Systems and methods for scaling performance of Ethernet ring protection protocol

The present disclosure provides systems and methods for scaling performance of Ethernet Ring Protection Protocol. Specifically, the systems and methods may apply to G.8032 and may provide protection switching control plane performance scaling benefits. In an exemplary embodiment, the present invention summarizes the per “virtual” ring control plane protocol into a single logical ring control plane protocol. Advantageously, the present invention transforms the G.8032 protocol from a per-virtual ring protocol to a per-logical ring control protocol. The mechanism/methodology that is used is to include minimal per-virtual ring instance information in to the Ring Automated Protection Switching (R-APS) (control) frames. Additionally, the present invention cleanly decouples the placement of the R-APS (control) channel block location on the ring from that of the virtual channel data blocks. Current G.8032 specifications tightly couple the location of each R-APS (control) channel block and the virtual channel block that it is managing.

FIELD OF THE INVENTION

The present invention relates generally to communication networks. More particularly, the present invention relates to systems and methods for scaling performance of Ethernet Ring Protection Protocol, G.8032, using a plurality of Virtual Rings (VRings) sharing a single Ring Automated Protection Switching (R-APS) channel.

BACKGROUND OF THE INVENTION

The Ethernet Ring Protection (ERP) protocol is an industry standard and is specified within International Telecommunication Union ITU SG15 Q9, under G.8032 “Ethernet ring protection switching” (G.8032v1-June 2008, and G.8032v2-July 2010). The ERP G.8032 protocol allows multiple “virtual” rings to be present on network elements (i.e., ring nodes) that form a closed loop (i.e., a logical ring). Each virtual ring (associated with the logical ring) has independent control frames (i.e., control planes) that need to be transmitted to manage the protection switching function of the “virtual” ring. Consequently, when the association between “virtual” rings to logical rings gets large (e.g., greater than two), there is considerable processing strain/stress placed on the process (e.g., software) within each ring node, since it is effectively supporting a separate control plane for each virtual ring. Disadvantageously, this additional and excess processing adversely impacts the protection switching time for traffic it is servicing. As G.8032 continues to proliferate with increased deployments within networks, the scaling problem described herein adversely impacts such deployments.

BRIEF SUMMARY OF THE INVENTION

In an exemplary embodiment, a network includes a plurality of interconnect network elements operating in a ring, N virtual rings over the ring, N greater than or equal to one, each of the N rings operating Ethernet Ring Protection thereon, and a single management channel over the ring, wherein the single management channel configured to provide messages for the Ethernet Ring Protection on the N virtual rings. The single management channel may include a Ring Automated Protection Switching (R-APS) channel. The network may further include a virtual ring instance indicator disposed within messages over the R-APS channel, wherein the virtual ring instance indicator denotes which of the N virtual rings is associated with the messages. Optionally, the virtual ring instance indicator is located within an Ethernet Operations, Administration, and Maintenance (OAM) Protocol Data Unit (PDU) message over the R-APS channel. Also, the virtual ring instance indicator may be located within a reserved section of R-APS specific information in the Ethernet OAM PDU message over the R-APS channel. Upon reception of a message over the R-APS channel, each of the plurality of interconnect network elements may be configured to process the message based on the virtual ring instance indicator. The network may further include N service data channel blocks with each of the N service channel blocks associated with one of the N virtual rings and with each of the N service channel blocks at one of the plurality of interconnect network elements, and a management channel block at one of the plurality of interconnected network elements, wherein each of plurality of interconnect network elements with one of the N service channel blocks is configured to include virtual ring instance indicator information in messages on the single management channel. Optionally, at least one of the N service channel blocks is at a different network element from the management channel block.

Under normal operating conditions, the network element including the management channel block is configured to source messages on the single management channel, and the network elements with the N service data channel blocks are configured to include the virtual ring instance indicator information in the sourced messages. Under a fault condition between two of the network elements, the two of the network elements are configured to install the N service channel blocks and the management channel block adjacent to the fault condition, and transmit fault indication messages on the single management channel. Upon receipt of the fault indication messages, each of the network elements is configured to flush a forwarding database, remove any previously installed of the N service data channel blocks, and remove any previously installed of the management channel block. Upon recovery of the fault condition between two of the network elements, the two of the network elements are configured to implement a guard timer, and transmit recovery indication messages on the single management channel. The fault indication messages and the recovery indication messages may include the virtual ring instance indicator information for each of the N virtual rings. Upon receipt of the recovery indication messages, each of the network elements is configured to implement a wait to restore timer, and reinstall the N service data channel blocks and the management channel block as previously configured prior to the fault condition at expiry of the wait to restore timer. Each of the ring and the plurality of virtual rings have no Virtual Local Area Network Identifications (VLAN IDs) in common.

