A Transit counter információs elem

The purpose of the transit counter information element is to limit the number of transit PTNXs that a call setup request may be routed through, in order to protect the network against indefinite looping.

               8  7  6  5  4  3  2  1
        1      0  0  1  1  0  0  0  1 = 0x31
        2            length  3
        3   1 ext 0  0  a  a  a  a  a - transit count (binary value)