Network-wide connections can be identified with the help of a call ID, which can be stored in the call data records. This makes it possible to link together call data records that stem from a connection's different recording locations (measurement at different path sections of a network-wide connection) at a later time for offline analysis of the call data records and for computing the costs.

The call ID has two levels and has a thread ID and a global ID: the thread and global IDs contain a three-level node number and a counter (sequence number). The call ID is assigned during the first call processing operation.

The thread ID does not change throughout the entire connection (even network-wide) and can therefore be consulted for a summary of all CDR records that belong to a connection.

The global ID changes with each call step such as transfer, call forwarding, etc.