFIG.7, pods722A and722B are linked to kernel data plane732via VRF707A of CRPD324. Pod722D is linked to virtual router206A of DPDK data plane734. A pod722can be modeled as a multihomed CE, that is, a pod can be connected to multiple VRFs. Further, the VRFs may be in different data planes of hybrid data plane734. In the example shown inFIG.7, pod722C is multihomed, and is linked to both kernel data plane732via VRF707A and virtual router206A of DPDK data plane734via VRF707B.

In response to orchestrator50(FIGS.1A and1B) creating a pod722, cRPD324dynamically creates one or more virtualized network interfaces. For example, when orchestrator50creates a pod that is configured to use kernel data plane732, cRPD324can create a veth pair communicatively coupling the pod to a VRF of cRPD324. cRPD324terminates one end of the veth link at the pod, other end is terminated inside a VRF on cRPD324. In the example shown inFIG.7, when orchestrator50crates pods722A-722C, cRPD324creates a veth pair between the respective pod and VRF707A. Because cRPD324has access to kernel380interfaces and network stack712, various routing protocols may be used between pods722A-722C and cRPD324. Examples of such protocols include E-BGP, IS-IS, and OSPF. Additionally, cRPD324can utilize kernel380and network stack712to apply various types of network overlays. Examples of such overlays include L3VPN, E-VPN (Type-2/Type-5) using different underlays/tunneling: MPLS, SR-MPLS, SRv6, MPLS over UDP/IPIP/GRE tunnels, etc. Additionally, cRPD324can utilize kernel380and network stack712to provide support for protocols such as IPsec, SRv6, IP-IP, etc. Further, the elements of kernel data plane732provide support for applications and workloads that utilize kernel380's native networking APIs (e.g., BSD sockets).

In response to orchestrator50creating a pod that is configured to use the DPDK data plane, cRPD324can create a vHost interface communicatively coupling the pod to a VRF of a DPDK-based virtual router of DPDK data plane730. In the example shown inFIG.7, when orchestrator50creates pods722C and722D, cRPD324creates a vhost interface between the respective pod and VRF707B of DPDK-based virtual router206A.

In some aspects, cRPD324creates VRFs/routing-instances for interfaces in kernel data plane732that are separate from the VRFs/routing-instances that cRPD324creates for interfaces in DPDK data plane730. For instance, in the example shown inFIG.7, cRPD324creates VRF707A for kernel data plane732, and VRF707B for virtual router707B in DPDK data plane734.

Additionally, cRPD324can create a vhost interface for each network interface port that has been assigned to virtual router206A. As an example, NIC721N assigned to virtual router206A has two ports: port0 and port1. cRPD324creates two vhost interfaces, vhost0 and vhost1, that correspond to port0 and port1 respectively.

A network packet that originates at one of pods722can be referred to as an “outbound packet.” Outbound packets that are transmitted to VRF707A (e.g., outbound packets from pods722A,722B, and the veth interface of pod722C) are directed to a kernel interface (e.g., a veth interface of cRPD324). In such cases, route lookup and encapsulation can be performed in kernel380and/or network stack712. Kernel380and network stack712create a fully formed L2 packet for the outbound packet that is then handed over to DPDK data plane730via a vhost interface. Packet processor710of virtual router206A transmits the packet via a NIC721(NIC721N in the example ofFIG.7). In some aspects, packet processor710does not perform any network processing of packets received from network stack712and/or kernel380other than to transmit the outbound packet via a NIC721, and thus acts as a “pass-through” entity.

Outbound packets that are transmitted from a pod configured to use DPDK are provided directly to VRF707B in the example shown inFIG.7. In this example, pods722D and722D are each configured to use DPDK. In this case, virtual router206A performs standard DPDK processing for the outbound packets and creates packets for transmission via a NIC721(NIC721N in the example ofFIG.7).

A network packet that is received by one of network interfaces721that originates from a network source outside of server700can be referred to as an “inbound packet.” Because all network interfaces of server700are assigned to DPDK data plane730, an inbound packet will be received at a DPDK-based virtual router. In the example ofFIG.7, inbound packets for one of pods722are received by virtual router206A. Packet processor710of virtual router206A can examine an inbound packet and use various criteria to determine if the packet requires kernel-based processing or not. Packet processor710operates as a “pass-through” for packets that it determines require kernel-based processing. Packet processor710delivers such packets to network stack712for delivery to the appropriate VRF. In the example shown inFIG.7, packet processor710does not perform any network processing of inbound packets having a destination of pods722A,722B, and the veth interface of pod722C other than to pass the inbound packet to network stack712for processing and delivery to VRF707A.

