<p>In theory asterisk can handle 8 spans, which means 192 concurrent calls if all spans are T1. In reality after 6 spans it starts giving problems.</p>
<p>I recently shipped a server to a client in Taiwan, and before shipment it was put under a load of 100 plus concurrent calls (zap channels) for two whole weeks without any break. It had 6 spans, Rhino T1, FXO and FXS cards all with on board EC. The server's processors combined were hardly 7% in use and no call quality issues. For the same client another server with 9 spans were causing asterisk to freeze once there are more than 96 calls, i.e. it going to 1st span of the second T1 card, which made it 9th span considering FXO and FXS spans, but server load remained low as usual.</p>
<p>So I think it is not your T1 card but some software/driver issue. Did you upgrade anything recently on this server?</p>
<p>--<br>
Zeeshan A Zakaria</p>
<p><blockquote type="cite">On 2010-03-24 8:49 PM, "James Lamanna" <<a href="mailto:jlamanna@gmail.com">jlamanna@gmail.com</a>> wrote:<br><br>Hi,<br>
Does anyone have any good empirical data suggesting what the maximum<br>
number of PRI calls (incoming and outgoing)<br>
without hardware echo cancellation can be handled on a single box is?<br>
I have a TE410P T1 (1st gen) card and I'm seeing interesting errors of<br>
D-Channels going down and then coming back up (See below).<br>
<br>
I've looked at the number of simultaneous calls at each of these<br>
points, and each time the span seems to<br>
have around 21-23 calls, and the total number of calls ranges between 47 and 53.<br>
I'm trying to figure out if this is a load issue or an issue on the<br>
provider side, though my provider says they<br>
do not see any errors on any of the T1s.<br>
Could this be some sort of hardware interrupt problem? If so, how can I check?<br>
<br>
The specs of the machine are, Dual Xeon 2.80Ghz (both single core but w/HT)<br>
4GB memory.<br>
Running asterisk 1.4.26.3 (32-bit)<br>
with libpri-1.4.7 and zaptel-1.4.12.9<br>
<br>
Thanks.<br>
<br>
-- James<br>
<br>
Please CC me on responses.<br>
<br>
<br>
[Mar 22 09:45:00] VERBOSE[8887] logger.c: == Primary D-Channel on span 2 down<br>
[Mar 22 09:45:00] WARNING[8887] chan_dahdi.c: No D-channels available!<br>
Using Primary channel 48 as D-channel anyway!<br>
[Mar 22 09:45:00] VERBOSE[8887] logger.c: == Primary D-Channel on span 2 up<br>
[Mar 22 09:59:23] VERBOSE[8886] logger.c: == Primary D-Channel on span 1 down<br>
[Mar 22 09:59:23] WARNING[8886] chan_dahdi.c: No D-channels available!<br>
Using Primary channel 24 as D-channel anyway!<br>
[Mar 22 09:59:23] VERBOSE[8886] logger.c: == Primary D-Channel on span 1 up<br>
[Mar 22 09:59:23] VERBOSE[8886] logger.c: == Primary D-Channel on span 1 down<br>
[Mar 22 09:59:23] WARNING[8886] chan_dahdi.c: No D-channels available!<br>
Using Primary channel 24 as D-channel anyway!<br>
[Mar 22 09:59:23] VERBOSE[8886] logger.c: == Primary D-Channel on span 1 up<br>
[Mar 22 10:36:11] VERBOSE[8886] logger.c: == Primary D-Channel on span 1 down<br>
[Mar 22 10:36:11] WARNING[8886] chan_dahdi.c: No D-channels available!<br>
Using Primary channel 24 as D-channel anyway!<br>
[Mar 22 10:36:11] VERBOSE[8886] logger.c: == Primary D-Channel on span 1 up<br>
[Mar 22 10:36:11] VERBOSE[8886] logger.c: == Primary D-Channel on span 1 down<br>
[Mar 22 10:36:11] WARNING[8886] chan_dahdi.c: No D-channels available!<br>
Using Primary channel 24 as D-channel anyway!<br>
[Mar 22 10:36:11] VERBOSE[8886] logger.c: == Primary D-Channel on span 1 up<br>
[Mar 22 10:44:36] NOTICE[8888] chan_dahdi.c: PRI got event: HDLC Bad<br>
FCS (8) on Primary D-channel of span 3<br>
[Mar 22 10:45:44] NOTICE[8886] chan_dahdi.c: PRI got event: HDLC Bad<br>
FCS (8) on Primary D-channel of span 1<br>
[Mar 22 10:59:33] NOTICE[8887] chan_dahdi.c: PRI got event: HDLC Abort<br>
(6) on Primary D-channel of span 2<br>
[Mar 22 11:30:53] VERBOSE[8886] logger.c: == Primary D-Channel on span 1 down<br>
[Mar 22 11:30:53] WARNING[8886] chan_dahdi.c: No D-channels available!<br>
Using Primary channel 24 as D-channel anyway!<br>
[Mar 22 11:30:53] VERBOSE[8886] logger.c: == Primary D-Channel on span 1 up<br>
[Mar 22 15:34:28] VERBOSE[8887] logger.c: == Primary D-Channel on span 2 down<br>
[Mar 22 15:34:28] WARNING[8887] chan_dahdi.c: No D-channels available!<br>
Using Primary channel 48 as D-channel anyway!<br>
[Mar 22 15:34:28] VERBOSE[8887] logger.c: == Primary D-Channel on span 2 up<br>
<br>
--<br>
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</blockquote></p>