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Avaya: Legacy SMB Systems (Partner/Merlin/Spirit) FAQ

PRI Troubleshooting

Troubleshooting PRI Problems by TouchToneTommy
Posted: 8 Oct 03 (Edited 24 Dec 05)

This is a "cut-n-paste" of a Word document that came from the Avaya help site. Hope it is helpful.

PRI TROUBLESHOOTING- D Channel Inoperative

1)    Check Permanent alarm table for any other T carrier related alarms (i.e., DS1 loss of  Signal). If present trouble shoot those alarms. (See Errors below)

2) Verify the status of the network and the DTE on the CSUs  LEDs. Troubleshoot
accordingly if either side shows a problem . (On 3160/3164 CSU, verify that the LEDs are assigned to DTE.

3) Verify that the CSU channels are mapped and Programmed for DATA
4) Verify that the CO (Central Office) switch selection in the PRI programming is correct
i.e., B8ZS/ESF

5) Verify that the Magix TEI is set for 0 ( Lines/Trunks>PRI>Protocol>TEI.)

6) Demand Test the 100d module

7) If the T carrier is set to AMI, verify that the CO (Central Office) has inverted the D-channel

8)Attempt to reset the PRI by disconnecting the cable at the 100D, wait 1 minute and then reconnect the cable

9) Run the CSU Loop back test to a 103 loop back or loop back plug towards the Magix at the Smart Jack

10) Verify that the Technician , while programming, did not program the PRI, then reprogram the T1 and then reprogram back to PRI. If so, system erase the Magix and re program the PRI and retest.

11) Cycle Power on the Magix

12) Verify the configuration of the CO (Central Office ) switch with the CO Technician
A)    If the CO is a 5ESS make sure they are running ATT Custom
B)    If the CO is a DMS 100 and/or DMS 250 make sure they have
Variant= NTNAPRI, (L1 flags in Trunk Sub Group = Yes) If set to æNOÆ the D channel will act problematic
C)    If DSX600E make sure Profile =p250.

13) Have the CO restart the PRI and determine why the D channel didnÆt come up.

14) Verify the continuity for the T by having the CO run a stress test to a loop back at the CSU

15) Replace the 100d

16) Replace the Processor    

17) At  this point the problem has to be a Network issue.


Cannot dial international long distance calls.

* on some PRI facilities, it is necessary, in the Special Service Table, to change
the ôType Of Numberö entry for international format, from æinternationalÆ to ænationalÆ

Can Call local, but are unable to dial any long distance numbers

+    Check the ôDigits to Deleteö section of the Special Service table. If there are digits being deleted, change all values to 0.  These digits send the dialing prefix ( 011, 01,1, etc) so the T1 carrier knows how to process the call, and are needed by some (mostly local) providers.  If the T1 is maintained by a long distance company like AT&T or Sprint, the prefix is not generally used so they are deleted.

Can dial local and long distance toll calls, but are unable to call toll-free (800, 888 etc) and / or intra-lata long distance.

*It may be necessary , under some circumstances, when all of the other Special Service Table entries are set at default (3 3 2 2 1 0 0 0), to change entry 5 to a 1.  Why this works is not documented, but has cleared trouble on several occasions.

Everything in programming looks  good , but still canÆt call in or out. Provider may report
That they cannot see the æDÆ channel.

*Verify with the vendor that the ôSwitch Typeö is correct, and that the appropriate protocol is being used. The protocol for the DMS-100 and other Nortel switches is NTNAPRI.  The protocol for 5ESS and other AT&T switches is AT&T Custom. Also for DMS 100 switches the L1 flag in the æTrunk Sub-groupÆ table is to be set for æYesÆ.

After a reset of the 100DS1 card a cold start of the switch or a brief disconnection of cabling for loop back testing, the T1 appears to come back up but calls cannot be made in or out.

*When a PRI connection is lost (for whatever reason) the T1 will normally reset itself and rebuild the connection to the Magix.  To do this, the ôDö channel is established first and then the ôBö channels are brought up either one at a time , or globally(all at once).  This is particularly significant because the success of the restart is entirely switch dependent.  If the Switch is a DMS-100, DMS-250, or DEX600E, it expects Nortel protocol.  Whenever the switch is reset, this protocol specifies that the first Layer-3 ôDö channel message must be a global RESTART message (bringing the ôBö channels up all together) sent from the network switch to the Magix.  If the switch is a 4ESS or 5ESS, it expects AT&T protocol. Whenever the switch is reset, the first Layer-3 ôDö channel message sent from the Network switch to the Magix must be a ô Bö channel SERVICE message (bringing the æBö channels up one at a time)

This is a newly provisioned service and  unable to call in or out.

