Ascend Archive
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: (ASCEND) Ascend going mad ? (was: Stable code for Max 1800)
At 10:56 1998/04/22 +0200, Andre Beck wrote:
>On Tue, Apr 21, 1998 at 05:43:10PM -0400, Tim Basher wrote:
>> > that the 1800 uses _one_ BRI as clock source and gets out of sync if other
>> > BRIs have remarkable swimming away clocks on other BRIs. This causes
>> > packet loss with all upper layer protocols (ping measures show up to 50%
>> > lost packets). The problem disappears (on upper layers) when PPP link
>> > compression is disabled, but this is just an observation, no solution.
>>
>> I am sorry, it is not that I don't believe that you are seeing a problem...
>> but your explanation doesn't make sense to me.
>
>It does not make much sense, Ok. Our observations were the packet loss
>and the fact that it disappears when Stac is switched off.
Yes, it does indeed sound strange, but when I still had 1800s online,
and once I put more than 6 BRI into each box, I saw the
EXACT same thing, extreme packet loss until I either disabled STAC
or disabled the line that was the clock source, thus causing the
master clock to become a differnet line, things would be fine
for a while (sometime days, hours, or only minutes)
>I don't actually see this behavior, but I cant debug the code in the
>Ascends to find out whats happening ;-)
>
>So how did I came to this "sync loss guess" at all ? When I first des-
>cribed the problem here on the list (Aug 97) we only knew that there is
>packet loss with Stac and no loss without. I got this reply from Jim
>Howard:
>
>-----------------------------------------------------------------------
>Date: Mon, 11 Aug 1997 15:01:18 -0400
>To: Andre Beck <beck@ibh-dd.de>
>From: Jim Howard <jhoward@lyceum.com>
>Subject: Re: (ASCEND) Weird Max1800/Stac phenomenon
[...]
I always get warm fuzzies when quoted like that ;^)
Like you, I cannot say that was definitely the cause,
but all the circumstancial evidence supports it.
In one box where lines 1-4 were all ordered from the Telco
at the same time, and were going into the same switch,
and lines 5-6 and 7-8 were ordered in pairs,
I almost never saw any problems at all.
In another box, where almost all lines were ordered individually,
and most likely to different switches, the problem
was bringing all traffic through the box to a standstill
until we would reboot the max or disable certain lines.
Because of business growth and management issues with dozens
of BRI lines, all our 1800s were replaced with 4000s and PRI,
and we had little desire to spend more time on the issue...
-Jim H
----
Jim Howard Sr Network Engineer Lyceum Internet
jhoward@lyceum.com http://www.lyceum.com/ 404.248.1733
My PGP Public Key: http://www.lyceum.com/~jhoward/pgp-key.txt
Fingerprint: 7E8B E2BA 1314 2535 CB08 CFF9 119B 7CD3 2488 954D
++ Ascend Users Mailing List ++
To unsubscribe: send unsubscribe to ascend-users-request@bungi.com
To get FAQ'd: <http://www.nealis.net/ascend/faq>