Chuck Scott, Pres.
Freeway, Inc.
cscott@freeway.net
On Thu, 12 Oct 1995, Dennis Simpson wrote:
> > My PM2ER20 WAN port locks up about every 7 days or so. Didn't do this
> > at first but started about a month ago. There are CRC and FRAME errors
> > but not many (<10). Resetting w1 clears the problem. Not too bad a
> > problem as long as it doesn't go unnoticed for more than a few minutes.
>
> We have seen this as well. We reported it to our carrier, since crc's
> typically indicate line trouble. They called in the telco, who fumbled
> with it for three weeks. They eventually made some line adjustments
> (said the signal was too hot), and we went from outages like you
> describe happening every few hours to outages happening once every
> several days now. They usually are accompanied by a small number of
> crc's like you describe. The telco's test equipment never reports any
> errors, of course. I suppose that if I paid for my CSU/DSU what they
> paid for their test equipment, my CSU/DSU would likely never have
> trouble either. :-)
> The telco swears there is nothing wrong with the line now, and the
> carrier swears we should never get even one crc, since we are on fiber.
>
> So who's not coming clean? I have replaced both the CSU/DSU and the
> router twice now, so I do not believe it is broken hardware. We have a
> new multi-port CSU/DSU coming in in a week or so, and then we will have
> the opportunity to see if the errors go away, in which case it means
> our Black Box CSU/DSU was at fault (compat/config/whatever).
>
> FWIW, we ran without this kind of trouble too, for months. It began
> September 4, when they upgraded our backbone from 128K to 256K. We will
> be going to 512K in the next few weeks, so it should be interesting to
> see what if anything happens to the problem then.
>
> In our case, we almost never reset the port, because it recovers on its
> own in a couple of minutes. Typically by the time we recognize the
> freeze, confirm it and try to reset, it has come recovered. Like you say,
> annoying but not a huge issue.
>
> > Any one else seen this? BTW there are no alarms or errors on my CSU/DSU
> > (ADTRAN TSU).
>
> When these problems occur, the Cisco 7000 at the carrier's end of our
> connection reports crc's as well; our CSU/DSU doesn't have any
> intelligence to be reporting anything to anyone. :-(
>
> > Do I need to upgrade ComOS (currently 3.1.2)? Not just a blanket upgrade
> > statment, please.
>
> Now that you mention it, that is one common factor on every hardware
> combo we have tried. Our 3.1.2 PM2ER-30 otherwise appears to be solid,
> and since horror stories can be heard about any release, we aren't
> going to upgrade ours unless we hear something specific about a fix to
> this particular problem in a new release. We won't upgrade without
> specific reason, since every change carries an element of risk.
>
> I would be interested in any informed feedback on this problem as well.
>
> Thx,
> dennis
>