MediaPack SIP 
MediaPack SIP User’s Manual   64  Document #: LTRT-65405 
Table  5-4: DTMF & Dialing Parameters (continues on pages 63 to 65) 
Parameter  Description 
Use Out-of-Band DTMF 
[IsDTMFUsed] 
Use out-of-band signaling to relay DTMF digits. 
No  [0] = DTMF digits are sent in-band (default). 
Yes  [1] = DTMF digits are sent out-of-band according to the parameter ‘Out-of-band 
DTMF format’. 
 
Note: When out-of-band DTMF transfer is used, the parameter ‘DTMF Transport Type’ 
is automatically set to 0 (erase the DTMF digits from the RTP stream). 
Out-of-Band DTMF Format 
[OutOfBandDTMFFormat] 
The exact method to send out-of-band DTMF digits. 
INFO (Nortel)    [1] = Sends DTMF digits according with IETF <draft-choudhuri-sip-
info-digit-00>. 
INFO (Cisco)    [2] = Sends DTMF digits according with Cisco format (default). 
NOTIFY (3Com)  [3] = NOTIFY format <draft-mahy-sipping-signaled-digits-01.txt>. 
 
Note 1: To use out-of-band DTMF, set ‘IsDTMFUsed=1’. 
Note 2: When using out-of-band DTMF, the ‘DTMFTransportType’ parameter is 
automatically set to 0, to erase the DTMF digits from the RTP stream. 
Declare RFC 2833 in SDP 
[RxDTMFOption] 
Defines the supported Receive DTMF negotiation method. 
No  [0] = Don’t declare RFC 2833 Telephony-event parameter in SDP 
Yes [3] = Declare RFC 2833 Telephony-event parameter in SDP (default) 
 
The MediaPack is designed to always be receptive to RFC 2833 DTMF relay packets. 
Therefore, it is always correct to include the ‘Telephony-event’ parameter as a default in 
the SDP. However some gateways use the absence of the ‘telephony-event’ from the 
SDP to decide to send DTMF digits in-band using G.711 coder, if this is the case you 
can set ‘RxDTMFOption=0’. 
DTMF RFC 2833 Negotiation
[TxDTMFOption] 
Disable  [0] = No negotiation, DTMF digit is sent according to the parameters ‘DTMF 
Transport Type’ and ‘RFC2833PayloadType’ (default). 
Enable  [4] = Enable RFC 2833 payload type (PT) negotiation. 
 
Note 1: This parameter is applicable only if ‘IsDTMFUsed=0’ (out-of-band DTMF is not 
used). 
Note 2: If enabled, the gateway: 
•  Negotiates RFC 2833 payload type using local and remote SDPs. 
•  Sends DTMF packets using RFC 2833 PT according to the PT in the received SDP.
•  Expects to receive RFC 2833 packets with the same PT as configured by the 
‘RFC2833PayloadType’ parameter. 
Note 3: If the remote party doesn’t include the RFC 2833 DTMF relay payload type in 
the SDP, the gateway uses the same PT for send and for receive. 
Note 4: If TxDTMFOption is set to 0, the RFC 2833 payload type is set according to the 
parameter ‘RFC2833PayloadType’ for both transmit and receive. 
RFC 2833 Payload Type 
[RFC2833PayloadType] 
The RFC 2833 DTMF relay dynamic payload type. 
Range: 96 to 99, 106 to 127; Default = 96 
The 100, 102 to 105 range is allocated for proprietary usage. 
Note 1: Cisco is using payload type 101 for RFC 2833. 
Note 2: When RFC 2833 payload type (PT) negotiation is used (TxDTMFOption=4), this 
payload type is used for the received DTMF packets. If negotiation isn’t used, this 
payload type is used for receive and for transmit. 
Use INFO for Hook-Flash 
[IsHookFlashUsed] 
No  [0] = INFO message isn’t sent (default). 
Yes [1] = Proprietary INFO message with hook-flash is sent when hook-flash is detected 
(FXS). FXO gateways generate a hook-flash signal when INFO message with hook-
flash is received. 
 
Note: When either of the supplementary services (Hold, Transfer or Call Waiting) is 
enabled, hook-flash is used internally, and thus the hook-flash signal isn’t sent via an 
INFO message.