*Print PRI information. IF the customer confirms that the PRI service is relatively generic and id utilizing Direct Inward Dial, here a some things to take a look at.

1)Is the switch type entered and correct?

2)Is the number of ôBö channels entered the same as the number of lines?

3)Is there any number entered in the TestTelNum Field? If so delete it.

4)Are they using Direct Inward Dialing? If so, make sure Incoming Routing is set to By Dial Plan.

5)Look at entry æ0Æ in the Call-by-call Service Table. Are the Patterns 0-9 entered?

6)Is the NtwkSer under Entry æ0Æ, for the call by call service table, set to no service?

7)Is the NtwkSer under Entry æ0Æ , for Dial Plan Routing Table, set to ôAny Serviceö?

Errors and Alarms:

**These error codes are most commonly seen with T1**

ERROR     DESC            ACTION            Quick Checks

0c03    All TTRs Unavailable        check to see if more        Test TTRs. How many
                    TTRs can be added

2C01   T1 access violation        Check T1 programming    Check T1 prog.
                                    Check CSU Prog

6c01    DS1 Loss of Signal        Usually not Magix        Make test calls ..ok?
                    Usually Network        Check T1 facility
                                    Cables Plugged in?

6c02   DS1 BLUE Alarm        Usually not Magix        Make test calls ..ok?
    All 1Æs received        Usually Network        Check T1 facility
                                    Check CSU prog

6c03  DS1 RED Alarm        Usually framing        Make test Calls..ok?
          Service on link lost                        Check T1 prog
                                    Check CSU prog
                                    Check T1 facility
                                    Cables plugged in?

6c04    DS1 Yellow Alarm        Usually Network        Make test calls..ok?
    Far end lost framing                        Check T1 prog
    Synchronization                        Check CSU prog
                                    Check T1 facility

6c05  DS1 loss of Multiframe        Usually Network        Check T1 prog
         Service on Link Lost                        Check CSU prog
                                    Check T1 facility
                                    Cables plugged in?

6c06    DS1 Remote Multiframe    Usually NONE        Check T1 facility
    Network Loss of Multiframe                    Check Prog
                                    Check CSU Lights.
6c07    DS1 Major Alarm        Usually Network        Make test calls..ok?
    Service on link lost                        Check T1 prog
    Bit error rate exceeded                    Check CSU lights

6c08    DS1 Minor Alarm        Usually Network        Check T1 prog
    Bit error rate exceeded                    Check T1 facility

6c09    DS1 Misframe Alarm        Usually Network        Check T1 Prog
    misses reached 18                        Check CSU lights                                        Check T1 facility

6c0A    DS1 Slip Alarm    Network or Magix Clocking        Check Clock prog
    Slips reached 88                        Check T1 facility

6c0B     Hardware Inoperative         Busy Out/Restore Slot    Check slot
status in maintenance

7404     Stuck Ringing            None on T1            Check T1 prog    
                                    Check Facility
7801    Not in Normal OP Mode                    Test T1 Card
                                    Reset/Restore Slot

7808    Test Result Registar Bad                    Reset/Restore Slot    

8403    No External Release        Usually Network        Check T1 facility
    communication problem                    Check for Bad cable
    between CO and Module                    Check CSU prog

8404     On Hook before WINK    Usually Network or        Check T1 prog
    dialing trouble on wink    Tie Line prog            Check T1 facility
    start of delay start Tie lines                    Test Card/Module
                                    Check for bad cable

8405    On Hook before Ready    Usually Network or        Check T1 prog
    dialing trouble on wink    Tie line prog            Check T1 facility
    start or delay start Tie                        Test Card
    Lines                                Check for Bad cable    

Quickie T1 troubleshooting

1.    Determine if the problem is with the SPAN, PBX or the distant switch (PBX, 4E/5E, etc..)
2.    If the SPAN is up (No DS1 Alarms) and incoming and outgoing calls are being made; but:
-calls are being disconnected
-there are fax transmission problems
-there are analog data (modem) transmission problems

Suspect Line Coding mismatch between AMI vs. B8ZS in the network or between network and the CSU
A)    Verify that all SPAN components  in the network are configured for the same line coding
B)    Call the provider of the T1 service and have SPAN STRESS tested through the Smart Jack and the CSU
C)    Verify the line coding configuration options in the CSU/Magix programming

3.    The SPAN is up (No DS1 alarms) BUT calls CANNOT be made.
A)    Verify that the trunk type ( tie , loopstart/groundstart etc..) and the signaling type ( WINK in/ WINK out etc.) in the local and remote switches are configured the same.

