CTI-ports and G.729

Unanswered Question
Aug 1st, 2007

Hi, could someone help, please.

If CCM (ver.4.0) supports G.729 for the CTI-ports? The problem I have is CTI-ports can't dial to ip-phones after CCM is configured to use G.729. With G.711 everything is ok.

Many thanks in advance.

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Loading.
dgahm Wed, 08/01/2007 - 07:16

What application is using the CTI ports? Do you have transcoders available? The Call Manager will use transcoders for G729 calls to devices that only support G711.

Please rate helpful posts.

Dave

AngryFriar Wed, 08/01/2007 - 07:39

Hi Dave,

>What application is using the CTI ports?

It's application developed by our company.

As I can see from the application logs, all dials from CTI-port to IP-phone are failed when the G.729 is used. CTI port just getting "LINECALLSTATE_DISCONNECTED" TAPI event when trying to make a call to an ip-phone.

>Do you have transcoders available?

I'm not sure what you mean. How to check this, please?

>The Call Manager will use transcoders for

>G729 calls to devices that only support G711.

In our case the target device ( 7902 ip-phone ) surely supports G.729. But we don't know if the source device (CTI-port) supports the G.729 too. And that is the question.

Thanks, Dave

dgahm Wed, 08/01/2007 - 08:11

Alex,

CTI ports are used when terminating a call on a server. In your case that means the custom TAPI app must be capable of doing G729 (or you need transcoders). You should talk to the developers to see if the G729 capability exists, but I would guess it does not.

Transcoders are used for codec conversion -- in your case to translate G729 to G711. Hardware transcoders will either be a DSP farm in an IOS router, or 6500 blades (6608 or CMM).

Here is a good CCM 4.0 doc on transcoding:

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_administration_guide_chapter09186a00801ec5bf.html

Please rate helpful posts.

Dave

AngryFriar Wed, 08/01/2007 - 08:46

Dave,

>CTI ports are used when terminating a call

>on a server. In your case that means the

>custom TAPI app must be capable of doing

>G729 (or you need transcoders).

The TAPI app just "ask" (via TAPI call lineMakeCall) to call from CTI-port to IP-phone. That's all. There is nothing codec-related for such a function call from the app's point of view. And the operation completes sucessfull if the G.711 is configured at the CCM side. But the _exactly_the_same_ operation fails if the G.729 is configured at the CCM side.

I think that CTI-ports just do not support G.729, but I need an "official" doc confirming that. Or I need a way to make it works as expected :)

>You should talk to the developers to see if

>the G729 capability exists, but I would

>guess it does not.

I'm one of the developers :) But I don't know an answer - there is nothing codec-related in our app. I think it should be "hidden" from the app which codec is used. The app just utilize TAPI calls. I hope you understand what I mean. Possibly I'm wrong :)

thanks again,

Alex

dgahm Wed, 08/01/2007 - 10:13

Alex,

Cisco TAPI does not support G729. You will need transcoders. We use a 3rd party TAPI ACD system, and I verified that G729 calls are being transcoded.

Do you have transcoders available?

Dave

AngryFriar Wed, 08/01/2007 - 10:20

Dear Dave,

>Cisco TAPI does not support G729

Could you provide me with a reference to an official documentation proving that, please.

>Do you have transcoders available?

I'm afraid, no. Are there any software transcoders or there are only hardware transcoders?

>G729 calls are being transcoded.

Do you mean CTI<->Phone calls ?

many thanks,

Alex

dgahm Wed, 08/01/2007 - 11:12

Alex,

I looked in the TAPI developers guide, and it appears that call setup using any codec is supported. Do you have the developers guide? The no G729 is apparently a limitation on our Interactive Intelligence system, though I'm not sure if it a wave driver issue or something else.

Does your application require that audio streams be terminated on the server or is it just controlling phones?

Transcoding requires hardware DSPs. The cheapest solution would be an ISR router with a DSP farm.

In our case calls are initially terminated on the server to play prompts, then the call is sent to a call agent phone. If a remote site that uses G729 calls in the call goes through a transcoder while connected to the server, then is direct to the agent phone at G729 with no transcoder.

Dave

AngryFriar Wed, 08/01/2007 - 11:26

Dave,

>I looked in the TAPI developers guide, and

>it appears that call setup using any codec

>is supported. Do you have the developers

>guide?

Yes, I have the doc. Do you mean the cisco TAPI extension available via the lineDevSpecific? I can find nothing codec-related in the "standard" TAPI set.

thanks,

Alex

AngryFriar Mon, 08/13/2007 - 07:28

Hi All,

There is still no working solution or explanation. Help, please.

Thanks a lot.

AngryFriar Wed, 08/29/2007 - 03:00

Does anybody know if it's possible at all or not, plz? I mean to use G.729 with CTI-ports.

jebaraj Wed, 08/29/2007 - 23:40

CTI Ports are supported only with G711 with the Cisco TSP for CallManager. The Wave Driver that accompanies the Cisco TSP does not support G729.

There is more difficult way to support CTI ports with G729, you will need to terminate your media and not use the Wave Driver.

AngryFriar Thu, 08/30/2007 - 04:34

>you will need to terminate your media and not use the Wave Driver.

Could you explain a bit more detailed, please?

Actions

This Discussion