This chapter is the first in a series of chapters that examine a specific SS7/C7 protocol layer. This chapter details the Layer 2 protocol, which is known as Message Transfer Part 2 (MTP2). MTP2 corresponds to OSI Layer 2 (the data link layer) and as such is the lowest protocol in the stack. Sitting on the physical layer, it provides a reliable means of transfer for signaling information between two directly connected signaling points (SPs), ensuring that the signaling information is delivered in sequence and error-free.
MTP2 performs the following functions:
Delimitation of signal units
Alignment of signal units
Signaling link error detection
Signaling link error correction by retransmission
Signaling link ...