Modified: for 12.1.1



This feature describes the SBC CNe Relay Service Pod (RS Pod). This pod handles all OOD non-INVITE messages (including REGISTER) except for OPTIONS, which are sent to the SC pod.

This pod includes the following functionalities:

  • RS Pod writes the data (Reg CB and Relay CB) into the Redis database.
  • RS Pod supports M:N redundancy. 

IP Peer status Learning using PathCheck

The PathCheck process inside the CS pod uses SIP OPTIONS messages to probe the liveness of an IP Peer, maintains a list of inactive IP Peer, and uses recovery algorithms to know when the IP Peer has become active again. The blacklist and whitelist notifications are broadcast to all the pods that subscribe to the CS pod.

Blacklisting of IP Peers using SIPARS

When configuring sipArsProfile with blacklistAlgorithms as retryAfter, the RS pod uses the sipArs module to detect whether an IP peer allows a specific sip-method. If the IP peer has returned a 503 with a retryAfter header for the non-INV OOD message as configured in the blkListAlgRetryAfterMethods and sends a blacklist information notification to the CS pod.

Whitelisting of IP PEERS using SIPARS

RS whitelists the peer after the retryAfter timer timeout. Once an IP PEER reachability is determined, the RS Pod sends whitelist notifications to the CS Pod. CS pod broadcasts the whitelist notifications to all other registered Pods.