Support of MC-APS to ATM VLLs and Ethernet VLL with ATM SAPs allows MC-APS to operate with pseudowire redundancy in a similar manner that MC-LAG operates with pseudowire redundancy.
The combination of these features provides a solution for access node redundancy and network redundancy as shown in Figure 1.
MC-APS groups are configured as follows:
MC-APS group between the MSAN on the left and Aggregation Nodes A and B
MC-APS group between the MSAN on the right and Aggregation Nodes C and D
Figure 1. Access and node and network resilience
An example of a customer application in the mobile market is shown in Figure 2.
In the application shown in Figure 2, 2G and 3G cell sites are aggregated into a Tier 2 or Tier 3 hub site before being backhauled to a Tier 1 site where the radio network controller (RNC) which terminates user calls is located. This application combines MC-APS on the RNC access side and pseudowire redundancy and pseudowire switching on the core network side. pseudowire switching is used to separate the routing domains between the access network and the core network.