IMG 1010 - SIP INFO Method - 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.

 This feature is enabled using the IMG 1010 - SIP DTMF Support pane. There are two ways of using the INFO Method for DTMF:

• INFO Using Pattern

• INFO DTMF Relay

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 IMG 1010 - SIP DTMF Support pane by selecting INFO with Pattern in the Method field. The implementation currently supported is shown below.

SIP INFO Header

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

• Signal parameter - used to carry the # or * character in the SDP.  

• Duration parameter - used in the SDP to store the length of time in milliseconds to play the digit.

• Content-Type header - will be changed to dtmf-relay when this feature is invoked.  
   

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

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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 IMG 1010 - 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)

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Example INFO Message: TDM-to-SIP

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:

• the IMG configuration is not set to INFO DTMF relay.

• the IMG configuration is set to INFO DTMF relay, but the Signal= line contains un-recognizable character.