[asterisk-users] Faxing issues

[Benny Amorsen]

Todd S <asterisk at myzionetworks.com> writes:

> 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