Trunk Interface
Field
Backup
None
Primary
None
Specifies, when a common channel signaling (CCS) protocol is being used, whether the trunk is to be used as the primary signaling channel, backup signaling channel (D-channel backup), or neither. Select Primary if this trunk is the primary signaling channel. Select Backup if this trunk is to be the backup channel. (If the protocol is ISDN, this applies only if D-channel backup is in use.) Select None if ISDN non-facility associated signaling (NFAS) is in use and this trunk is not to carry signaling information. This parameter does not apply to channel associated signaling (CAS).