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Cisco Signaling Controllers

Cisco PGW 2200 SS7 Continuity Testing

Document ID: 48300

Updated: Feb 02, 2006

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Introduction

This document explains how Continuity Testing (COT) works for the Cisco PGW 2200 in configured signaling mode. COT is an automated diagnostic procedure performed in the Signaling System 7 (SS7) Public Switched Telephone Network (PSTN) between switches to ensure that circuits are in service and not experiencing excessive signal loss. This validation is performed by sending tones across the bearer channel. It is performed on a sampling basis. For instance, on 10 percent of the calls (in the Cisco PGW 2200, the sampling rate is defined by CotPercentage).

Prerequisites

Requirements

Readers of this document should have knowledge of these topics:

Components Used

The information in this document is based on the Cisco PGW 2200 Softswitch.

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Conventions

For more information on document conventions, refer to the Cisco Technical Tips Conventions.

Background Information

Since the bearer path is distinct from the signaling path, SS7 requires specific means to validate the bearer channel before the call is established.

COT is requested by the Cisco PGW 2200 originating as an IAM request or as a separate SS7 ISUP message using the Continuity Check Request (CCR) or Circuit Reservation Message (CRM). Two types of COT are Loopback and Transponder (Tone check) methods (see the table). The destination Cisco PGW 2200 places the related circuit in either Loopback mode 2010 Hz or in Transponder mode 1780 Hz (see the table). The Loopback form of COT is used on 4-wire trunks. In the 2-wire case, when the originating switch sends a tone, the receiving switch sends a different frequency tone in response. This is the Transponder mode of COT. If the circuit testing fails during COT, alarm information is generated allowing diagnostic software to busy out the trunk, which can be checked with the man-machine language (MML) command rtrv-alms. Calls are prevented from being routed to the circuit and are COT failed.

COT Type (Loop and/or Tone) NI2+ Tones Rx Tones Tx
Loop 2010 2010
Tone 1780 2010

Cisco PGW 2200 - SS7 COT Configuration and Troubleshooting in Signaling Mode

The Cisco PGW2200 software application performs the signaling and/or call control tasks. This section will talk about the signaling mode. The Cisco PGW 2200 sends NI2+ commands to NAS to transmit and detect tones or loopback circuit.

  • Termination - The Cisco PGW 2200 receives an IAM, CCR or CRM indicating that COT is required.

    Single Tone (Loop)

    pgw_cot_nailed_switch1-2.gif

  • Origination - The Cisco PGW 2200 sends an IAM, CCR, or CRM indicating that COT is required.

    • Single Tone (Loop)

    • Percentage Based (0 - 100%)

    pgw_cot_nailed_switch1-3.gif

    pgw_cot_nailed_switch1-4.gif

  • The Cisco PGW 2200 MML tst-cot command.

SS7 COT Working

Look at an SS7 sniffer trace (Cisco Snooper PT-MTC) for an SS7 IAM message. This is used to check the message into the IAM on CONTINUITY CHECK IND which has a value equal to 1. This indicates that you need to do a CCR required on this circuit.

Note: No test is performed in case the value equals 0 (0 Continuity_check_not_required).

ISUP. -> IAM (01) CIC=0001 
********************************** DETAIL ********************************** 
CIC                            1 
MESSAGE TYPE                   0x01 IAM - Initial_Address_Msg 
NATURE_OF_CONNECTION           0x06 
   LENGTH:                        0x01 FIXED DATA 0x08 
   SATELLITE IND                  0 no_satellite_circuit_in_connection 
   CONTINUITY CHECK IND    1 Continuity_check_required_on_this_circuit 

<snip> 

******************       END_OF_MSG              ****************** 
  

14:37:21.854899  10.15.13.6:3001  10.15.13.132:3001    
                                       NMM....... -> NSCMD_REQ (03) PROT:43 
                                        OPER: COT_TP_IN (04) 
                                       IN_TONE: 218     OUT_TONE: 218 
14:37:21.865164  10.15.13.132:3001  10.15.13.6:3001      
                                       NMM....... -> NSCMD_RES (02) PROT:43 
                                   OPER: COT_TP_IN (04) RESULT: SUCCESSFUL (02) 
14:37:23.796451  214-110-005   214-110-035  ITU ISUP. -> COT (05) CIC=0001 
                                                    SLS=123 Pr:2 Ni:NTL 

