Editing Message Transfer Part (section)

===Signalling Data Link Functional Level===
''MTP Level 1'' is described in [http://www.itu.int/rec/T-REC-Q.702/en/ ITU-T Recommendation Q.702], and provides the ''Signalling Data Link'' functional level for narrowband signalling links. For broadband signalling links,
[http://www.itu.int/rec/T-REC-Q.2110/en/ ITU-T Recommendation Q.2110] or
[http://www.itu.int/rec/T-REC-Q.2111/en/ Q.2111] describe the signalling data link function.

MTP1 represents the physical layer. That is, the layer that is responsible for the connection of SS7 Signaling Points into the transmission network over which they communicate with each other. Primarily, this involves the conversion of messaging into electrical signal and the maintenance of the physical links through which these pass. In this way, it is analogous to the Layer 1 of ISDN or other, perhaps more familiar, protocols.

MTP1 normally uses a timeslot in an [[E-carrier]] or [[T-carrier]]. The Physical interfaces defined include E-1 (2048&nbsp;kbit/s; 32 64&nbsp;kbit/s channels), DS-1 (1544&nbsp;kbit/s; 24 64&nbsp;kbit/s channels), V.35 (64&nbsp;kbit/s), DS-0 (64&nbsp;kbit/s), and DS-0A (56&nbsp;kbit/s).