Secure data flow open information analytics

Provided are methods and systems for processing a secure data flow. An example method for processing a secure data flow includes receiving a data packet, determining network conditions associated with the data traffic, and determining that the data packet is associated with the secure data flow. Upon determination that the data packet is associated with the secure data flow, the data packet is analyzed. Thereafter, the method proceeds to classify the secure data flow based on the analysis. Subscriber data associated with the data packet may be obtained. The method can then process the secure data flow based on the subscriber data and the classification of the secure data flow.

TECHNICAL FIELD

This disclosure relates generally to data processing and, more specifically, to processing of secure data flows.

BACKGROUND

The approaches described in this section could be pursued but are not necessarily approaches that have previously been conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.

In network communications, amount of secure data flows is increasingly growing. Encryption of data traffic is typically used by content providers in attempt to protect privacy of end users. For this purpose, content providers offer a plurality of mechanisms for encryption of the content inside data packets. However, while satisfying privacy concerns of end users, the encryption of data traffic may create problems for network service providers. The network service providers may perform classification of the data traffic to understand which type of the data traffic is flowing over the network or with which application the data traffic is associated.

To classify the data traffic, network service providers often rely on analysis of the content of the data traffic. One of the techniques used by the network service providers for analysis of the data traffic is deep packet inspection. Using the deep packet inspection, the network service providers may analyze a payload of a data packet to determine the type of the data flow or an application category to which a particular data flow belongs. However, conventionally used data traffic analysis techniques may not be available for encrypted data traffic. Therefore, network service providers may have difficulties in analyzing and understanding secure data flows.

SUMMARY

The present disclosure is related to processing of a secure data flow. Specifically, a method for processing a secure data flow may include receiving a data packet. The method may further include determining network conditions associated with the data traffic. The method can include determining that the data packet is associated with the secure data flow. Upon determination that the data packet is associated with the secure data flow, the data packet may be analyzed. The method can further include classifying the secure data flow based on the analysis. Furthermore, subscriber data associated with the data packet may be obtained. The method may further include processing the secure data flow based on the subscriber data and the classification of the secure data flow

According to another approach of the present disclosure, there is provided a system for processing a secure data flow. The system may comprise a servicing node and an analyzing unit. The servicing node can be operable to receive a data packet and to determine that the data packet is associated with the secure data flow. Additionally, the servicing node can be operable to obtain subscriber data associated with the data packet. The analyzing unit can be operable to analyze the data packet and, based on the analysis, classify the secure data flow. The analyzing unit can further be operable to process the secure data flow based on the subscriber data and based on the classification of the secure data flow.

In further example embodiments of the present disclosure, the method steps are stored on a machine-readable medium comprising instructions, which when implemented by one or more processors, perform the recited steps. In yet further example embodiments, hardware systems or devices can be adapted to perform the recited steps. Other features, examples, and embodiments are described below.

DETAILED DESCRIPTION

The following detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show illustrations in accordance with example embodiments. These example embodiments, which are also referred to herein as “examples,” are described in enough detail to enable those skilled in the art to practice the present subject matter. The embodiments can be combined, other embodiments can be utilized, or structural, logical, and electrical changes can be made without departing from the scope of what is claimed. The following detailed description is therefore not to be taken in a limiting sense, and the scope is defined by the appended claims and their equivalents. In this document, the terms “a” and “an” are used, as is common in patent documents, to include one or more than one. In this document, the term “or” is used to refer to a nonexclusive “or,” such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated.

The techniques of the embodiments disclosed herein may be implemented using a variety of technologies. For example, the methods described herein may be implemented in software executing on a computer system or in hardware utilizing either a combination of microprocessors or other specially designed application-specific integrated circuits, programmable logic devices, or various combinations thereof. In particular, the methods described herein may be implemented by a series of computer-executable instructions residing on a storage medium such as a disk drive, or computer-readable medium. It should be noted that methods disclosed herein can be implemented by a computer (e.g., a desktop computer, a tablet computer, a laptop computer, and a server), a game console, a handheld gaming device, a cellular phone, a smart phone, a smart television system, and so forth.

