soft-upgrade vs failover and back to/from 2nd-ary system

[Massimo Cesaro]

On Wed, 2005-01-26 at 11:33, Matthias Lang wrote:
> 
> Keeping the voice connection up when the signalling state has been
> lost is bad. It leaks connection resources and leaves subscribers
> stuck in broken calls. Better to keep it simple and just drop the call
> that triggered the problem.
> 
> Matthias
On the other hand, for IP telephony keeping connections up even when the
signalling state is lost is acceptable. Given that the job of the
(stateless) call agent is mainly to setup calls between intelligent
gateways (i.e. telephones), a redundant system can take care of the
hangup at the end of the call, if the primary system crashes after
establishing the same call. The two endpoints have an HTTP-like approach
to the signalling server, thus the failover/failback mechanism fits
pretty well.

Massimo