[SR-Users] What happens to calls when Kamailio restarts?

[Alex Balashov]

On Wed, Jul 12, 2017 at 09:05:27AM +0000, Samuel F. wrote:

> Suppose Kamailio crashes (and started again), is restarted or failed
> over to a different server (same IP). What then happens with calls?

Speaking generically, not a lot. 
 
All SIP messages passing through the proxy can be forwarded statelessly
and based on properties of the SIP message alone. This may break route
advance or failover scenarios reliant on state, but it will not break
the fundamental end-to-end SIP message reachability. In other words, a
proxy restart does not fundamentally prevent subsequent signalling for
the same call, or even subsequent messages within an open transaction,
from reaching their intended destination.

"Loose routing" and "record routing" are not opposed; loose routing is a
concept that incorporates Route header processing. 

The impact on accounting will depend on whether the accounting is done
with recourse to TM or dialog state, which exists in runtime, or in a
stateless manner based on received SIP messages.

-- Alex

-- 
Alex Balashov | Principal | Evariste Systems LLC

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