NCR invocation attempts fail

Last Updated : Jan 25, 2014 |

Proposed solution 1

Procedure

  1. Verify that no problems exist with BSR polling and interflow operations when Network Call Redirection (NCR) is not administered on the Best Service Routing Application Plan screen.
  2. Ensure that the Net Redir field on the Best Service Routing Application Plan screen is y for all locations that use NCR.

Proposed solution 2

About this task

You can check the ISDN message trace information that Message Sequence Tool (MST) provides for the ISDN trunk D-channel that is associated with NCR invocation attempts.

Perform the following steps to configure MST:

Procedure

  1. Type the ch MST Switch Administration Terminal command.
  2. Administer ISDN-PRI as y, Port Type as d-channel, and Port as the DS1 D-channel switch location that is associated with the PRI trunk in use with NCR.
  3. Use the enable mst and list mist cont Switch Administration Terminal commands to view NCR-related MST trace data.
  4. When vector processing or manual call transfer, call conference, or call release starts an NCR NCT-type invocation, Communication Manager sends a D-channel message to the PSTN switch. This message initiates the merging of the two B-channels associated with the first and second call-legs of a trunk-to-trunk call.

    The following MST trace example is for a NCR Two B-Channel Transfer D-channel invocation message that has the same general format as for the MCI NCT, ETSI ECT, or NCD protocols:

    <msg #> 62 <time stamp> 40 01 18 0F 08 02 80 02 62 1C 09 91 A1

 06 02 01
                04 02 01 06

    Search the 91 A1 data-byte sequence in the trace example to verify that Communication Manager sends an NCR invocation D-channel message.

  5. If the NCR NCT-type invocation is successful, the PSTN switch returns a D-channel message to the Communication Manager that has the following general format: 
    
<msg #> 60 <time stamp> 00 00 4B 17 08 02 93 E5 62 1C 06
03 02 01 
                01

    Search the 91 A2 data-byte sequence in the message to verify that the PSTN switch accepted the NCR invocation request. A D-channel message instead sent by the PSTN switch that has 91 A3 or 91 A4 data-byte sequence indicates the NCR invocation attempt was rejected. Use the display events System Administration Terminal command to view vector events that will explain why the NCR invocation failed.

  6. For the NCR ETSI ECT protocol, a NCR Request LinkID D-channel message is first sent to the PSTN switch by Communication Manager to determine which D-channel to use for this NCR ETSI ECT invocation: This will result in the PSTN sending a Returned LinkID D-channel message to Communication Manager, where an example of an Ericsson AXE-10 single-byte LinkID MST message is as follows: 
    
<msg #> 60 <time stamp> 40 01 18 0F 08 02 00 57 62 1C 13 91 A2

10 02 01
               0B 30 0B 06 06 04 00 82 71 01 04 02 01 FE
  7. Communication Manager sends an Invoke Explicit ECT D-channel message to the PSTN switch using the LinkID returned by the PSTN switch, where an example Ericsson AXE-10 single-byte LinkID MST message is as follows: 
    
<msg #> 62 <time stamp> 40 01 18 0F 08 02 01 92 62 1C 11 91 A1

0E 02 01
               0C 06 06 04 00 82 71 01 01 02 01 FE
  8. For any of the NCR NCT-type protocols, a successful invocation results in both legs of the trunk-to-trunk connection being dropped by the PSTN switch after the B-channels are merged.

    An example of the PSTN switch first dropping the second call-leg by sending a Disconnect, the Avaya switch sending back a Release, and the PSTN switch sending a Release Complete D-channel message is as follows:

    
<msg #> 60 <time stamp> D  40 01 18 0F 08 02 81 92 45 08 02 82 90 1C 23 91
                               D  A1 20 02 02 00 80 02 01 22 30 17 A1 0F 30 06 02
                               D  01 00 02 01 01 30 05 05 00 02 01 02 82 01 00 83
                               D  01 00 1C 06 91 A2 03 02 01 0C
<msg #> 62 <time stamp> 40 01 18 0F 08 02 01 92 4D
<msg #> 60 <time stamp> 40 01 18 0F 08 02 81 92 5A

    An example of the PSTN switch completing the NCR call-redirection operation by dropping the first call-leg by sending a Disconnect, Communication Manager sending a Release, and the PSTN switch sending a Release Complete D-channel message. To verify the called number information associated with the NCR setup of the second call-leg is correct and to see the trunk-related denial events that are generated if the NCR fails, use the list trace tac <trunk group number> Switch Administration Terminal command.

Proposed solution 3

Procedure

To view the behavior of a particular VDN or vector and to identify NCR errors, use the list trace vdn and list trace vector Switch Administration Terminal commands.

Proposed solution 4

About this task

You can check BSR processing to identify NCR errors.

Procedure

  1. If you are logged in at the Switch Administration Terminal (SAT) using the init login, type go tcm.
  2. At the tcm1> system prompt, type the rdd:dp_mgr Bsr_applloc command to see all NCR attempts, internal errors, network errors, successful redirections, and disconnects peg counts that are associated with BSR call interflows where NCR was invoked.

    Peg counts are free-running and are only reset when you use the ch best SAT command to gain access to the Best Service Routing Application Plan screen for a particular BSR application number.

Proposed solution 5

Procedure

If NCR vector invocation by Call Vectoring fails for previous calls, type the display events SAT command to obtain a real-time display of vector events that are logged for call redirection attempts.

The possible NCR vector events are as follows:

  1. 68: Adjunct Route via NCT failed
  2. 310 NCR: Invoke trunk not ISDN
  3. 311 NCR: Bad NCR trunk admin
  4. 312 NCR: No NCT PSTN service
  5. 313 NCR: No NCT outgoing trk
  6. 314 NCR: NCT outgo trk drop
  7. 315 NCR: PSTN NCT invoke err
  8. 316 NCR: PSTN NCT netwrk err
  9. 317 NCR: Used NCT trk-to-trk
  10. 318 NCR: No NCD PSTN service
  11. 319 NCR: NCD invalid PSTN nmbr
  12. 320 NCR: NCD call connect err
  13. 321 NCR: PSTN NCD invoke err
  14. 322 NCR: PSTN NCD netwrk err
  15. 323 NCR: PSTN NCD max redirs
  16. 324 NCR: PSTN NCD no disc
  17. 325 NCR: Internal system err