The present disclosure relates to methods and systems for processing a secure data flow. An example system of the present disclosure may include a servicing node positioned after a first network hop in a data traffic path between a subscriber and a server. As used herein, a network hop may include one portion of the data traffic path, such as the data traffic path between two routing devices or other data traffic processing devices in the network. Each time the data traffic is passed to the next device, such as, for example, a router, a gateway, or a bridge, a further network hop occurs. Therefore, the servicing node may be positioned, for example, after the first routing device in the data traffic path from the subscriber to the server.

Due to the positioning after the first network hop, the servicing node may be operable to see subscriber-related information unavailable to further devices positioned after further network hops in the data traffic path. Specifically, each device that receives the data traffic may process and modify data associated with the data traffic. For example, a router that receives the data traffic may implement routing functions by replacing a subscriber address with a router address. Therefore, data associated with the data traffic and sent by the router to a further network device may include only the router address but not the subscriber address. Therefore, positioning of the servicing node after the first network hop may provide access to specific subscriber-related information, which may be lost or modified further down the data traffic path.

In the case of encrypted data traffic, data associated with headers of data packets may be available, while data associated with a payload being encrypted may be unavailable to the servicing node. In this case, the servicing node may be able to analyze only open data associated with the data packets. The open data may include subscriber-related information that the servicing node can process. The open data may include a subscriber machine address, a source network address, a destination network address (DNA), data packet size, data flow direction, data packet sequence, and so forth. Additionally, the servicing node may obtain subscriber data associated with the data packets. For example, the subscriber data may be obtained from a database or third parties.

Based on the analysis of the open data and the subscriber data, the servicing node may classify the secure data flow. The classification may include attributing the secure data flow to a certain type of data traffic, such as, for example, chat, video, voice; attributing the secure data flow to a certain subscriber; and the like. Therefore, the classification may include differentiating data flows from different subscribers and data flows associated with different applications. The servicing node may process the secure data flow based on the classification. For example, the servicing node may transmit the secure data flow to a further servicing node further down the network path and provide the further servicing node with certain open data associated with the secure data flow, which may be needed for further processing of the secure data flow by the further servicing node.

Referring now to the drawings,FIG. 1illustrates an environment100within which methods and systems for processing a secure data flow can be implemented. The environment100may include a network110, a subscriber120, a server130, a system300for processing a secure data flow, and a database140. The subscriber120may include a network machine, a network resource, or a user that establishes a secure network session with the server130by sending secure data packets150. The server130may be associated with a plurality of services, applications, and websites accessible over the network110. The server130may communicate with the subscriber120by sending secure data packets160to the subscriber120in response to receiving the secure data packets150from the subscriber120. The subscriber120and the server130may communicate with each other using the network110.

The network110may include the Internet or any other network capable of communicating data between devices. Suitable networks may include or interface with any one or more of, for instance, a local intranet, a Personal Area Network, a Local Area Network, a Wide Area Network, a Metropolitan Area Network, a virtual private network, a storage area network, a frame relay connection, an Advanced Intelligent Network connection, a synchronous optical network connection, a digital T1, T3, E1 or E3 line, Digital Data Service connection, Digital Subscriber Line connection, an Ethernet connection, an Integrated Services Digital Network line, a dial-up port such as a V.90, V.34 or V.34bis analog modem connection, a cable modem, an Asynchronous Transfer Mode connection, or a Fiber Distributed Data Interface or Copper Distributed Data Interface connection. Furthermore, communications may also include links to any of a variety of wireless networks, including Wireless Application Protocol, General Packet Radio Service, Global System for Mobile Communication, Code Division Multiple Access or Time Division Multiple Access, cellular phone networks, Global Positioning System, cellular digital packet data, Research in Motion, Limited duplex paging network, Bluetooth radio, or an IEEE 802.11-based radio frequency network. The network110can further include or interface with any one or more of an RS-232 serial connection, an IEEE-1394 (Firewire) connection, a Fiber Channel connection, an IrDA (infrared) port, a Small Computer Systems Interface connection, a Universal Serial Bus (USB) connection or other wired or wireless, digital or analog interface or connection, mesh or Digi® networking. The network110may include a network of data processing nodes that are interconnected for the purpose of data communication.

The system300may receive a secure data flow170. The secure data flow170may include the secure data packets150associated with the subscriber120and/or the secure data packets160associated with the server130. The system300may process the secure data flow170. The processing may include analyzing data associated with the secure data flow170and open data related to the subscriber120or the server130. The system300may communicate with the database140in which the open data may be stored.

