Hi Mike,
> Hello:
> I have 3 pm3's all connected with channelized T1 lines. I have been
> running several months with no problems (that I know of). Recently, I have
> had a couple of customers complain of slow data transfers, even to our web
> site. One customer sent me a traceroute from his 95 machine. This is what
> displayed on his screen:
>
> C:\>tracert www.wcoil.com
Looks like MS traceroute..check out the 3.7 release notes for specific
details, but in this release we don't support it.
>
> Tracing route to www.wcoil.com [206.230.70.4]
> over a maximum of 30 hops:
>
> 1 * * * Request timed out.
> 2 217 ms 203 ms 201 ms gwwcoil.wcoil.com [206.230.70.1]
> 3 207 ms 211 ms 206 ms www.wcoil.com [206.230.70.4]
>
> Trace complete.
>
> Notice the time out on the connection between his modem and the pm3.
> I then looked at the pm3 he is coming in on and noticed the following errors
> when I did a sh line0
>
> pm10> sh line0
> ---------------------- line0 - T1 Inband DS0 ---------------
>
> Status: UP Framing: ESF Encoding: B8ZS PCM: u-law
>
> Signaling: Trunk E&M wink start
>
> Receive Level: -7.5dB to -15dB
>
> Alarms Violations
> ----------------------------- -----------------------------
> Blue 0 Bipolar 34149025
> Yellow 2 CRC Errors 25
> Receive Carrier Loss 8 Multiframe Sync 173006
> Loss of Sync 3
>
It's the loss of sync and carrier loss values that I'd be most concerned
with, since the violations increase dramatically when these occur. They
may have happenned in a burst, so take this as a checkpoint and monitor
to see if those alarms increase.
> pm10> ver
> Livingston PortMaster PM-3 ComOS 3.5.1b8
> System uptime is 91 days 1 hours 30 minutes
>
Not bad given the age of the product.
> The number of Bipolar errors is obviously alarming. Where do I look for the
> problem. The pm3? The T1 line? New ComOS? Any help would be greatly
> appreciated.
That reading is coming directly from the built-in csu/dsu so it's
basically at the physical layer. If you have a spare line1, then you
could swap the circuit and monitor from there, but usually this stuff
is caused by a brief outage(s) on the line from the telco.
Regards..Todd
>
> Thank You
>
> Mike O'Connor
> West Central Ohio Internet Link
> mike@wcoil.com
>
-- E. Todd Taylor Livingston Enterprises Inc. Phone: (800) 458-9966 Support Engineer 4464 Willow Road Fax: (510) 737-2110 todd@livingston.com Pleasanton, CA 94588 http://www.livingston.com/