I have a UC520 (CME) system connected to PSTN via a SIP trunk provider. The SIP trunk supports T.38 faxing.
I have a fax server setup with StoneFax to terminate the faxes. I have setup an incoming dialpeer with one of my DIDs. upon sending a fax, the line rings once, then seems to connect, but it is just dead silence. The microsoft fax service on the fax server shows 'answering' but nothing ever happens.
I am mostly concerned about my dial-peer config.
Here is the dialpeer config that StoneFax suggests:
dial-peer voice 20 voip
description INCOMING FAX FROM PSTN TO STONEFAX
destination-pattern <<DID HERE>>
session target ipv4:<<FAX SERVER IP>>:1721
dtmf-relay h245-alphanumeric
codec g711alaw
fax rate 14400
fax protocol t38 ls-redundancy 0 hs-redundancy 0 fallback cisco
no vad
should this work ok over a SIP trunk? are there any other system settings i should change? I am wondering about the DTMF settings. Cisco configs usually show h245-signal, and all my voice dialpeers are rtp-nte.