FIG. 2shows a process flow diagram of a method200for processing a secure data flow, according to an example embodiment. In some embodiments, the operations may be combined, performed in parallel, or performed in a different order. The method200may also include additional or fewer operations than those illustrated. The method200may be performed by processing logic that may comprise hardware (e.g., decision making logic, dedicated logic, programmable logic, and microcode), software (such as software run on a general-purpose computer system or a dedicated machine), or a combination of both.

The method200may commence with a servicing node receiving a data packet at operation210. In an example embodiment, the data packet may belong to an Internet Protocol (IP) User Datagram Protocol network session, IP Transmission Control Protocol (TCP) network session, and so forth. The method200may further include determining that the data packet is associated with the secure data flow at operation220. In an example embodiment, the determining that the data packet is associated with the secure data flow may include determining that a payload associated with the data packet is encrypted. It should be noted that it may be impossible to conclude, for a single data packet, that the data packet contains encrypted content. However, if the data flow is initially determined to be secure, all further data packets of the secure data flow may be considered to be secure by association with the secure data flow.

Upon determining that the data packet is associated with the secure data flow, the method200may continue with analyzing of the data packet at operation230. The analysis may be performed by an analyzing unit. In an example embodiment, the analyzing of the data packet may include analyzing of unsecure data associated with the data packet. Additionally, the analyzing of the data packet may be based on Domain Name System (DNS) data and Dynamic Host Configuration Protocol (DHCP) data.

The unsecure data may include open data associated with the data packet. The open data may include data available to network devices. In an example embodiment, the unsecure data may include at least one of the following: a machine address, such as a media access control (MAC) address, a source network (IP/port) address prior to network address translation (NAT) and after the NAT, a DNA, a data packet size, a flow direction, a data packet sequence, an interpacket gap, a certificate, a security key, a secure sockets layer (SSL) certificate common name, and so forth. Additionally, the open data may be based on third-party data.

In a further example embodiment, the open data may include data captured with regard to related data flows received prior to receiving of the secure data flow. The related data flows may include DNS flows, DHCP flows, authentication flows, and so forth. The open data associated with the DNS flows may include one or more of the following: a domain name address, a response IP address, a DNS host IP address, store data (a host IP address, the response IP address, the domain name). The open data associated with the DHCP flows may include allocated subscriber IP addresses. The open data associated with the authentication flows may include subscriber network session start and end indications, a host IP address, and store data (e.g., subscriber information).

At operation240, the secure data flow may be classified based on the analysis. In an example embodiment, the classifying of the secure data flow associated with the data packet may be further based on the third-party data.

The method200may further include obtaining of subscriber data associated with the data packet at operation250. In some embodiments, the subscriber data may be acquired during a subscriber discovery process or from subscriber authentication related data flows. In an example embodiment, the obtaining of the subscriber data may include obtaining host data associated with the data packet. The host data may be matched to a subscriber in a database. In further example embodiments, the host data may include at least one of the following: a session start indication, a session end indication, a host IP address, a subscriber identifier (ID), and so forth. Additionally, the open data may be associated with the subscriber data.

At operation260, the secure data flow may be processed based on the classifying of the secure data flow and based on the subscriber data. In an example embodiment, the processing of the secure data flow may include one or more of the following: providing a security policy associated with the secure data flow to a further servicing node, providing a relay policy associated with the secure data flow to the further servicing node, relaying the unsecure data to a network controller for behavioral analysis, and so forth.

In an example embodiment, the further servicing node may include a policy enforcement engine. In fact, the unsecure data related to the data packet may be unavailable for the policy enforcement engine. However, based on the unsecure data obtained from the servicing node, the policy enforcement engine may apply specific policies to the subscriber associated with the data packet. The example specific policies may include suggesting or providing premium class services to the subscriber, applying a specific security policy to the subscriber or a group of subscribers, and so forth. Therefore, different policies may be applied to different subscribers based on analysis of the unsecure data of data flows associated with different subscribers.

