For SS7 Trouble shooting you will need a protocol analyser and an understanding of the
nodes that are used to convey / trasport SS7 packet data units.
To understand SS7 you will need
to look at the Layer 2 and 3 Frames. Good start is with: Message Signal Unit (MSU), Link Status Signal Unit (LSSU) and Fill-in Signal Unit (FISU). Feel free to search for MTP, SCCP, TCAP, ISUP, INAP and MAP.
Sigtran – Signalling Transport – is basicially SS7 over Internet Protocol (SS7overIP). A good understanding of TCP/IPver4.0 / 6.0 and
SCTP will help.