[asterisk-users] Rxfax and Txfax on Asterisk 1.4

[Ardjan Zwartjes]

>It's not a timing problem, it's a "that just happens when you do faxing

>over typical VoIP channels" problem.  The reason it happens is because 
>of jitter... and more specifically, packet loss.  On UDP communications

>packets are not retransmitted if they get dropped by a router or switch

>or hub.  You can't just take a data stream and chop out small chunks of

>it here and there and expect the receiving end to be okay with it.

I think you missed my point here, I understand the risks of faxing over
VOIP but our problem ONLY occurs when then entire path of the fax is in
voip. If we use a 10 times longer VOIP path combined with a small path
over a regular telephony channel everything works fine, even though this
would still suffer from packetloss. You're problably right about the
jitter part (which is a timing problem as far as I can see) and I expect
that the regular telephony channel fixes the problem since it has strict
timing characteristics.

Kind regards,
Ardjan Zwartjes.