The unsecure data determined by the servicing node may include unsecure data derived directly from the data packet and unsecure data determined by statistical or behavioral analysis of the data flow. In another example embodiment, the servicing node may receive the data packet associated with the secure data flow and determine that a uniform resource locator is encrypted and, therefore, unavailable. Therefore, information about a destination of the data packet may be unavailable for the servicing node. However, the servicing node may have access to an IP address of the subscriber, which can be included in the open data of the TCP protocol. The servicing node may perform a DNS request or a reverse DNS request and determine that the data packet is associated with a certain domain, e.g., a Google domain. Therefore, the servicing node may understand the destination of data packet. Additionally, as further servicing nodes may not be operable to perform the DNS request or the reverse DNS request, the servicing node may share the data associated with the destination of data packet associated with the secure data flow with the further servicing nodes.

In a further example embodiment, the servicing node may determine that a certificate associated with the data packet is issued by a certain domain, e.g., Google domain. Therefore, the servicing node may determine that a destination IP address is also associated with Google domain.

FIG. 3shows a block diagram illustrating various modules of a system300for processing a secure data flow, according to an example embodiment. Specifically, the system300may include a servicing node310and an analyzing unit320. In an example embodiment, the analyzing unit320may be an integral part of the servicing node310. Therefore, all functions performed by the analyzing unit320may be considered to be performed by the servicing node310.

The servicing node310may be operable to receive a data packet. Upon receipt of the data packet, the servicing node310may determine that the data packet is associated with the secure data flow. In example embodiments, the determining that the data packet is associated with the secure data flow includes determining that a payload associated with the data packet is encrypted.

Additionally, the servicing node310may be operable to obtain subscriber data associated with the data packet. In an example embodiment, the subscriber data may be acquired during a subscriber discovery process. In a further embodiment, the subscriber data may be obtained from a subscriber controller disposed in the network. The subscriber data may include host data, such as a host IP address; a subscriber ID, such as subscriber name; International Mobile Subscriber Identity, and the like.

In an example embodiment, the obtaining of the subscriber data may include obtaining host data associated with the data packet. Upon obtaining of the host data, the servicing node310may perform matching of the host data to a subscriber in a database. In an example embodiment, the host data may include at least one of the following: a session start indication, a session end indication, a host IP address, a subscriber ID, and so forth.

Upon determination that the data packet is associated with the secure data flow, the servicing node310may provide the data packet to the analyzing unit320. The analyzing unit320may be operable to analyze the data packet. In example embodiments, the analyzing of the data packet may include analyzing of unsecure data associated with the data packet. For example, the analyzing unit320may obtain host data, a source IP address, or a destination IP address from the data packet of an IP data flow.

Additionally, the analyzing may include associating the open data with the subscriber data. For example, the host data may be associated with subscriber data stored in the database. More specifically, the subscriber data may be determined based on an acquired source IP address and using a lookup table stored in the database. Additionally, the open data may be obtained based on a predefined collection policy and the subscriber data. Furthermore, the open data may be obtained using third party servers or databases.

In a further example embodiment, based on an acquired destination IP address, a domain name may be determined using a DNS flow lookup table in the database. In further embodiments, based on an acquired certificate key and common name, a vendor lookup table may be used to update subscriber data.

Additionally, the analyzing of the data packet may be based on DNS data and DHPD data. Based on the analysis, the analyzing unit320may classify the secure data flow. In some embodiments, the classifying of the secure data flow associated with the data packet may be further based on third-party data.

In an example embodiment, the servicing node may be further operable to relay the unsecure data to a network controller for behavioral analysis. The unsecure data may include at least one of the following: a MAC address, a source network (IP/port) address prior to NAT (private IP address), a source network (IP/port) address after the NAT (public IP address), a DNA, a data packet size, a flow direction, a data packet sequence, an interpacket gap, a certificate, a security key, and an SSL certificate common name.

Some characteristics may not be taken from the open data, but may be determined by the servicing node based on the open data. In example embodiments, after the private IP address is changed to the public IP address by the NAT function, the public IP address may change and data associated with the subscriber may be lost for further devices in the network. Therefore, the servicing node may determine the private IP address and relay the private IP address to the network controller for further processing or use by other devices of the network. Further characteristics determined by the servicing node may be obtained by statistical analysis or behavioral analysis of a plurality of data flows.

In a further example embodiment, a snapshot of the data flow may be created. The snapshot may represent all characteristics of the data flow. Based on the statistical analysis of the characteristics associated with the data flow, the analyzing unit may determine the type of the data traffic, such as video streaming, voice streaming, chatting, and the like. Therefore, an application associated with the secure data flow may be determined.

The servicing node310may be further operable to process the secure data flow based on the classifying of the secure data flow and the subscriber data at operation260. The processing of the secure data flow may include one or more of the following: providing a security policy associated with the secure data flow to a further servicing node, providing a relay policy associated with the secure data flow to the further servicing node, providing a collection policy associated with the secure data flow to the further servicing node, and the like. More specifically, the collection policy may define open data that needs to be collected. The security policy may include an access control policy. In an example embodiment, the access control policy may include a blacklist created based on open data or subscriber data. The access control policy may further include rules for data traffic steering based on the open data (e.g., determining of a servicing node associated with a further network hop). The relay policy may prescribe open data that needs to be relayed to a further servicing node.

In some embodiments, data provided by the servicing node to the further servicing nodes, such as collected or determined open data or selected policies, may be compressed or encrypted to be understandable to the further servicing nodes.

FIG. 4is a block diagram400showing collecting of open data associated with a secure data flow. A network hop410may be present in a network path of a secure data flow420between a subscriber host430and a server440. In an example embodiment, a servicing node (not shown) may be positioned after the network hop410. Upon passing of the secure data flow420through the network hop410, open data related to the secure data flow420may be acquired. For example, host data associated with the secure data flow420may be obtained. Furthermore, a query to obtain subscriber data may be sent to a subscriber controller450. The subscriber data and the open data may be relayed to a network controller460for further analysis. Additionally, the subscriber data and the open data may be relayed through a further network hop in the network shown as a network hop470. The network hop470may receive the secure data flow420and process the secure data flow420based on the subscriber data and the open data.

Two basic relaying modes may be available for multi-hop data flow transmission: in-band mode and out-of-band mode. In in-band mode, a network service header (NSH) and TCP header may be used. In out-of-band mode, Syslog, Netflow, Internet Protocol Flow Information Export (IPFIX), and Inter-Domain Policy Routing (IDPR) protocols may be used.

FIG. 5represents schematic diagrams505,515,525,535showing an NSH and headers of the NSH of a data packet. The NSH may be added onto encapsulated data packets to realize subscriber-to-server service paths. The NSH may provide a mechanism for metadata exchange along the instantiated subscriber-to-server service path. As shown on a schematic diagram505, the NSH may include a base header510, a service path header520, and context headers530.

Version number 585 that provides data plane versioning, for example “Ver=0x0”;

Flags bits that are used to define changes of the base header510or parsing behavior within a network version. Two flags may be defined, such as O-bit flag540and C-bit flag545. When the O-bit flag540is set, e.g., “O bit=0x0,” the data packet may be an operation, administration, and management (OAM) packet. The C-bit flag545, e.g., “C bit=0x0,” may indicate the presence of important metadata encoded as a type-length-value (TLV) element.

Length550is a total length of the NSH, including optional variable TLV elements, in 4 byte words. The length may be equal to or greater than 6.

MD Type555, e.g., “MD Type=0x2.” The NSH may define two MD types: “0x1,” which may indicate that format of the header includes fixed length context headers, and “0x2,” which may not mandate any headers beyond the base header and service path header, and may contain optional variable length context information.

Next Protocol560, e.g. “Next Protocol=0x1 (IPv4),” may indicate the protocol type of the original data packet.

The service path header520is shown in detail on a schematic diagram525. The service path header520may be a 4-byte service path header that follows the base header510and defines two fields used to construct a service path: service path identifier565and service index570. The service path identifier565may be used to identify the service path that interconnects the needed service functions. The service index570may identify the location of the data packet within a service path.

The context headers are shown in detail on a schematic diagram535as optional variable length context headers575. Choosing of MD type580as “MD-type=0x2” allows for full flexibility for headers beyond the base header and service path header.

The optional variable length context headers575may binary, compressed, and encrypted. The optional variable length context headers575may include a parseable string with following example comma-separated parameters:

“SSL-Common-Name=secure.google.com”, and so forth.

The information contained in the NSH may be provided to the analyzing unit using reporting protocols. The reporting protocols may include Netflow, IPFIX, Syslog, and IDPR. The Netflow and IPFIX protocols may include binary records with predefined informational elements. The Syslog protocol may include American standard code for information interchange records with comma-separated (or other delimiter) parameters. The IDPR protocol may include binary records according to an IDPR protocol specification.

