Fax over Gamma Sip Trunking G729

[MMWTEK]

Hi

I have a site that uses gamma sip trunks - Avaya ip office 500 v2 9.1. Iam having issues with the bt line and was hoping
to change the gamma codec from g711 to g729. Problem is I have a couple of analog extn ports being used for the main fax mchn
and a franking machine. When I change the codec obviously doesnt work over g729. I have T.38 activated on the gamma cisco router
and have changed the settings in the ip office - sip -voip - T38 . I left the T.38 fax tab to use default values. In the extn tab
for the fax mchn I ticked it to be fax machine. When I try and send a fax from my home fax mch I get connecting on the screen then
busy , then hangs up.

Just wondered if anyone else has had fax working over gamma sip trunks using g729 and what combination of t.38 settings would get this
working..

cheers

mik

 

[amriddle01]

You're on a loser straight away with Fax or Frnking over SIP, you need a flawless connection end to end, we're talking no delay no jitter and even then franking is going to be a long shot, faxing perhaps at 9600 but not 100% even then

 

[ipohead]

Fax is chancing it! Some have an 'overseas' setting which is more tolerant of errors.

Have a word with your franking machine provider as many machines can be upgraded to update over the internet. In the UK they will needed to be upgraded or replaced to work with the latest Royal Mail systems.

 

[janni78]

T.38 usually works fine, at least here.
But if you need to change the codec to g.729 because of bandwidth issue your most likely not going to get a fax through.

"Trying is the first step to failure..." - Homer

 

[MMWTEK]

Thanks for the replies , think I will steer away from trying that option and probably save alot of wasted time

 

[jamie77]

We have sites running T.38 with Gamma, mainly on assured though.

Do you have Allow Re-Invite ticked on the SIP trunk?

Jamie Green

[bold]A[/bold]vaya [bold]R[/bold]egistered [bold]S[/bold]pecialist [bold]E[/bold]ngineer

 

[MMWTEK]

Hi

Jamie - Yes I have Re - invite supported within the sip - voip tab selected. I then selected T.38 for fax transport support and
in the alog extn tab set for fax machine. It is a gamma assured 10 broadband. With this all set and the codec changed on the gamma portal
to g729 , when I ring the fax i was getting busy coming up on my home fax mchn. I have been having major issues with the bt lines into
this building and going round in circles with bt . I had it on g729 earlier in the month and all was stable at that bandwidth only problem
is the fax / franking machine. I could get some traces , line is stable this weekend on g711 so might be ok as is but very doubt it lol.
Cheers for getting back..