Switching White Papers
Routing Updates Over APS on POS Interfaces
Overview This paper clarifies how routing protocols operate over Packet Over SONET (POS) interfaces configured as working or protective members of Automatic Protection Switching (APS) setups. The Cisco 12000 series APS implementation supports unidirectional and bidirectional APS modes. The default operational mode is bidirectional, which means that either W or P is active at any moment. The two Network Elements (NEs) must agree on which circuit to receive. Whether the W or P circuit is to be active is negotiated between the two NEs over the P circuit using a protocol defined in the SONET frame's K1K2 bytes. Unidirectional mode means that the two NEs choose independently which circuit to receive, without negotiation.
| Publisher | Cisco Systems | File Format | |
|---|---|---|---|
| Date Published | May 2006 | Downloads | 45 |
| Format | White Papers | ||
| Topics | |||



