atcomsystems.ca/forum Forums Other TDM Phone Systems Executone-Isoetec Telephones & Systems Dropouts on Music On Hold

Gotta love my 3rd cabinet-- music on hold is really problematic on it. What is happening, is that callers that come in to the 3rd cabinet (whether on T1 or on the ground start card) occasionally get very poor quality hold music, including dropouts lasting a few seconds at a time and strange variances in volume. However, this doesn't happen on every call and not on all lines at the same time.

I performed test calls with two phones, and sometimes the quality on a given line is absolutely perfect, and on the other line, the quality is bad. After hanging up and repeating the test, suddenly both lines sound perfectly fine. It's important to note that I'm watching the F screen so I know exactly what line is receiving the call, so I know the problem intermittently affects any given line.

Additionally, I have tried using both the MOH and the BGM inputs, and adjusting the MOH/BGM sources on the B screen, as well as tinkering with the volume pots.

Because the music quality is not consistent between lines (it should either be good for all lines at the same time, or bad for all lines), I suspect it's the EVCM-- but before I go replacing hardware (or even trading EVCMs between cabinets) I wanted any other suggestions... (I even looked for an option like "Randomize Music Crappiness" in the B screen but it wasn't there...)

So the problem is limited to lines in cabinet 3 only? If so,I agree the EVCM could be to blame especialy since you say it is affecting different trunk cards.

Yes, just lines in Cabinet 3-- lines on both a T1 and on a Ground Start card.

Just what I was thinking, always good to hear it again from someone else and knowing I haven't missed something obvious.

I suppose I could trade the EVCMs between cabinets without breaking anything... or will I break something?



[This message has been edited by Orac (edited July 29, 2005).]

The EVCMs in the first two cabinets are silkscreened with 21680 -- the EVCM in Cab3 is silkscreened with 21640 (and also has (c)1993 but I can't see a date on the other two.)

I'd hate to break something by trading them around -- will this still work if I do? It seems from looking at the manual that the 21680 is an acceptable substitute-- maybe a higher revision?

According to Aable
21680
EVCM w/ CPLD Internal modem. Replaces 21640 EVCM

Was the 21680 for adding caller id to the switch?After my time as a dealer with them but thats what I'm thinking.

you can switch any of the evcm's around, just mark which on is which, so that you know where it was, as far as the newer 21680, I think it was mainly when they started putting on the ' smaller componets ' I know there is a Name for them, I just can't think of it .

VLSI? (Very Large-Scale Integration?)

I do notice that the older model EVCM has a huge daughterboard connected to it on standoffs-- the newer one is much more sleek.

Could be the newer card is using surface mount components or smt.

One could say the old one also had SMT, but it just wasn't all that advanced.

The very very odd thing is-- I'm not getting the dropouts anymore -- none in Cab3 (which had the dropouts originally), yet also none in Cab 2 (which I thought should start getting them because I moved the "bad" card to it.) Of course, I'll be doing gobs of testing to be sure, because I can't come up with very logical reasons for this to have occured. Poor seating of EVCM? Poor seating of ribbon to Fiber MUX? Elfin magic?

Although it's "changing the subject" slightly-- could a bad EVCM also cause ACD to not function properly? Sometimes there are calls holding in a queue despite agents being available in the same queue. Even if they attempt to pull the call manually (by dialing 47xx), they can't get the call. It seems that to resolve it they must place an intercom call to another station, preferably to a station in a different cabinet from the one they are in.