cRPD324can install forwarding state in both kernel data plane732and DPDK data plane734for DPDK-based virtual routers. For example, cRPD324creates a logical representation of VRFs that are created for the DPDK data plane that have substantially the same routing tables as corresponding DPDK VRFs. In the example ofFIG.7, VRF707B′ is a logical representation of VRF707B, and includes substantially the same routing tables as VRF707B with minor differences. For example, the routing tables for VRF707B and707B′ can contain same set of route entries/prefixes, but will have different values in the next-hop fields for the routes/prefixes handled by the kernel data-plane. For such entries, VRF7707B has a routing table entry that has a next-hop value that instructs the packet to be delivered to kernel. For the same prefix, VRF707B′ has a routing table entry with a next-hop value that indicates how kernel380is to decapsulate the packet and perform lookup in the routing table of VRF707B′. Thus, for packets having destination address indicating that the packet is to be processed by kernel380, cRPD324may program the routing table of VRF707B to set the next hop to an interface of kernel380(e.g., vhost0 or vhost1), indicating that packet processor710should forward the packet to kernel380, for example via the vhost interface. When kernel380receives a packet via the vhost interface, it can determine that the next-hop field in the routing table entry associated with the destination address is the loop-back address, indicating that the kernel should process the inbound packet.

Packet processor710can perform standard DPDK processing for inbound packets having a destination that indicates a VRF in DPDK data plane730. For example, packet processor710can perform DPDK processing for inbound packets having a destination of the vhost interface of pod722C or of pod722D.

FIGS.8A and8Bare sequence diagrams illustrating example processing of outbound and inbound packets, in accordance with techniques of the disclosure.FIGS.8A and8Bwill be discussed in the context of the Cloud Native Router702shown inFIG.7. In the examples shown inFIGS.8A and8B, two pods722A and722D send and receive network packets. Pod722D is configured to utilize DPDK-based networking. Based on this configuration, cRPD324configures a vhost connection to communicatively couple pod722D to VRF707B. Pod722A is configured to use kernel-based networking. Based on this configuration, cRPD324configures a veth pair to communicatively couple pod722A to VRF707A.

FIG.8Ais an example sequence diagram illustrating example processing of outbound packets, in accordance with techniques of the disclosure. In the example shown inFIG.8A, pods722A and722D each transmit an outbound packet. Pod722A transmits an outbound packet at operation810. Pod722A is configured to use the kernel data plane, and thus the outbound packet will be referred to as a kernel-based outbound packet. VRF707A receives the outbound packet, and at operation812, kernel380and/or network stack712process the outbound packet. Such processing may include LAUNDRY LIST. After the processing at operations812, the kernel-based outbound packet will be a fully formed L2 packet. At operation814, network stack712forwards the packet to DPDK virtual router206A via a vhost interface. Packet processor710of virtual router206A receives the kernel-based outbound packet (as encapsulated by network stack712), and because the packet virtual router receives the packet via the vhost interface between itself and network stack712, virtual router206A, does not perform any processing of the packet other than to forward the kernel-based outbound packet to the corresponding physical port at operation816. As an example, if virtual router206A receives a packet from network stack712via the vhost1 interface, packet processor710will act as a pass-through device and forward the packet to NIC721N for transmission via port1 (the port corresponding to vhost1).

Pod722D transmits an outbound packet at operation818. Pod722D is configured to use the DPDK data plane, and thus the outbound packet will be referred to as a DPDK-based outbound packet. VRF707B of virtual router206A can receive the outbound packet via a vhost interface or via DPDK APIs. Virtual router206A performs DPDK based processing of the packet and forwards the DPDK-based outbound packet to NIC721N at operation820.

Operations810-820may be performed in a different order than that shown inFIG.8A. For example, pod722D may transmit an outbound packet before pod722A. Further, operations shown inFIG.8Amay take place concurrently.

FIG.8Bis an example sequence diagram illustrating example processing of an inbound packet, in accordance with techniques of the disclosure. In the example shown inFIG.8B, an inbound packet is received by NIC721N. As noted above, each of NICs721are assigned to the DPDK data plane. Thus, at operation830, NIC721N provides the inbound packet to virtual router206A. Packet inspector710performs packet inspection832to determine if the inbound packet has a DPDK-based pod as a destination, or if the inbound packet is to be provided to kernel380for further processing or if the packet is to be processed by virtual router206A (384). Packet inspector710can use various rules and heuristics to determine if an inbound packet is to be provided to kernel380for further processing. For example, in some aspects, packet inspector710may determine an encapsulation type for the packet, and provide the packet to kernel380for processing if the encapsulation type is one that is not supported by DPDK-based virtual router. Examples of such encapsulations include IP-IP, VX-LAN, GRE, MPLS, EVPN, IPsec, SRV6 etc. As an example, packet processor710may establish an “deliver-to-host path” that specifies a vhost interface (e.g., vhost0 or vhost1 in the example ofFIG.7) that packet processor710is to use when packets have encapsulations that require kernel-based processing.

