PRI Cause Error

[bluewhite4]

Have a long time customer who got a new managed/sip-based PRI product from their carrier. Its used only for outbound calls. Several times per hour, on multiple channels, they will all the sudden get "Bearer capability not authorized" on an outbound call. The phones display "Access Denied" and the call fails to complete. The carrier insists its not them, but if the customer repeatedly tries the call, it eventually goes through. Anyone seen anything like this or have an idea how to convince the carrier its them?

[ralph]

Haven't seen it but it sure looks like carrier to me.
Having said that, I'd reboot the PRI card next.

You may have to capture it via ccs trace commands to see if you can catch the carrier sending a d-channel message.

Ralph

[bluewhite4]

Thanks Ralph. We actually rebooted the whole controller over the weekend just to try to elliminate things.

An edt trace vdsu namnum is what shows the "Bearer capability not authorized" being returned from the carrier. I don't usually run ccs traces when trying to diagnose PRI problems, what would I be looking for in that stream?

[ralph]

Not sure what you'd be looking for in this case.
When I get back to my office I'll see if I can hunt up the doc I have that tells how to read the traces.
You you have MOL access that doc is online there too.

Ralph

[bluewhite4]

You you have MOL access that doc is online there too.

Didn't know that. I'll look for it...

[bluewhite4]

Just a quick update, we found the problem.

This was an 11-channel PRI. And they had all 11 channels, but could use no more than 3 of them at any given time. Anytime a 4th call would attempt, either inbound or outbound, it would fail. Carrier finally saw this to and corrected their config.

[ralph]

Ah!  Been there done that one.  Even bought the T-shirt!
Exact same thing happened to me just didn't get the same error.  Once I nailed what it was it the carrier easily fixed it.  Took longer for me to convince the customer this was a carrier issue and not something we did.

Ralph

[bluewhite4]

See the customer was the easy part in all of this. They all along thought it was the carrier, but obviously didn't have the proof. Neither did I outside of the cause code until I noticed the max three call pattern while on-site.