Continuity Testing Call Flow (CCR/COT)

Continuity tests are used to make sure that the SS7 ISUP interface circuit groups (CIC) are aligned with the physical links (E1/T1) properly. Toolpack version 2.7 allows users of the TMG to do ISUP Continuity Testing via 3 methods by CIC Group or individual CIC:

Incoming Continuity testing outside a call

This circuit testing occurs when one of the nodes wants to validate a currently idle circuit. It is recommended that the switch first blocks the circuit to prevent calls to use the circuit during the testing.

For ITU:

Peer SP                                        TMG
IAM            - - - - - - - - - - -> 
Check tone     - - - - - - - - - - -|
                - - - - - - - - - -
REL            - - - - - - - - - - ->
               < -- - - - - - - - - -          RLC

For ANSI:

Peer SP                                        TMG
CCR            - - - - - - - - - - -> 
               < -- - - - - - - - - -          LPA
Check tone     - - - - - - - - - - -|
                - - - - - - - - - -
REL            - - - - - - - - - - ->
               < -- - - - - - - - - -          RLC

Incoming Continuity testing within a call

This circuit testing occurs when the forward side (originating side) sets the ‘continuity test required’ field of the ‘nature of connection indicators’ IE into the IAM message.

Peer SP                                        TMG
IAM           - - - - - - - - - - ->
Check tone    - - - - - - - - - - -|
              - - - - - - - - - - -
COT (successful) - - - - - - - - -->
             <- - - - - - - - - - -            ACM
              - - - - - - - - - - -            Ringing tone
             <- - - - - - - - - - -            ANM
Connectivity - -  - -  - -  - -  - -           Connectivity
REL          - - - - - - - - - - ->
             <- - - - - - - - - - - RLC

Outgoing COT testing

Peer SP                                        TMG
            < - - - - - - - - - - -            CCR
            |- - - - - - - - - - -             Check tone
              - - - - - - - - - -
            < - - - - - - - - - - -            REL 
RLC          -- - - - - - - - - - ->    

Configuration

• Web Portal v2.7: Outgoing COT testing