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Old 12-16-2019, 02:01 AM
rime rime is offline
Join Date: Dec 2011
Posts: 66
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Default T.38 fax for fax server connected with ISDN PRI to G450

With a fax server connected via ISDN PRI (QSIG) to a G450 Media Gateway, is it possible to have the Media Gateway accepting a T.38 connection with the remote side on the public telephone network, connected over a SIP trunk? At this point I have the Media Gateway rejecting T.38 and negotiating G.711 but then the fax transmission fails. With an analog fax connected to the G450, the G.450 recognizes the fax tones and accepts T.38 but with a fax server connected over ISDN, I do not know if the G450 Media Gateway can terminate the T.38 flow and convert to PCM A-law for the ISDN QSIG connection to the fax server.

signaling flow
fax server <--- ISDN PRI (QSIG) ---> G450 <--- H.248 ---> CM 6.3 <--- SIP ---> SM 6.3 <--- SIP ---> Audiocodes Mediant 1000 <--- SIP ---> public telephone network <--- T.38 ---> fax

media flow

fax server <----- ISDN PRI (QSIG) ---> G450 <---> Audiocodes MP1000 <--- SIP service provider ----> T.38 fax

Thanks in advance!
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