Abstract:
A communications network comprising a plurality of nodes supporting connection-oriented traffic and connectionless traffic, wherein management traffic between the nodes is propagated as connectionless traffic having a common management identifier. Also disclosed is a communications network component comprising logic that supports connection-oriented traffic and Virtual Local Area Network (VLAN)-based connectionless traffic, wherein the logic propagates management messages as VLAN-based connectionless traffic having a unique VLAN identifier (VID). Included is a communications network component comprising at least one processor configured to implement a method comprising provisioning a unique VID for management messages, and selectively propagating management messages with the unique VID.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to U.S. Provisional Patent Application Ser. No. 60/914,432 filed Apr. 27, 2007 by Sultan et al. and entitled “System for Performing Connectivity Fault Management in Networks Supporting Both Connectionless and Connection-Oriented Traffic.” The present application also claims priority to U.S. Provisional Patent Application Ser. No. 60/970,428 filed Sep. 6, 2007 by Sultan et al. and entitled “Data Communications Network for the Management of an Ethernet Transport Network.” These provisional applications are incorporated herein by reference as if reproduced in their entirety. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     REFERENCE TO A MICROFICHE APPENDIX 
     Not applicable. 
     BACKGROUND 
     Modern communication and data networks are comprised of nodes that transport data through the network. The nodes may include routers, switches, and/or bridges that transport the individual data frames and/or packets through the network. Some networks support both connectionless frame transfer (e.g., Provider Backbone Bridging (PBB)) and connection-oriented frame transfer (e.g., PBB Traffic Engineering (PBB-TE)). Providing management services (e.g., Data Communication Network services and/or connectivity fault management) in such networks is desirable. 
     SUMMARY 
     In a first aspect, the disclosure includes a communications network comprising a plurality of nodes supporting connection-oriented traffic and connectionless traffic, wherein management traffic between the nodes is propagated as connectionless traffic having a common management identifier. 
     In a second aspect, the disclosure includes a communications network component comprising logic that supports connection-oriented traffic and Virtual Local Area Network (VLAN)-based connectionless traffic, wherein the logic propagates management messages as VLAN-based connectionless traffic having a unique VLAN identifier (VID). 
     In a third aspect, the disclosure includes a communications network component comprising at least one processor configured to implement a method comprising provisioning a unique VID for management messages, and selectively propagating management messages with the unique VID. 
     These and other features will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of this disclosure, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts. 
         FIG. 1  is a block diagram of a system with a Data Communications Network (DCN). 
         FIG. 2  is a block diagram of an embodiment of an Ethernet Transport Network managed via an Ethernet DCN. 
         FIG. 3  is a block diagram of an embodiment of a network component. 
         FIG. 4  is a flowchart of an embodiment of a management method. 
         FIG. 5  is a block diagram of an embodiment of a general-purpose network component. 
     
    
    
     DETAILED DESCRIPTION 
     It should be understood at the outset that although an illustrative implementation of one or more embodiments are provided below, the disclosed systems and/or methods may be implemented using any number of techniques, whether currently known or in existence. The disclosure should in no way be limited to the illustrative implementations, drawings, and techniques illustrated below, including the exemplary designs and implementations illustrated and described herein, but may be modified within the scope of the appended claims along with their fall scope of equivalents. 
     As described herein, embodiments of the disclosure involve propagating management messages or traffic in a hybrid networking system that supports connection-oriented traffic and connectionless traffic (e.g., traffic based on VLANs). In some embodiments, connection-oriented frame transfers are based on PBB-TE and connectionless frame transfers are based on PBB. In such hybrid network systems, management messages can be propagated as connectionless traffic having a unique management identifier. The management messages may correspond to DCN services or other management services. 
       FIG. 1  is a block diagram of an embodiment of a system  100  with a DCN  120 .  FIG. 1  is provided to better understand the use of the term DCN in the disclosure. In  FIG. 1 , a telecommunications service provider may deploy network elements  130  such as Synchronous Optical Network (SONET) or Synchronous Digital Hierarchy (SDH) components. The DCN  120  is deployed to support management connectivity between an Operations Support System (OSS)  110  and individual network elements  130 , which comprise a Transport Network. The DCN  120  (e.g., International Telecommunication Union Standardization Sector (ITU-T) G.7712/Y.1703) makes it unnecessary to provide direct connections between the OSS  110  and each individual network element  130  of the transport network. The DCN  120  requires the deployment of a routing protocol such as Open Systems Interconnect (OSI) routing or Internet Protocol (IP) routing in the network elements  130 . Information carried by the DCN  120  includes Operation, Administration, Management, and Provisioning (OAM&amp;P) messages, configuration and backup files, billing data, and software downloads. In some embodiments, the DCN may be called a Communications Management Network or a Management network. In other embodiments, the DCN VLAN may be called a Management VLAN, a Network Management VLAN, a Network Management System (NMS) VLAN, or a Communications Network Management (CNM) VLAN. 
