[Asterisk-Users] sip qualify=yes interval

[Rich Adamson]

> So;
> qualify=1000|yes
> means query for SIP OPTIONS, then take then unregister the peer if no
> response in 1000ms.
> 
> But, how do you set/determine the frequency at which a peer is queried?
> Does this go on indefinitely after a peer fails to respond to make sure
> the peer is re-registered when available again? Can the interval be set
> on a per peer basis?

There are no hard and fast rules in terms of what value is used. It all
depends 100% on the "reliability" of your sip connections, and what might
be good for me may not even come close to addressing your needs.

In other words, the more reliable your sip connections are (end-to-end),
the greater the value can be. 

I've got multiple remote sip phones where reliability is "usually" not an
issue, and setting qualify=10000 (ten seconds) is fine. The trade-off is
the lower the value, the more sip traffic generated. If your asterisk box
is behind a low speed dsl connection or on a broadband connection that
gets charged for usage exceeding a certain traffic volume limit, you
might want to use a larger qualify value. If bandwidth is not an issue and
reliability is a major issue, then use a low value.

It is sort of like setting rx and tx gains on analog pstn cards; there is
no such thing as a standard value that works for everyone.