# Cisco Call Manager - Ascom IP-DECT



## Robvha (Jul 27, 2012)

Hello,

I have no idea if someone has knowledge about this combination but any information is welcome. Please move my question to another part of the forum if it doesn't belong here.

Short introduction:
- There is one main office and several branch offices;
- The CCM (Cisco Call Manager) is located at the main office;
- The branch offices have separate Cisco gateways which are coupled to ISDN and are registered at the CCM in the main office;
- There are several Cisco phones at the main and branch offices;

We would like to couple an Ascom IP-DECT system to the CCM. The Ascom IP-DECT system will be placed at the several branch offices. The registration of an Ascom IP-DECT phone on the CCM already succeeded. They are registered as basic SIP devices. 

Problem description:
When we are at one of the branch offices and we make an external outbound call with one of the Cisco phones this happens:
The CCM uses Skinny to talk to the phones. He will setup the conversation and will map the audiostream directly between two endpoints: the Cisco phone and the Cisco Gateway(which is on the same location). On this manner the audiostream will stay inside the local LAN of the branch office. The connection between the main office and the branch office will only be used for setting up call's, status signaling etc. So far so good. If we do the same with the Ascom IP-DECT handset we see this behavior: The call will be setup and the audio stream will flow from the Ascom to the CCM and from the CCM to the Cisco Gateway and the other way around. This behavior is not acceptable because the bandwidth of the connection between the main office and branch office is very narrow. Another thing is that the CCM must handle extra load because of this voice traffic. 

I don't have any explanation for this behavior. The only thing I can think of is that the Ascom is talking SIP and the Cisco Gateway is talking H.323. Because of this translation the voice is going via the CCM and not directly between the Ascom and the Cisco Gateway. We tried to change the protocol from SIP to H.323 in the Ascom IP-DECT without any success. 

As mentioned, any information is welcome!

Thanks for reading the story!

Best regards,

Rob


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## glocke (Sep 23, 2012)

Hi Robvha,

do you still need the informations ?? We did a nearly similar installation 4 weeks ago in our offices in the nordic region.

Let me know if you need some informations and esp. what kind of informations.

Regards
Glocke


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## Robvha (Jul 27, 2012)

Hi Glocke,

I would be very grateful if you can tell me how you configured this scenario. Are the Ascom basestations working with H.323 or SIP? Is your audiostream staying in the local network and not running via the CCM? Do you have an example of the Ascom basestation config? What kind of user did you create on the CCM for the Ascom basestation users to log on to. 

Every information is welcome, we are on a dead end right now. 

Thank you very much!

Best regards,

Rob


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