In another exemplary embodiment, a network element includes two or more Ethernet ports configured in a physical ring with a plurality of other network elements, a forwarding database for the two or more Ethernet ports, a controller communicatively coupled to the two or more Ethernet ports and the forwarding database, N virtual rings operating Ethernet Ring Protection on the two or more Ethernet ports, N greater than or equal to one, and a single Ring Automated Protection Switching (R-APS) channel on the two or more Ethernet ports, the single R-APS channel being shared by each of the N virtual rings. The network element may further include an algorithm associated with the R-APS channel to differentiate messages on the R-APS channel based on the N virtual rings.

In yet another exemplary embodiment, a method includes operating a plurality of network elements in a physical ring, provisioning one or more virtual rings on the physical ring with the one or more virtual rings utilizing Ethernet Ring Protection, and provisioning a single management channel on the physical ring, the single management channel including an algorithm to differentiate messages based on the one or more virtual rings. The method may further include installing a service data channel block for each of the one or more virtual rings at one or more of the plurality of network elements, installing a management channel block for the single management channel at one of the plurality of network elements, at the network element with the management channel block, sourcing management messages on the single management channel, and, at each of the plurality of network elements with service data channel blocks, updating based on the algorithm to differentiate management messages based on the one or more virtual rings. The method may further include, under a fault condition between two of the network elements, installing a service data channel block for each of the one or more virtual rings and the management channel block adjacent to the fault condition, transmitting fault indication messages on the single management channel with the algorithm configured such that each of the network elements processes the fault indication messages, upon reception of the fault indication messages on the single management channel, flushing a forwarding database and removing any previously installed service data channel blocks and the management channel block, upon recovery of the fault condition between two of the network elements, implementing a guard timer and transmitting recovery indication messages on the single management channel, and, upon receipt of the recovery indication messages, implementing a wait to restore timer and reinstalling any previously installed service data channel blocks and the management channel block as previously configured prior to the fault condition at expiry of the wait to restore timer.

DETAILED DESCRIPTION OF THE INVENTION

In various exemplary embodiments, the present invention provides systems and methods for scaling performance of Ethernet Ring Protection Protocol. Specifically, the systems and methods may apply to G.8032 and may provide protection switching control plane performance scaling benefits. In an exemplary embodiment, the present invention summarizes the per “virtual” ring control plane protocol into a single logical ring control plane protocol. Keeping in mind that the association between virtual rings to logical rings is many-to-one, ring nodes now only need to participate in a single logical ring protocol session (which may support many virtual rings), instead of many virtual ring protocol sessions. The associated decrease in processing at the ring nodes allows G.8032 to scale supporting more virtual rings, while retaining/maintaining the rapid sub-50 ms protection switching times. Advantageously, the present invention transforms the G.8032 protocol from a per-virtual ring protocol to a per-logical ring control protocol. The mechanism/methodology that is used is to include minimal per-virtual ring instance information in to the Ring Automated Protection Switching (R-APS) (control) frames. Additionally, the present invention cleanly decouples the placement of the R-APS (control) channel block location on the ring from that of the virtual channel data blocks. Current G.8032 specifications tightly couple the location of each R-APS (control) channel block and the virtual channel block that it is managing.

Referring toFIG. 1, in an exemplary embodiment, a network10is illustrated of network elements12A-12F (collectively referred to herein as network elements12) in a ring14providing Ethernet Ring Protection. Also, the network10may include network elements16A,16B interconnected via the ring14. The network elements12,16A,16B may include optical switches, optical cross-connects, SONET/SDH devices with layer two traffic, Optical Transport Network (OTN) switches with layer two traffic, Ethernet switches, routers, or any other device commonly known to forward data packets in a network. The network elements12are physically configured in a ring topology and the ring14is a logical construct that forms a closed loop over the physical network infrastructure. The network elements12may utilize G.8032 Ethernet Ring Protection over the ring14to provide rapid protection switching below 50 ms. Advantageously using G.8032, the ring14and the network elements12may be client and server layer agnostic while using existing (and commodity) IEEE 802.1 (bridging) and IEEE 802.3 (MAC) hardware. Connections between adjacent network elements12in the ring14(i.e., the ring spans) are assumed to be bi-directional, and may be a link, a link aggregation group, or a subnet (e.g., Multiprotocol Label Switching (MPLS), Provider Backbone Bridge Traffic Engineering (PBB-TE), SONET/SDH, OTN, etc.). Also, the ring spans associated with the ring14need not be the same bandwidth nor server layer technology. In Ethernet Ring Protection, a “virtual ring” (VRing) is associated with the ring14and each VRing includes two channels18,20—an R-APS channel18used for transport of ring control Protocol Data Units (PDUs) and a service data channel20used for transport of client data traffic.

