oozenoz

gts,

this sounds like a line provisioning discrepancy of some sort. obviously, something has been changed if the problem just started.

can you clarify the situation a bit further; you say if you call and get a reorder message, you redial and you can get through. does this happen when there are no calls in progress on the bri, or maybe one call on the bri and the second channel is getting a call?

do you know how the telco has the telephone numbers provisioned - are they in a hunt group? are they assigned sequentially across a series of bri circuits - maybe one or two tn's per bri?

verify the provisioning of each bri at one site (chances are whatever has happened at one site is going to be the cause of the problem at all of them).

verify the following:
tn's assigned to each bri
number of simultaneous voice calls allowed on each bri
SPIDs for each bri

then verify the programming in the terminal adapter - make extra certain that you verify the SPIDs are EXACTLY programmed as the telco has them in their switch. I once chased a problem on a bri for three days, until (by use of a protocol analyzer) I found that the t/a had an extra space at the end of one of the SPIDs.

you may need to take all but one bri out of service at a time, and test each for it's ability to receive two calls, until you find the one that is in trouble.