SIP SUBSCRIBE/NOTIFY Method for DTMF

Overview

The IMG accepts user agent subscription requests (SIP SUBSCRIBE method) and the ability to respond to those user agents with the appropriate DTMF digit events via the SIP NOTIFY method. Below is chart on which characters are supported and which builds they are supported in.

 

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- (****,***,**,*)

 

RFC: 3265 Session Initiation Protocol (SIP)-Specific Event Notification

 

Benefits

You can develop user-specific applications that reside on your network entity and have the ability to subscribe for event services supported by the IMG.  If the network entity wants the ability to detect an entered DTMF digit (only telephone event of “###” are currently supported) from the TDM-side of a call to the IP side of a call, the entity can subscribe to the IMG for these events and receive SIP NOTIFY events containing the digit event.

 

Limitations

 

Configuration

You enable and configure this feature with the SIP DTMF Support pane. In the Method field select Subscribe and then configure other fields as required.

 

 

Call Flows

CF_SIP_SubNot_Succ_PerCall.png

 

CF_SIP_SubNot_Succ_PerGW.png

 

CF_SIP_SubNot_Refresh.png

 

Call Tracing

Each SIP request received or transmitted for the SIP SUBSCRIBE and NOTIFY methods will be displayed in the normal call tracing.  For the NOTIFY method, the trace will also display the NOTIFY method’s payload.  In the case of detected DTMF digits, the characters will be displayed in the call tracing.

 

Example Trace

The following is an example call trace showing SIP Subscribe Notify for DTMF. Related lines are in bold.

 

---> [10.129.55.74, 5060]

       SUBSCRIBE sip:8519@10.129.55.80:5060 SIP/2.0

       Via: SIP/2.0/UDP 10.129.55.74:5060

       From: 7340 <sip:7340@10.129.55.74:5060>;tag=1

       To: 8519 <sip:8519@10.129.55.80:5060>;tag=a94c095b773be1

       dd6e8d668a785a9c84113d

       Call-id: 1-2104@10.129.55.74

        Cseq: 1 SUBSCRIBE

       Contact: <sip:sipp@10.129.55.74:5060; transport=UDP>

       Event: telephone-event;duration=300

       Expires: 600

       Content-Length: 0

                                                          

18:17:08.733 SIP (W)  

       <--- [10.129.55.74, 5060 <- 10.129.55.80, 5060]

        SIP/2.0 200 OK

       Via: SIP/2.0/UDP 10.129.55.74:5060;received=10.129.55.74

       Call-ID: 1-2104@10.129.55.74

       From: 7340 <sip:7340@10.129.55.74:5060>;tag=1

       To: 8519 <sip:8519@10.129.55.80:5060>;tag=a94c095b773be1

       dd6e8d668a785a9c84113d

        CSeq: 1 SUBSCRIBE

       Server: Cantata-SIP/10.3.3.129 SIP-Gateway1 0

       Expires: 600

       Content-Length: 0

        <--- [10.129.55.74, 5060 <- 10.129.55.80, 5060]

        NOTIFY sip:sipp@10.129.55.74:5060 SIP/2.0

        Via: SIP/2.0/UDP 10.129.55.80:5060; rport;branch=z9hG4bK- 5c5e-1163009828-19999-33

        Call-ID: 1-2104@10.129.55.74

         CSeq: 1 NOTIFY

        Max-Forwards: 70

        To: <sip:7340@10.129.55.74>;tag=1

        From: <sip:8519@10.129.55.80>;tag=a94c095b773be1dd6e8d668a785a9c84113d

        User-Agent: Cantata-SIP/10.3.3.129 SIP-Gateway1 0

        Event: telephone-event;duration=300

          Subscription-State: Active;expires=600

        Content-Length: 0

                      

                                             

18:17:08.753 SIP (W)  

         ---> [10.129.55.74, 5060]

         SIP/2.0 200 OK

         Via: SIP/2.0/UDP 10.129.55.80:5060; rport;branch=z9hG4bK- 5c5e-1163009828-19999-33

         From: <sip:8519@10.129.55.80>;tag=a94c095b773be1dd6e8d668a785a9c84113d

         To: <sip:7340@10.129.55.74>;tag=1;tag=1

         Call-ID: 1-2104@10.129.55.74

          CSeq: 1 NOTIFY

         Contact: <sip:10.129.55.74:5060; transport=UDP>

         Content-Length: 0

 

NOTIFY sip:sipp@10.129.55.74:5060 SIP/2.0

          Via: SIP/2.0/UDP 10.129.55.80:5060; rport;branch=z9hG4bK-d37-1163009863-19998-33

          Call-ID: 1-2104@10.129.55.74

           CSeq: 2 NOTIFY

          Max-Forwards: 70

          To: <sip:7340@10.129.55.74>;tag=1

          From: <sip:8519@10.129.55.80>;tag=a94c095b773be1dd6e8d668a785a9c84113d

          User-Agent: Cantata-SIP/10.3.3.129 SIP-Gateway1 0

          Event: telephone-event;duration=300

          Subscription-State: Active;expires=125

          Content-Type: application/ dtmf-relay

          Content-Length: 26

 

           Signal= #

           Duration= 160

                                                                    

18:17:43.893 SIP (W)  

          ---> [10.129.55.74, 5060]

          SIP/2.0 200 OK

          Via: SIP/2.0/UDP 10.129.55.80:5060;rport;branch=z9hG4bK-d37-1163009863-19998-33

          From: <sip:8519@10.129.55.80>;tag=a94c095b773be1dd6e8d668a785a9c84113d

          To: <sip:7340@10.129.55.74>;tag=1;tag=1

          Call-ID: 1-2104@10.129.55.74

          CSeq: 2 NOTIFY

          Contact: <sip:10.129.55.74:5060;transport=UDP>

          Content-Length: 0

 

Troubleshooting

If you are experiencing problems with this feature, ensure the following: