At the calling side, the network shall check that the bearer service requested by the calling user in the Bearer capability information element matches with the bearer services provided to that user by the network. If a mismatch is detected, then the network shall reject the call using one of the causes listed in 5.1.5.2.
Network services are described in Recommendations I.230 [47] and I.240 [48] as bearer services and teleservices,respectively.