The elements of procedure in this subclause provide for physical layer and/or data link layer rearrangements after a call has entered the Active state as defined in 2.2.1.8. The procedure is restricted to use on the same interface structure, and resumption on the same B-channel. The use of call rearrangement procedure is restricted to basic access, i.e. it will not be available for primary rate access. For call rearrangements controlled by an NT2, see 5.6.7.
The activation of this procedure at a user-network interface may correspond to a number of possible events such as the following:
a) physical disconnection of user equipment and reconnection;
b) physical replacement of one user equipment by another;
c) the human user moves from one equipment to another;
d) suspension of call and its subsequent reactivation at the same user equipment.
These procedures have only local significance, i.e. the invocation of call rearrangement affects only states at the originating end, and it does not affect any terminating states.
The procedures in this subsection are described in terms of functional messages and information elements.
If the procedures for call suspension in this subsection are not followed prior to the physical disconnection of the terminal from the interface, then the integrity of the call cannot be guaranteed by the network.