This object determines the method used to verify the TCF(Training Check Field). For UDP-based fax transport, its value should be set to networkTCF. For TCP-based fax transport, its value should be set to localTCF. A value of localTCF may be used in rare circumstances for UDP-based fax transport. A value of networkTCF implies that date rate management is done end-to-end between the group 3 fax terminals, in a manner similar to the PSTN(Public Switched Telephone Network). In this case, the TCF training signal is passed transparently by the IP network. A value of localTCF implies that media gateways are actively involved in the training and data rate management procedure, including the generation of the TCF training signal. Data rate management is done by one of the media gateways on the basis of local results and results forwarded over the IP network by the other gateway. The other gateway generates the TCF training signal towards its group 3 fax terminal.