atcomsystems.ca/forum Forums TDM Business Telephone Systems Samsung Telephones & Systems Echo on tandem trunk calls (PRI) from remote nodes (networked 7200s)

I have a customer experiencing frequent and annoying echo when calling in or out across a remote PRI circuit.

Networked systems consist of five (5) OS 7200s all running v2.69 with MGI 16s at v1.17. The 4 remote nodes receive trunking from a central PRI located at the 5th node.

1) Bursty, "talker" echo is present at all of the remote nodes when calling from TDM phones at the remotes and connecting to the PRI (in or out)

2) No echo when calling from extension to extension - remote nodes 1-4 to extension at node 5 (PRI location)

3) No echo when calling in/out locally at Node 5 - PRI location

4) Network is excellent. 100Mb fiber backbone with minimal delay - avg 2 -3 ms.

5) We have isolated the problem to an issue between the MGI(s) and the PRI at Node 5:

Took system off of customer's network. Registered an IP set to 7200 and connected IP set, MCP and 2-MGI 16s to a stand alone data switch. Experienced the echo in much the same fashion.

I think there is an issue with the echo canceller.

Samsung Tech Support not much help - want to blame the network and then the carrier.

Has any one varied from the default EC Length in mmc xxx (64)? I am toying with running it up to 128.

Any suggestions would be greatly appreciated. Customer is becoming frustrated as are we.

Thanks.

to the forum. If you would please read the sticky with the red ! here

This is a tough problem and is something that needs to be addressed in private. Other posters will more than likely use the pm or email feature to assist you in this. Please feel free to pm any of the very qualified and hard working tech's that frequent this forum.

There will probably be several questions so please be patient. While we are on the topic, you should request installer access in the general catagory. We would be able to help you more openly in that forum.

Thanks for joining and I hope you find the answers you are seeking

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