Re: Poor audio between ip5550 consoles over ip trunks 1

[mitelgear]

I have two 3300 mxe controllers both on version 8.0.5.12. they have ip trunks between them and both have ip5550 consoles. Whenever a call is made over the ip trunks between ip console and any other device, the audio on the ip5550 console deteriorates and as the call continues, it gets worse. This is only on the ip5550 set, the other party can hear the speech fine. this happens on either site as long as an ip5550 is involved in the conversation. The fault occurs on both systems with their consoles. But using any of the 5340 handsets, the audio over the ip trunks is perfect. If the ip5550 consoles dial out using the tdm trunks, audio works fine. There are no vlans on the network, so i dont think diffserv would play a role in this. Has anybody come across this fault before and if so, what was done to rectify it ?

Any help will be hugely appreciated!

 

[TheMitelGuy]

Sounds like your console is not on the correct vlan and your console is using Layer 3 routing to get to the voice vlan. Just an assumption with the little that I know.

 

[mitelgear]

The network guys say that their network isnt using any vlans and that its a flat network. How would i be able to prove that its not the 3300 ? Sorry if i seem a little bit daft on the subject, this is one of my "grey area's

 

[TheMitelGuy]

Nope, that is okay.

As with any VoIP-enabled network, QoS MUST be enabled. The larger the network, the more QoS is needed. We do not install VoIP on any flat network that is over 16 users. Even 16 users are not immune to this type of issue, but it's rare to see.

 

[mitelgear]

QOS is enabled on the link and its a 2mg between the 3300's. Each site has approx 30 ip5340's and one ip5550 console. The problem only exists when the ip5550 console is used across the ip link. Howcome the fault doesnt occur for 5430ip set calling another 5340ip set across the ip link ?
It just seems so weird to me!!!!!!!!!

 

[kwbMitel]

You seem to be confusing two methods of prioritization. Vlans and Diffserv are not the same.

I'll give you the same answer I give my customers who choose not to Create VLAN's for voice.

Call me when you do, until then bad design = bad quality troubleshooting is pointless.

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Occam's Razor - All things being equal, the simplest solution is the right one.

 

[nappyshock]

If the site uses structured cabling you could see if you could do some repatching in the data cabinet and patch the 5550 into a switch port used by a known good 5340 and plug the good 5340 into the switch port that was used by the 5550 and see if the fault stays with the 5550. You might be in luck and the fault then goes onto the 5340 and you have some proof to blame the network.