In some aspects, packet processor can determine to forward a packet to kernel380based on the destination address. As described above, a routing table in virtual router206A may be programmed to set the next-hop address to kernel380. In this case, the packet is forwarded to kernel380for further processing.

In some aspects, packet processor710may determine that it does not know how to handle the packet. In this case, packet processor710may forward the packet to kernel380on the assumption that kernel380will know how to handle the packet. As an example, packet processor710may establish an “exception-to-host path” that specifies a vhost interface (e.g., vhost0 or vhost1 in the example ofFIG.7) that packet processor710is to use when encountering packets it does not know how to handle. For example, the “exception-to-host” path may be used to forward a packet for kernel-based processing if packet processor710encounters a label in a packet header that it does not know how to handle.

If packet inspector710determines that the packet is to be provided to kernel380, then at operation836(“YES” branch of834), packet processor710provides the inbound packet to network stack712of kernel380for further processing (838) by kernel380using network stack712. In this case, packet processor710does not perform any processing on the inbound packet other than to forward the packet to kernel380. For example, DPDK processing operations of virtual router206A are bypassed, and any TTL values for the inbound packet are not modified.

If packet inspector710determines that the packet has a DPDK pod as a destination and does not require kernel processing, (“NO” branch of834), virtual router206A performs standard DPDK packet processing and at operation842, provides the packet to DPDK-based pod722D using a vhost interface or DPDK APIs.

FIG.9is an example deployment specification for a pod, in accordance with techniques of the disclosure. The example shown inFIG.9is in the YAML Ain't Markup Language (YAML) format. In the example shown inFIG.9, a pod named “odu-pod1” is to be connected to two networks upon creation. A first network definition902indicates that a first interface “net1” is to be used to connect the pod to a network named “vswitch-pod1-bd100.” The “dataplane” field has a value of “linux” indicating that this interface is to be created for a kernel data plane (e.g., a linux kernel data plane). A second definition904A first network definition902indicates that a second interface “net2” is to be used to connect the pod to a network named “vswitch-pod1-bd200.” The “dataplane” field has a value of “DPDK” indicating that the pod supports DPDK communication and that this interface is to be created for a DPDK data plane.

FIG.10is a flow diagram illustrating operations of a DPDK-based virtual router. A data plane development kit (DPDK)-based virtual router receives, from a physical interface, a packet destined for a containerized application (1005). The DPDK-based virtual router determines whether a kernel network stack executed by the processing circuitry is to perform tunneling processing for the packet (1010). In response to determining that the kernel network stack is to perform tunneling processing for the first packet, the DPDK-based virtual router forwards the packet to the kernel network stack (1015).

The techniques described herein may be implemented in hardware, software, firmware, or any combination thereof. Various components, functional units, and/or modules illustrated in the figures and/or illustrated or described elsewhere in this disclosure may perform operations described using software, hardware, firmware, or a mixture of hardware, software, and firmware residing in and/or executing at one or more computing devices. For example, a computing device may execute one or more of such modules with multiple processors or multiple devices. A computing device may execute one or more of such modules as a virtual machine executing on underlying hardware. One or more of such modules may execute as one or more services of an operating system or computing platform. One or more of such modules may execute as one or more executable programs at an application layer of a computing platform. In other examples, functionality provided by a module could be implemented by a dedicated hardware device. Although certain modules, data stores, components, programs, executables, data items, functional units, and/or other items included within one or more storage devices may be illustrated separately, one or more of such items could be combined and operate as a single module, component, program, executable, data item, or functional unit. For example, one or more modules or data stores may be combined or partially combined so that they operate or provide functionality as a single module. Further, one or more modules may operate in conjunction with one another so that, for example, one module acts as a service or an extension of another module. Also, each module, data store, component, program, executable, data item, functional unit, or other item illustrated within a storage device may include multiple components, sub-components, modules, sub-modules, data stores, and/or other components or modules or data stores not illustrated. Further, each module, data store, component, program, executable, data item, functional unit, or other item illustrated within a storage device may be implemented in various ways. For example, each module, data store, component, program, executable, data item, functional unit, or other item illustrated within a storage device may be implemented as part of an operating system executed on a computing device.