One way Audio

m.batts · ‎04-11-2008

Hi,

i have started to maintain a 4.1(3)sr2 callmanager with about 150 phones and two 2821 routers with e1 connections running ios 12.4(3c)

Apparently the odd user has complained that at any point during a call the voice path from the ip phone drops. i.e the ip phone can still hear but the person on the other end cannot.

It only occurs during external calls and has been happening since the system went in two years ago.

My first thought is that this is a bug either in the phone load or in the ios gateway though i can't seem to find any related bug.

I know i probably need to to an upgrade to sr6 but was wandering whether anyone else had seen a similiar issue.

The issue is always in the same direction and there is no break up in the voice quality.

cheers

mark

Carl.Mayne-Wheeler · ‎04-11-2008

are these GW's 323 or MGCP?

if they are 323 it may well be worth putting in the 323 bind statement on the interface that CCM knows it by.

m.batts · ‎04-15-2008

hi

they are mgcp and they have the mgcp bind command added.

cheers

mark

Carl.Mayne-Wheeler · ‎04-15-2008

hi there. SR wont make a difference on CCM as that is only used for signaling. Problem lies here with the RTP stream.what version of IOS on you on?

m.batts · ‎04-16-2008

my hunch is that its a bug in the phone load or the IOS. I am going to upgrade to SR6 which gives a new phone load.If not i will then update the IOS as its quite old at 12.4(3c)

craig.eyre · ‎04-16-2008

Hi,

I've found this doc to be very useful when troubleshooting issues like this.

http://www.cisco.com/en/US/tech/tk652/tk698/technologies_tech_note09186a008009484b.shtml