atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services T1's, CSU's and DSU's Dropped calls on PRI

Good day, I've got a PRI that links a Nortel MICS and a Panasonic TDE200. In the ISDN trace the TDE is "PBX" and the MICS is "QSIG Line". Here's an example of a failed call - it appears the MICS ends the call for no good reason (as if the user had pressed release, but they have not.) I've x'd out a couple digits of the Calling Party.

Ideas?




PBX->QSIG line No.5205 Port:1 (elapsed time from LPR reset) 01/01/03 04:50:06
L2: I SAPI:0 TEI:0
L3:
SETUP crn:006F (O)
Bearer Capability: 80 90 A2 (Speech Mu-Law)
Channel Identity: A1 83 96 (channel=B22 pref.)
Facility: 91 AA 06 80 01 00 82 01 00 8B 01 00 A1 1A 02 01 40 06 04 2B 0C 09 00 80 0F 4E 65 77 66 6F 75 6E 64 6C 61 6E 64 20 20 20
([Inv] id= 40 op= callingName)
Calling Party Number: 09 80 31 37 30 39 39 39 38 3X 3X 3X 3X
Type of Number= Unknown, Numbering Plan= Private
Number= 1709998XXXX
Called Party Number: 89 32 32 31
Type of Number= Unknown, Numbering Plan= Private
Number= 221
02 01 AC D4 08 02 00 6F 05 04 03 80 90 A2 18 03
A1 83 96 1C 28 91 AA 06 80 01 00 82 01 00 8B 01
00 A1 1A 02 01 40 06 04 2B 0C 09 00 80 0F 4E 65
77 66 6F 75 6E 64 6C 61 6E 64 20 20 20 6C 0D 09
80 31 37 30 39 39 39 38 32 33 32 33 70 04 89 32
32 31


QSIG line->PBX No.5206 Port:1 (elapsed time from LPR reset) 01/01/03 04:50:07
L2: I SAPI:0 TEI:0
L3:
CALL PROCEEDING crn:006F (D)
Channel Identity: A9 83 96 (channel=B22 excl.)
00 01 D4 AE 08 02 80 6F 02 18 03 A9 83 96


QSIG line->PBX No.5207 Port:1 (elapsed time from LPR reset) 01/01/03 04:50:07
L2: I SAPI:0 TEI:0
L3:
ALERTING crn:006F (D)
00 01 D6 AE 08 02 80 6F 01


QSIG line->PBX No.5208 Port:1 (elapsed time from LPR reset) 01/01/03 04:50:26
L2: I SAPI:0 TEI:0
L3:
CONNECT crn:006E (D)
00 01 D8 AE 08 02 80 6E 07


PBX->QSIG line No.5209 Port:1 (elapsed time from LPR reset) 01/01/03 04:50:26
L2: I SAPI:0 TEI:0
L3:
CONNECT ACK crn:006E (O)
02 01 AE DA 08 02 00 6E 0F


QSIG line->PBX No.5210 Port:1 (elapsed time from LPR reset) 01/01/03 04:50:26
L2: I SAPI:0 TEI:0
L3:
CONNECT crn:006F (D)
00 01 DA B0 08 02 80 6F 07


PBX->QSIG line No.5211 Port:1 (elapsed time from LPR reset) 01/01/03 04:50:26
L2: I SAPI:0 TEI:0
L3:
CONNECT ACK crn:006F (O)
02 01 B0 DC 08 02 00 6F 0F


QSIG line->PBX No.5212 Port:1 (elapsed time from LPR reset) 01/01/03 04:50:34
L2: I SAPI:0 TEI:0
L3:
DISCONNECT crn:006F (D)
Cause: 80 90
Cause Value= "#16 Normal clearing"
Location= "user"
00 01 DC B2 08 02 80 6F 45 08 02 80 90


PBX->QSIG line No.5213 Port:1 (elapsed time from LPR reset) 01/01/03 04:50:34
L2: I SAPI:0 TEI:0
L3:
RELEASE crn:006F (O)
Cause: 80 90
Cause Value= "#16 Normal clearing"
Location= "user"
02 01 B2 DE 08 02 00 6F 4D 08 02 80 90


QSIG line->PBX No.5214 Port:1 (elapsed time from LPR reset) 01/01/03 04:50:34
L2: I SAPI:0 TEI:0
L3:
RELEASE COMPLETE crn:006F (D)
00 01 DE B4 08 02 80 6F 5A

Actually, I had that wrong - the TDE is disconnecting the calls from the MICS after 19 seconds:

PBX->QSIG line No.5218 Port:1 (elapsed time from LPR reset) 01/01/03 04:50:53
L2: I SAPI:0 TEI:0
L3:
SETUP crn:0070 (O)
Bearer Capability: 80 90 A2 (Speech Mu-Law)
Channel Identity: A1 83 97 (channel=B23 pref.)
Facility: 91 AA 06 80 01 00 82 01 00 8B 01 00 A1 16 02 01 40 06 04 2B 0C 09 00 80 0B 4C 45 41 4E 4E 45 20 48 49 43 4B
([Inv] id= 40 op= callingName)
Calling Party Number: 09 80 31 37 38 30 39 30 34 3X 3X 3X 3X
Type of Number= Unknown, Numbering Plan= Private
Number= 1780904XXXX
Called Party Number: 89 32 32 31
Type of Number= Unknown, Numbering Plan= Private
Number= 221
02 01 B8 E2 08 02 00 70 05 04 03 80 90 A2 18 03
A1 83 97 1C 24 91 AA 06 80 01 00 82 01 00 8B 01
00 A1 16 02 01 40 06 04 2B 0C 09 00 80 0B 4C 45
41 4E 4E 45 20 48 49 43 4B 6C 0D 09 80 31 37 38
30 39 30 34 3X 3X 3X 3X 70 04 89 32 32 31


QSIG line->PBX No.5219 Port:1 (elapsed time from LPR reset) 01/01/03 04:50:53
L2: I SAPI:0 TEI:0
L3:
CALL PROCEEDING crn:0070 (D)
Channel Identity: A9 83 97 (channel=B23 excl.)
00 01 E2 BA 08 02 80 70 02 18 03 A9 83 97


QSIG line->PBX No.5220 Port:1 (elapsed time from LPR reset) 01/01/03 04:50:54
L2: I SAPI:0 TEI:0
L3:
ALERTING crn:0070 (D)
00 01 E4 BA 08 02 80 70 01


QSIG line->PBX No.5221 Port:1 (elapsed time from LPR reset) 01/01/03 04:50:57
L2: I SAPI:0 TEI:0
L3:
CONNECT crn:0070 (D)
00 01 E6 BA 08 02 80 70 07


PBX->QSIG line No.5222 Port:1 (elapsed time from LPR reset) 01/01/03 04:50:57
L2: I SAPI:0 TEI:0
L3:
CONNECT ACK crn:0070 (O)
02 01 BA E8 08 02 00 70 0F


PBX->QSIG line No.5223 Port:1 (elapsed time from LPR reset) 01/01/03 04:51:16
L2: I SAPI:0 TEI:0
L3:
DISCONNECT crn:0070 (O)
Cause: 80 9F
Cause Value= "#31 Normal unspecified"
Location= "user"
02 01 BC E8 08 02 00 70 45 08 02 80 9F


PBX->QSIG line No.5224 Port:1 (elapsed time from LPR reset) 01/01/03 04:51:16
L2: I SAPI:0 TEI:0
L3:
RELEASE crn:0070 (O)
02 01 BE E8 08 02 00 70 4D


QSIG line->PBX No.5225 Port:1 (elapsed time from LPR reset) 01/01/03 04:51:16
L2: I SAPI:0 TEI:0
L3:
RELEASE crn:0070 (D)
00 01 E8 BE 08 02 80 70 4D

Well, to me the question is whether the problem is with the PBX or the span.

Have you tried stress testing the PRI?

Sam

Yes, but this message clearly comes through and is the reason the call disconnects, also - there are no errors showing on the T1 span from either side, it runs quite cleanly.

PBX->QSIG line No.5223 Port:1 (elapsed time from LPR reset) 01/01/03 04:51:16
L2: I SAPI:0 TEI:0
L3:
DISCONNECT crn:0070 (O)
Cause: 80 9F
Cause Value= "#31 Normal unspecified"
Location= "user"
02 01 BC E8 08 02 00 70 45 08 02 80 9F

I'm afraid that I'm too far removed for that display to mean anything to me. But when you say you've tested the span, can I ask how?

We always liked to stress test it - 5 minutes of all 1s, 5 minutes of all 0s, 15 minutes of 3-24, 15 minutes of 2-23 and then QRS (at least 15 minutes).

If the span passes that, and we're talking just an hour of your time here, try it again, this time with two test sets, running head-to-head.

If it passes that, then I would say that the span is fine and you need to look closer at the PBXs and what they're doing.

Sam

Cause Value= "#31 Normal unspecified"
Location= "user"

If I understand these 2 fields, the telephone system is indicating normal call clearing from the user's direction.

Still....is there any indication that the T1 is bouncing or seeing incrementing errors to the point that the system resets the T1?

Is this happening to multiple users or only 1? If multiple, do they all drop @ the same time?

Point to point PRI should not be giving you this problem if it tests good.
What kind of CSU are you using?

Using built in CSU's for both KSU's, no error stats show up so I don't think a stress test would reveal anything.

Notice there is no "Normal Clearing" message from the MICS (Qsig Line) before the "Normal Unspecified" message from the TDE.

I don't believe it's happening to all users at the same time, but it is affecting multiple extensions on the Nortel system (none on the Panasonic).

The only "mismatch" I can think of is that the TDE is set for "Qsig Master" but the Nortel doesn't have a QSIG option. I don't think that's causing any issues except for the fact we cant light a message waiting lamp on the Nortel from the Panasonic... (we don't see any errors in message flow of normal call traffic)

Did you set one of them to provide the clocking and the other to slave off it? This is not the same as Qsig master.