IMG 1010 - SIP INFO Method - SUBSCRIBE-NOTIFY
- Kelli Higdon
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
Patterns of 1-4 pound and wildcard (#)(*) characters are supported
The ‘Pending’ state is not supported
The IMG cannot send a SIP SUBSCRIBE
Configuration
You enable and configure this feature with the IMG 1010 - SIP DTMF Support pane. In the Method field select Subscribe and then configure other fields as required.
Call Flows
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:
Subscribe is enabled in the SIP SGP
The correct SIP SGP is assigned to the External Remote Gateway