asterisk users - Aug 2016 - chan_pjsip ignoring endpoint device state (qualify) on dial

Hi,

We have been migrating our PBX system from Asterisk 1.8 and chan_sip to
Asterisk 13 and chan_pjsip. Things are mostly, ok, but now I have
stumbled on a behaviour difference I don't like.

With chan_pjsip when a phone went unexpectedly offline (Ethernet cable
disconnected) Asterisk would detect this quickly (through the 'qualify'
pings), mark the phone as 'Unavailable' and fail immediately with
'CHANUNAVAIL' when dialling this phone.

With Asterisk 13 and chan_pjsip qualify still works for determining
current phone availability (endpoint shown as 'Unavailable' shortly
after disconnecting the cable), but the phone is being dialled like
nothing is wrong ? Asterisk sends the INVITE and waits for the response,
until SIP timeout (a bit more than 30s total). That is much longer time
until 'CHANUNAVAIL' than I expect. It is also longer than the dial
timeout in some cases, so I would get 'NOANSWER' instead of
'CHANUNAVAIL' which breaks my dialplan logic.

Is that that the expected behaviour, a bug or a configuration problem?
Am I supposed to check for device availability in my dialplan?

Greets,
Jacek

Jacek,
This might be a bug or configuration issue, but you need to understand the
SIP Session Timers. With Session Timers you can control the round trip time
and Call Setup time of SIP Requests.
In case of GSM Network with high delay you need to set the T1 timer a
higher value like 1000ms (500 ms default). Similarly you can reduce the
Call setup time by configuring 'T2' upto you choice as per you telephony
network. Configure t1min, timert1 and timerb according to your network.
Also set session-type=uas.


Regards,
Muhammad Faheem

On Tue, Aug 9, 2016 at 12:03 PM, Jacek Konieczny <jajcus at jajcus.net>
wrote:
> Hi,
>
> We have been migrating our PBX system from Asterisk 1.8 and chan_sip to
> Asterisk 13 and chan_pjsip. Things are mostly, ok, but now I have
> stumbled on a behaviour difference I don't like.
>
> With chan_pjsip when a phone went unexpectedly offline (Ethernet cable
> disconnected) Asterisk would detect this quickly (through the
'qualify'
> pings), mark the phone as 'Unavailable' and fail immediately with
> 'CHANUNAVAIL' when dialling this phone.
>
> With Asterisk 13 and chan_pjsip qualify still works for determining
> current phone availability (endpoint shown as 'Unavailable' shortly
> after disconnecting the cable), but the phone is being dialled like
> nothing is wrong ? Asterisk sends the INVITE and waits for the response,
> until SIP timeout (a bit more than 30s total). That is much longer time
> until 'CHANUNAVAIL' than I expect. It is also longer than the dial
> timeout in some cases, so I would get 'NOANSWER' instead of
> 'CHANUNAVAIL' which breaks my dialplan logic.
>
> Is that that the expected behaviour, a bug or a configuration problem?
> Am I supposed to check for device availability in my dialplan?
>
> Greets,
> Jacek
>
> --
> _____________________________________________________________________
> -- Bandwidth and Colocation Provided by http://www.api-digital.com --
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On 2016-08-09 10:06, Faheem Muhammad wrote:
> Jacek,
> This might be a bug or configuration issue, but you need to understand
> the SIP Session Timers. With Session Timers you can control the round
> trip time and Call Setup time of SIP Requests.
I don't think you really mean SIP Session Timers 
(https://tools.ietf.org/html/rfc4028) these do not affect RTT or call 
setup, but provide kind of 'keepalive' and session expiration for 
established calls.
> In case of GSM Network with high delay you need to set the T1 timer a
> higher value like 1000ms (500 ms default). Similarly you can reduce the
> Call setup time by configuring 'T2' upto you choice as per you
telephony
> network. Configure t1min, timert1 and timerb according to your network.
> Also set session-type=uas.
Yes, tweaking the T1 and T2 timers may work for me. I'll try that, 
though the old 'qualify' magic with chan_sip was quite convenient. I 
wonder why it doesn't work with chan_pjsip.

Jacek

On 2016-08-09 10:06, Faheem Muhammad wrote:
> trip time and Call Setup time of SIP Requests.
> In case of GSM Network with high delay you need to set the T1 timer a
> higher value like 1000ms (500 ms default). Similarly you can reduce the
> Call setup time by configuring 'T2' upto you choice as per you
telephony
> network. Configure t1min, timert1 and timerb according to your network.
No, that won't work.

First ? 't1min', 'timert1' and 'timerb' are chan_sip,
not pjsip options.

Second ? the 'timer_t1' and 'timer_b' settings available in
'pjsip.conf'
are global and not per-endpoint. I cannot change T1 for trunks, as they 
might not be fast enough to respond and I cannot set it for phones only.

It seems I need to bring back the chan_sip behaviour ? 'do not bother 
with INVITE to Unreachable devices'.


Jacek
> On Tue, Aug 9, 2016 at 12:03 PM, Jacek Konieczny <jajcus at jajcus.net
> <mailto:jajcus at jajcus.net>> wrote:
>
>     Hi,
>
>     We have been migrating our PBX system from Asterisk 1.8 and chan_sip to
>     Asterisk 13 and chan_pjsip. Things are mostly, ok, but now I have
>     stumbled on a behaviour difference I don't like.
>
>     With chan_pjsip when a phone went unexpectedly offline (Ethernet cable
>     disconnected) Asterisk would detect this quickly (through the
'qualify'
>     pings), mark the phone as 'Unavailable' and fail immediately
with
>     'CHANUNAVAIL' when dialling this phone.
>
>     With Asterisk 13 and chan_pjsip qualify still works for determining
>     current phone availability (endpoint shown as 'Unavailable'
shortly
>     after disconnecting the cable), but the phone is being dialled like
>     nothing is wrong ? Asterisk sends the INVITE and waits for the
response,
>     until SIP timeout (a bit more than 30s total). That is much longer time
>     until 'CHANUNAVAIL' than I expect. It is also longer than the
dial
>     timeout in some cases, so I would get 'NOANSWER' instead of
>     'CHANUNAVAIL' which breaks my dialplan logic.
>
>     Is that that the expected behaviour, a bug or a configuration problem?
>     Am I supposed to check for device availability in my dialplan?
>
>     Greets,
>     Jacek
>
>     --
>     _____________________________________________________________________
>     -- Bandwidth and Colocation Provided by http://www.api-digital.com --
>     New to Asterisk? Join us for a live introductory webinar every Thurs:
>                   http://www.asterisk.org/hello
>
>     asterisk-users mailing list
>     To UNSUBSCRIBE or update options visit:
>       http://lists.digium.com/mailman/listinfo/asterisk-users
>     <http://lists.digium.com/mailman/listinfo/asterisk-users>
>
>
>
>