Sound Quality on call forwarding, Legend

[hkettel]

Customer has a Legend w/remote users. We have phantom extensions set up that are forwarded to the offsite locations. Customer has POTS lines. (not coming in off a T1) They are complaining that when calls are forwarded, the sound quality is so bad that they have to hang up and call the caller back. They have reported the trouble to AT&T and they are being told the lines are fine.
I have many other customers that use this feature w/ no problems and I have never run into this issue where it was not a provider issue. Does the Legend have a chip or something that could go bad? I don't want to just replace the processor if it won't fix the problem.

 

[tdaugirdas]

There is always "some" drop in quality when a call is forwarded - just as in conferencing - but it should not be substantial. I would try to have the customer monitor if this occurs on EVERY forwarded call or just some calls. Maybe the system is picking a "noisy" or "staticky" line evry "x" remote forwards. If you only have one or two lines assigned to the adjunct for forwarding - experiment with changing the line(s) assigned - to see if it makes a difference in call quality.

Tom Daugirdas,
President
STCG, Inc.
stcg.com

 

[hkettel]

The customer reports that this happens on every call. The adjunct picks up a line out of the pool, so it is using a number of different outbound lines. I would expect some degredation, but they claim the call quality is so bad, they cannot continue the call.

 

[SYQUEST]

LOOP LOSS is cumulative. When you Forward calls thru the Legend/Magix on analogue trunks/lines the loss is doubled!

Now depending on what your loop length, grade or class of service your lines have, will determine what transmission losses to expect from your service provider. That is probably why the provider says nothing is wrong. Without actually measuring the transmission loss of each line you won't know just how bad they are! On POTS grade or class of service most telcos allow up to -8.0dB loss referenced to 600 or 900 ohm termination @ 1kHz. Using the central office Milliwatt test and a Transmission Measuring Set you can determine which lines have lots of loss or other problems.

Now to "fix" the "problem" you need to find out from the telco what their transmission level standard is for the POTS grade or class of service. If this value is exceeded then you have some choices about what to do:

1. If it's a telco problem get repair involved. Open a trouble ticket. Escalate to supervisor if no action occurs to get resolution of the problem.
2. Change grade or class of service to PBX trunk. This type of trunk usually has a garanteed transmission level of no more than -5.0dB loss per loop. Sometimes you can even request a specific level, like -3.5dB for design.
3. If conditions or costs justify change service to DS1 or PRI. Both DS1 and PRI types of service are "lossless" to the switch.
4. You may have bad trunk/line ports or wiring issues on the Legend/Magix. This needs to be check out also.
5. You can add VF loop repeaters on the loops to improve the level losses.
6. Using CENTREX lines with "trunk-to-trunk" call transfer feature, you can elimiate the problem also, since the transfer point is in the CO switch and not the Legend/Magix. You also don't tie up lines using this method either. Compared to looping lines thru the Legend/Magix system.

This is alot to consider, but I hope it provides some help for you.

....JIM....