3Com® VCX V7111 VoIP Gateway User Guide 251the MWI lamp is configured, the phones lamp (on a phone that is equipped with an MWIlamp) is lit. The gateway can subscribe to the MWI server per port (usually used on FXS) orper gateway (used on FXO).To configure MWI set the following parameters: EnableMWI MWIServerIP MWIAnalogLamp MWIDisplay StutterToneDuration EnableMWISubscription MWIExpirationTime SubscribeRetryTime SubscriptionMode CallerIDType (determines the standard for detection of MWI signals) ETSIVMWITypeOneStandard BellcoreVMWITypeOneStandardConfiguring the DTMF Transport TypesYou can control the way DTMF digits are transported over the IP network to the remoteendpoint. These modes are supported:1 Using NOTIFY messages according to :In this mode DTMF digits are carried to the remote side using NOTIFY messages.To enable this mode set: RxDTMFOption = 0 (Declare RFC 2833 in SDP = No). TxDTMFOption = 2 (1 st to 5 th DTMF Option = NOTIFY). Note that in this mode DTMFdigits are erased from the audio stream (DTMFTransportType is automatically set to0 (DTMF Mute)).2 Using RFC 2833 relay with Payload type negotiation:In this mode, DTMF digits are carried to the remote side as part of the RTP stream inaccordance with RFC 2833 standard.To enable this mode set: TxDTMFOption = 4 (1 st to 5 th DTMF Option = RFC 2833). RxDTMFOption = 3 (Declare RFC 2833 in SDP = Yes). Note that to set the RFC 2833payload type with a different value (other than its default, 96) configure theRFC2833PayloadType (RFC 2833 Payload Type) parameter. The gateway negotiates