4.    SPAN down (DS1 Alarm present)
A)    Verify there is and indication of a DS1 signal at the Smart Jack, CSU and PBX
B)    Verify options of the CSU and the Magix
C)    Make appropriate loop backs to isolate the problem into the PBX, CSU, cabling or Network. Check cabling for intermittent conditions by moving to test for poor physical connections

A 103 connecting block can be wired as a loop back plug by strapping / punching pins 1 to 3 and 2 to 4. This provides a transmit to receive connection.

A "103 connecting block" is an Avaya specific surface jack. When they refer to the pins to strap, they are talking about where you punch down an I/W to this jack. To make a loop back with a standard CAT-5, 568-B jack, strap White/Blue to White/Orange, and Orange/White to Blue/White. Or, put another way, strap pin 1 of the jack to pin 5 of the jack, and pin 2 of the jack to pin 4 of the jack.
end of edit

Loop backs-
+    Network Signal OKùLoop DTE to CSU
+    DTE Signal OK--    Loop Network to CSU

Causes of Red and Yellow alarms are:

Synchronization can be lost
Repeaters might send a 1 instead of a 0
Hits on the line can change a Bit
Understand that these alarms are for serious problems that affect the entire T1 bit stream.


A Red alarm is initiated by the local DS1 board when the framing on the incoming DS1 bit stream is not recognizable. This would also be the case if too many framing bits are in error ( 3 out of 16).  Upon initiation of a Red alarm, the switch sends a Yellow alarm code (bit 2 set to a ô0ö on all 24 channels with the D4 framing or alternating bytes of eight ô1ös followed by eight ô0ös on the embedded FDL (4 Kbps ôFacility Data Linkö with ESF) on the outgoing DS1 bit stream.
 [ In a nutshell- If my switch finds its out of sync it presents a Red alarm to the other switch. The other switch now knows IÆm in trouble.  It will not send the alarm right away. It will first try to reestablish synchronization, if it canÆt in 2.5 seconds it sends the alarm]


A Yellow alarm is transmitted to the distant end switch to indicate that there is a Loss of Signal, RED ALARM or BLUE ALARM at that location.  The format of the yellow alarm code employed is dependant on the type of framing. For D4 framing, the yellow alarm code is recognized as bit 2 of each channel set to zero (ô0ö).  For ESF, a Yellow alarm is recognized as alerting bytes of eight ô1ös followed by eight ô0ös on the embedded 4 Kbps data link (FDL).
 [In a Nutshell- IÆm sending stuff but the other end is in trouble. The other end has received a bad DS1 signal and is in a RED alarm stat]


A Blue alarm is recognized as a DS1 signal comprised of a continuous stream of Unframed ô1ös.  Depending on its options,  a CSU will generate a Blue alarm ( AIS=Alarm Indication Signal) also know as a keep alive signal when it looses the DS1 signal from its attached DS1 module/board.  The end receiving a Blue alarm sends a Yellow alarm to the distant end.
In other words a Blue alarm signals the next terminal ædownstreamÆ that a failure or alarm
Condition has occurred æupstreamÆ.
[In a Nutshell- Network originated signal when the far end is down. This will almost always be the network, unless the CSU gets unplugged from the Smart Jack]

Examples of ALARM Conditions

+    If the TRANSMIT side between the Magix DS1 board and the CSU is open, the 4E (CO side) will go into BLUE (AIS) alarm and SEND a YELLOW towards the Magix.  The Magix would show a YELLOW alarm.  This indicates the Magix RECEIVE side is good.

+    If the Magix RECEIVE side is open between the CSU and Magix DS1 card , the Magix Sends a YELLOW to the 4E (CO). The CO would see the Yellow and the Magix would indicate LOS (Loss of Signal) Alarm.

+    If the 4E (CO) goes into a RED alarm it will SEND a YELLOW and the Magix would see a YELLOW alarm in the error log.

+    If the Magix DS1 board goes into a RED alarm we will send a YELLOW to the 4E (CO) that sees the YELLOW. The Magix error log will show a RED alarm.


A misframe could be programming. ESF/D4 donÆt match on both ends or switch or CSU programming is wrong.


