Frame Relay Stress Testing

[Yehey]

Hi All,

My network has a bouncing frame relay circuit. Every time our link takes a hit, we call the carrier and they would perform a stress test for that bouncing circuit and all they say after the stress test is, "there where no errors found". They told me that they used intrusive and passive tests. I really dont know what these test are, so my questions is,

1) What are the types of test performed on a frame relay circuit?

2) What could be the problem with the bouncing circuit? (Already replaced WAN cable from router to CSU/DSU, router configurations are all good and no extended demarc)

3) What troubleshooting approach should i do to isolate the problem?

Usually after the stress testing, circuit would be up and running pretty well for 2-3days. Then the circuit goes bad again after that. seen lots of crc and input errors on the serial interface btw.


Thanks

 

[jeter]

intrusive tesing is the carrier looking at the circuit running a test across the link. They normally do this for 10 to 15 minutes. If there is no loss they call it good.

When you type show frame-relay pvc do you see exessive FECN or BECN and or discard eligible? Verify LMI type and monitor up time of lmi.

Also type sh service-module to verify signal/circuit problems, you could type clear counters to reset and monitor.

Whenever I come across this problem it usually a bad card or loose jumper in the central office or field.




Cpl NVARNG
Tek-TIP Member 19,650

 

[jneiberger]

When you say that it is bouncing, what exactly do you mean? Is the interface on your router actually going down or does the link just become unavailable? Does the circuit stay up but line protocol goes down? Is it staying down for very long? Have you looked at the NIU while the circuit is down?

 

[Yehey]

Hi jeter,

I spoke with the carrier and they told me that there where errors found when they tested the circuit, eventually they re-terminated/replaced the jumper at the CO, this fixed the problem.

Read your previous posts about "Sprint Frame Relay", would you be so kind to explain to me or give me a reference about what the carriers do when they usually test a frame relay circuit.

Hi jneiberger,

Bouncing is another term for intermitent link.



Thanks.

 

[jneiberger]

Yehey, I know what a bouncing circuit is. I just wanted more details. There are a lot of different things that can cause a circuit to bounce and each variation will have different symptoms:

* Bad cabling
* Bad NIU
* Bad port on the frame relay switch
* Bad repeater
* Misconfigured line code
* Electrical interference

Those are just a few examples. I'm glad you got it fixed.

 

[Yehey]

jneiberger, didn't mean it that way

We were basically receiving lots of input errors from the circuit on our router that was due to the bad cabling. Good thing they found the problem.

Thanks

 

[jeter]

Sorry for the delay, I had drill this weekend.

The answer really depends on the carrier technician.

I hate to say it but most of them are very lazy and do not have a clear understanding of what the circuit is doing and they only test from the CO to the customer premise.

Mostly advising that the problem is always yours and not the circuit.

The best advise I can give is always insist to have the tech call you. You can then review want they have done and advise of additional troubleshooting if needed....




SPC NVARNG
Tek-TIP Member 19,650