Providing VPLS-like service over native ATM networks
View Patent ↗A method and apparatus for emulating VPLS within an ATM network. Provider Edge devices are configured for VPLS connections. For each pair of provider edge devices supporting the same VPLS ID, one device establishes a virtual circuit between the pair. Thus, a full mesh of virtual circuits is established between provider edge devices, and a VPLS-like service can be offered to users without having to implement MPLS. Establishing the virtual circuits within a PNNI hierarchy maybe facilitated by each provider edge device propagating through the hierarchy an information group containing an association between the ATM address of the device and a VPLS ID, so that each provider edge device learns all ATM addresses to be associated with each VPLS ID. The method of advertising ATM addresses can be applied to other services requiring a number of interconnections between provider edge devices, such as Virtual Private Networks.
1. A method of emulating Virtual Provide Local Area Network Service (VPLS) in an Asynchronous Transfer Mode (ATM) network, comprising:
configuring, at a plurality of provider edge devices (PEs) arranged in a Private Network-Network Interface (PNNI) hierarchy, a VPLS having a VPLS Identifier (ID);
at each PE, generating a PNNI Topology State Element (PTSE) including a VPLS Information Group (IG), the VPLS IG indicating the VPLS ID and an ATM address associated with the VPLS;
flooding each VPLS IG throughout the PNNI hierarchy to exchange information between the PEs;
establishing a mesh of virtual circuits in the ATM network to emulate VPLS by attaching virtual circuits to pairs of PEs, each of the pairs of PEs in the mesh comprising a first PE and a second PE, wherein establishing each virtual circuit between the first PE and the second PE comprises:
selecting the first PE and the second PE for the virtual circuit when the first PE determines that the second PE supports the VPLS ID;
determining whether the first PE or the second PE should initiate the virtual circuit;
automatically establishing the virtual circuit between the first PE and the second PE using the respective ATM address of each PE as endpoints of the virtual circuit, wherein the virtual circuit has a traffic characteristic equal to a minimum traffic characteristic of the first PE and the second PE.
2. The method of claim 1 wherein at each PE, the respective ATM address associated with the VPLS is unique to the VPLS.
3. The method of claim 1 , wherein a second VPLS is emulated at a plurality of the PEs, and wherein at each such PE the respective ATM address associated with the VPLS is also associated with the second VPLS.
4. The method of claim 1 , further comprising:
at each PE, flooding the PTSE throughout a peer group of the PE, each peer group having a peer group leader;
at each peer group leader, receiving each PTSE generated by a PE within the peer group of the peer group leader and flooding such PTSEs throughout a parent logical group of the peer group leader;
at each peer group leader, receiving at least one other PTSE, each other PTSE containing a VPLS IG indicating an association between the VPLS ID and an ATM address, from the parent logical group of the peer group leader; and
at each peer group leader, flooding the at least one other PTSE throughout the peer group of the peer group leader.
5. A method of emulating Virtual Provide Local Area Network Service (VPLS) in an Asynchronous Transfer Mode (ATM) network, comprising:
configuring, at a plurality of provider edge devices (PEs), arranged in a Private Network-Network Interface (PNNI) hierarchy, a VPLS having a VPLS Identifier (ID);
associating an ATM address with the VPLS ID;
at each PE, generating a Private Network-Network Interface (PNNI) Augmented Routing (PAR) Service IG including the VPLS ID, an ATM address associated with the VPLS, and a traffic characteristic associated with both the VPLS ID and the ATM address;
advertising the association between the VPLS ID and the ATM address to other nodes within the ATM network;
flooding each PAR Service IG throughout the ATM network;
establishing a mesh of virtual circuits in the ATM network to emulate VPLS by attaching virtual circuits to pairs of PEs, each of the pairs of PEs in the mesh comprising a first PE and a second PE, wherein establishing each virtual circuit between the first PE and the second PE comprises:
selecting the first PE and the second PE for the virtual circuit when the first PE determines that the second PE supports the VPLS ID;
determining whether the first PE or the second PE should initiate the virtual circuit;
determining other ATM addresses within the ATM network which are associated with the VPLS;
for each such other ATM address, determining whether the first PE or the second PE is to set up a virtual circuit with the ATM address;
automatically establishing the virtual circuit between the first PE and the second PE using the respective ATM address of the first PE and the second PE as endpoints of the virtual circuit, wherein the virtual circuit comprises a traffic characteristic equal to the minimum traffic characteristic of the first PE and the second PE.