     In at least some embodiments, an instance of a bridged VLAN supports connectivity between a NMS and the bridging devices associated with an Ethernet Transport Network (Institute of Electrical and Electronic Engineers (IEEE) Draft Std. 802.1Qay). The role of the VLAN with respect to the Ethernet Transport network is similar to the role of the DCN (ITU-T G.7712/Y.1703)  120  in a traditional (e.g., SONET/SDH) telecommunications network. The VLAN used for this purpose may be called an Ethernet DCN. 
     Embodiments provide an efficient method of interconnecting a NMS with Ethernet Transport Devices (802.1Qay compliant bridges) because it is unnecessary to provide a direct connection between the NMS and each individual Ethernet Transport Device. This is similar to the efficiency provided by a DCN in a SONET network. A particular advantage of using a VLAN for this purpose is that the 802.1Qay bridge natively supports VLANs. This makes it unnecessary to introduce additional protocols to the 802.1Qay bridge in order to support the DCN function. 
       FIG. 2  is a block diagram of an embodiment of an Ethernet Transport Network (ETN)  200  managed using a reserved VLAN  250  that acts as an Ethernet DCN. In at least some embodiments, the ETN  200  follows the IEEE Draft Std. 802.1Qay protocol, which specifies the means by which VLAN Bridges  230  may be used to support traffic-engineered paths. A network deploying such paths can transport data in a manner similar to a SONET or SDH network. In  FIG. 2 , the ETN  200  is managed by a NMS  210  in a manner similar to the way in which a SONET-based transport network is managed by the OSS  110 . As in the case of the SONET-based transport network, it is useful to avoid the direct interconnection between the NMS  210  and each bridging device  230  within the ETN  200 . It is observed that an 802.1Qay-compliant device  230  can concurrently support instances of VLANs and instances of traffic-engineered paths  240 . Thus, DCN-type services in the ETN  200  are provided using the reserved VLAN  250 , which interconnects the NMS  210  with ETN devices  230 . In this manner, direct connection of the NMS  210  with each individual device  230  is unnecessary and an additional network technology need not be introduced to support the Ethernet DCN. This can be contrasted with the use of a traditional DCN  120 , which requires the introduction of a layer-3 protocol, such as OSI routing or IP routing in the network elements  130 . 
     In general, the reserved VLAN  250  of the ETN  200  can be used to carry the same types of information as the traditional DCN, which includes OAM&amp;P (such as alarm, control, and test messages), configuration and backup files, billing data, and software downloads. In addition, the reserved VLAN  250  is useful in carrying Connectivity Fault Management (CFM) information related to traffic-engineered Ethernet paths. For additional information regarding CFM services in hybrid communication networks, reference may be had to U.S. patent application Ser. No. 12/056,405 filed Mar. 27, 2008 by Sultan et al. and entitled “Fault Verification for an Unpaired Unidirectional Switched-Path” and to U.S. Provisional Patent Application Ser. No. 60/914,432 filed Apr. 27, 2007 by Sultan et al. and entitled “System for Performing Connectivity Fault Management in Networks Supporting Both Connectionless and Connection-Oriented Traffic”, which are herein incorporated by reference as if reproduced in their entirety. 
     The reserved VLAN  250  enables connectivity among all nodes/bridges in the entire ETN  200 . The PBB-TE protocol requires all network connectivity paths to be explicitly created (instead of spanning tree). For a network with only PBB-TE paths, intermediate nodes along PBB-TE paths cannot reach each other. By creating an Ethernet DCN, each node/bridge in the PBB-TE network is reachable from every other node/bridge in the network. In such case, various management functions can be supported. For example, the Ethernet DCN can support remote access from any PBB-TE nodes to other PBB-TE nodes. In this manner, an operator at one location can remotely login to another node to perform OAM&amp;P functions. Additionally or alternatively, the reserved VLAN  250  supports segment connectivity testing or other diagnostic operations. As an example, any intermediate node can test its connectivity to other nodes along ESP paths. Using such connectivity testing faults can be isolated along any PBB-TE segment. 
