You are here: CSP Developer’s Guide: Internet Protocol > 5 Session-Initiation Protocol (SIP) Software > Report REFER Request URI in PPL Event Indication
Report REFER Request URI in PPL Event Indication
Overview
The REFER message implements a call transfer service.
A user agent (referrer) uses the REFER message to request another user agent (referee) that it is in session-establish state with, to contact a third user agent (refer target).
The Refer target is identified by a SIP URI in the Refer-To header field in the REFER message.
You can enable this feature to get the Request-URI, in the Request-Line of the REFER message, reported to the host.
Example: With a SIP-to-ISDN call, if any ISDN related information like UUI, UUI encoding, or presentation indicator is present as a parameter in the Request-URI, this feature allows the host to get this data.
Pertinent Specification
RFC 3261
Description
This feature enhances the CSP SIP stack to report the Request-URI in the REFER message, including the parameters, to the host. This reporting is a configurable option in the CSP SIP stack and is disabled by default. This feature does not provide write access to Request-URI for a REFER message generated by CSP SIP stack.
Prior to this feature, the CSP SIP could not report the Request-URI in REFER to the host. When this feature is enabled, the Request-URI in the inbound REFER message is reported to the host using the following TLVs within the PPL Event Indication for REFER (Comp: 0x00A7, Event: 0x0021/0x0022 for Blind and Consultative REFER respectively)
• SIP Request URI User Name - 0x2954
• SIP Request URI Password - 0x2946
• SIP Request URI Host Name - 0x2955
• SIP Request URI Port - 0x2956
• SIP Request URI Parameters - 0x2958
• SIP Request URI Headers - 0x2947
Important! All TLVs except the port number TLV ends with a NULL terminator, therefore the actual data supported is one less than the maximum length supported for the TLVs. Also note that the CSP nacks all SIP requests of a size greater that 1500 bytes with the 513 message, Too Large
API Call Control Messages
PPL Event Indication (0x0043)
API and CSA Configuring and Querying
This feature can be configured either using the API or CSA.
API Configuring and Querying
Reporting of Request-URI in the REFER message is a configurable option and is be disabled by default. To enable this reporting, set bit 21 of PPL Event Notification Mask TLV (0x027F) and send it in the VoIP Protocol Configure (0x00EE) message.
CSA Configuring and Querying
To configure and query the SIP stack for this feature, view the Configure SIP Advanced screen, Additional Host Signaling Parameters, and select Report of Request-URI.
Call Flow - Refer Request
The call flow below is a simplified scenario to depict this feature. Assume the CSP is enabled to report Request-URI in inbound REFER to the host. The CSP acts an endpoint, though in most scenarios it acts as a gateway. Once the CSP and UA1 are in session-established state (answered), UA1 puts the session on-hold (Re-INVITE), sends a REFER request to CSP and releases the call. The CSP accepts the Re-INVITE. After the CSP receives the REFER, it responds with the appropriate response (202 in the example) and reports the Request-URI to the host within the PPL Event Indication for the REFER message.
Call Trace - Refer Request
API Trace:
X->H
