[asterisk-users] DAHDI Error and poor audio quality

[Tom O'Connor]

On Sun, Jul 19, 2009 at 10:57 AM, <research at businesstz.com> wrote:

> Hello Team
>
> I have installed the new DL580 and used the new TE420B to add capacity on
> our ivr. Before I put new E1’s I decided to first move the old e1 from the
> old system to this new one but it has errors which not only affect the
> audio quality, but also cause the asterisk to refuse any call after
> sometime even though the channels seems up and active {seems d-channel
> fails}..


<SNIP>

>
> [Jul 18 07:24:01] NOTICE[15961] chan_dahdi.c: PRI got event: HDLC Bad FCS
> (8) on Primary D-channel of span 1
> [Jul 18 07:27:59] NOTICE[15964] chan_dahdi.c: PRI got event: HDLC Abort
> (6) on Primary D-channel of span 4
> [Jul 18 07:30:58] NOTICE[15963] chan_dahdi.c: PRI got event: HDLC Bad FCS
>

Am I right in reading that you're using a HP DL580?I had very similar
problems using a DL145, earlier on, and a number of users suggested that
this might be due to custom PCI bridge chipsets on HP motherboards.
The theory is that the PCI chipsets are designed with specialist timing to
shave nanoseconds off interrupt times, so that you get better hard disk
throughput.

However, it does tend to murder E1 timing, and breaks the entire system.
I resolved the problem by using a non-branded server with a more standard
Tyan motherboard, all timing problems went away, and the system worked
perfectly.
I know it doesn't really sound very helpful to blame the entire server
manufacturer, but some others might agree, brand spanking new and shiny
might not be the best thing for Asterisk, especially these cards.
HTH
-- 
Tom O'Connor

http://www.twinhelix.org
tom at twinhelix.org
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