In the preceding figure, 7210-1 is used to deliver some services to customers connected to the device, and additionally it needs to pass through transit from other nodes on the ring (example – traffic from 7210-2 to 7210-3 OR from 7210-2 to 7750 –SR onto the core network).
Without default QinQ SAPs, the user would need to configure a service on 7210-1, with access-uplink SAPs for each service originating on some other node in the ring. With support for default QinQ SAPs, all traffic that does not need to be delivered to any customer service configured on 7210-1 can be switched using the Epipe service. The following are the sample configuration commands in this scenario:
ALA-1>config>service# epipe 8 customer 1 svc-sap-type null-star create
sap 1/1/5:*.* create
statistics
ingress
exit
exit
exit
sap 1/1/6:*.* create
statistics
ingress
exit
exit
exit
no shutdown
exit