[01 f2 00 2d 00 0c 01 00 01 0d 03 00 64 0c 00 33 01 03 00 33 01 de 00 1a 27 4e 00 02 00 05 27 7e 00 03 08 00 00 29 19 00 06 31 31 31 31 31 00 29 1b 00 0c 31 30 2e 31 30 2e 31 2e 32 35 30 00 29 1c 00 04 00 00 13 c4 29 23 00 06 32 30 35 39 37 00 29 25 00 0c 31 30 2e 31 30 2e 31 2e 32 35 30 00 29 26 00 04 00 00 13 c4 29 28 00 08 22 53 75 62 62 75 22 00 29 2d 00 06 32 30 35 39 37 00 29 2f 00 0a 31 30 2e 31 30 2e 31 2e 32 00 29 30 00 04 00 00 13 c4 29 33 00 01 01 27 18 00 08 02 00 00 00 05 20 59 70 27 17 00 06 02 00 05 11 11 10 29 16 00 01 01 29 54 00 06 31 31 31 31 31 00 29 55 00 0c 31 30 2e 31 30 2e 31 2e 32 35 30 00 29 56 00 04 00 00 13 c4 29 50 00 36 33 61 30 36 66 61 33 30 66 65 33 30 64 64 34 33 40 63 33 4a 68 61 6d 56 75 5a 48 4a 68 4c 57 6c 69 62 53 35 44 62 33 4a 77 4c 6e 68 73 4c 6d 4e 76 62 51 2e 2e 00 29 51 00 09 33 39 30 65 37 34 30 31 00 29 52 00 09 39 33 36 33 31 31 32 36 00 2a 0e 00 04 0a 0a 01 02 29 9a 00 20 29 9b 00 02 00 22 29 9c 00 16 29 5e 00 0a 31 30 2e 31 30 2e 31 2e 32 00 29 5f 00 04 00 00 13 c4 29 4a 00 04 80 00 00 00 29 ff 00 91 2a 0e 00 04 0a 0a 01 02 2a 01 00 85 2a 03 00 01 00 2a 07 00 04 00 00 20 72 2a 13 00 01 00 2a 02 00 13 2a 08 00 02 00 02 2a 09 00 01 02 2a 0b 00 04 00 00 1f 40 2a 02 00 13 2a 08 00 02 00 01 2a 09 00 01 01 2a 0b 00 04 00 00 1f 40 2a 02 00 13 2a 08 00 02 00 16 2a 09 00 01 16 2a 0b 00 04 00 00 1f 40 2a 02 00 13 2a 08 00 02 00 12 2a 09 00 01 12 2a 0b 00 04 00 00 1f 40 2a 02 00 13 2a 08 00 02 00 17 2a 09 00 01 17 2a 0b 00 04 00 00 1f 40]
H->X
[00 0c 00 2d 00 0c 01 00 01 0d 03 00 64 0c]
H->X
[00 0c 00 2d 00 0c 01 00 01 0d 03 00 64 0c]
H->X
[00 11 00 bf 00 00 01 00 02 0d 03 00 64 0c 0d 03 00 64 0c]
X->H
[00 07 00 bf 00 00 01 00 10]
H->X
[00 0d 00 ba 00 00 01 00 01 0d 03 00 64 0c 01]
X->H
[00 07 00 ba 00 00 01 00 10]
X->H
[00 51 00 43 00 18 01 00 01 0d 03 00 64 0c 00 a7 00 1e 01 03 00 33 00 3b 00 01 29 ff 00 35 2a 0e 00 04 00 00 00 00 2a 01 00 29 2a 03 00 01 00 2a 07 00 04 00 00 20 72 2a 13 00 01 02 2a 02 00 13 2a 08 00 02 00 02 2a 09 00 01 02 2a 0b 00 04 00 00 1f 40]
H->X
[00 05 00 43 00 18 01]
X->H
[00 70 00 43 00 19 01 00 01 0d 03 00 64 0c 00 a7 00 21 01 03 00 33 00 5a 00 08 29 2d 00 06 32 30 35 39 37 00 29 19 00 06 31 32 33 34 35 00 29 1b 00 0c 31 30 2e 31 30 2e 31 2e 32 35 30 00 29 1c 00 04 00 00 13 c4 29 29 00 06 32 30 35 39 37 00 29 54 00 06 31 31 31 31 31 00 29 55 00 0c 31 30 2e 31 30 2e 31 2e 32 35 30 00 29 56 00 04 00 00 13 c4]
H->X
[00 05 00 43 00 19 01]
X->H
[00 57 00 69 00 0c 01 00 01 0d 03 00 64 0c 02 02 1e 2a 00 05 01 04 00 04 00 00 00 00 01 05 00 04 00 00 00 41 01 11 00 04 00 00 01 1c 01 10 00 04 00 00 28 a0 01 12 00 04 00 00 b1 80 03 00 33 00 18 00 03 27 4e 00 02 00 10 27 92 00 04 0a 0a 01 bf 27 93 00 04 00 00 3e c4]
H->X
[00 05 00 69 00 0c 01]
SIP Trace:
1 -RECEIVED From 10.10.1.2:5060 at 4390
INVITE sip:11111@10.10.1.250:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.2:5060;branch=z9hG4bK-d87543-a35cc125786fec3e-1--d87543
-;rport
Max-Forwards: 70
Contact: <sip:20597@10.10.1.2:5060>
To: <sip:11111@10.10.1.250:5060>
From: "Subbu"<sip:20597@10.10.1.250:5060>;tag=390e7401
Call-ID: 3a06fa30fe30dd43@c3JhamVuZHJhLWlibS5Db3JwLnhsLmNvbQ..
CSeq: 1 INVITE
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INF
O
Content-Type: application/sdp
Supported: eventlist
User-Agent: eyeBeam release 3010n stamp 19039
Content-Length: 425
v=0
o=- 146862411 146862468 IN IP4 10.10.1.2
s=eyeBeam
c=IN IP4 10.10.1.2
t=0 0
m=audio 8306 RTP/AVP 100 0 8 3 18 98 97 5 101
a=alt:1 1 : EAF29E5C 000000DE 10.10.1.2 8306
a=fmtp:101 0-15
a=rtpmap:100 speex/16000
a=rtpmap:0 pcmu/8000
a=rtpmap:8 pcma/8000
a=rtpmap:3 gsm/8000
a=rtpmap:18 g729/8000
a=rtpmap:98 ilbc/8000
a=rtpmap:97 speex/8000
a=rtpmap:5 dvi4/8000
a=rtpmap:101 telephone-event/8000
a=sendrecv
2 -SENT To 10.10.1.2:5060 at 4390
SIP/2.0 100 Trying
To: <sip:11111@10.10.1.250:5060>;tag=93631126
From: "Subbu"<sip:20597@10.10.1.250:5060>;tag=390e7401
Call-ID: 3a06fa30fe30dd43@c3JhamVuZHJhLWlibS5Db3JwLnhsLmNvbQ..
