sundance-communications.com Forums General General Telephone & Systems Information Echo on 3Com Phone System

Need some help please...

First, I'm not a phone guy so please excuse my lack of knowledge - but I'm trying to help a customer out. They have a 3Com IP phone system with a dozen or so Centrex lines coming in. Occasionally they report echo problems on BOTH internal and external calls. The problem appears to be random and sporatic.

As they experience this on internal calls as well as external, my initial thought is that it is an internal and/or 3Com issue. Does that sound right? Could it be the telephone company? Where should we start???

Any and all help appreciated!

It's the 3Com --- common on IP when the data "pipe" isn't robust enough. There are several things to look for --- especially the bridges/hubs.
Good luck.

It is common with IP phones. They are bandwidth hogs. Customer needds to increess there bandwidth capability on there network backbone.

That is why most techs love Legacy systems with IP capability.

Good Luck!!

Thanks for the help! I'll take a look and bandwidth.

Doing a little more research on my own I see that a station to station calling feature is part of their Centrex lines. Could that be an issue?

The delay remind you of a bad cell phone call? Delay with echo? Slightly out of freq? Your data flow is being restricted and the network is seeing errors and asking to "send again". Data doesn't care - it just runs a little slower. Voice does care. You end up with slow send - receive and your ear can hear it. Betcha it ain't the Centrex. It is nominally set to talk duplex just like any other system. The only time you would even come close to the echo, etc. of an IP connection was in the old days of long distance over carrier with a bad echo suppressor and out of balance power on the carrier. Over simplified, Centrex is just a central office using PBX features.

That is exactly it. Thanks again all! We are going to take a closer look at bandwidth.

The head IT Guru at a place I used to work had the right idea --- "One big honkin' pipe" to every location we went. OC3 was just big enough for him! This was before IP telephony. I bet an OC48 wouldn't make him happy now.

Multiplex and it works --- IT wants bandwidth --- when will they get into the real world and have 99.999% uptime? Why else would there be a full time computer guy on site and not a full time phone guy?



Ken.

As KLD said earlier, centrex is nothing but a telco provided switch,smdr would be a big help in trouble isolation. If you had a long trunk you would experience the trouble on both outside calls and centrex handled internal calls. not being on site just my 2 cents.

an OC3 is like 27 T1 lines normally used by something like Yahoo or a phone company. This guy wants that for a simple IP system? how much money does that cost a month? My gosh, that is insane!

Bigger Than That. A DS3 is 28 DS1's (a T1 rides on a DS1 channel on a mux. an OC3 is 3 DS3's or 84 DS1's