[sr-dev] Outbound: Flow Timer, tcp_connection_timeout, and WebSocket pings

[Peter Dunkley]

Hi,

I just wanted to raise this to see if anyone can see any flaw/problem in
my thought processes.

When using outbound it is mandatory to have some form of SIP keep-alive
between the UA and the edge proxy.  However, in the case where SIP over
WebSocket is used the WebSocket transport has its own ping/pong keepalive
mechanism.

So to my mind, SIP keep-alives are optional when WebSocket is in use?

In my last email I asked about the flow timer and said that I thought it
should be set in conjunction with the tcp_connection_lifetime value, but
when WebSocket is in use I believe:

* tcp_connection_lifetime on the edge proxy should be slightly larger than
* websocket:keepalive_timeout on the edge proxy, which should be slightly
larger than
* the flow timer value the registrar sets in 2xx responses to REGISTERs

Regards,

Peter


-- 
Peter Dunkley
Technical Director
Crocodile RCS Ltd