Referring toFIG. 2, in an exemplary embodiment, the ring14is illustrated with two VRings22A,22B provisioned thereon. Each of the VRings22A,22B has a service data channel20providing client traffic flows over the ring14that share a common provisioned channel block. Also, each client micro traffic flow may have a Virtual Local Area Network (VLAN) associated with it. Also, the multiple VRings22A,22B on a given Ring cannot have an overlapping VLAN Identification (VID) space. Each of the VRings22A,22B also includes a channel block24A,24B (collectively referred to herein as a channel block24) that prevents VLAN tagged traffic from being relayed/forwarded between [ring or client] ports. Thus, each of the VRings22A,22B includes an R-APS channel18and a service data channel20. Each channel18,20needs at least a single channel blocking point on the ring14, i.e. the channel block24A,24B. Using Ethernet Ring Protection, there is a central node called the Ring Protection Link (RPL) owner node which blocks, using the channel block24, one of the ports, known as the RPL port, to ensure that no loop forms for the Ethernet traffic. Ring Automated Protection Switching (R-APS) messages are used to coordinate the activities of switching the RPL link on or off. Ethernet Shared Protection Ring (E-SPRing) is one instantiation, i.e. one embodiment, of the ERP standard.

Referring toFIG. 3, in an exemplary embodiment, a functional block diagram illustrates an exemplary channel block24in the network element12. The network element12is illustrated with two exemplary ports28A,28B (referred to a LAN A and LAN B). The network element12may include higher level entities30, ingress/egress rules32, port state34, and a filtering database information36. The channel block24function prevents traffic from being forwarded by the receive ring port. However, it does not prevent traffic from being received by the higher level entities30(e.g., G.8032 Engine) on the network element12. In an exemplary embodiment, the channel block24may be realized by ingress/egress rules34placed on a [virtual] ring port28. The following Channel block rules should be applied such that each of the channels18,20must have at least a [single] channel block24installed (at all times) and the location of the “provisioned” channel block24(associated with the Ring Protection Link) is [currently] operator determined.

Referring toFIG. 4, in an exemplary embodiment, the ring14is illustrated showing a failure sequence using G.8032 Ethernet Ring Protection on the network elements12. At a first point41inFIG. 4, the ring14is operating under a normal configuration, i.e. no failures. In this example, the channel block24is at the network element12A facing the network element12B. At a point42, a failure occurs on a ring span between the network elements12E,12D. At a point43, a signal failure (SF) is detected on the ring, port blocking is applied at the network elements12E,12D via channel blocks24, and R-APS Failure Indication Messages (FIM) are transmitted. At a point44, each of the network elements12will receive the R-APS FIM and flush their current Forwarding Database (FDB) and the channel block24will be removed at the network element12A upon receipt of the R-APS FIM. The FDB includes information which contains the routing configuration from the point of view of the current network element. Under G.8032, general protocol guidelines used to support protection switching within 50 ms are 1) Time for a R-APS message to circulate an entire ring (i.e., ring circumference and nodal transit delays) should be ≦10 ms, 2) Time taken to install channel blocks should be ≦15 ms, 3) Time taken to cleanse stale entries found in the FDB associated with Ring should be ≦10 ms, and 4) Time taken to remove channel blocks should be ≦15 ms.

