LTP is described as follows:

There may be up to 8 physical terminals on an S-Bus. Each physical terminal may comprise a number of logical terminals which cater, for example, for speech and data and each of the logical terminals may have a different subscriber number and will require different Bearer Services. The set of parameters used in the exchange to describe these logical terminals comprise the Logical Terminal Profile (LTP). The LTP uses the Terminal Endpoint Identifier (TEI) of the LAPD signalling protocol of layer 2 to identify a specific Logical Terminal in a Physical Terminal. (see Address Field in Layer 2, LAPD).

In this way LTP may be used for connecting an incoming call with the appropriate terminal on the S-Bus.