Echo/Scratchy noise on incoming calls over SIP Trunk

[wayneo4528]

Good day all.

I have the following equipment on site and I’m having the following issue.

IP Office 500 V2 (8.1.67)
Combo Card - BRI
15 x 9608
Cisco Switch
Phones register to LAN
SIP Trunk on WAN

This site was installed about 3 months ago with no problems. One fine Monday morning the client called complaining of echo/scratchy noise on incoming calls but no echo/scratchy noise on SIP extensions.
I then setup a second SIP trunk to a different ISP and there was no echo/scratchy. My thinking was that their current ISP had made changes on the SIP account or gateway and that was causing the echo/scratchy noise.

However I setup the clients SIP trunk at our office and had no echo/scratchy noise on incoming calls.

I have replaced all hardware on site with no luck in fixing the problem. I also have many clients with the same setup going to the same ISP with no problems.

PLEASE HELP!!!!

 

[phoneguy610]

It's not going to be their config we are a sip provider as well and there is no configuration that will cause echo ... It's something to do with the connexion in between . Is there anything providing qos?

ddcommllc.com
Avaya/Toshiba/SyntelSolutions

ACIS

"Will work for stars

 

[wayneo4528]

Hi

The link comes in on fiber and terminates on a Cisco router. The services provider for the SIP trunk has a SIP gateway in the data centre of the services provider offering the fibre. If it was a QOS issue would the test SIP trunk I setup going to a different service provider not have given the same problem?

 

[phoneguy610]

It depends... Are you sharing that data connection for the entire network without any kind of qos?

Who knows what kind of bandwidth you were using When The echo was popping up.

We have never had an echo issue be something in our data center... It's always no qos or a faulty router or poor Internet connection


ddcommllc.com
Avaya/Toshiba/SyntelSolutions

ACIS

"Will work for stars

 

[wayneo4528]

The voice is on it's own link which is a 1mb fibre link. I was onsite today with no other users and I had the same problem.

 

[phoneguy610]

Run some ping tests latency can cause that issue as well

ddcommllc.com
Avaya/Toshiba/SyntelSolutions

ACIS

"Will work for stars

 

[phoneguy610]

And 1mb up and down? What's the call volume like ?
Have you run any speed tests or any tests for that matter


1mb its pretty slow

ddcommllc.com
Avaya/Toshiba/SyntelSolutions

ACIS

"Will work for stars

 

[wayneo4528]

Hi

I don't think it's the size of the link that's the problem because if I move the IPO onto the 5mb link which is used for data they have the same problem. However there polycom phones don't have echo on them only the Avaya handsets.

 

[hairlessupportmonkey]

Under System / VCM Tab try tweaking these:

Configuration Settings

Echo

Echoes are typically generated by impedance mismatches when a signal is converted from one circuit type to another, most notably from analog to IP. To resolve this issue, an estimated echo signal can be created from one output and then subtracted from the input to hopefully remove any echo of the output.
• Echo Return Loss (dB): Default = 6dB. IP400 VCM, IP500 VCM, IP500 VCM V2 and IP500 Combination Cards.
This control allows adjustment of expected echo loss that should be used for the echo cancellation process. The options are 0dB, 3dB, 6dB and 9dB.



Comfort Noise/NLP

A low level of comfort noise is required on digital lines during periods where there would normally be just silence. This is necessary to reassure users that the call is still connected. These controls allow adjustment of the comfort noise generated by the nonlinear processor (NLP) component of the VCM.
• Nonlinear Processor Mode: Default = Adaptive. IP400 VCM, IP500 VCM, IP500 VCM V2 and IP500 Combination Cards.
Allows selection of one of the following options:
• Adaptive
Adaptive means the comfort noise generated by the NLP will try to match background noise.
• Silence
Silence means the NLP will not generate comfort noise at all
• Disabled
Nonlinear processing is not applied, in which case some residual echo may be heard.
• NLP Comfort Noise Attenuation: Default = -9dB. IP500 VCM, IP500 VCM V2 and IP500 Combination Cards.
Options are -3dB, -6dB and -9dB.
• NLP Comfort Noise Ceiling: Default =-30dB. IP500 VCM, IP500 VCM V2 and IP500 Combination Cards.
Options are -30dB and -55dB.

ACSS - SME
General Geek

 

[phoneguy610]

Also how is your internal network setup

ddcommllc.com
Avaya/Toshiba/SyntelSolutions

ACIS

"Will work for stars

 

[Westi]

if I see that right you said that the Polycom phones do not have that problem, they are SIP phones while the Avaya are h.323 sets.
It could be a bad VCM card but if you have replaced the hardware already that is unlikely, it could be also caused by a speed mismatch on your network port of the IPO.
Sometimes if the network switch is hardcoded it can cause the weirdest audio issues that point to hardware or programming.

Do you have DMP enabled for the extensions which would take the IPO out of the equation once the call is established (make sure the VCM's are dropped by making a test call and watch the resources in SSA) that will only happen if your internal and line codec are the same.

Joe W.

FHandw, ACSS (SME), ACIS (SME)

http://convergednetworks.ca

Give a tech a solution and he will be back tomorrow to ask you the next question, teach a tech how to read the manual and he will be able to solve the problems for a life time.

 

[phoneguy610]

To add to joe.. What polycoms the analog conf units or sip devices
?

ddcommllc.com
Avaya/Toshiba/SyntelSolutions

ACIS

"Will work for stars

 

[wayneo4528]

phoneguy610 - The IPO connects to Cisco switch on the LAN port. The switch is default and only carries voice traffic.
phoneguy610 - The Polycom's are connected using SIP

Westi - DMP is on. I have tested with it on and off.