What is SS7 ISUP ?
SS7 (signalingSystem 7) or “out-of-band” signaling is the most widely used signaling system where the signals are transmistted on a seperate physical channel from the call channel. Because of that SS7 network can examine all parts of a call route for free lines an allocate them at once. This leads to a more efficient network and fast call setup times in generally in and about 3 seconds where as in early CAS systems this might take about 20 seconds. Also it has many more advantages compared to the early signaling systems such as CAS (Channel Associated Signaling) or “in-band” signaling where signals and the call are transmitted on the same channel.