A Loss of Signal is a condition where no pulses or too few pulses (digital signal) are being received by the DS1 board from the Network.

Additional T1 troubleshooting and information:

Problem Reported:                            Check Magix For:

No Wink on Incoming                        Number of TTRs
                                    Test TTRs
                                    Tie or DID wink start                                         programming

Slipping                                Magix Clock Settings
                                    CSU Clock settings
Misframe                                Magix frame format                                         options
                                    CSU frame options

Dead Air                                Check Magix errors

Caller hears dial tone                            Check Tie line
Instead of ringing                            programming and
                                    Verify with vendor
                                    Their prog. Is correct
                                    Number or TTRs?
                                    TEST TTRs

Echoing                                Check Tie Line prog.
                                    Tie lines should be set                                 for Tie Toll if C.O. is
                                    No Echo suppression                                     from C.O.

Restricted Set Can Call Out                        Check Tie line prog.
                                    Tie lines should be
                                    Tie Toll if CO is
                                    Tie PBX ignores

Noise/ Static                                Generally Clocking
                                    / External
                                    Check modules bad
                                    MLX     card could
                                    Cause this or 016 tip
                                    Ring module next to
                                    100d card could cause                                 this.

CanÆt Put calls on Hold                    Answer Supervision not
Or transfer, # has no effect                    being received        
                                Answer supervision program
                                Wrong in C.O.

Cut Offs                            Check Magix Clock settings
                                Check Magix Suppression if
                                Correct refer to Network

Voice Channels cut off                    ô                                      ô
Data Channels OK                        Noise


Useful Network Terms

DACS            Digital Cross Connect in Central Office, Compression Point,
            Requires programming in C.O., if it is wrong wonÆt pass sig
            -naling bits to us ( No wink seen by Magix)

Stress Test        A test performed by Network Provider while T-1 is down
            Low density stress test is all 0Æs pattern
            High density stress test is all 1Æs pattern
            Random density stress test is 1Æs and 0Æs

MIONOP        Tie line emulation with immediate seizure and no
            Digits sent.  In Magix this is Tie Line with Auto IN

ICOPNOP        Tie line emulation with wink start and no digits
            Magix will not match this, therefore canÆt do it.

Dial Tone Start    Tie line emulation with immediate seizure, waits for dial tone
            Before collecting  digits.  In Magix it is the same programming
            But if we use ARS this may fail.  Magix prefers Tie lines with
            Wink start.

Loop Back        Smart Jack loop back test service from the C.O. to the Smart Jack
            CSU loop back test from DS1 card to loop back point
            DTE loop back test towards the Magix

DNIS            Dialed Number Identification Service ( Works like DID)

ISDN    Integrated Service Digital Network either BRI ( Basic Rate Interface) or PRI (Primary Rate Interface)

3160 CSU Commonly used Options

To check Frame Format and Suppression for both the NET and DTE
1    Press Double Arrow UP
2    Select Config-Active-Edit-DTE-Next
3    Select ESF or D4
4    Hit Next
5    Select B8ZS or AMI-ZCS
6    Single UP arrow
7    Select Net
8    Select ESF or D4
9    Hit next
10    Select B8ZS or AMI-ZCS
11    Hit Double arrow UP
12    If options were changed, it will prompt you to save
13    Hit Active

To Check Clock Source
1    Hit Double UP arrow
2    Select Config- Active- Edit
3    Hit RIGHT arrow Twice
4    Select GEN- Next
5    Select NET or DTE
6    Hit Double UP arrow
7    If options were changed, it will prompt to save
8    Hit active

To Display Current Channel Configuration
1    Hit Double UP arrow
2    Select Config- Active- Edit
3    Hit RIGHT arrow ONCE
4    Select Chan- Display- Net
5    The N1-N2-N3 refer to Network Channel 1-3
6    If it shows D1 it refers to DTE channel 1
7    If it shows just a -, it is not programmed
8    If it shows PRT1, it is programmed as a Data Port
9    When finished hit double Arrow UP

To Assign Channels as Voice
1    Hit Double Arrow UP
2    Select Config- Active- Edit
3    Hit RIGHT arrow ONCE
4    Select DTE û Assign
5    It displays N1-N2- N3, select the corresponding æFÆ key to assign
6    It now will show D* (* will be populated with the corresponding Channel #)
7    After assigning the voice channels, hit double UP arrow
8    If options were changed, you will be prompted to save æyes or noÆ
9    Select Active.

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