Referring toFIG. 5, in an exemplary embodiment, the ring14is illustrated showing a recovery sequence using G.8032 Ethernet Ring Protection on the network elements12. The recovery sequence includes a recovery from the failure illustrated inFIG. 4between the network elements12D,12E. At a point51, a ring span recovery is detected between the network elements12D,12E and R-APS Recovery Indication Messages (RIM) are transmitted along with guard timers started at the network elements12D,12E. At a point52, when a root port node receives the R-APS RIM, a wait-to-restore (WTR) timer is started. At a point53, when the WTR expires, the RPL port block is installed at the network element12A and R-APS OK messages are transmitted. Also, each of the network elements12flush their FDB when the R-APS OK messages are received as well as removing port block such as at the network elements12D,12E when the R-APS OK messages are received.

Referring toFIGS. 6 and 7, in an exemplary embodiment, the network10is illustrated with plural VRings22each with separate R-APS channels18(FIG. 6) and with a combined R-APS channel60(FIG. 7).FIG. 6illustrates typical G.8032 operation where each of the data channels20has a corresponding R-APS channel18. In this exemplary embodiment ofFIG. 6, assume there are N VRings22such that VRing:Ring→N: 1, where N≧1, the following associations apply to the Ring14ofFIG. 6: Data Channel:VRing→1:1; R-APS Channel:VRing→1:1; and R-APS Channel:Ring→N:1, where N≧1. Let X1represent {vidi1, . . . , vidj1} associated with VRing1, and let Xnrepresent {vidan, . . . , vidbn} associated with VRingn, accordingly (X1∉Xn) and (X1∩Xn=Ø). In particular with G.8032, the channel block24location for the R-APS channel18and the service data channel20associated with a given VRing22need not be co-located at the same network element12. For example, channel blocks24on the service data channel20may be distributed across the ring14to support load distribution and ring traffic engineering. Traffic bandwidth utilization associated with the R-APS channel18is very low, especially when compared to service data20traffic bandwidth utilization. Channel loop prevention for the R-APS channel18is guaranteed by VID filters against ingress/egress ports, or the ring network element12sourcing the R-APS messages will be responsible for stripping the frame from the ring based upon R-APS SA (or R-APS Node Id),

FIG. 7illustrates the ring14with a single R-APS channel60for the plural VRings22. The single R-APS channel60is a management channel that is shared by the plural VRings22while still operating according to the Ethernet Ring Protection protocol. In this exemplary embodiment ofFIG. 7, assume there are N VRings22such that VRing:Ring→N: 1, where N≧1: the following associations apply to the Ring14ofFIG. 7: Data Channel:VRing→1:1, R-APS Channel:Ring→1:1. Let X1represent {vidi1, . . . , vidj1} associated with VRing1, let Xnrepresent {vidan, . . . , vidbn} associated with VRingn, and let Y represent {vidy} associated with the ring14, accordingly the ring14ofFIG. 7exhibits the following characteristics(X1∉Xn) and (X1∩Xn=Ø) and (Y∉X1) and (Y∉Xn). Each of the VRings22has its own service data channel20which share the single R-APS channel60that manages/controls all VRings22associated with ring14. In particular, the network elements12that have a R-APS channel block active (i.e., installed) will be responsible for transmitting the R-APS messages for all of the VRings22, and message summarization techniques may be applied. VRing22service data channel20blocks24are distributed across the ring as needed. Network elements12that own a VRing22service data channel20block24include “VRing instance” information into the R-APS OK messages that are in transit. R-APS FIM/RIM messages contain information associated with all “VRing instances.” Accordingly, network elements12(associated with a VRing22) will only process R-APS messages that are in transit, if it contains “VRing instance” information that it is configured with.

Referring toFIG. 8, in an exemplary embodiment, a VRing instance indicator70is illustrated within an Ethernet OAM PDU message72. The messages72are used for Ethernet Operations Administration and Maintenance (OAM) and are defined in IEEE 802.1ag “Connectivity Fault Management” (September 2007). For example, the messages72may be utilized for fault detection. Also, the messages72include R-APS specific information74. In an exemplary embodiment, the VRing instance indicator70may be included in the R-APS specific information74as a bit vector in the reserved section of the R-APS specific information74. Thus, every R-APS message for the single R-APS channel60includes this VRing instance indicator70such that the different VRings22may be able to share the same R-APS channel60. That is, the VRing instance indicator70provides a mechanism to differentiate between the different VRings22on the same R-APS channel60. Specifically, the network elements12that receive the message72will take action upon the R-APS specific information74only if there is a VRing instance at that network element12based on the VRing instance indicator70.

