PRI - Frame slips 2

[seanrich]

We are having reports of a lot of clicking on the the lines that come though our PRI. Our phone tech says they sound like frame slips, but we can't seem to track down the cause. Usually resetting the DS1 card has taken care of the problem, but that is not working every time. The clicking seems to be more pronounced on the 'other' end of the line, as we just hear some faint noises on this end. Some calls have been dropped altogether and modem communications are nearly impossible.

Has anyone else seen this? We are on a Merlin Legend with 3 DS1 cards, among other things. All three cards are set to clock off of the card that the PRI comes through.

Any ideas?

Thanks.

Sean

 

[gregarican]

The first thing I would recommend is monitoring the performance stats. Going through Maintenance-->Slot-->the DS1 card slot #-->Error Events you can view performance. Some DS1 cards only offer Current Hour and Previous Hour, while newer DS1 cards give you 24 hour's worth of Intervals and the 24-hour Total as well.

The MIS represents misframes, the SLP indicates frame slips, the ES represents Errored Seconds, the BS represents Bursty Errored Seconds, the SEC represents Severely Errored Seconds, the BPV represents Bipolar Violations, and the FS represents Failed Seconds. If one interval has a considerable number of errors coinciding with dropped calls and poor voice quality then you can present these stats to your telco provider. Chances are they can nonintrusively monitor the circuit and see what you're seeing to validate things.

For a broader, higher-level indication of performance you can go through SysProgram-->Print-->Error Logs to see if there are misframes and slips listed there. These will make the system error log if they're severe enough.

I think that for most applications of the Merlin Legend system Avaya recommends having an external CSU. For our setup I split voice and data coming into our Legend with an Adtran Atlas 550. That's great for checking performance stats and whatnot.

Let me know if you want more detailed information on DS1 troubleshooting. I have some third-party docs that break down the various error conditions and how to narrow things down.

 

[Vmail]

gregarican,

I am having similiar problems with my pt to pt T1 from one site to another. Bothe are provisioned as T1, but I am having issues with a channel or 2 ring w/ no answer? I have checked the error logs and see some mis and slps, but nothing else. This is magix 2 to magix 3.0?

Any ideas?

 

[Pepperz]

Clicking and dropping of calls on a p[oint to point network are usually synch problems. Make certain that one side is set as "PBX" and the other as "Network" and that one side is set for loop synch and the other for local.

Pepperz at newper dot net

 

[marktfsmith]

In all cases - open a ticket with your carrier - get them to check there logs or even find a time when they can take down the circuit and test - also get them to check for timing slips (if it is timing slips then it will be your problem - another post). If all this shows clean the the problem still persists - get the carrier to pull hdsl pm's and even ask for a copy - this will show what is happening on the span (last mile of cable) which is where 90% of the trouble usaully is.