Once you know SLC (Signalling Line Code) for a particular time slot then these are the few things you can check:
- Trunk b/w source (SSP) and Destination (SCP)
- DPC(Destination Point Code) and OWNSP
- Signaling Link set.
- Network ID(NAT0 & NAT1)
- PCM channel on which link is creating
If these all things are working then your PCM link should be up.