Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Transcoding between Unity and Unity

Hi, we just recently started deploying Unity 3.1.5 replacing our installed base of Avaya UM users. We decided to use Unity's GSM codec to save on Exchange storage and the portability of the voice message. The cost of the disk space wasn’t the problem; it was more the time to backup the increased storage amounts.

We also have a large installed base of Octel voice servers (+10,000 accounts). So, we need to be able to exchange voice messages between Unity and Octel. The Octel support folks do not want to use AMIS and they only offer Octelnet.

We purchased the Unity Bridge with the expectation that we would be able to connect the Unit Bridge to the Octel voice server and use Octelnet to exchange voice messages.

The problem we ran into is with the support codecs on the Unity Bridge. The bridge only supports 711 or 729a.

We really do not want to change the codec on Unity, because it is meeting our needs. However, I need to find a resolution to connecting Unity to the Unity Bridge. I am thinking that I can configure the FXS ports that I will be using to connect the Unity Bridge to the PSTN for connecting to the Octel voice server in their own region that uses 711 and then use my 6608 modules to transcode between GSM and 711 codecs. I have plenty of 6608 capacity, so I can easily set up a couple ports as transcoders.

Does anyone know if I can transcode between Unity and the Unity Bridge?




Re: Transcoding between Unity and Unity

The limitation isn’t between the Bridge and the Octel; it’s between the Unity and the Bridge.

In your case the message recorded in Unity is encoded using GSM. That message is sent to the Bridge as an email attachment. Then the Bridge needs to decode the message and transfer it using a normal analog phone call. The problem is that the Bridge can only decode g.711 and g.729. Therefore you aren’t even going to get an analog call.

Basically you can’t get around recording the messages with g.711 or g.729.

Hope that helps,


New Member

Re: Transcoding between Unity and Unity

Thanks Keith. I would like to go to g.711, but our exchange administrator is not too pleased with the storage size. So, we will have to bite the bullet with g.729a not being portable.

Do you think there will be any chance of a future release of the Brige supporting GSM?

Thanks for the reply,



Re: Transcoding between Unity and Unity

Yeah I brought up support for GSM once before. I don't believe it has been road mapped though.

I can tell you that at Cisco, we listen to customers and build features based on their business needs. The way to make feature requests is through your account team. They can submit a PERS request on your behalf.