IP Phone Quality 2

[chrismac52]

IPO 406v2
8 digital phones
2 ip phones
3 analog lines
4 channel VCM

The call quality is great internal, but when an outside call (analog) comes in, the quality is not so good. Has a lot of feedback and modulation. Appears to be a problem between the analog to ip conversion?

Any ideas?

 

[webin]

I'm sorry to piggy back on your question Chris, but I have a very similar issue, so I thought I'd provide the details I know.

After upgrading to the latest firmware, 3.1(65), we get a tremendous amount of echo in our handsets. The caller on the other end gets good sound quality from us, but we get an echo of us talking, delayed just enough to make it annoying. I've played with gain settings on both the line and individual extensions, with line gain (-4 to +3.5) having no real effect, and extension VoIP gain (-31 to +31) either making the reciever mic way too sensitive with loud echos, or dulling the volume to the point where a caller can (quite literally) shout and barely be heard. Setting a smaller negative gain reduces the echo, but also reduces volume to unacceptably low levels.

But I noticed yesterday that the feedback echo only happens on IP phones to outside analog lines, and never on digital phones. This makes me think its an issue with VoIP conversion or compression, but so far I haven't found any settings that improve it.

 

[dizzyphil]

Couple things to check;
1. Make sure the setting 802.1Q is set to off
2. Avoid Hubs:
Hubs introduce echo and congestion points. If the customer network requires LAN connections beyond the capacity of the IP Office Control Unit itself, Ethernet Switches should be used. Even if this is not the case, Ethernet Switches are recommended as they allow traffic prioritization to be implemented for VoIP devices and for other device such as the Voicemail Server PC.

Diz

 

[chrismac52]

One of our IP Phones does pass through a hub. However, the other phone goes into a linksys router and then into the system. Would bypassing the router and going straight to the system help?

 

[kristiandg]

I had the same problem as soon as I got the new "Echo Cancelling" ATM 4U module. I have a VCM 5 (not the new 4 w/ EC) and as soon as I had the EC version of the 4-port trunk card, the problem started.

I have no idea whats causing it. I guess I need to open a tkt w/ Avaya on it.

Kris G.

 

[dizzyphil]

Chris,

If you can hook the ip phones directly to the ip office without too much hassle, it could help the troubleshooting process to get you on the right track.

Diz

 

[kholladay]

We have the same issue on IP Phones at two sites with analog trunks however the interesting thing is when you put the caller on hold then pick them back up the echo is gone and the call is perfectly clear both ways... anyone else experienced this?

Kyle Holladay
Certified: ACACN, ACSCI, ACSCM, TIA-CTP
"If it worked the way it should you wouldn't need me

 

[phantomiii]

Well guess I'll hop on this thread too. I've had users complain the same thing on IPO SOE over the analog trunks with IP Phones. I haven't been able to recreate it though. I also have a 412 with over 100+ IP Phones, I have some groundstart trunks, and some PRI trunks. Users are complaining of echo/static over both I think. I'm going to do extensive testing and try and recreate it. I'm on release 3.1.5602 for everything. I'll post my results.

 

[jconrad0305]

i was getting alot of echo on my ip phones to. i turned of the AGC (auto gain control) and that stopped it for the most part. still have a little every now and then but 95% less then before

 

[phantomiii]

Do the 5602sw IP phones have AGC? I think they do, because I have put -10db for my PRI channels for the Tx and Rx gain. The volume hasn't changed on the 5602sw, but on the 5610 you can manually change the AGC to disabled, it's a whole lot quieter on the PRI to the point you can't hear the caller very well. Are there any adjustments to the AGC on a 5602 if indeed they do have AGC?

My testing has confirmed that the echo is indeed present over both PRI and groundstart trunks. The echo is only heard on the IP Office side. I have called from the same phone, using the same channel on the PRI, and called the same number. About 33% of the time I have a faint echo of my voice. I have changed codecs, changed gain Tx and Rx settings on the PRI, AGC on the 5610, and monitor VCM resources via monitor looking for anything out of whack. (Of course I tried other IP phones too, same thing happens)

So far absolutely nothing has helped. Changing the Tx and Rx gain settings on the PRI has helped some and makes the echo a little more faint, but it's still there. I'm on 3.1.5602 on a 412 with 60 VCM's btw. Also, I tested the system while it was idle doing nothing else but serving my calls.

