RightFax with CUCM 6.1 integration via H.323

Unanswered Question
Jan 26th, 2009

Hello all,

I have to help Rightfax vendor to integrate it with CUCM at my customer's location. It should go over h323 gateway (same thing with GFI faxmaker in my company works well). When we try to send fax from fax server back to fax server, it works well (goes over CCM). However when we try to send it from the outside or even to call fax number from IP phone, Rightfax doesn't seem to get the route code(DID/DNIS) and doesn't know how to route the incoming fax. The situation is more complicated as the Rightfax vendor doesn't have CCM knowledge or instructions about the setup, and we are not allowed to give each other's passwords. I tried all possible h323 settings about it's always the same.

If anybody had similar experience please let me know,


goran pilat

I have this problem too.
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jujin.cisco.mai... Mon, 01/26/2009 - 02:14

Please, post the network scheme, CUCM route pattern configuration, RightFax h.323 configuration and sniffer trace from CUCM and RightFax.

goranpilat Mon, 01/26/2009 - 03:19


please find the route-pattern config, h323 config and trace in wireshark taken from CUCM.

IP address of CUCM is and Rightfax (so you can filter it out with this IP). No access-list between the two. When I call from IP phone Rightfax extension I hear fax signal but there is no route code and the fax cannot be routed. Thanks for the help,


goran Pilat

goranpilat Mon, 01/26/2009 - 06:05

It is Dialogic/Brooktrout TR1034 8 channel IP enabled board,


CCSI_Instructor_2 Mon, 01/26/2009 - 08:26

I quickly reviewed wireshark trace - does not talk to (probably Pub), it is talking to (probably Sub), which is ok. The trace shows “connect” successfully. No problems with call setup.

Looked at jpg. Noticed your route pattern is only 3 digits, while gateway has “Significant Digits” = all. If you are trying to send from PSTN how are you translating into the 3 digits? This might be one of your problems. Do a “debug isdn q931” on voice gateway to determine what is coming in and out.

Finally, try deselecting, “Wait for Far End H.245 Terminal Capabilities Set” on the gateway page.

Not sure if this will fix problem, but it may be a start. Good luck.

goranpilat Mon, 01/26/2009 - 11:21


thanks for the reply. Provider is sending me only three digits from his CPE so this is ok. I am also trying to call from my IP phone this 3digit number and I am getting fax signal but the call setup cannot be completed (ok, it si phone not fax, but anyway) since it is not sending route code (at least this is what RightFax admin keeps telling me)



goranpilat Wed, 01/28/2009 - 04:12

hi Marco,

Rightfax is not under my jurisdiction. But as faxes go through when it is sent from rightfax to rightfax, I think there is route code configured...,,


Goran Pilat

goranpilat Tue, 02/10/2009 - 08:10

Hi all,

Just a follow-up.

The issue was resolved when the t38 was turned on on MGCP gateways by following commands:

mgcp package-capability fxr-package

voice service voip

fax protocol t38 ls-redundancy 2 hs-redundancy 0 fallback none


session transport udp

no mgcp fax t38 inhibit

Now faxes go in and out the Rightfax and ATA-s to the PSTN. However a new issue occurs. ATA Faxes cannot send fax to Rightfax and vice versa. I read here in one thread that it is because ATAs don't support t38 and Rightfax doesn't support fax pass-through. Is there a workaround for this. Because now I have users on the same CCM that cannot send faxes between each other and seems they don't plan to change the setup in near future...


goran pilat

drubery Wed, 03/25/2009 - 13:26


We were having a similar issue with FaxPress which went unresolved with faxes coming from PSTN. All fax numbers hit a single DID which hit a hunt list containing the ports of the FaxPress server. Problem was the destination digits are passed in the data stream where-as FaxPress wanted the DTMF tones for the destination digits to be passed in-band.

I am not sure the T38 configuration would have helped us for how do pass multiple destination digits to one DID and preserve the destination in-band for passing to the fax server.

Misc Notes:

Capabilities and Priorities

Cisco H.323 gateways advertise capabilities using H.245 capabilities messages. By default, they advertise that they can receive all DTMF relay modes. If the capabilities of the remote gateway do not match, the Cisco H.323 gateway transmits DTMF tones as in-band voice.

Configuring DTMF relay on the Cisco H.323 gateway sets preferences for how the gateway handles DTMF transmission. You can enable more than one DTMF relay option for a particular dial peer. If more than one option is enabled and if the peer indicates that it is capable of receiving DTMF in more than one of these formats, the gateway sends DTMF using the method among the supported formats that it considers to be the most preferred. If the remote device supports multiple formats, the gateway chooses the format according to the following priority:

1.cisco-rtp (highest priority)



Configuring H.323 Gateways

How to Configure H.323 Gateways


Cisco IOS H.323 Configuration Guide


5.None-DTMF sent in-band



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