8 7 6 5 4 3 2 1 1 Call identity 2 Call identity 3 Call identity 4 Sign. point code .. LSB 5 Spare | MSB.............Call identity - A code expressing in pure binary representation the identification number allocated to the call.
The fields of the call reference information elements are: 8 7 6 5 4 3 2 1 +--------------+---------------+ |0 0 0 0 |lenght of Crv | +--+-----------+---------------+ |f | call reference value | <- BRI f=0 origination side, f=1 destination side +--+---------------------------+ | call reference value | <- BRI PRI +------------------------------+Call reference values are assigned by the originating side of the interface for a call. The numerical value of the global call reference is zero.