10-04-2013 05:23 PM - edited 03-16-2019 07:43 PM
Hello All,
I have an issue with fax, it is connected to an fxs port on my h323 gateway. When a call comes from PRI and get connected to fax after I hear the fax tone the fax drops. IOS is Version 15.0(1)M4, and DSP is PVDM3.
My analysis:
The external calls hit gateway and it matches the pots dialpeer where my fax connected to. From the "debug voip vtsp all", I see Primary Fax Protocol=CISCO_FAX_RELAY, which is not enabled and we are using T38 relay and modem passthrough method for faxing. I believe PVDM3 does not work with Cisco Relay and couldn't allocate any dsp resources for the call and it drops. But still I wonder how gateway takes cisco relay.
Config:
voice service voip
allow-connections h323 to h323
fax protocol t38 ls-redundancy 0 hs-redundancy 0 fallback none
h323
emptycapability
modem passthrough nse codec g711ulaw
!
dial-peer voice 1001 pots
tone ringback alert-no-PI
description PSTN Incoming, Pattern:.
translation-profile incoming PSTN-to-PhoneDN
incoming called-number .
direct-inward-dial
!
dial-peer voice 999030 pots
tone ringback alert-no-PI
destination-pattern 3027898
progress_ind setup enable 3
port 0/3/0
Output of vtsp debug
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
Oct 4 20:30:07: //6824/97F0D7BD8350/VTSP:(0/1/0:15):7:1:1/vtsp_dsm_save_fax_config:
Fax Relay=ENABLED
Primary Fax Protocol=CISCO_FAX_RELAY, Fallback Fax Protocol=NONE_FAX_RELAY
Fax Relay CM Suppression :=ENABLED, Fax Relay ANS Suppression :=DISABLED
Fax Parameters Set By=Dialpeer, Peer=999030 (this is the peer where my fax connected to)
I have converted the port to MGCP and found its working, while faxing I see vtsp outputs
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
Oct 4 23:57:29: //7181/8FE17FEF8379/VTSP:(0/3/0):-1:1:2/vtsp_dsm_save_fax_config:
Fax Relay=DISABLED - MGCP Application
Primary Fax Protocol=IGNORE_FAX_RELAY, Fallback Fax Protocol=IGNORE_FAX_RELAY
Fax Relay CM Suppression :=ENABLED, Fax Relay ANS Suppression :=DISABLED
Fax Parameters Set By=MGCP Call Type --> I believe MGCP disabled the cisco fax relay and switch over to T38.
Oct 4 23:57:40: //7181/8FE17FEF8379/VTSP:(0/3/0):-1:1:2/vtsp_dsm_save_fax_config:
Fax Relay=ENABLED
Primary Fax Protocol=T38_FAX_RELAY, Fallback Fax Protocol=NONE_FAX_RELAY
Fax Relay CM Suppression :=ENABLED, Fax Relay ANS Suppression :=DISABLED
Fax Parameters Set By=MGCP Call Type
Can some one kindly suggest how to make it work on H323, also how we can force disabling cisco fax relay?
10-05-2013 01:56 PM
Try this:
voice service pots
fax rate disable
HTH
--
Jorge Armijo
Please remember to rate helpful responses and identify helpful or correct answers.
10-08-2013 03:03 PM
Hi Jorge,
Thanks for your advise. It works as I hear fax tones.
But still in the logs I see primaty fax protocol as Cisco Fax Relay. Why its showing like this? Is this the default behaviour?
Thanks.
10-08-2013 05:45 PM
That's becuase the IOS will always try to use Cisco Fax Relay as the first fax protocol, to avoid that, you need to configure under voice service voip:
voice service voip
fax protocol none
After adding that command, you have to re configure whatever fax protocol you want to use.
HTH
--
Jorge Armijo
Please remember to rate helpful responses and identify helpful or correct answers.
10-09-2013 01:32 PM
Incoming now works with both MGCP and H323. Now I have the problem with Outgoing fax. When the port is configured as MGCP, either I need to remove allow-connections h323 to h323 or modem passthrough nse codec g711ulaw command to make that work. I am bit confused on this. Could you help?
10-09-2013 01:57 PM
Well, that's weird...
Can you post a debug for a failing fax call?
deb mgcp pack
deb ccm-manager back pack
deb voice ccapi inout
deb isdn q931
Also, please post the complete full configuration.
--
Jorge Armijo
Please remember to rate helpful responses and identify helpful or correct answers.
10-09-2013 04:53 PM
10-14-2013 04:32 PM
I don't quite understand the problem, are you using MGCP or H323?
What's the need of having mixed protocols?
Unless you're testing MGCP Fallback, it should work with with MGCP or H323 separately.
--
Jorge Armijo
Please remember to rate helpful responses and identify helpful or correct answers.
10-16-2013 06:36 PM
As I mentioned earlier, we are using MGCP for that particular fax port and the gateway we use as H323.
Even I'm not pretty sure about using mixed protocol, I believe this gateway gonna used to support call center calls. SInce MGCP is easy for configs they might have confiugred only the port as MGCP endpoint.
Now its not working with both the cases, not in mgcp as well as fallback mode. Can you reveiw the debugs and see why I have to remove "modem passthrough" command from voice service voip section which of our standard config and works well with all other gateway of ours. Please help here.
10-18-2013 05:59 PM
Hi Jorge,
Can you help?
Thanks.
10-18-2013 08:26 PM
Got it. Interesting, can you please post the latest complete config so I can review it along with the debugs?
--
Jorge Armijo
Please remember to rate helpful responses and identify helpful or correct answers.
10-19-2013 08:46 AM
10-22-2013 03:51 AM
hi Jorge,
Hope you are looking on this. Did you get the issue?
Thanks
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