       FIG. 3  is a block diagram of an embodiment of a network component  300 . For example, the network component  300  may be representative of an 802.1Qay bridge as described for  FIG. 2 . In  FIG. 3 , the network component  300  comprises logic  302  that supports various functions. The logic  302  may be representative of hardware, firmware, and/or software modules as understood by those of skill in the art. As shown, the logic  302  comprises a connection-oriented traffic module  304  that supports connection-oriented traffic (represented by the solid arrows). The logic  302  also comprises a connectionless traffic module  306  that supports VLAN-based communications (represented by the dashed arrows). Finally, the logic  302  comprises a management traffic control module  308  that enables the network component  300  to generate and/or to handle management traffic. 
     For example, in some embodiments, the management traffic control module  308  enables the network component  300  to generate messages relate to Loopback, Linktrace, and/or Connectivity Check operations. It further supports the connection-oriented Probe Request Message (PBM) and the connectionless Probe Response Message (PBR) as described within U.S. patent application Ser. No. 12/056,405 filed Mar. 27, 2008 by Sultan et al. and entitled “Fault Verification for an Unpaired Unidirectional Switched-Path”, which is incorporated herein by reference as if reproduced in its entirety. Additionally or alternatively, the management traffic control module  308  enables the network component  300  to generate OAM&amp;P messages, configuration, and backup files, billing data, software downloads, or other management traffic as connectionless traffic. Additionally or alternatively, the management traffic control module  308  enables the network component  300  to respond to incoming management traffic. Regardless of the management traffic type and/or source, a management VID is associated with the management traffic. The management VID corresponds to the reserved VLAN  250  and Ethernet DCN discussed previously with respect to  FIG. 2 . The management VID may be temporarily provisioned or globally reserved. 
       FIG. 4  is a flowchart of an embodiment of a management method  400 . As shown, the method  400  starts by provisioning a unique VID for management messages (block  402 ). For example, the unique VID may be temporarily provisioned or globally reserved as a management VID. At block  404 , management traffic associated with the unique VID is selectively propagated. Steps  402  and  404  can be performed by a single device or by multiple devices of a communications network. In some embodiments, the method  400  further comprises steps such as generating and/or responding to management traffic using the unique VID. As an example, the method  400  enables a network operator to perform DCN functions in an Ethernet network. 
     The components and methods described above may be implemented on any general-purpose network component, such as a computer, router, switch, or bridge, with sufficient processing power, memory resources, and network throughput capability to handle the necessary workload placed upon it.  FIG. 5  illustrates a typical, general-purpose network component suitable for implementing one or more embodiments of a node disclosed herein. The network component  500  includes a processor  502  (which may be referred to as a central processor unit or CPU) that is in communication with memory devices including secondary storage  504 , read only memory (ROM)  506 , random access memory (RAM)  508 , input/output (I/O) devices  510 , and network connectivity devices  512 . The processor may be implemented as one or more CPU chips. 
     The secondary storage  504  is typically comprised of one or more disk drives or tape drives and is used for non-volatile storage of data and as an over-flow data storage device if RAM  508  is not large enough to hold all working data. Secondary storage  504  may be used to store programs that are loaded into RAM  508  when such programs are selected for execution. The ROM  506  is used to store instructions and perhaps data that are read during program execution. ROM  506  is a non-volatile memory device that typically has a small memory capacity relative to the larger memory capacity of secondary storage  504 . The RAM  508  is used to store volatile data and perhaps to store instructions. Access to both ROM  506  and RAM  508  is typically faster than to secondary storage  504 . 
     While several embodiments have been provided in the present disclosure, it should be understood that the disclosed systems and methods might be embodied in many other specific forms without departing from the spirit or scope of the present disclosure. The present examples are to be considered as illustrative and not restrictive, and the intention is not to be limited to the details given herein. For example, the various elements or components may be combined or integrated in another system or certain features may be omitted, or not implemented. 
     In addition, techniques, systems, subsystems, and methods described and illustrated in the various embodiments as discrete or separate may be combined or integrated with other systems, modules, techniques, or methods without departing from the scope of the present disclosure. Other items shown or discussed as coupled or directly coupled or communicating with each other may be indirectly coupled or communicating through some interface, device, or intermediate component whether electrically, mechanically, or otherwise. Other examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the spirit and scope disclosed herein.