T1 DSU-CSU card problem

[kevin2003]

Hi,

How can I test to see if my DSU-CSU card is working properly?
the phone company is saying that my t1 line is good and running. When I pinged my dsu-csu card ip address, I got about 15 good replies and 3 timeout. And it has been very consistent.

Thanks,

Kevin

 

[svermill]

Ask your telco to provide you with the 15 minute stats for the last 40 intervals. That forces them to actually look at the quality of the circuit as opposed to glancing at some red/green indicator.

I assume this is a circiut that has been up for some time and suddenly went bad? If so, I wouldn't be too worried about the config. If not, make sure you are set up correctly for your telco's circuit. Off hand, it sounds as if the circiut is flakey. But it doesn't sound as if you've looked at your interface stats on your own router. I'd be looking at those more than I'd be looking at ping results.

 

[kevin2003]

I just got off the phone with my Telco and they said that everything on their end is good, including the loop back test. Yes, this has been running then suddendly went out on me. How do I test my hardware to see if it is working properly?

 

[svermill]

Well, you need to figure out whether those timeouts are hardware related or not. Could be that the router is struggling to keep up with its load. ICMP generated by a router gets a low priority relative to other traffic. Is this a busy router? Does 'sh proc' and 'sh proc mem' give you anything to worry about? Also, again, those interface stats will tell you what, if anything, the interface thinks is wrong. As for testing the hardware, I'm not sure what to tell you. I'm not aware of any kind of self test that you can run. You just need to do some testing and troubleshooting. If that points to your CSU, try another one.

Gotta go for the evening. Maybe someone else has good suggestions....

Good luck!

 

[ewiley]

The way I always prove that my DSU is workign properly is with a looping plug:

http://www.tencorp.com/SALESTIP.NSF...3a2e09e82833139c85256bce0041e876!OpenDocument

setup the serial interface for encapsulation of HDLC and the interface should come up when you insert the plug. Test the interface by doing a bunch of extended pings of varying sizes (just type the 'ping' command into IOS and follow the prompts).

Also you can do a 'clear serial ser[slot]/[port]' and it will force it to run a self-test.

Hope this helps!

 

[ewiley]

Oops, I think the URL I gave you doesn't work.. just search Google for 'dsu loop plug' and it should give you the url you need.

 

[MJewell]

Try this one: also includes instructions for creating the loopback plug

http://www.cisco.com/warp/public/471/hard_loopback.html