VOIP between (2) 1552 Wireless Bridge. Should I use G.729?

[Matthew Michaluk]

Hello all,

I have this scenario where we have about 15 cisco phones at a remote site which is pretty much across the street and they are connected via 2 1552 wireless bridges outdoor.  Currently we are using CUCM 8.5 with that region is using G.711.  I started to notice some quality issues between this site.  I was thinking of dropping it down to G.729 as the 1552 Wireless Bridge do not support Qos.  It is best effort only.  Any input is appreciated.

[paolo bevilacqua]

Contrary to common belief, G.729 behaves worst than G.711 in presence of packet loss. A better codec, perhaps, would be iLBC. However I have many customer using wirelss and everything works perfectly without any QoS configures, so I recommend you check the antenna for perfect alignement, etc.

[Matthew Michaluk]

The symptom is the called party will experience dead air in the middle of caller speaking from this remote site.  The user at this site does not noticed though.  The link between the two sites does not have high utilization.  This issue has been a bit tricky.

[paolo bevilacqua]

Update AP software and give network a throught check.

[Matthew Michaluk]

What is your shoot from the hip reaction?  AP and controller software?  Or something in the path?

[paolo bevilacqua]

It can be anything. Sudden one-way voice is not packet loss, but some device that stops forwarding media flow. You have to find which one, that may be not easy, so before taking the forensic route, better put things shipshape anyway.