System and method for providing support for multipoint L2VPN services in devices without local bridging
AssigneeCisco Technology, Inc.
InventorsHarshavardhan Parandekar, Ali Sajassi, Sanjay Dhar
Life of this patent
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Abstract
A network device has a network interface to allow the device to send and receive traffic across a network. The device also has a cable connection to allow the device to exchange data with at least one cable modem and a processor to associate a cable interface and cable service identifier with a cable modem; receive a packet from the cable modem; and insert a layer 2 network identifier, the identifier comprising two service provider VLAN (SP-VLAN) tags, into the packet. The processor in the network device identifies a virtual trunk interface based on the outer SP-VLAN tag and identifies the virtual private network based on the inner SP-VLAN tag.
Claims20
A method comprising:
- receiving a packet from a cable modem;
- identifying a cable interface and cable service identifier associated with the cable modem;
- inserting a layer 2 (L2) network identifier into the packet, the L2 network identifier comprising inner and outer Service Provider Virtual Local Area Network (SP-VLAN) tags to be used within a service provider network to bridge the packet across the service provider network, wherein the inner SP-VLAN tag represents a customer VPN in a multipoint L2VPN service wherein the inner SP-VLAN tag is associated with a particular bridge group, wherein the outer SP-VLAN tag represents a single attachment circuit and wherein the outer SP-VLAN tag is associated with a virtual interface trunk;
- wherein the inner SP-VLAN tag and the outer SP-VLAN tag are added to the packet upon entry into the service provider network;
- and
- transmitting the double SP-VLAN tagged packet to an upstream network device;
- wherein the inner SP-VLAN tag and the outer SP-VLAN tag are removed from the packet prior to exiting the service provider network.
A system comprising:
- an ingress CMTS configured to map at least one attachment circuit to an outer SP-VLAN tag of a double SP-VLAN tagged packet,
- wherein an inner SP-VLAN tag represents a broadcast domain and the outer SP-VLAN tag uniquely identifies a single attachment circuit on the ingress CMTS in the broadcast domain;
- wherein, if a packet arrives at the ingress CMTS with a customer edge VLAN (CE-VLAN) tag in a header, the ingress CMTS adds the inner and outer SP-VLAN tags without removing the CE-VLAN tag from the header;
- wherein the inner SP-VLAN tag represents a customer VPN in a multipoint L2VPN service and is associated with a particular bridge group;
- wherein the outer SP-VLAN tag is associated with a virtual interface trunk;
- wherein the inner SP-VLAN tag and the outer SP-VLAN tag are added to the packet upon entry into a service provider network and wherein the inner SP-VLAN tag and the outer SP-VLAN tag are removed from the packet prior to exiting the service provider network.
A system comprising:
- means for accessing a configuration file, wherein the configuration file includes information for associating a cable modem (CM) with a particular customer VPN and an SP-VLAN inner tag, wherein the inner SP-VLAN tag is associated with a bridge group;
- means for adding the SP-VLAN inner tag to a packet upon ingress into a service provider network;
- means for discovering a customer VPN in the configuration file;
- means for selecting and adding an SP-VLAN outer tag corresponding to the customer VPN to the packet from a plurality of available tags, wherein the plurality of available tags is limited to a number of tags associated with corresponding attachment circuits associated with the customer VPN, wherein the outer SP-VLAN tag is associated with a virtual trunk interface;
- means for transmitting the packet on an egress interface to an upstream aggregation node;
- and
- means for removing the inner SP-VLAN tag and the outer SP-VLAN tag from the packet prior to exiting the service provider network.
Dependencies are inferred from the claim text.