We have integrated Thomson Cable Modems THG541. Our Customers use the VoIP with Telephones and also Fax Machines.
Our Customers encounter problems with sending FAX over the cable modem. Receive FAX is not a problem.
We also have Fritzbox 6360 in our Network, here we do not have problems with sending and receiving FAX with this type.
I compared the config files between Fritzbox 6360 and THG541 and don't see any different configuration.
For the THG 541 we use the FW hg541-af.01.23-110412-s-1ff-e.img. I don't know if the fax problem is related to the config file or to the FW.
I tried to get in contact with technicolor but could not succeed because we are not a distributor. And our distributor can not support me with this problem
Can anyone help me out with this problem, I would appreciate your help
Thanks
Harald
Hi,
Have you solve your issue ?
Can you post the config. file for Fritzbox 6360 and THG541 ?
Can you specify if you use SIP or MGCP ?
I've an open case of SIP VoIP Fritzbox 6360 provisioning. I've configuration file for THG541 and I'm interested into exchange information.
C.
Our cable VoIP deployments use SIP protocol. In this type of fault, I would trace the fax negotiations using Wireshark which will show all the SIP protocol in detail and will quickly determine whether it is the modem or even softswitch related. Are you sending traditional in-band G711 fax or out of band T38 compressed fax? As a tip, what we have experienced here is if the modem is sending G711A fax but the softswitch offers T38 codec in the SIP INVITES , it can crash the SIP negotiations and the fax connection fails. It can be both modem and softswitch fw updates to fix these types of issues.
Regards
Rob
Hi Rob,
thanks for your help, just today I found out that this is issue we have in our Network (The T.38 with SIP). The Fritzbox indeed use only the G711 and does not negotiate with the softswitch the T.38. The Thomson Modem tries always to use T.38. I hope I can change the config for the Thomson modem not to negotiate T.38
Regards
Harald
Glad I could assist with the debugging. If the Technicolor emta has T38 fax set as default, you may be able to disable this in your MTA (Voice) config file. A quick search shows that the below mib might help with Integer set to '0' which may allow G711 to be negotiated.
sipEndPntConfigUserDataMode OBJECT-TYPE
SYNTAX INTEGER{ dataModeNoPreference(0),
dataModeVBD(1),
dataModeT38(2)
}
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"The preferred mode for data exchange."
DEFVAL {dataModeVBD}
::= { sipEndPntConfigUserEntry 11 }
Regards
Rob