SIP INFO Method for DTMF

This feature allows the use of the SIP INFO method to send a DTMF digit to another gateway. The voice stream is established after a successful SIP 200 OK-ACK message sequence.

 

Note: A more robust method to use for sending DTMF digits in SIP is SIP SUBSCRIBE/NOTIFY Method for DTMF.

 

This feature is enabled using the SIP DTMF Support pane. There are two ways of using the INFO Method for DTMF:

 

INFO Using Pattern

After a match of the configured number of # or * characters in the voice stream, the IMG will send a character in the SIP INFO to the same endpoint to which the 200 OK ACK was sent. The voice stream is established after a successful SIP 200 OK-ACK message sequence. The SIP INFO will contain a SIP header of Signal (showing the character) and the duration header (showing the length in milliseconds of the duration to play the character signal).  

 

Configuration

You enable this feature using the SIP DTMF Support pane by selecting INFO with Pattern in the Method field. The implementation currently supported is shown below.

Software Builds

Digits Supported

10.3.3 ER2 - 10.3.3 ER6

(####,###,##,#)

10.3.3 ER7 +

(####,###,##,#) -or- (****,***,**,*)

10.5.0 ER1

(####,###,##,#)

10.5.0 ER2

(####,###,##,#) -or- (****,***,**,*)

10.5.1 +

(####,###,##,#) -or- (****,***,**,*)

 

 

SIP INFO Header

The existing header of the SIP INFO method will be modified to carry the digit.

 

The following shows a SIP INFO header with the changes:

             INFO sip:8570@150.129.39.105:5060 SIP/2.0

             Via: SIP/2.0/UDP 150.129.38.217:5060; rport;branch=z9hG4bK-1170-1145483948-19998-190

             Call-ID: 1c5-403-3192006215856-MFG_5-0@10.129.38.217

              CSeq: 2 INFO

             Max-Forwards: 70

             To: <sip:8570@150.129.39.105>;tag=75001a07

             From: <sip:3280@150.129.38.217>;tag=95ffcd055e0f78f7d5d397020e89288de8b1

             User-Agent: Excel-Open-SIP/10.3.1.56 MFG_5 0

             Timestamp: 04192006215908

             Accept: application/ sdp

             Content-Length: 26

             Content-Type: application/ dtmf-relay

             

              Signal= #

                 Duration= 120

 

 Call Flow: # Character in SIP INFO

cf_sip_info_dtmf.png

 

 

 

INFO DTMF Digit Relay

With this feature the IMG supports out-of-band tone passage of a single DTMF digit (0- 9, *, #, a, b, c, d) using the SIP INFO method.

 

Configuring the Feature

You enable this feature by selecting INFO DTMF digit relay in the Method field of the SIP DTMF Support pane.

 

Digits Received from TDM Side

The IMG will send out a single DTMF digit in the INFO if it receives a digit from a TDM Channel (no pattern match required)

cf_sip_dtmf_relay.png

 

Example INFO Message: TDM-to-SIP

 

INFO sip:10.129.39.95:5060 SIP/2.0

Via: SIP/2.0/UDP 10.129.39.49:5060;rport;branch=z9hG4bK-

16cf-1182872402-19997-319

Call-ID: 5331-400-5262007153956-YUE_NODE-0@10.129.39.49

CSeq: 2 INFO

Max-Forwards: 70

To: <sip:22233333@10.129.39.95:5060>;tag=1

From: <sip:123@10.129.39.49>;tag=95ffcd055e0f78f7d5d3970

20e89288dc959

User-Agent: Cantata-SIP/10.3.3.172 YUE_NODE 0

Accept: application/sdp

Content-Type: application/dtmf-relay

Content-Length: 26

Signal= 6

Duration= 100

 

Digits Received from IP Side

The IMG will send out a single DTMF digit in the INFO if it receives a SIP INFO request that has the Content-Type set to “application\dtmf-relay”. When the Content-Type header of incoming INFO request has value “application/dtmf-relay”, the IMG will look for a DTMF digit in the “Signal=” line and the digit interval in the “Duration=” line. If there is more than one digit in the “Signal=” line from incoming INFO, the IMG will only accept first digit. If the Duration= line is not present, the interval will be set to 100.

 

Error Conditions

The IMG will return a 488 if an INFO message with the Content-Type set to application/dtmf-relay is received and:

 

cf_sip_dtmf_relay2.png