No Ringback

Unanswered Question

Hi, running the following

CVP 4.1

ICM 7.2.2

CUCM 6.1

Used to have a CUPS server as SIP Proxy but took that out because of MTP issues. Currently just using static routes on Call server.

Noticed in the last couple of days that when internal caller (ip phone) dials into contact centre they herre the normal prompt and Q music but when call gets send to an agent, the caller hears no ringback.

IP Phone to IP Phone works fine

PSTN caller to Call Centre works fine (ringback is fine)

Ip Phone to CC get normal prompts but from there to agent, IP phone hears no ringback.

Any ideas?



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Overall Rating: 4.5 (2 ratings)
jbyron Fri, 05/30/2008 - 03:22
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The ringback during the transfer to the agent is controlled by OAMP on the Call Server device->SIP tab.

- 'DN on the Gateway to play the ringtone' usually specifies 91919191.

- Since you now have no proxy, you must specifically have 91919191 associated with a VXML gateway IP address in the "Local Static Routes".

- If you have all this configured, check the CVP Error log to see if there is some message about an error playing ringtone.


jbyron Fri, 05/30/2008 - 03:38
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One other thing to do... On the VXML gateway that you have targeted in your 91919191 static route, turn on 'debug voip application tcl' and 'debug voip application script' and 'debug voip dialpeer' Place a call and look at that gateway log. You should see the call arrive to the voip dial-peer you have assigned for incoming called-number 91919191, then you should see the ringtone.tcl script get executed.

I've got the same problem in Canada.

It works in my lab with an FXS card, so I know how to set this up - but not in Canada on a gateway with the carrier Bell Canada. Since the gateways are in production for pass through to a Nortel Symposium and under load, I could not easily run heavy debugs. But I could use a command to show the running applications - and the ringback.tcl was running. I can't recall the exact command.

Mike Oldham said it could be an issue with the bearer channel - not that I know what that is. ;-) But could some Telcos handle this differently?



jbyron Fri, 05/30/2008 - 12:19
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ringback.tcl simply plays a .wav file. In that respect it is no different than what happens on the VXML gateway. I don't see how this could be telco dependent at all.

Are *all* callers not able to hear the ringtone, or is it sporadic? Are you routing the 91919191 calls to a single VXML gateway or load balancing to a bunch of VXML gateways?



Ah, that last question made me think.

There are 2 gateways at that site. I am routing the label through the CUPS SIP Proxy Server. There are two static routes on this pattern, 1 to each of the gateways.

If the incoming call is on one gateway and the label is being sent to the other gateway, we have a problem. Right?

Since the agents have auto-answer on headset through Call Manager set up, all the testing with normal conditions did not reveal this issue. It was only when I started testing what happens if an agent forgets to press the headset button that I noticed no ringback. I only made a few test calls, and did not hear the ringback on any calls - perhaps if I had made a number of calls I would have heard sporadic ringback.



jbyron Mon, 06/02/2008 - 02:40
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No, it will not be a problem if the incoming call and the ringtone are on different GW's. The fact that you are seeing the ringtone execute when you look at running applications on the GW says that at least the 91919191 ringtone is routing there successfully. Several things:

1. Are you sure the ringtone.tcl file and ringback.wav files both exist in flash on both gateways?

2. Is "no ip routing" set on either of the gateways? This setting prevents prompts from being heard.

3. Is this a CMM by any chance? CMM's don't call flash "flash" and would cause the ringtone.tcl file to error.

4. Since you can't set verbose debugs for production, at least Set 'debug voip application error' to see if any errors appear in the GW log.


Janet wrote:

>4. Since you can't set verbose debugs for production, at least Set 'debug voip application error' to see if any errors appear in the GW log.

Unbelievable. There is an error there, saying "no service ringtone configured". But there is the normal settings in the config for the ringtone service. What is going on?

Then I checked the flash and there is no ringtone.tcl but there is a RINGTONE.TCL!! I copied that file to flash:ringtone.tcl and then ringback started working.

All files like the CVP wav files and the tcl files were installed in flash as CAPITAL letters - like HANDOFF.TCL. Some of this was obviously working, but not all. I made copies to flash with the correct lower case names.

How this happened is as follows.

Initially I logged into the gateways and pulled all the mandatory CVP files from my TFTP server. Subsequently, the flash had to be increased to hold B-ACD and to hold (marketing) music for multicast from the gateway (actually does not work with SIP but that's another story).

The engineer who installed the flash used a PC and a card reader to copy the flash from the small one to a much bigger one, and the program must have capitalized some names. Not sure exactly how this all transpired.

Thanks for pointing me in the right direction, Janet.




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