Taking a PRI down gracefully? (Water on DMARC) 4

[Frav82]

Good Morning,

I've been working at a small hospital for a few months now and I just found out that water has been running down our DMARC for years. I have Frontier coming out tomorrow to move all remaining live copper from their DMARC into our 100 pair feeder cabinet right beside it. I've only been working on this Siemens OpenScape 4000 V7 R2 for about 4 months so yes I'm a newbie. Can anyone please walk me through bringing down a PRI gracefully so that I don't kill any existing calls? We have two PRI's and I need to bring one down, wait until the frontier tech moves it into our cabinet, then bring it back up, and then repeat the process for the second PRI. Below is the information I have for our two PRI's. One is in our first of four local selves and the second is on our IPDL shelf 21 located in a rack right beside the other four shelves.

Thank you for any help with this, have a good week gentlemen.

Rob

DIU2U-M Q2216-X
1-01-091-001
1-21-007-000

 

[donb01]

You want to use DEA-DSSU with an offtype of "DC" for deactivate conditionally, you want the type to be "BCHAN" to down the B-channels, and then the PEN1 would be either 1-01-091-001 or 1-21-007-000 depending on which circuit you want to shut down. I don't want to DO it right now so I'm not sure if it asks you if you want them all or you specify a range.

When you reactivate you will use ACT-DSSU with an ontype of "AUL", type "BCHAN" and the same PEN1 you used to shut down.

It might take a while for the whole circuit to go down when you do a courtesy stop, because you have to wait for all the calls to end. Doing this at a low traffic time will make that less painful. You can keep an eye on the status by doing DIS-SDSU:ALL,,PEN,PER2,1,01,091; (that will show both circuits on the board). When all the channels say UNACH (unactivated channel) instead of READY/BUSY/CP your circuit should be down.

Don Bruechert, Voice Comm Analyst II
CareTech Solutions @ Holy Family Memorial
Manitowoc, WI, USA

 

[sbcsu]

If you DIS-BUEND:,B; you will see the trunk groups that have busy circuits.
As Don says to 'courtesy down' a circuit use the DC
Example:
DEA-DSSUC,PEN,1-2-3-0;

Then DIS-BUEND:,B; to see how many are free/busy on that circuit.

When all the channels are free/unused then proceed as follows:

DEA-DSSU:L,PEN,1-2-3-0;

Do the work required.

Then to activate:

ACT-DSSU:AUL,BCHAN,1-2-3-0;
RES-DSSUEN,1-2-3-0;

After that you can then DIS-BUEND:,B; to see them back in action

 

[Frav82]

Good Morning donb01 and sbcsu,

I actually lucked out because Frontier informed me that today will just be exploratory to see what's live on our copper. However I want to thank you both for your responses because now I know exactly what to do when they do decide to move our copper. You guys are AWESOME, thank you both!

Have a nice week Gentlemen and thank you for helping newbies like me stay out of trouble

 

[Moriendi]

Courtesy down is not worth the hassle. While it's in that state, the trunk will refuse incoming calls so incoming calls are going to get busy tone or NU, depending on how the release message is mapped. You can't leave it like that for long and people can talk for ages, you could end up stopping all your incoming calls for 10/15 minutes or more, waiting for the last B channel to clear. Much better to just keep an eye on it and disconnect when idle. As soon as it's off, incoming calls will go to the other trunk. You can use DSSU if you want to, but if you don't, 4K will just bring it back in service when it's reconnected. Deactivating B channels or turning off with l for long term deactivation it just not necessary. dea-dssu:di,pen,1-1-91-0; is all you need to turn it off, and act-dssu:aul,pen,1-1-91-0; to bring it back.

 

[sbcsu]

If you have 2 circuits and the carrier have configured it correctly, then when the calls are cleared down (courtesy down) the calls will fall over to the other circuit.
End users are not disconnected so you can do it during the working day.

The correct official procedure to restart a trunk from V3 onwards is as described.

 

[Moriendi]

Why do you think the calls will fall over to the other circuit? You think network provider will place a new call? Generally, they don't. I would expect calls on that trunk to start receiving busy as soon as the dssu is made.

What document do you have that describes dssu with long term deactivation and b channel reset as 'official procedure'? Certainly nothing I've seen. Like I said, it's just not necessary. Won't do any harm, but you're wasting your time and making it over complicated.

 

[sbcsu]

Where I work generally the carrier has multiple physical access points to an important site.
ISDN as such can fail over with Direct Dial In numbering overflowing incoming and outgoing.
Normally on sites we would have at least 2 circuits with the carrier sending calls in alternately on both circuits, then if one goes faulty or has to be taken out of service it would overflow to the working circuit without any noticeable difference to the end users.
This also facilitates maintenance on the circuits (one at a time).
With some patience you can down a circuit without any interruptions to end users, this is normally used only during working hours.

When working on V1 we had a problem whereby ISDN channels would not come back into service.
Even after physically in/out of the board the channels would not show ready, also with DEA-DSSU and ACT-DSSU still not showing ready.
We passed the problem (at that time) to our support which was ITSCBRU - long gone now.
The recommendation was as stated.
That recommendation restarted our ISDN and it has never failed since - unless you have a physical disconnection, reversal or carrier problem.
If you have a similar issue then I know it will resolve it.

 

[Moriendi]

So what you got from ITSC was a "try this, it's worth a go". If you have a problem, it makes sense to try resetting B channels because if that fails then the next step is a trip to site to reseat the card and take an ISDN tester if available. But generally, it's not needed and there is no documentation advising that should be done for every circuit reset. Around V1 was when you added a trunk, you had to reset the B channels to bring them in service but that was a long time ago. Just administering via pen is usually ample. The only time I reset B channels individually is when one of the channels is bad in software (might show READY on one side and BUSY on the other, or refuse a call in READY state), and I can reset the single channel if I don't want to reset the whole circuit. But Rob does not have a fault here, he just wants to drop the circuit and bring it back up. He can turn off B channels if he wants, it won't break anything. But like I said, it's not necessary.

If there are 2 circuits on this 4K, we don't know if the DDI is being delivered ABABABAB or AAAA with overflow to B, etc. But when a dea-dssu:dc is made on one of those circuits, the CO will still try to deliver calls on it, because it will look in service to them. The 4K will respond to incoming setup with a release, cause temporary failure. So CO may at that point try the other circuit, or just return busy or NU to A-party, it's down to their configuration. Maybe it will, but I usually don't see it, which is why I don't bother using dc. Best thing to do is try it. Make 5 calls incoming while running the RDS ISDN tracer, and see where they come in, Then deactivate the busiest circuit with DC, and make 5 more calls with trace again. I would be interested in the results.

 

[sbcsu]

In my part of the world ISDN still features heavily, and we still have V1 systems in daily use. We even had a Hicom V3 SA11 up to recently.
The original poster requested a method of 'bringing down a PRI gracefully' and he was given that information.
I will read through the responses and will certainly take on board your helpful comments.