[asterisk-users] Maximum number of PRI calls on 1 asterisk box (no HW echo)

[Alejandro Kauffmann]

James Lamanna wrote:
> Hi,
> Does anyone have any good empirical data suggesting what the maximum
> number of PRI calls (incoming and outgoing)
> without hardware echo cancellation can be handled on a single box is?
> I have a TE410P T1 (1st gen) card and I'm seeing interesting errors of
> D-Channels going down and then coming back up (See below).
>
> I've looked at the number of simultaneous calls at each of these
> points, and each time the span seems to
> have around 21-23 calls, and the total number of calls ranges between 47 and 53.
> I'm trying to figure out if this is a load issue or an issue on the
> provider side, though my provider says they
> do not see any errors on any of the T1s.
> Could this be some sort of hardware interrupt problem? If so, how can I check?
>
> The specs of the machine are, Dual Xeon 2.80Ghz (both single core but w/HT)
> 4GB memory.
> Running asterisk 1.4.26.3 (32-bit)
> with libpri-1.4.7 and zaptel-1.4.12.9
>
> Thanks.
>
> -- James
>
> Please CC me on responses.
>
>
> [Mar 22 09:45:00] VERBOSE[8887] logger.c:   == Primary D-Channel on span 2 down
> [Mar 22 09:45:00] WARNING[8887] chan_dahdi.c: No D-channels available!
>  Using Primary channel 48 as D-channel anyway!
> [Mar 22 09:45:00] VERBOSE[8887] logger.c:   == Primary D-Channel on span 2 up
> [Mar 22 09:59:23] VERBOSE[8886] logger.c:   == Primary D-Channel on span 1 down
> [Mar 22 09:59:23] WARNING[8886] chan_dahdi.c: No D-channels available!
>  Using Primary channel 24 as D-channel anyway!
> [Mar 22 09:59:23] VERBOSE[8886] logger.c:   == Primary D-Channel on span 1 up
> [Mar 22 09:59:23] VERBOSE[8886] logger.c:   == Primary D-Channel on span 1 down
> [Mar 22 09:59:23] WARNING[8886] chan_dahdi.c: No D-channels available!
>  Using Primary channel 24 as D-channel anyway!
> [Mar 22 09:59:23] VERBOSE[8886] logger.c:   == Primary D-Channel on span 1 up
> [Mar 22 10:36:11] VERBOSE[8886] logger.c:   == Primary D-Channel on span 1 down
> [Mar 22 10:36:11] WARNING[8886] chan_dahdi.c: No D-channels available!
>  Using Primary channel 24 as D-channel anyway!
> [Mar 22 10:36:11] VERBOSE[8886] logger.c:   == Primary D-Channel on span 1 up
> [Mar 22 10:36:11] VERBOSE[8886] logger.c:   == Primary D-Channel on span 1 down
> [Mar 22 10:36:11] WARNING[8886] chan_dahdi.c: No D-channels available!
>  Using Primary channel 24 as D-channel anyway!
> [Mar 22 10:36:11] VERBOSE[8886] logger.c:   == Primary D-Channel on span 1 up
> [Mar 22 10:44:36] NOTICE[8888] chan_dahdi.c: PRI got event: HDLC Bad
> FCS (8) on Primary D-channel of span 3
> [Mar 22 10:45:44] NOTICE[8886] chan_dahdi.c: PRI got event: HDLC Bad
> FCS (8) on Primary D-channel of span 1
> [Mar 22 10:59:33] NOTICE[8887] chan_dahdi.c: PRI got event: HDLC Abort
> (6) on Primary D-channel of span 2
> [Mar 22 11:30:53] VERBOSE[8886] logger.c:   == Primary D-Channel on span 1 down
> [Mar 22 11:30:53] WARNING[8886] chan_dahdi.c: No D-channels available!
>  Using Primary channel 24 as D-channel anyway!
> [Mar 22 11:30:53] VERBOSE[8886] logger.c:   == Primary D-Channel on span 1 up
> [Mar 22 15:34:28] VERBOSE[8887] logger.c:   == Primary D-Channel on span 2 down
> [Mar 22 15:34:28] WARNING[8887] chan_dahdi.c: No D-channels available!
>  Using Primary channel 48 as D-channel anyway!
> [Mar 22 15:34:28] VERBOSE[8887] logger.c:   == Primary D-Channel on span 2 up
>
>   
I believe your problem is IRQ sharing which is why you are getting the 
"...HDLC Bad FCS..." notices in your debug.  Make
 sure the card is not sharing IRQs with the network card(s), or the hard 
drive(s).  You MIGHT get by with it sharing with other
 devices.  Upgrade to a newer  Digium card that is not as picky with IRQ 
sharing or switch brands.  I've had several TE410
 cards and they don't like to share.

Alex