cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
386
Views
0
Helpful
1
Replies

SIP Registered Fax Calls Using Only PCMU.

I have a client using a SIP Fax machine (Ricoh MFD) registered with CUCM 10.5 and the machine/extension is able to receive external calls/faxes fine. It is when he tries to make and outbound call that they fail.

If the the MFD is powered off and the extension/account registered with on a 3CX softphone, the outbound calls work fine without any issues.

I collected the debugs on GW and in the SDP noticed that for the working call, both PCMA and PCMU were being negotiated, while for the non-working call, only PCMU was being negotiated:-

---

v=0

o=CiscoSystemsCCM-SIP 179406599 1 IN IP4 10.252.128.130

s=SIP Call

c=IN IP4 10.107.228.147

b=TIAS:64000

b=AS:64

t=0 0

m=audio 40016 RTP/AVP 0 8 3 101

a=ptime:20

a=rtpmap:0 PCMU/8000

a=rtpmap:8 PCMA/8000 >>>>>>>>>> working in this case

a=rtpmap:3 GSM/8000

a=rtpmap:101 telephone-event/8000

a=fmtp:101 0-15

 

 

v=0

o=CiscoSystemsCCM-SIP 179319315 1 IN IP4 10.252.128.130

s=SIP Call

c=IN IP4 10.252.255.162

b=TIAS:64000

b=AS:64

t=0 0

m=audio 30002 RTP/AVP 0 101

a=rtpmap:0 PCMU/8000 >>>>>>>>>> not working in this case

a=rtpmap:101 telephone-event/8000

a=fmtp:101 0-15

---

 

The configurations on CUCM also appear fine and the fact that calls for the same settings via a softphone work but not for the Ricoh MFD, makes me suspect whether it is the Ricoh MFD which supports PCMA or not.

 

Am I missing something?

1 Reply 1

Was this working before? 
call and fax work entirely different way. If you make calls and if working you cannot assure that fax will work.

 

in my region  if I use T.38 protocol fax will not work. I need to use g711 pass through to make fax working. 



Response Signature


Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: