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.
Peer SP TMG
IAM - - - - - - - - - - ->
Check tone - - - - - - - - - - -|
- - - - - - - - - -
REL - - - - - - - - - - ->
< -- - - - - - - - - - RLC
For ANSI protocol: 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 -- - - - - - - - - - ->