Referring toFIG. 9, in an exemplary embodiment, a flowchart of a network element G.8032 processing method80for utilizing the VRing instance indicator70with R-APS messages. The processing method80may be implemented as part of a larger G.8032 engine which implements the various functions for G.8032 protection as described herein. In particular, the processing method80is implemented by one of the network elements12. Upon receiving a R-APS message (step81), the processing method80requires a network element12to implement various functions based thereon. Note, the network element12is configured to read the VRing instance indicator70in the message72. The network element12is configured to process R-APS messages based thereon, i.e. if there is no instance at that network element12or if there is no required action such as a channel block modification, the network element forwards that R-APS message (step82). The R-APS message may require the network element12to remove an existing channel block, such as in the case of a R-APS FIM message (step83). Here, the network element12removes its channel blocks and forwards the R-APS message. Also, the R-APS message could require the network element12to install a channel block (step84), such as based on an R-APS OK message. Here, the network element12will install a channel block, update the R-APS message with appropriate VRing instance indicators70and forward the updated R-APS message.

Referring toFIGS. 10-19, in an exemplary embodiment, a sequence of network diagrams of the ring14illustrate an exemplary operation of the single R-APS channel60with two VRings22(referred to inFIGS. 10-19as VRing A and VRing B). In this exemplary embodiment, a R-APS channel block90is provisioned at the network element12A, a VRing A channel block92is provisioned at the network element12E, and a VRing B channel block94is provisioned at the network element12C. Note, the VRings A and B22share the same R-APS channel60, and the channel blocks90,92,94are at different locations for the R-APS channel60and the VRing data channels.FIG. 10illustrates initial provisioning90of the ring14. TheFIGS. 11-19illustrate various steps100-108showing operation under various conditions of the ring14. At a first step100illustrated inFIG. 11, the ring14is operating in a normal or idle (steady) state, i.e. normal operating conditions. As the R-APS channel block90is provisioned at the network element12A, the network element12A generates R-APS messages that traverse the ring14. That is, the network element12A generates R-APS OK messages112clockwise to the network element12B and R-APS OK messages114counterclockwise to the network element12E. The VRing instance indicator70is included inFIGS. 11-19denoting “A” for the VRing A and “B” for the VRing B. Note, the VRing instance indicator70takes into account the channel blocks92,94. That is, for the VRing A, the network element12E is the demarcation point for R-APS messages with the VRing instance indicator70showing “A.” For the VRing B, the network element12C is the demarcation point for R-APS messages with the VRing instance indicator70showing “B.” As described herein, the ring network elements12will only perform VRing processing of the R-APS messages if the VRing instance70info is found within R-APS message body. Also, tables116illustrate the VRing instance70traversing the ring14.

At a step101illustrated inFIG. 12, the ring14experiences a fault120between the network elements12D and12E. Subsequent to the fault120, the network elements12D,12E install the service channel blocks92,94and the R-APS channel block90on the faulted segment. The network elements12D,12E transmit R-APS FIM messages122,124to all of the network elements12, and the R-APS FIM messages122,124include the VRing instance70with both VRings A and B included in the instance. At a step102illustrated inFIG. 13, all of the network elements12receive the R-APS FIM messages122,124and each of the network elements12will perform actions since the R-APS FIM messages122,124include VRing instance70for both of the VRings. In particular, each of the network elements12perform a FDB flush such as on a per ring port per Forwarding Information Base (FIB) basis. The network elements12remove any previous installed VRing channel blocks, i.e. the network elements12C and12E remove the channel blocks92,94on their ports. The network elements12also remove any previously installed R-APS channel blocks, i.e. the network element12A removes the channel block90.

At a step103illustrated inFIG. 14, the fault120is removed between the network elements12D and12E. Note, the channel blocks90,92,94are still in place at the network elements12D and12E. Upon the network elements12D,12E detecting the link recovery, the network elements12D,12E each start a guard time130and transmit R-APS RIM messages132,134. Similar to the R-APS FIM messages122,124, the R-APS RIM messages132,134include the VRing instance70for both of the VRings. At a step104illustrated inFIG. 15, the guard timers130have expired clearing the fault120and each of the network elements12have received the R-APS RIM messages132,134. When the network element12E (which is the VRing A channel block92owner) receives the R-APS RIM messages132,134, the network element12E starts a Wait-to-Restore (WTR1) timer136. When the network element12C (which is the VRing B channel block94owner) receives the R-APS RIM messages132,134, the network element12C starts a Wait-to-Restore (WTR2) timer138. When the network element12A (which is the logical ring R-APS channel block90owner) receives the R-APS RIM messages132,134, the network element12A installs the channel block90.

