[asterisk-dev] pjsip and timers configuration

[Michael Maier]

On 05.09.20 at 23:18 Michael Maier wrote:
> Hello all,
> 
> according [1], there are those options in pjsip regarding support of timers:
> 
> _______________________________________________________________
> timers
> 
>     no
>     yes
>     required
>     always
>     forced - Alias of always
> _______________________________________________________________
> 

I tested with asterisk 16.13.0 and bundled pjsip.

> 
> I'm wondering about their meanings.
> 
> - "No" seems to be clear. No timers support at all.
> 
> - "Always"? I have no idea. Therefore I tested it. I couldn't find any timers support mentioned in INVITE or 200 OK at all.

- "Always" behaves like "no"

> 
> - "Required"? Same as "yes" - the only difference was the timer:require in asterisk's outbound Invite.

All given options are reflected in pjsip show endpoint endpointname

> 
> 
> Is this the expected behavior, especially regarding "always"?
> 
> 
> 
> Another question:
> I can see here the following (with timer=yes):
> On *outbound* calls, the provider says in 200 ok: refresher is uas (means: provider). The first refresh coming in as update, the provider says: refresher is uac (that would be
> asterisk) and asterisk acks it in the 200 ok. But the provider does send all following updates (always with uac as refresher). Asterisk itself doesn't send any update (I would expect
> it - or is asterisk just not fast enough and provider is always faster? Min-SE is 900 and Session-Expires is 1800 - updates from provider are coming exactly each 900 s).
> 
> Is this the expected behavior?
> I can't see this behavior on inbound calls. Here, refresher in 200 ok and following updates doesn't differ.

Sorry, one more question:
If set to yes (=default) asterisk always gives the refresher to the caller in inbound call. Is there any possibility to say asterisk to do the refreshing by its own?

> 
> 
> Thanks
> Michael
> 
> 
> 
> [1] https://wiki.asterisk.org/wiki/display/AST/Asterisk+17+Configuration_res_pjsip#Asterisk17Configuration_res_pjsip-endpoint_timers

Documentation is the same for asterisk 16.