No audio on toll free number

[tnestel]

I have an IPO R10 or so with a PRI. One toll-free phone number that rings to a group of 3 is having intermittent no audio calls. They are always incoming, and if the caller calls in again, the 2nd time goes through normally.

No other phone numbers or phones have this trouble. The 877 number comes in on the PRI like all other calls.

The provider has looked at it, and the issue went away for 3-4 days, but now it's back. The provider did not confirm or deny that they saw an issue or fixed anything.

Any ideas? I have looked for errors (none) and rebooted the phone system.

I think it has to be a provider issue, but I don't want to say that if there is something else I should try.

 

[IamaSherpa]

If it's a toll free maybe the didn't provide the "connect" on the ISDN, what do you see via SysMon?

 

[tnestel]

Forgot to also mention that I was unable to recreate the issue, so I didn't see anything on Monitor.