Posted: Fri May 22, 2009 11:07 pm Post subject: [asterisk-users] Faxing issues
We seem to be having a good bit of issues sending faxes and can't pinpoint the issue. I'm hoping someone here may have a different outlook on the issue that leads to a resolution.
Our call path is Sip trunk from MAX TNT - Asterisk - T1 - Adtran endpoint converting sip trunk to copper line for house wiring.
Users at the endpoint can receive faxes without a problem. However, sending faxes are not so friendly. 1 out of 5 faxes will send successfully. The remaing 4 continually fail with the fax machines reporting "Poor Line Quality". QoS is setup on both ends and working as expected across all traffic to and from both sides of the call. Voice quality is good on calls from the same lines. I've checked all sides and had all vendors look at their equipment and they are all pointing the finger at each other. I've got sip traces from both ends and both look good with the exception of random BYE's being sent from the Adtran side of the call during random fax calls. T.38 is enabled on both ends as well.
Anyone have any possible ideas where to look further or an idea of how i could at least improve the situation?
Posted: Fri May 22, 2009 11:13 pm Post subject: [asterisk-users] Faxing issues
Todd S wrote:
Quote:
Our call path is Sip trunk from MAX TNT - Asterisk - T1 - Adtran
endpoint converting sip trunk to copper line for house wiring.
Users at the endpoint can receive faxes without a problem. However,
sending faxes are not so friendly. 1 out of 5 faxes will send
successfully. The remaing 4 continually fail with the fax machines
reporting "Poor Line Quality". QoS is setup on both ends and working
as expected across all traffic to and from both sides of the call.
Voice quality is good on calls from the same lines. I've checked all
sides and had all vendors look at their equipment and they are all
pointing the finger at each other. I've got sip traces from both ends
and both look good with the exception of random BYE's being sent from
the Adtran side of the call during random fax calls. T.38 is enabled
on both ends as well.
Anyone have any possible ideas where to look further or an idea of how
i could at least improve the situation?
Is T.38 actually being used? If not, then please see:
If T.38 is being used then it's probably due to a T.38 bug in one or
more of the gateways, and you'll need to work with the provider of that
T.38 gateway for a resolution.
Thanks,
Lee.
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Posted: Sun May 24, 2009 12:59 pm Post subject: [asterisk-users] Faxing issues
What's the bets way to verify T.38 is being used on both incoming an outgoing transaction?
On Fri, May 22, 2009 at 8:08 PM, Lee Howard <faxguy@howardsilvan.com (faxguy@howardsilvan.com)> wrote:
Quote:
Todd S wrote:
> Our call path is Sip trunk from MAX TNT - Asterisk - T1 - Adtran
> endpoint converting sip trunk to copper line for house wiring.
>
> Users at the endpoint can receive faxes without a problem. However,
> sending faxes are not so friendly. 1 out of 5 faxes will send
> successfully. The remaing 4 continually fail with the fax machines
> reporting "Poor Line Quality". QoS is setup on both ends and working
> as expected across all traffic to and from both sides of the call.
> Voice quality is good on calls from the same lines. I've checked all
> sides and had all vendors look at their equipment and they are all
> pointing the finger at each other. I've got sip traces from both ends
> and both look good with the exception of random BYE's being sent from
> the Adtran side of the call during random fax calls. T.38 is enabled
> on both ends as well.
>
> Anyone have any possible ideas where to look further or an idea of how
> i could at least improve the situation?
Is T.38 actually being used? If not, then please see:
If T.38 is being used then it's probably due to a T.38 bug in one or
more of the gateways, and you'll need to work with the provider of that
T.38 gateway for a resolution.
Thanks,
Lee.
_______________________________________________
-- Bandwidth and Colocation Provided by http://www.api-digital.com --
Posted: Sun May 24, 2009 7:46 pm Post subject: [asterisk-users] Faxing issues
Todd S <asterisk@myzionetworks.com> writes:
Quote:
What's the bets way to verify T.38 is being used on both incoming an
outgoing transaction?
I don't know about "best", but there's sip set debug ip whatever, or my
personal favourite:
tcpdump -s0 -vnieth0 udp
You can easily tell if t38 is used because the UDP traffic will (almost)
stop being two-way and instead just come from the sender of the fax. The
size of the packets will also change (t38 packets are quite small).
You can also see it by reading the SIP packets, but that takes actual
work.
/Benny
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