********************************** DETAIL **********************************

You can check the status on the network access server (NAS) ISDN interface channel using the command show isdn service. You can also check the status of the B-channel which is currently sending the COT testing into state 5 [ Maitenance Pending].

nas#show isdn service 2 
   PRI Channel Statistics: 
   ISDN Se2:23 SC, Channel [1-24] 
     Configured Isdn Interface (dsl) 2 
      Channel State (0=Idle 1=Proposed 2=Busy 3=Reserved 4=Restart  5=Maint_Pend) 
       Channel :  1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 
       State   :     0 5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
      Service State (0=Inservice 1=Maint 2=Outofservice) 
       Channel :  1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 
       State   :     0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
      Channel blocked? (0=No 1=Yes) 
       Channel :  1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 
                       0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

SS7 COT Configuration on the Cisco PGW 2200

If you want to check the configuration using MML, run the command prov-rtrv:sigsvcprop to find out the COT settings. You need to edit the properties.dat using MML commands to set-up the method (Loop or Tone) and tones (2010 and 1780) correctly.

PGW2200a mml>prov-rtrv:sigsvcprop:name="ss7path" 
   MGC-01 - Media Gateway Controller 2004-01-28 18:07:36.727 MET 
M  RTRV 
   "session=cot11:sigsvcprop" 
   /* 
ACCRespCatName = default 
ACCRespCntlInhibit = 0 
ACLDur = 5 
ADigitCCPrefix = 0 
AInternationalPrefix = NULL 
ANationalPrefix = NULL 
<snip> 

COLDefaultAllowed = 0 
CotInTone = 2010 
CotOutTone = 2010 
CotPercentage = 0 
EchoCanRequired = 0 
ExtCOT = Loop 

<snip> 
Info: Percentage (0-100) is the percentage of the trunk group COT has passed 

Note: In general, MML commands are not case sensitive (ExtCOT is an example of a case-sensitive command). However, property values are case sensitive.

To change the value:

PGW2200a  mml>prov-sta::srcver="active",dstver="cot11" 
   MGC-01 - Media Gateway Controller 2004-01-28 18:05:49.681 MET 
M  COMPLD 
   "PROV-STA" 
   ; 
PGW2200a mml>prov-ed:sigsvcprop:name="ss7path",ExtCOT="Loop" 
   MGC-01 - Media Gateway Controller 2004-01-28 18:11:34.972 MET 
M  COMPLD 
   "sigsvcprop: 
    WARNING: Restart may be needed based on the property(s) added/modified. 
    Refer to MGC Provisioning Guide." 
   ; 
PGW2200a mml>prov-ed:sigsvcprop:name="ss7path",CotInTone="2010" 
   MGC-01 - Media Gateway Controller 2004-02-03 16:51:50.233 MET 
M  COMPLD 
   "sigsvcprop: 
    WARNING: Restart may be needed based on the property(s) added/modified. 
    Refer to MGC Provisioning Guide." 
   ; 
PGW2200a mml>prov-cpy or prov-dply 

Note: The two values that are provisionable are 1780 and 2010 for the COT tones. Table 4-4: Provisionable Properties lists the properties that can be provisioned and indicates if the modified property value takes effect without stopping and restarting the Media Gateway Controller software.

On the NAS, no COT configuration task is requested. Please be aware that for Nailed solution you are using ISDN switch-type isdn switch-type primary-ni2c between the PGW 2200 and NAS.

SS7 COT Troubleshooting on the Cisco PGW 2200 in Signaling Mode

If you run into a COT test failure, this can be viewed on the Cisco PGW 2200 in a variety of ways. The simplest is to use the MML utility and the MML command rtrv-alms:cont to receive continuous alarm updates.

PGW2200a mml>rtrv-alms:cont 
   Virtual Switch Controller 2003-12-20 091938 
M  RTRV 
   ; 
   Virtual Switch Controller 2003-12-20 092041.308 
A  "dpc-ss7ALM=\"ISUP COT FAILURE 
   ; 
   Virtual Switch Controller 2003-12-20 092043.488 
A  "dpc-ss7ALM=\"ISUP COT FAILURE 
; 
  1. Clear alarms using the MML command clr-alm:<comp>:"<alm cat>".

    Note: From Cisco PGW 2200 release 9.4(1) clr-alms is removed from the MML command (refer to Cisco bug ID CSCdy63984 (registered customers only) for further information). You can first retrieve the current alarm status using rtrv-alms. Entering help at the mml> prompt provides you with a listing of all MML commands.

  2. Attempt to put the Circuit Identification Code (CIC) back into service (the remote end may not comply).

    1. On the Cisco PGW 2200, use the MML command unblk-cic:<point code>:CIC=<number>. You can then retrieve the CIC status by using the MML command rtrv-cic:<point code>:CIC=<number> or use the rtrv-tc:all command.

    2. On the NAS, use the configuration command isdn service dsl <dsl #> b_channel <channel #> state <0 = In service> available under the interface Serial0:15 interface command. You can then retrieve the B-channel status using the show isdn service command at the console log.

      For example:

      AS5300(config-if)#isdn service dsl 0 b_channel 1 state 0 
  3. Next, you can also run a manual COT testing again. Manual COT tests can be initiated on the Cisco PGW 2200 without requiring the SS7 network to initiate a COT test.

    For example, on PGW2200a:

    mml> tst-cot:<point code>:CIC=<number>
    

    If you run into COT problems, issue the debug isdn q931 command on the NAS, as shown in this figure.

    pgw_cot_nailed_switch1-1.gif

    This figure xplains the MML tst-cot command and the CCR sent out to the SS7, including the debug isdn q931command output.

SS7 COT Troubleshooting on the Cisco PGW 2200 in Call Control

This section contains the MGCP COT callflow for the PGW 2200 Call Control situation. The Media Gateway Control Protocol (MGCP) organizes the communication between a Media Gateway controller [Cisco PGW2200] and a Media Gateway [Cisco AS5xxx]. This section shows Cisco snooper trace detail for a hairpinning call with loopback COT' and a manual MML cot test from the PGW 2200.

In this figure, COT is initiated by the PSTN switch that sends the IAM request. This PSTN switch reports the test result using a SS7 COT message if successful or a SS7 Release message if failed. The Cisco PGW 2200 puts the related circuit either in loopback mode or in transponder mode. The Cisco PGW 2200 that receives an IAM requesting COT (or a CCR message) first checks for the ExtCOT parameter in the /opt/CiscoMGC/etc/properties.dat file.

pgw_cot_nailed_switch1-5.gif

Hairpinning Call Example with Loopback COT

Upon recept of the SS7 IAM message with the CONTINUITY CHECK IND = 1 which means Continuity_check_required_on_this_circuit, the PGW 2200 recognizes that a continuity test has been requested. It immediately sends a CRCX CreateConnection message to the Cisco Gateway with a M: loopback to put a loopback on the incoming trunk.

16:41:04.349197  1-021-1[02217]       1-003-1[02073]       ITU  ISUP. -> IAM (01) CIC=00093  CDPN=52929728 CGPN=3600
                                                                         SLS=11 Pr:0 Ni:NTL  

********************************** DETAIL **********************************
CIC                            93
MESSAGE TYPE                   0x01 IAM - Initial_Address_Msg
NATURE_OF_CONNECTION           0x06
   LENGTH:                        0x01 FIXED DATA 0x04 
   SATELLITE IND                  0 no_satellite_circuit_in_connection
   CONTINUITY CHECK IND           1 Continuity_check_required_on_this_circuit
   ECHO SUPPRESSOR IND            0 outgoing_half_echo_suppressor_not_included
FORWARD CALL IND.              0x07
   LENGTH:                        0x02 FIXED DATA 0x28 0x01 
   NATL/INTL CALL IND             0 incoming_national_call
   END-TO-END METHOD IND          0 no_end_to_end_method_available
   INTERWORKING IND               1 interworking_encountered
   END-TO-END INFO IND            0 no_end_to_end_information_available
   ISUP IND.                      1 ISUP_used_all_the_way
   ISDN PREFERENCE IND            0 isdn_up_pref_all_the_way
   ISDN ACCESS IND.               1 originating_access_ISDN
   SCCP Method                    0 no indication
CALLING PARTYS CATEGORY        0x09
   LENGTH:                        0x01 FIXED DATA 0x00 
   CALLING PARTYS CATEGORY        0 Partys_Category_unknown_default
TRANSMISSION MEDIUM REQUIRED   0x02
   LENGTH:                        0x01 FIXED DATA 0x03 
   TRANSMISSION MEDIUM REQUIRED   3 3_1_kHz_audio
INDEX TO CALLED PTY ADDRESS    0x02
INDEX TO OPTIONAL PART         0x08
CALLED PARTY NUMBER PARM       0x04
   LENGTH:                        0x06 VAR.  DATA 0x01 0x13 0x25 0x29 0x79 0x82 
   ODD/EVEN IND                   0 even_number_of_digits
   NATURE OF ADDRESS IND          0x01 subscriber_number
   INTERNAL NETWORK PARM          0 routing to internal network number allowed
   NUMBERING PLAN                 1 ISDN_Telephony_Numbering_Plan
   DIGITS:                        52929728
OPTIONAL PARAMETERS:
CALLING PARTY ADDRESS          0x0A
   LENGTH:                        0x04 OPT.  DATA 0x03 0x17 0x63 0x00 
   ODD/EVEN IND                   0 even_number_of_digits
   NATURE OF ADDRESS IND          0x03 unique_national_number
   NUMBER INCOMPLETE IND.         0 complete
   PRESENTATION IND.              1 address_presentation_restricted
   SCREENING IND.                 3 network_provided
   NUMBERING PLAN                 1 ISDN_Telephony_Numbering_Plan
   DIGITS:                        3600
END OF OPTIONAL PARAMETERS     0x00
******************       END_OF_MSG                       ******************


16:41:04.380800  10.48.84.25:2427     10.48.84.26:2427     MGCP...... -> CRCX 411 s3/ds1-1/31@v5350-3.cisco.com MGCP 0.1 
                                                                         C: 39 
                                                                         L: e:off,fxr/fx:t38-loose 
                                                                         M: loopback 
                                                                         R:   
                                                                         S:   
                                                                         X: 19A 

The Cisco gateway acknowledges [200 OK] the CRCX messages of the connection, and sends back the identification of the newly created connection and the session description used to receive audio data:

16:41:04.406307  10.48.84.26:2427     10.48.84.25:2427     MGCP...... -> 200 411 OK 
                                                                         I: 2 
                                                                         v=0  
                                                                         o=- 2 0 IN IP4 10.48.84.26  
                                                                         s=Cisco SDP 0  
                                                                         c=IN IP4 10.48.84.26  
                                                                         t=0 0  
                                                                         m=audio 17906 RTP/AVP 0 8 99 101 2 102 4 103 104 105 106 18 0 125 100  
                                                                         a=rtpmap:99 G.726-16/8000  
                                                                         a=rtpmap:101 G.726-24/8000  
                                                                         a=rtpmap:102 G.723.1-H/8000  
                                                                         a=rtpmap:103 G.723.1-L/8000  
                                                                         a=rtpmap:104 G.729b/8000  
                                                                         a=rtpmap:105 G.723.1a-H/8000  
                                                                         a=rtpmap:106 G.723.1a-L/8000  
                                                                         a=rtpmap:125 G.nX64/8000  
                                                                         a=rtpmap:100 X-NSE/8000  
                                                                         a=fmtp:100 200-202  
                                                                         a=X-sqn:0  
                                                                         a=X-cap: 1 audio RTP/AVP 100  
                                                                         a=X-cpar: a=rtpmap:100 X-NSE/8000  
                                                                         a=X-cpar: a=fmtp:100 200-202  
                                                                         a=X-cap: 2 image udptl t38  
16:41:04.430601  10.48.84.25:2427     10.48.84.26:2427     MGCP...... -> CRCX 412 s3/ds1-0/9@v5350-3.cisco.com MGCP 0.1 
                                                                         C: 39 
                                                                         L: e:off,fxr/fx:t38-loose,nt:LOCAL 
                                                                         M: sendrecv 
16:41:04.433474  10.48.84.26:2427     10.48.84.25:2427     MGCP...... -> 200 412 OK 
                                                                         I: 3 
                                                                         v=0  
                                                                         o=- 3 0 LOCAL EPN S3/DS1-0/9  
                                                                         s=Cisco SDP 0  
                                                                         c=LOCAL EPN S3/DS1-0/9  
                                                                         t=0 0  
                                                                         m=audio 0 LOCAL 0  
16:41:05.354843  1-021-1[02217]       1-003-1[02073]       ITU  ISUP. -> COT (05) CIC=00093  
                                                                         SLS=11 Pr:0 Ni:NTL  

The COT passes and the PSTN sends a "continuity passed" message (COT). The PGW 2200 then sends a modify connection message to the Cisco gateway.

********************************** DETAIL **********************************
CIC                            93
MESSAGE TYPE                   0x05 COT - Continuity_Msg
   CONTINUITY IND.                1 continuity_check_successful
******************       END_OF_MSG                       ******************


16:41:05.370661  10.48.84.25:2427     10.48.84.26:2427     MGCP...... -> MDCX 414 s3/ds1-1/31@v5350-3.cisco.com MGCP 0.1 
                                                                         C: 39 
                                                                         I: 2 
                                                                         L: e:off,nt:LOCAL 
                                                                         M: sendrecv 
                                                                         R:   
                                                                         S:   
                                                                         X: 19D 
                                                                         v=0  
                                                                         o=- 3 0 LOCAL EPN S3/DS1-0/9  
                                                                         s=Cisco SDP 0  
                                                                         c=LOCAL EPN S3/DS1-0/9  
                                                                         t=0 0  
                                                                         m=audio 0 LOCAL 0  
16:41:05.371148  1-003-1[02073]       1-010-1[02129]       ITU  ISUP. -> IAM (01) CIC=00040  CDPN=929728F CGPN=3600
                                                                         SLS=08 Pr:0 Ni:NTL  

********************************** DETAIL **********************************
CIC                            40
MESSAGE TYPE                   0x01 IAM - Initial_Address_Msg
NATURE_OF_CONNECTION           0x06
   LENGTH:                        0x01 FIXED DATA 0x00 
   SATELLITE IND                  0 no_satellite_circuit_in_connection
   CONTINUITY CHECK IND           0 Continuity_check_not_required
   ECHO SUPPRESSOR IND            0 outgoing_half_echo_suppressor_not_included
FORWARD CALL IND.              0x07
   LENGTH:                        0x02 FIXED DATA 0x28 0x01 
   NATL/INTL CALL IND             0 incoming_national_call
   END-TO-END METHOD IND          0 no_end_to_end_method_available
   INTERWORKING IND               1 interworking_encountered
   END-TO-END INFO IND            0 no_end_to_end_information_available
   ISUP IND.                      1 ISUP_used_all_the_way
   ISDN PREFERENCE IND            0 isdn_up_pref_all_the_way
   ISDN ACCESS IND.               1 originating_access_ISDN
   SCCP Method                    0 no indication
CALLING PARTYS CATEGORY        0x09
   LENGTH:                        0x01 FIXED DATA 0x00 
   CALLING PARTYS CATEGORY        0 Partys_Category_unknown_default
TRANSMISSION MEDIUM REQUIRED   0x02
   LENGTH:                        0x01 FIXED DATA 0x03 
   TRANSMISSION MEDIUM REQUIRED   3 3_1_kHz_audio
INDEX TO CALLED PTY ADDRESS    0x02
INDEX TO OPTIONAL PART         0x08
CALLED PARTY NUMBER PARM       0x04
   LENGTH:                        0x06 VAR.  DATA 0x81 0x10 0x29 0x79 0x82 0x0F 
   ODD/EVEN IND                   1 odd_number_of_digits
   NATURE OF ADDRESS IND          0x01 subscriber_number
   INTERNAL NETWORK PARM          0 routing to internal network number allowed
   NUMBERING PLAN                 1 ISDN_Telephony_Numbering_Plan
   DIGITS:                        929728F
   EXTENSION DIGIT                F -ST
OPTIONAL PARAMETERS:
CALLING PARTY ADDRESS          0x0A
   LENGTH:                        0x04 OPT.  DATA 0x03 0x17 0x63 0x00 
   ODD/EVEN IND                   0 even_number_of_digits
   NATURE OF ADDRESS IND          0x03 unique_national_number
   NUMBER INCOMPLETE IND.         0 complete
   PRESENTATION IND.              1 address_presentation_restricted
   SCREENING IND.                 3 network_provided
   NUMBERING PLAN                 1 ISDN_Telephony_Numbering_Plan
   DIGITS:                        3600
RESERVED/UNKNOWN OPT PARM      0x3D
   LENGTH:                        0x01 OPT.  DATA 0x1F 
RESERVED/UNKNOWN OPT PARM      0x39
   LENGTH:                        0x02 OPT.  DATA 0x3D 0xC0 
END OF OPTIONAL PARAMETERS     0x00
******************       END_OF_MSG                       ******************