 

[chrismac52]

Sounds like this is a common problem on this unit. Has anyone talked to avaya support about this issue?

 

[BoyRacer1001]

plantomii, the problem you describe is unlikely to be the IPO or probably even your PRI, the echo you hear is nearly always generated at the remote end, ie the destination you are calling. Several reasons, including poor headsets, 4 wire to 2 wire conversions, A-D or D-A conversions etc.

The new VCM cards have increased echo cancellation which helps. Also, Codecs with less processing delay also reduce the effect of echo - eg change to G711 from G729a. Don't use Auto.

Also, AGC can be turned on/off from the 46xxSettings file.

We have many sites running VoIP phones now, the rare times echo is heard it should only occur for the 1st word or two before the cancellation kicks in.

 

[phantomiii]

well the new VCMs don't come in the VCM 30 flavor, so no luck there. All IP Phones are G711 codec. The PRI on my end is 4 wire, not sure on the remote side. It could very well be the remote end. I can't get the echo on a call to a "Local" destination across the PRI, although other users have heard it on a local call.

 

[voippbx]

I've had the same problem on 406V2 with all IP sets, 5610's. I have had avaya in 3 times, numerous data experts to reinvent the LAN including new VLans new Extreme POE 48 port switch etc. Still echo. Changed processor - vcm - 16 ATM - and even had LEC change smartjack for the PRI. Still no fix. Honestly I don't think its the LAN but something in the IPO? I am curious of anyone whom seen this and fixed it??

 

[BoyRacer1001]

Phantomiii - we had the same problem with the older VCM's and spend a huge number of hours trying to improve things. In the end Avaya supplied us with prototype VCM's with the extra echo cancellation and the problem effectively went away. These got modified further to become the current model VCM.
Unfortuantely it means with a 30 you're pretty much stuffed - we dont use older VCMs at all anymore, and have a policy not to sell system requiring a 30 or 60.
Obviously doesn't help you, but am trying to say I probably wouldn't waste too much time from a technical perspective.

 

[chrismac52]

I changed the gain on the extension to a -5 and so far that seems to have helped quite a bit.

 

[SuperJenks]

I have to say that I have experienced all of the above at a current site with all the same problems and symtoms. I still have not resolved it. Im basically in the same boat as everyone else here. Ive tried everything here mentioned except have the providor switch out their equipment. Im at my witts end and the customer is too. If I dont fix the problem or figure it out, they want the system out at the end of this month. I have been working on this for 3 or more months now with no luck. I think the problem is the IP office (406v2 running 3.1.65). We have litteraly swapped out all the hardware with no change in echo issues. Has anyone tried downgrading the 56xx firmware. I may even load like 3.0 or 2.1 just to make the system stable.

 

[bbmk]

Are these echoing symptoms being experienced by any specific installation variant,ie, uk/european, north american, or can it happen on any installation? I am currently trying to resolve a problem on a UK installation which only has the normal digital phones but problem seems to depend on who makes the actual call, i.e if they are aurally sensitive to slight side tone / noise. Problem does appear to depend on who is called, which would highlight an incompatibility problem as quoted previously in this forum.

 

[BoyRacer1001]

I've only dealt with New Zealand enz CC.
We avoid Analogue trunks, and don't have gain adjustment like US do on T1's.
We have one Telco provider who we have far more echo on than the other major ones, and they have acknowledged inconsistant setups/levels through their network, but don't do anything about it.
From our side all we can is request/use more echo cancellation (ie increased time window for cancellation and increased cancelling levels). Avaya have done this twice, and are supposedly doing it again 2007. Be nice to have it adjustable like ACM.

 

[SuperJenks]

Since my last post on this thread, I have tried changing out the 56xx series phone with 46xx to resolve the echo. The problem has not gone away after the swap out of phones. I did this because a user reported that they had echo on an outside caller on the handset, they then switched to the speaker phone and the echo disappeared. This indicated to me that the problem was with the sets themselves. I have now ruled out that possibility. They did say that is helped by 50% margin but the echo is still occuring. Now what? I think at this point, the only thing I can try is upgrading to 3.2