FIG. 6illustrates a computer system600that may be used to implement embodiments of the present disclosure. The system600ofFIG. 6can be implemented in the contexts of the likes of computing systems, networks, servers, or combinations thereof. The computing system600ofFIG. 6includes one or more processor units610and main memory620. Main memory620stores, in part, instructions and data for execution by processor units610. Main memory620stores the executable code when in operation. The computer system600ofFIG. 6further includes a mass data storage630, portable storage device640, output devices650, user input devices660, a graphics display system670, and peripheral devices680. The methods may be implemented in software that is cloud-based.

The components shown inFIG. 6are depicted as being connected via a single bus690. The components may be connected through one or more data transport means. Processor units610and main memory620is connected via a local microprocessor bus, and the mass data storage630, peripheral devices680, portable storage device640, and graphics display system670are connected via one or more input/output buses.

Mass data storage630, which can be implemented with a magnetic disk drive, solid state drive, or an optical disk drive, is a non-volatile storage device for storing data and instructions for use by processor units610. Mass data storage630stores the system software for implementing embodiments of the present disclosure for purposes of loading that software into main memory620.

Portable storage device640operates in conjunction with a portable non-volatile storage medium, such as a floppy disk, compact disk, digital video disc, or a USB storage device, to input and output data and code to and from the computer system600ofFIG. 6. The system software for implementing embodiments of the present disclosure is stored on such a portable medium and input to the computer system600via the portable storage device640.

User input devices660provide a portion of a user interface. User input devices660include one or more microphones, an alphanumeric keypad, such as a keyboard, for inputting alphanumeric and other information, or a pointing device, such as a mouse, a trackball, stylus, or cursor direction keys. User input devices660can also include a touchscreen. Additionally, the computer system600as shown inFIG. 6includes output devices650. Suitable output devices include speakers, printers, network interfaces, and monitors.

Graphics display system670includes a liquid crystal display or other suitable display device. Graphics display system670receives textual and graphical information and processes the information for output to the display device.

Peripheral devices680may include any type of computer support device to add additional functionality to the computer system.

The components provided in the computer system600ofFIG. 6are those typically found in computer systems that may be suitable for use with embodiments of the present disclosure and are intended to represent a broad category of such computer components that are well known in the art. Thus, the computer system600ofFIG. 6can be a personal computer, hand held computing system, telephone, mobile computing system, workstation, tablet, phablet, mobile phone, server, minicomputer, mainframe computer, or any other computing system. The computer may also include different bus configurations, networked platforms, multi-processor platforms, and the like. Various operating systems may be used including UNIX, LINUX, WINDOWS, MAC OS, PALM OS, ANDROID, IOS, QNX, and other suitable operating systems.

It is noteworthy that any hardware platform suitable for performing the processing described herein is suitable for use with the embodiments provided herein. Computer-readable storage media refer to any medium or media that participate in providing instructions to a central processing unit, a processor, a microcontroller, or the like. Such media may take forms including, but not limited to, non-volatile and volatile media such as optical or magnetic disks and dynamic memory, respectively. Common forms of computer-readable storage media include a floppy disk, a flexible disk, a hard disk, magnetic tape, any other magnetic storage medium, a Compact Disk Read Only Memory disk, digital video disk, BLU-RAY DISC, any other optical storage medium, Random-Access Memory, Programmable Read-Only Memory, Erasable Programmable Read-Only Memory, Electronically Erasable Programmable Read Only Memory, flash memory, and/or any other memory chip, module, or cartridge.

In some embodiments, the computer system600may be implemented as a cloud-based computing environment, such as a virtual machine operating within a computing cloud. In other embodiments, the computer system600may itself include a cloud-based computing environment, where the functionalities of the computer system600are executed in a distributed fashion. Thus, the computer system600, when configured as a computing cloud, may include pluralities of computing devices in various forms, as will be described in greater detail below.

Thus, methods and systems for processing a secure data flow are disclosed. While the present embodiments have been described in connection with a series of embodiments, these descriptions are not intended to limit the scope of the subject matter to the particular forms set forth herein. It will be further understood that the methods are not necessarily limited to the discrete components described. To the contrary, the present descriptions are intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the subject matter as disclosed herein and defined by the appended claims and otherwise appreciated by one of ordinary skill in the art.