[asterisk-dev] On PRIs, blocked channels, congestiona and telco technicians

Tony Mountifield tony at softins.clara.co.uk
Thu May 29 09:58:40 CDT 2008

In article <20080529142043.GA24247 at k7.mavetju>,
Edwin Groothuis <edwin at mavetju.org> wrote:
> It has been discussed before here, unfortunately without result or
> outcome.
> The issue? After about two months of operation, all 31 channels of
> our PRI bcome, according to our telco, in a "blocked" state. What
> that precisely means I am not really sure of, but all my SETUP PDUs
> are answered with a RELEASE COMPLETE PDU:
> [...]

> < Protocol Discriminator: Q.931 (8)  len=9
> < Call Ref: len= 2 (reference 3/0x3) (Terminator)
> < Message type: RELEASE COMPLETE (90)
> < [08 02 82 a2]
> < Cause (len= 4) [ Ext: 1  Coding: CCITT (ITU) standard (0)  Spare: 0  Location: Public
> network serving the local user (2)
> <                  Ext: 1  Cause: Circuit/channel congestion (34), class = Network
> Congestion (resource unavailable) (2) ]
> Tomorrow I will be talking to a telco technician about this problem
> and hopefully I can get the right data out of him to explain what
> exactly happens and why their exchanges decide that a channel is
> blocked.
> If somebody has a good question I can ask that technician which
> could give me the right hint on where I could look for it in the
> asterisk code, this is your chance...

If you can capture the PRI debug over an extended period, it would be
very interesting to know what the last activity was on a channel before
it got blocked.

When Asterisk does its hourly reset of idle channels, do the blocked
channels get included?

Tony Mountifield
Work: tony at softins.co.uk - http://www.softins.co.uk
Play: tony at mountifield.org - http://tony.mountifield.org

More information about the asterisk-dev mailing list