Echo

[avayaconsultant]

I have an IPO 3.0.59 recently installed on customer site. They are now complaining of echo on the 56xx series phones. No difference between internal and external calls. Currently the extensionare set to auto on the codec. Would it hurt to set them all to g711 ulaw? I thought that this may increase the overall quality of the phones. If it helps, they are running off a Cajun switch and are on a flat scope with PCs as well.

 

[Belrick]

Set to G711 for sure, however check and see which VCM there running. Make sure its the new VCM 4, 8 or 24. Not a VCM 5,10 or 30 as the newer cards come with one channel per 5 dedicated for echo suppression.

 

[mytelecoms]

Chances are the the Auto option has used G729a first, as the preferred order is as follows; G729a, G723.1, G711 A-LAW, G711 U-LAW.

G729a is great on a WAN, but useless on the LAN, where G711 should be the choice. Depending on your locale, you can play between A-LAW and U-LAW. With G711 turned on and a good LAN, you should not need any other ticks in the boxes such as Silent Surpression, Faststart, etc.

Good idea from AgileSup, but you should still be able to operate on the LAN without echo using the old cards.

Are you implementing any kind of QoS on the LAN. Ideally, I'd recommend you have three VLAN's - one for voice, one for data, and the other for routing/web (tagged for the other two VLANs), and where routing is required, tag the packets using QoS. Your Cajuns should be fully managed so you could setup VLANs and QoS on them. Failing that, you could run the PCs off the back of the phones (depending on the model) as this gives voice priority.

If your data LAN is bandwidth hungry, it will affect your voice performance, hence the need for QoS.