| 摘要 |
<p>A method and an apparatus for negotiating the used communication mode in a telecommunications system, wherein a connection is arranged between at least two system elements. The system elements exchange messages and check whether a first in-band signalling protocol is supported. The communication mode is selected according to the first signalling protocol if the system elements support the first signalling protocol. If the first signalling protocol is not supported, support for a tandem free operation (TFO) protocol is checked and communication between the system elements is continued according to TFO procedures if the system elements support TFO. If the first signalling protocol and TFO are not supported, the communication mode between the system elements may be selected according to a second inband signalling protocol.</p> |
