Application
protocols
Protocol
layers (”levels”) of SS7
MTP - Message Transfer Part
SCCP - Signalling Connection Control Part
UP
- User Part AP - Application Part
CAP
INAP
MAP
ISUP
TCAP
SCCP
TUP
MTP level 3
MTP level 2 (link-layer
protocol)
MTP level 1 (64 kbit/s PCM
time slot)
routing