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New Member

Question - Interface Problems

"Serial3/0:0 is reset" what does this means?

Does it means that the interface has been reset again!

line protocol is down - i know this means that from the telco part is down

Correct me if i'm correct!

  • Other Network Infrastructure Subjects

Re: Question - Interface Problems

Most likely, there is some type of controller in slot 3/0. A channel group is set up on this controller. If the facility coming into the controller is down, any channel groups (serial interfaces)built on the controller will be shown as "reset". If the controller is a T1 interface, enter the command "show controller t1 3/0" and check the status of the T1.



New Member

Re: Question - Interface Problems

yup. the serial interface was down all right. the telco was testing the loopback, what i was told.

Wanna to ask i have my router's leased line bouncing, once it was down @ midnight and it went back up during just before commencement of work. could you pls advise, what could be done with a bouncing leased line! Co-ordinate with telco and it says that their connection was fine.

pls advise,


Re: Question - Interface Problems

See if power is brought down at one site or the other. I've heard of situations where management or landlords cut of power during non-business hours to save a couple cents. In the routers at each end, do a "show version" command and see how long it has been since the router was power-cycled.



New Member

Re: Question - Interface Problems


Here is the captured screen! Seems that the last time it was rebooted was,

System returned to ROM by power-on

System restarted at 04:28:06 UTC+8 Thu Jul 24 2003

System image file is "slot0:c3640-jk8o3s-mz.122-10.bin"

Asked my colleague from the other office and there wasn't any power outage recently. strange! Not sure if the mice are fooling with the power...


Re: Question - Interface Problems

Do a SHOW CONTROLLER and look for the stats for ES (Errored Seconds) SES (Severely Errored Seconds), CRC errors, frame slips, clock slips, etc.

Check to see that the clock source is set to line, not internal (if you're connected to a Telco).

Clock slips can cause the random resets when the clocks eventually fall out-of-sync. The Telco network is (usually) the best source of clock, since they are operating on a (very precise) Stratum 1 clock.

If you're getting a lot of random errors (ES,SES,CRC,Frame slip, etc), then also check your cabling from the SmartJack (and/or SmartJack to the "Extended Demarc" - the link from where you actually plug the device in to where the Telco's SmartJack is actually located).

UTP / Cat5,5e,6 is actually NOT rated for T1 use, though most systems will tolerate it. In very long runs from the SmartJack / Extended Demarc, the signal can degrade with external noise or crosstalk.

"Real" T1 cable ("Premesis cabling") has each pair shielded, with an overall shield in the jacket (which must be properly grounded/terminated to be effective).

Depending on what the physical interface is (T1/E1 or PRI ISDN) the controller may have the capability to amplify or attenuate the signal (Cablelength short/long gain26/gain36 -0 -7.5 -22 ...).

Or are you using a serial interface to a CSU/DSU?

What is the physical interface? What kind of errors are you seeing (if any) at the controller level?


New Member

Re: Question - Interface Problems

here is the sh controller caputred screen!

Data in current interval (580 seconds elapsed):

0 Line Code Violations, 0 Path Code Violations

0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins

0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs

Total Data (last 24 hours)

0 Line Code Violations, 59 Path Code Violations,

2 Slip Secs, 184 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins,

0 Errored Secs, 0 Bursty Err Secs, 1 Severely Err Secs, 183 Unavail Secs

clock size is set to "line": - Framing is CRC4, Line Code is HDB3, Clock Source is Line

as u could see on the second part (last 24 hrs)

There are lots of error. is this affecting the wan link as well!

we are using E1 and itz runing on Serial Interface. this week has been a disastrous one, this happens every midnight and it comes back on after a couples of hrs.

Pls advise!

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