Controlled Slips on my PRI...is that a good thing ? 1

[monaco]

I have two PBXs cabled together with a T1 crossover cable, one is a G3siV6, and the other is a S8400 with CM 5.2. Both systems have TN4464F circuit paks in them, and the link between them is configured as an ISDN-PRI trunk. When I do a "list measurements" on the G3 DS1, this is what I see:

DS-1 LINK PERFORMANCE MEASUREMENTS DETAILED LOG REPORT

Counted Since: 9:20 am FRI JAN 2, 2009

Date Time ES BES SES UAS/FS CSS LOFC

03/31 12:03 13 0 0 0 13 0
03/31 11:48 12 0 0 0 12 0
03/31 11:33 12 0 0 0 12 0
03/31 11:18 13 0 0 0 13 0
03/31 11:03 12 0 0 0 12 0
03/31 10:48 13 0 0 0 13 0
03/31 10:33 12 0 0 0 12 0
03/31 10:18 12 0 0 0 12 0
03/31 10:03 13 0 0 0 13 0
03/31 09:48 12 0 0 0 12 0
03/31 09:33 13 0 0 0 13 0
I have the same numbers in the CSS and ES column. When I run the same report on the S8400 I have virtually the same numbers in the CSS colunm, but zeros in the ES column. When I run a "test board XXXX" on either side, they both fail test 144, with a value between 1 and 10 usually. I've checked and done everything listed in the maintenance manual to resolve the error, but can't seem to figure it out.

Can anyone out there give me a hand ?

 

[Mitch672]

post the "DS1" form from each switch, you may also have a noise issue on the cabling. I would suggest the individually shield pairs on a proper T1 cable, or use 2 separate pairs in a jacketed sets if using a multiple pair bundle.

Mitch

AVAYA Certified Expert

 

[monaco]

Here's the DS1 configs...
Here's the S8400:

DS1 CIRCUIT PACK

Location: 01A03 Name: Tie to PBX
Bit Rate: 1.544 Line Coding: b8zs
Line Compensation: 1 Framing Mode: esf
Signaling Mode: isdn-pri
Connect: host
TN-C7 Long Timers? n Country Protocol: 1
Interworking Message: PROGress Protocol Version: b
Interface Companding: mulaw CRC? n
Idle Code: 11111111
DCP/Analog Bearer Capability: 3.1kHz

T303 Timer(sec): 4


Slip Detection? n Near-end CSU Type: integrated

Echo Cancellation? y Block Progress Indicator? n
EC Direction: inward
EC Configuration: 4


And here's the G3si:


DS1 CIRCUIT PACK

Location: 01E20 Name: Tie to S8400
Bit Rate: 1.544 Line Coding: b8zs
Line Compensation: 1 Framing Mode: esf
Signaling Mode: isdn-pri
Connect: network
Country Protocol: 1
Interworking Message: PROGress Protocol Version: b
Interface Companding: mulaw CRC? n
Idle Code: 11111111
DCP/Analog Bearer Capability: 3.1kHz




Slip Detection? n Near-end CSU Type: integrated

 

[Mitch672]

those DS1 configs look fine to me, is this a long cable or are these switches right next to each other? You may have a cabling issue with leakage between the transmit and receive pairs.


Mitch

AVAYA Certified Expert

 

[monaco]

The cable is about 10 feet long, I can make another and give that a try. I cut the ends off a standard CAT5 network cable, that's what I'm using now.

 

[Mitch672]

check your pairing, 1+2 connect to 4+5, and vica versa, make sure the pairs are correct (using 1 pair for 1+2 and a different pair for 4+5), sounds almost like you have crossed pairing on the cable.


Mitch

AVAYA Certified Expert

 

[monaco]

I'm using a 568B cable, so on one end pins 1&2 are white/orange-orange/white, and pins 4&5 are blue/white-white/blue. On the far end I have pins 1&2 as blue/white-white/blue, and 4&5 are white/orange-orange/white. The circuit comes right up when I plug in, and the everything is in-service/idle when I status it. I'll keep an eye on the "list meas ds1" for a while and see if it cleans up.

Thanks for your response.

 

[phoneguy55]

how about setting one DS1 to connect: PBX and interface: network and the other DS1 to connect: PBX and interface: user

 

[monaco]

I had the DS1s set that way when I first configured it, and I was getting the exact same errors/counts. I changed it yesterday after reading several postings on this site to see if it changed anything, and so far it hasn't.

I've read every posting I could find about slips/errored seconds/etc, tried several different combinations of changes to the DS1, signal group, and trunk group. I just changed the T1 crossover cable about 30 mins ago, and I'm still getting the exact same error counts (which seems weird).

Thanks phoneguy

 

[phoneguy55]

with the way I suggested did you have errors on both ends? Did you try flipping the network and user from one DS1 to the other?

 

[DAVIDPAYNE]

Just a thought do you have the cable plugged into 120Ax?
Also, you might want to try disabling the Echo Cancellation 01A03.

 

[Mitch672]

good catch DAVIDPAYNE, EC could affect it for sure.



Mitch

AVAYA Certified Expert

 

[monaco]

davidpayne...I do have both ends plugged into 120Ax on both ends, I know I don't have to for such a short distance, but I don't have any other way(no amphenol cables).

phoneguy...I do have CSS counts on both ends (identical), but only have ES counts on the G3 end, which is the "network" end, haven't tied switching those yet.

 

[DAVIDPAYNE]

You might want to try newer 120Ax on both ends just be be sure. And did you try removing the echo Cancellation on 01A03?

 

[NewNic]

With both PBX so close (10" cable) it sounds like the CKT may be too hot, im not sure how to to do this, but attenuating the ckt, padding it down might take care of it

 

[AvayaTier3]

That is done on the add / change ds1 form with line compensation field. Mitch and Dave have both explained how to resolve this. Echo cancellation is another way to adjust gain or loss in the circuit. Obviously not needed here and the csu's are not needed here either.

Wiring on T1 should always use shielded transmit and shielded receive pairs with separation.


A great teacher, does not provide answers, but methods to teach others "How and where to find the answers"

bsh

36 years Bell, AT&T, Lucent, Avaya
Tier 3 for 26 years and counting

http://bshtele.com

 

[monaco]

davidpayne- I did turn off the echo cancellation, still getting the 12-13 slips every 15 mins on both ends.

Will try playing with the cable, see if I can find one that has shielded pairs. I wondering how to connect the two with a network-type cable (RJ45 ends)without the CSUs (120Ax) ??

 

[phoneguy55]

356A.

http://www.tek-tips.com/viewthread.cfm?qid=1460191&page=3

 

[lopes1211]

Sounds like the slave PBX may be using the tone clock as the synch source. You need them in synch to eliminate slips. Assuming there are no PSTN circuits interfacing PBX-B, "change synch" and set the slave PBX to synch off of the ds1 connected to the host.

-CL

 

[monaco]

It would appear that lopes1211 gets the prize on this one, I changed the "slave" PBX to sync off the ds1 connected to the "host" PBX, and I just had my first 15 minute time slice on "list measure ds1" without any CSS/ES counts....all zeros on both ends.

Thanks CL