16:41:05.372707  10.48.84.26:2427     10.48.84.25:2427     MGCP...... -> 200 414 OK 
                                                                         v=0  
                                                                         o=- 2 1 LOCAL EPN S3/DS1-1/31  
                                                                         s=Cisco SDP 0  
                                                                         c=LOCAL EPN S3/DS1-1/31  
                                                                         t=0 0  
                                                                         m=audio 0 LOCAL 0  
16:41:05.623454  1-010-1[02129]       1-003-1[02073]       ITU  ISUP. -> ACM (06) CIC=00040  
                                                                         SLS=08 Pr:0 Ni:NTL  

********************************** DETAIL **********************************
CIC                            40
MESSAGE TYPE                   0x06 ACM - Address_Complete_Msg
BACKWARD CALL IND              0x11
   LENGTH:                        0x02 FIXED DATA 0x02 0x14 
   CHARGE IND                     2 charge
   CALLED PTYS STATUS IND         0 no_indication_default
   CALLED PARTYS CATEGORY         0 no_indication_default
   END-TO-END METHOD IND          0 no_end_to_end_method_available
   INTERWORKING IND               0 no_interworking_encountered
   END-TO-END INFO IND            0 no_end_to_end_information_available
   ISUP IND.                      1 ISUP_used_all_the_way
   REVERSE HOLDING IND            0 reverse_holding_not_required
   ISDN ACCESS IND.               1 terminating_access_ISDN
INDEX TO OPTIONAL PART         0x01
OPTIONAL PARAMETERS:
OPTIONAL BACKWARD CALL IND     0x29
   LENGTH:                        0x01 OPT.  DATA 0x01 
   FORWARDING IND                 0 no_indication
   INBAND INFO IND                1 inband_information
   SIMPLE SEGMENTATION            0 no additional information will be sent
   NET EXCESSIVE DELAY            0 no_indication
   USER NETWORK INTERACTION       0 no_indication
END OF OPTIONAL PARAMETERS     0x00
******************       END_OF_MSG                       ******************


16:41:05.640586  10.48.84.25:2427     10.48.84.26:2427     MGCP...... -> MDCX 416 s3/ds1-0/9@v5350-3.cisco.com MGCP 0.1 
                                                                         C: 39 
                                                                         I: 3 
                                                                         L: e:off,nt:LOCAL 
                                                                         M: sendrecv 
                                                                         R:   
                                                                         X: 19F 
                                                                         v=0  
                                                                         o=- 2 1 LOCAL EPN S3/DS1-1/31  
                                                                         s=Cisco SDP 0  
                                                                         c=LOCAL EPN S3/DS1-1/31  
                                                                         t=0 0  
                                                                         m=audio 0 LOCAL 0  					
16:41:05.642898  10.48.84.26:2427     10.48.84.25:2427     MGCP...... -> 200 416 OK 
                                                                         v=0  
                                                                         o=- 3 1 LOCAL EPN S3/DS1-0/9  
                                                                         s=Cisco SDP 0  
                                                                         c=LOCAL EPN S3/DS1-0/9  
                                                                         t=0 0  
                                                                         m=audio 0 LOCAL 0  
16:41:05.660510  1-003-1[02073]       1-021-1[02217]       ITU  ISUP. -> ACM (06) CIC=00093  
                                                                         SLS=11 Pr:0 Ni:NTL  

