On Fri, Nov 11, 2011 at 9:46 PM, Alex Crow <acrow@integrafin.co.uk> wrote:
Brian,
I am *not* going out to/in from the world at large from/to the FS box via T38. I don't have a T38 capable gateway at the moment, and this is for an emergency box to replace a machine with several analog modems attached to the Mitel PBX.
Therefore I have to translate t38modem's T38 I/O into audio over SIP to send to/rcv from our (non-T38-understanding) Mitel PBX which connects via E1 trunks to the PSTN.
I know it's not ideal but it does seem to work OK so far.
We have an older fax server (analog lines) where the modem does not support ECM. We virtually never have any problems sending or receiving faxes from this machine. However if you or anyone else can help get ECM working in this setup I'd be happy, but I have my doubts due to the G.711 step between the FS machine and the Mitel, probably causing jitter.
To clarify, here is the topology:
Hylafax<---Audio---->t38modem<---T38--->Freeswitch/t38gateway<----G.711/SIP--->Mitel 3300(T38 unsupported, grr)<---ISDN30---->PSTN
I have to do the transcode as the Mitel is the weak link.
If I could pop an E1 card in the FS box I'm sure things would work a lot better, but we don't have a spare card or indeed a spare circuit right now!
Hope this make sense....
Alex
I would use an analogue or PRI/BRI (depending on volume) card in the Mitel going to modems/dialogic card(s) in the Hylafax server. You might also want to look at IAX modem instead of T38