Compression

[bearvalley]

I have a few grey areas with compression and am hoping someone can help.

Teleworker 4.1

Why would I use the G.729 compression on the teleworker server when I can let the 3300 do it for me using zone compression which does not require a license ?

3300

How come I can turn compression on, on an IP Trunk when I don't have any compression licenses ?

 

[Weasel5053]

It is true that you could put a teleworker phone in a different compression zone and compress when the far end call is another IP phone, but as soon as a TDM device is involved (ie a trunk) then you would need a DSP card and compression licenses in the 3300.

We have always preferred to use the g.729 transcoding in the teleworker gateway because it is less expensive (free in versions prior to 4.1) than provisioning compression on the 3300 (in the case of multiple gateways for example you would to add compression to all of them) and is less programming for the user to set up a new phone. Also consider the situation where a user wants to bring a phone back and forth between the office and a remote location. Using the transcoding capability in the teleworker gateway is superior here because it does not require the compression zone to be changed to allow full g.711 in the office.

Mitel has inexplicably removed the free transcoding capability in release 4.1, requiring even existing customers to repurchase that functionality.

Note that Mitel has recommended for some time that you provision the compression on the 3300 side saying that will result in higher voice quality. We have not been able to tell the difference.

 

[bearvalley]

Great

Thanks for the reply.