MSRP and High Availability

Following a High Availability (HA) switchover on platforms that support Message Session Relay Protocol (MSRP), the new active Oracle® Enterprise Session Border Controller (ESBC) responds with a TCP RST to the first MSRP message received on an MSRP session that a UA established with the former active ESBC. This response provides for a timely detection of the HA switchover and enables the UA to re-initiate the MSRP session by sending a SIP re-INVITE.

Upon a switchover, the first MSRP packet arriving at the newly active SBC triggers a TCP RST to be sent back immediately because the newly active does not have the TCP connection to receive the packet. This timely response allows the UA that sends the packet to quickly detect the connection interruption and send a reINVITE to set up a replacement session.