Re: Fax failure in hairpinned configuration

pax_2111 · ‎03-14-2006

We have a PGW call-controlled setup for voice. Most of the bearer channels terminate on AS5850's. Clients connected through PRI's are experiencing intermitant Fax problems. Some destinations fail, others send only a header and still others are successful but the image is garbled.

Since most of the calls are hairpinned on the AS5850, I don't know what exactly is causing this problems. Voice calls are successful.

Any ideas on how and where to look for the problem? I have run out of ideas.

iostres · ‎03-14-2006

Hi!

Did you check for slips on bearer channels?

Ivan

pax_2111 · ‎03-15-2006

Yes actually there is SLIP on the channels.

AFAIK SLIP is caused by synchronization problems.

Any other causes? Faulty cabling ?

pax_2111 · ‎03-15-2006

another question. The SLIPs that I see are only on one side. I see SLIP on the controller of the SLT that does drop&insert for the bearer channels.

On the AS5850 side I don't see any SLIPs.

Is this normal for SLIP?

iostres · ‎03-15-2006

Hi!

There should no slips on the whole path of your voice/fax. Please look at http://www.cisco.com/en/US/tech/tk713/tk628/technologies_tech_note09186a008014f8a6.shtml how to set a proper clock synchronization.

Regards,

Ivan