At a step105illustrated inFIG. 16, a reversion process begins with the network element12A transmitting R-APS OK messages140,142. The WTR timers136,138are still active, and the network elements12E,12C will not include VRing instance70information in the R-APS OK messages140,142. At a step106illustrated inFIG. 17, the reversion process continues with the WTR timer136expiring (note, the WTR timer138is still active for illustration purposes). Upon expiry of the WTR timer136, the network element12E installs the channel block92and the network element12E starts to process the R-APS OK messages140,142including VRing A instance information in the VRing instance70of the R-APS OK messages140,142(shown also in tables150). The network elements12that receive the R-APS OK messages140,142with the VRing A instance information in the VRing instance70will flush their FDB (with respect to the VRing A). Also, the network elements12E,12D will remove their channel blocks92for the VRing A. Now, the VRing A service traffic channel is effectively restored (VRing B service traffic has not yet been restored).

At a step107illustrated inFIG. 18, the reversion process continues with the expiration of the WTR timer138. Upon expiry of the WTR timer138, the network element12C installs the VRing B channel block94and starts to process the R-APS OK messages140,142including VRing B instance information in the VRing instance70of the R-APS OK messages140,142(shown also in tables152). The network elements12that receive the R-APS OK messages140,142with the VRing B instance information in the VRing instance70will flush their FDB (with respect to the VRing B). Also, the network elements12E,12D will remove their channel blocks94for the VRing B. Now, the VRing B service traffic channel is effectively restored. Finally at a step108illustrated inFIG. 19, the ring14is back in the normal or idle (steady) state operation described above inFIG. 11at step100.

Referring toFIG. 20, in an exemplary embodiment, a block diagram illustrates an exemplary implementation of the network element12. In this exemplary embodiment, the network element12is an Ethernet network switch, but those of ordinary skill in the art will recognize the present invention contemplates other types of network elements and other implementations, such as, for example, a layer two switch integrated within an optical network element. In this exemplary embodiment, the network element12includes a plurality of blades302,304interconnected via an interface306. The blades302,304are also known as line cards, line modules, circuit packs, pluggable modules, etc. and refer generally to components mounted within a chassis, shelf, etc. of a data switching device, i.e. the network element12. In another exemplary embodiment, the functionality of each of the blades302,304may be integrated within a single module, such as in the layer two switch integrated within an optical network element. Each of the blades302,304may include numerous electronic devices and optical devices mounted on a circuit board along with various interconnects including interfaces to the chassis, shelf, etc. Two exemplary blades are illustrated with line blades302and control blades304. The line blades302generally include data ports308such as a plurality of Ethernet ports. For example, the line blade302may include a plurality of physical ports disposed on an exterior of the blade302for receiving ingress/egress connections. Additionally, the line blades302may include switching components to form a switching fabric via the backplane306between all of the data ports308allowing data traffic to be switched between the data ports308on the various line blades302. The switching fabric is a combination of hardware, software, firmware, etc. that moves data coming into the network element102out by the correct port308to the next network element. “Switching fabric” includes switching units, or individual boxes, in a node; integrated circuits contained in the switching units; and programming that allows switching paths to be controlled.

Within the context of the present invention, the control blades304include a microprocessor310, memory312, software314, and a network interface316to operate within the network management system100. Specifically, the microprocessor310, the memory312, and the software314may collectively control, configure, provision, monitor, etc. the network element102. The network interface316may be utilized to communicate with an element manager, a network management system, etc. Additionally, the control blades304may include a database320that tracks and maintains provisioning, configuration, operational data and the like. The database320may include a forwarding database (FDB)322. In this exemplary embodiment, the network element12includes two control blades304which may operate in a redundant or protected configuration such as 1:1, 1+1, etc. In general, the control blades304maintain dynamic system information including Layer two forwarding databases, protocol state machines, and the operational status of the ports308within the network element12. In an exemplary embodiment, the blades302,304are configured to implement a G.8032 ring, such as the ring14, and to implement the various processes, algorithms, methods, mechanisms, etc. described herein for implementing a plurality of VRings22using the single R-APS channel60with the VRing instance indicator70in R-APS messages over the R-APS channel60.