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