6. The method of claim 5 , wherein at least one other PE uses Proxy PAR to exchange with PEs ATM addresses to be associated with the VPLS.
7. The method of claim 6 , wherein the at least one other PE is attached to the ATM network via an ATM link employing an ATM User Network Interface (UNI) signaling protocol.
8. The method of claim 6 , wherein the at least one other PE is attached to the ATM network via an ATM link employing an ATM Inter-Network Interface (AINI) signaling protocol.
9. A method of emulating a Virtual Private Local Area Network Service (VPLS) at a Provider Edge device (PE) within an Asynchronous Transfer Mode (ATM) network, comprising:
configuring, at the PE, a VPLS Identifier (ID) associated with the VPLS, including associating an ATM address with the VPLS ID;
advertising the association between the VPLS ID and the ATM address to other nodes within the ATM network, including advertising at least one traffic characteristic to be associated with the VPLS ID and the ATM address;
determining other ATM addresses within the ATM network which are associated with the VPLS;
generating a PNNI Topology State Element (PTSE) including a VPLS information group (IG), the VPLS IG indicating the VPLS ID and the ATM address associated with the VPLS;
flooding the PTSE throughout the peer group of the node;
generating a Private Network-Network Interface (PNNI) Augmented Routing (PAR) Service information group (IG) including the VPLS ID and the ATM address;
flooding the PAR Service IG throughout the ATM network; and
establishing a mesh of virtual circuits in the ATM network to emulate VPLS by attaching virtual circuits to pairs of PEs, each of the pairs of PEs in the mesh comprising a first PE and a second PE, wherein establishing each virtual circuit between the first PE and the second PE comprises:
for each such other ATM address, determining whether the first PE or the second PE is to set up the virtual circuit with the ATM address;
selecting the first PE and the second PE for the virtual circuit when the first PE determines that the second PE supports the VFLS ID;
determining whether the first PE or the second PE should initiate the virtual circuit; and
automatically establishing the virtual circuit between the first PE and the second PE using the respective ATM address of the first PE and the second PE as endpoints of the virtual circuit, wherein the virtual circuit comprises a traffic characteristic equal to a minimum of the at least one traffic characteristic and a second traffic characteristic associated with the other ATM address.
10. The method of claim 9 , further comprising:
setting up the virtual circuit in conformance with the at least one traffic characteristic.
11. A node within an Asynchronous Transfer Mode (ATM) network, wherein the node is part of a Private Network-Network Interface (PNNI) hierarchy, comprising:
means for receiving a Virtual Private Local Area Network Service (VPLS) identifier (ID); and
a VPLS controller comprising a computer-readable medium encoded with instructions, the computer-readable medium comprising:
instructions for receiving a service identifier (ID) identifying a service;
instructions for generating a PNNI Topology State Element (PTSE) including a service information group (IG), the service IG indicating the service ID and an ATM address to be associated with the service;
instructions for flooding the service IG throughout the PNNI hierarchy by generating at least one message, each message containing at least two PTSEs;
instructions for determining other ATM addresses within the ATM network which are associated with the VIPLS ID;
instructions for, for each such other ATM address, determining whether the node is to set up a virtual circuit with the other ATM address, the instructions for guaranteeing that only one virtual circuit is set up between the node and the other ATM address;
instructions for establishing a mesh of virtual circuits to emulate VPLS by attaching virtual circuits to pairs of PEs, each of the pairs of PEs in the mesh comprising a first PE and a second PE, wherein the instructions for establishing each virtual circuit between the first PE and the second PE further comprise:
instructions for selecting the first PE and the second PE for the virtual circuit when the first PE determines that the second PE supports the VPLS ID;
instructions for determining whether the first PE or the second PE should initiate the virtual circuit; and
instructions for automatically establishing the virtual circuit between the first PE and the second PE using the respective ATM address of the first PE and the second PE as endpoints of the virtual circuit.
12. The node of claim 11 , further comprising:
instructions for generating a PNNI Augmented Routing (PAR) Service information group (IG), the PAR service IG including the VPLS ID and the ATM address to be associated with the VPLS; and
instructions for flooding the PAR service IG throughout the ATM network.
13. The node of claim 11 , wherein the instructions for advertising the association between the ATM address and the VPLS ID comprise instructions for delivering the association to a second node using Proxy PAR.