292 V7122 GatewayUser GuideThe default value of the Interface ID is identical to the number of the physical T1 trunk (0 forthe first gateway trunk, 1 for the second gateway T1 trunk and the like up to 7).To define an explicit Interface ID for a T1 trunk (that is different from the default), use thefollowing parameters: ISDNIBehavior_x = 512 (x = 0 to 7 identifying the gateway’s physical trunk) ISDNNFASInterfaceID_x = ID (x = 0 to 255)• Usually the Interface Identifier is included in the Q.931 Setup/ChannelIdentification IE only on T1 trunks that doesn’t contain the D-channel. Callsinitiated on B-channels of the Primary T1 trunk, by default, don’t contain theInterface Identifier. Setting the parameter ‘ISDNIBehavior_x’ to 2048’ forcesthe inclusion of the Channel Identifier parameter also for the Primary trunk.• The parameter ‘ISDNNFASInterfaceID_x = ID’ can define the ‘Interface ID’ forany Primary T1 trunk, even if the T1 trunk is not a part of an NFAS group.However, to include the Interface Identifier in Q.931 Setup/ChannelIdentification IE configure ‘ISDNIBehavior_x = 2048’ in the ini file.Working with DMS-100 SwitchesThe DMS-100 switch requires the following NFAS Interface ID definitions: InterfaceID #0 for the Primary trunk InterfaceID #1 for the Backup trunk InterfaceID #2 for a 24 B-channel T1 trunk InterfaceID #3 for a 24 B-channel T1 trunk Etc.For example, if four T1 trunks on a gateway are configured as a single NFAS group, withPrimary and Backup T1 trunks, that is used with a DMS-100 switch, the following parametersshould be used:NFASGroupNumber_0 = 1NFASGroupNumber_1 = 1NFASGroupNumber_2 = 1NFASGroupNumber_3 = 1DchConfig_0 = 0 ;Primary T1 trunkDchConfig_1 = 1 ;Backup T1 trunkDchConfig_2 = 2 ;B-Channel NFAS trunkDchConfig_3 = 2 ;B-channel NFAS trunkIf there is no NFAS Backup trunk, the following configuration should be used:ISDNNFASInterfaceID_0 = 0ISDNNFASInterfaceID_1 = 2ISDNNFASInterfaceID_2 = 3ISDNNFASInterfaceID_3 = 4ISDNIBehavior = 512 ;This parameter should be added because of;ISDNNFASInterfaceID configuration aboveNFASGroupNumber_0 = 1