********************************** DETAIL **********************************
CIC                            93
MESSAGE TYPE                   0x06 ACM - Address_Complete_Msg
BACKWARD CALL IND              0x11
   LENGTH:                        0x02 FIXED DATA 0x02 0x14 
   CHARGE IND                     2 charge
   CALLED PTYS STATUS IND         0 no_indication_default
   CALLED PARTYS CATEGORY         0 no_indication_default
   END-TO-END METHOD IND          0 no_end_to_end_method_available
   INTERWORKING IND               0 no_interworking_encountered
   END-TO-END INFO IND            0 no_end_to_end_information_available
   ISUP IND.                      1 ISUP_used_all_the_way
   REVERSE HOLDING IND            0 reverse_holding_not_required
   ISDN ACCESS IND.               1 terminating_access_ISDN
INDEX TO OPTIONAL PART         0x01
OPTIONAL PARAMETERS:
OPTIONAL BACKWARD CALL IND     0x29
   LENGTH:                        0x01 OPT.  DATA 0x01 
   FORWARDING IND                 0 no_indication
   INBAND INFO IND                1 inband_information
   SIMPLE SEGMENTATION            0 no additional information will be sent
   NET EXCESSIVE DELAY            0 no_indication
   USER NETWORK INTERACTION       0 no_indication
END OF OPTIONAL PARAMETERS     0x00
******************       END_OF_MSG                       ******************


16:41:15.384246  1-010-1[02129]       1-003-1[02073]       ITU  ISUP. -> ANM (09) CIC=00040  
                                                                         SLS=08 Pr:0 Ni:NTL  

********************************** DETAIL **********************************
CIC                            40
MESSAGE TYPE                   0x09 ANM - Answer_Msg
INDEX TO OPTIONAL PART         0x01
OPTIONAL PARAMETERS:
BACKWARD CALL IND              0x11
   LENGTH:                        0x02 OPT.  DATA 0x02 0x04 
   CHARGE IND                     2 charge
   CALLED PTYS STATUS IND         0 no_indication_default
   CALLED PARTYS CATEGORY         0 no_indication_default
   END-TO-END METHOD IND          0 no_end_to_end_method_available
   INTERWORKING IND               0 no_interworking_encountered
   END-TO-END INFO IND            0 no_end_to_end_information_available
   ISUP IND.                      1 ISUP_used_all_the_way
   REVERSE HOLDING IND            0 reverse_holding_not_required
   ISDN ACCESS IND.               0 terminating_access_non_ISDN
ACCESS TRANSPORT               0x03
   LENGTH:                        0x04 OPT.  DATA 0x1E 0x02 0x81 0x82 
END OF OPTIONAL PARAMETERS     0x00
******************       END_OF_MSG                       ******************


16:41:15.492711  1-003-1[02073]       1-021-1[02217]       ITU  ISUP. -> ANM (09) CIC=00093  
                                                                         SLS=11 Pr:0 Ni:NTL  

********************************** DETAIL **********************************
CIC                            93
MESSAGE TYPE                   0x09 ANM - Answer_Msg
INDEX TO OPTIONAL PART         0x01
OPTIONAL PARAMETERS:
BACKWARD CALL IND              0x11
   LENGTH:                        0x02 OPT.  DATA 0x02 0x04 
   CHARGE IND                     2 charge
   CALLED PTYS STATUS IND         0 no_indication_default
   CALLED PARTYS CATEGORY         0 no_indication_default
   END-TO-END METHOD IND          0 no_end_to_end_method_available
   INTERWORKING IND               0 no_interworking_encountered
   END-TO-END INFO IND            0 no_end_to_end_information_available
   ISUP IND.                      1 ISUP_used_all_the_way
   REVERSE HOLDING IND            0 reverse_holding_not_required
   ISDN ACCESS IND.               0 terminating_access_non_ISDN
ACCESS TRANSPORT               0x03
   LENGTH:                        0x04 OPT.  DATA 0x1E 0x02 0x81 0x82 
END OF OPTIONAL PARAMETERS     0x00
******************       END_OF_MSG                       ******************

You also can run the MML tst-cot command to execute a continuity test on a specified remote switch circuit.

  • Format: tst-cot:<sig path>:CIC=<number>

  • Description:

    • * sig path—MML component name of a provisioning component signal path.

    • * CIC=<number>—A numeric value which identifies the ISUP circuit identification code number.

For example, this MML command executes a continuity test on c7srv-bru7 for CIC-2:

PGW2200a mml>tst-cot:c7srv-bru7:cic=2
MGC-01 - Media Gateway Controller 2002-09-19 13:26:51.530 WET
M RTRV
SCNF
"c7srv-bru7"
/* Passed */
;
PGW2200a mml> 

From the MGCP CRCX message, you can see the co1 of 2010 Hz or [co2 of 1780 Hz].

----------------- 
 MESSAGES DISPLAY  
 ----------------- 
 
Time stamp       Orig IP address      Dest IP address      Prot          Msg  Data 
------------------------------------------------------------------------------------------------------- 


13:26:48.590752  10.48.84.128:2427    10.48.84.110:2427    MGCP...... -> CRCX 12587 s6/ds1-2/2@vsig5400-a2.cisco.com MGCP 0.1 
                                                                         C: 1AF 
                                                                         L: e:off 
                                                                         M: recvonly 
                                                                         R: T/co1(N) 
                                                                         S: T/co1 
                                                                         X: 312A 
13:26:51.050405  10.48.84.128:2427    10.48.84.110:2427    MGCP...... -> CRCX 12587 s6/ds1-2/2@vsig5400-a2.cisco.com MGCP 0.1 
                                                                         C: 1AF 
                                                                         L: e:off 
                                                                         M: recvonly 
                                                                         R: T/co1(N) 
                                                                         S: T/co1 
                                                                         X: 312A 
13:26:51.096961  10.48.84.110:2427    10.48.84.128:2427    MGCP...... -> 200 12587 OK 
                                                                         I: D 
                                                                         v=0  
                                                                         o=- 13 0 IN IP4 10.48.84.110  
                                                                         s=Cisco SDP 0  
                                                                         c=IN IP4 10.48.84.110  
                                                                         t=0 0  
                                                                         m=audio 19198 RTP/AVP 18 0 8 101 102 2 103 4 104 105 106 107 125 
99  
                                                                         a=rtpmap:101 G726-16/8000  
                                                                         a=rtpmap:102 G726-24/8000  
                                                                         a=rtpmap:103 G7231-H/8000  
                                                                         a=rtpmap:104 G7231-L/8000  
                                                                         a=rtpmap:105 G729b/8000  
                                                                         a=rtpmap:106 G7231a-H/8000  
                                                                         a=rtpmap:107 G7231a-L/8000  
                                                                         a=rtpmap:125 GnX64/8000  
                                                                         a=rtpmap:99 telephone-event/8000  
                                                                         a=fmtp:99 0-15  
                                                                         a=X-sqn:0  
                                                                         a=X-cap: 1 image udptl t38  
13:26:51.120463  3-005-2[06186]       3-005-1[06185]       ITU  ISUP. -> CCR (11) CIC=00002  
                                                                         SLS=02 Pr:0 Ni:NTL  
13:26:51.517150  10.48.84.110:2427    10.48.84.128:2427    MGCP...... -> NTFY 4 s6/ds1-2/2@vsig5400-a2.cisco.com MGCP 0.1 
                                                                         X: 312A 
                                                                         O: T/co1 
13:26:51.531608  3-005-2[06186]       3-005-1[06185]       ITU  ISUP. -> REL (0c) CIC=00002  Cause 16 = Normal Call Clearing
                                                                         SLS=02 Pr:0 Ni:NTL  
13:26:51.531939  10.48.84.128:2427    10.48.84.110:2427    MGCP...... -> 200 4 OK 
                                                                         C: 1AF 
13:26:51.532220  10.48.84.128:2427    10.48.84.110:2427    MGCP...... -> DLCX 12589 s6/ds1-2/2@vsig5400-a2.cisco.com MGCP 0.1 
                                                                         C: 1AF 
                                                                         I: D 
                                                                         R:   
                                                                         S:   
                                                                         X: 312C 
13:26:51.577503  10.48.84.110:2427    10.48.84.128:2427    MGCP...... -> 250 12589 OK 
                                                                         P: PS=0, OS=0, PR=0, OR=0, PL=0, JI=0, LA=0 
13:26:51.652675  3-005-1[06185]       3-005-2[06186]       ITU  ISUP. -> RLC (10) CIC=00002  
                                                                         SLS=02 Pr:0 Ni:NTL  

Note: Continuity test is not part of the UK ISUP V3 and COT message is not a valid message for this protocol.

Related Information

Updated: Feb 02, 2006
Document ID: 48300