CSeq: 1 INVITE
Contact: 11111<sip:11111@10.10.1.250:5060>
Via: SIP/2.0/UDP 10.10.1.2:5060;branch=z9hG4bK-d87543-a35cc125786fec3e-1--d87543
-;rport
User-Agent: Excel_CSP/83.10.66
Content-Length: 0
3 -SENT To 10.10.1.2:5060 at 4391
SIP/2.0 180 Ringing
To: <sip:11111@10.10.1.250:5060>;tag=93631126
From: "Subbu"<sip:20597@10.10.1.250:5060>;tag=390e7401
Call-ID: 3a06fa30fe30dd43@c3JhamVuZHJhLWlibS5Db3JwLnhsLmNvbQ..
CSeq: 1 INVITE
Contact: 11111<sip:11111@10.10.1.250:5060>
Via: SIP/2.0/UDP 10.10.1.2:5060;branch=z9hG4bK-d87543-a35cc125786fec3e-1--d87543
-;rport
User-Agent: Excel_CSP/83.10.66
Content-Length: 0
4 -SENT To 10.10.1.2:5060 at 4391
SIP/2.0 200 OK
To: <sip:11111@10.10.1.250:5060>;tag=93631126
From: "Subbu"<sip:20597@10.10.1.250:5060>;tag=390e7401
Call-ID: 3a06fa30fe30dd43@c3JhamVuZHJhLWlibS5Db3JwLnhsLmNvbQ..
CSeq: 1 INVITE
Contact: 11111<sip:11111@10.10.1.250:5060>
Supported: timer
Session-Expires: 1800; refresher=uas
Via: SIP/2.0/UDP 10.10.1.2:5060;branch=z9hG4bK-d87543-a35cc125786fec3e-1--d87543
-;rport
User-Agent: Excel_CSP/83.10.66
Content-Type: application/sdp
Content-Length: 131
v=0
o=sip 1155656630 1155656630 IN IP4 10.10.1.250
s=SIP_Call
c=IN IP4 10.10.1.191
t=0 0
m=audio 16068 RTP/AVP 0
a=sendrecv
5 -RECEIVED From 10.10.1.2:5060 at 4392
ACK sip:11111@10.10.1.250:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.2:5060;branch=z9hG4bK-d87543-7f2675358918741f-1--d87543
-;rport
Max-Forwards: 70
Contact: <sip:20597@10.10.1.2:5060>
To: <sip:11111@10.10.1.250:5060>;tag=93631126
From: "Subbu"<sip:20597@10.10.1.250:5060>;tag=390e7401
Call-ID: 3a06fa30fe30dd43@c3JhamVuZHJhLWlibS5Db3JwLnhsLmNvbQ..
CSeq: 1 ACK
User-Agent: eyeBeam release 3010n stamp 19039
Content-Length: 0
6 -RECEIVED From 10.10.1.2:5060 at 4393
INVITE sip:11111@10.10.1.250:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.2:5060;branch=z9hG4bK-d87543-b6777511fb20a408-1--d87543
-;rport
Max-Forwards: 70
Contact: <sip:20597@10.10.1.2:5060>
To: <sip:11111@10.10.1.250:5060>;tag=93631126
From: "Subbu"<sip:20597@10.10.1.250:5060>;tag=390e7401
Call-ID: 3a06fa30fe30dd43@c3JhamVuZHJhLWlibS5Db3JwLnhsLmNvbQ..
CSeq: 2 INVITE
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INF
O
Content-Type: application/sdp
Supported: eventlist
User-Agent: eyeBeam release 3010n stamp 19039
Content-Length: 187
v=0
o=- 146862411 146865057 IN IP4 10.10.1.2
s=eyeBeam
c=IN IP4 0.0.0.0
t=0 0
m=audio 8306 RTP/AVP 0
a=alt:1 1 : EAF29E5C 000000DE 10.10.1.2 8306
a=rtpmap:0 pcmu/8000
a=sendonly
7 -SENT To 10.10.1.2:5060 at 4393
SIP/2.0 100 Trying
To: <sip:11111@10.10.1.250:5060>;tag=93631126
From: "Subbu"<sip:20597@10.10.1.250:5060>;tag=390e7401
Call-ID: 3a06fa30fe30dd43@c3JhamVuZHJhLWlibS5Db3JwLnhsLmNvbQ..
CSeq: 2 INVITE
Contact: 11111<sip:11111@10.10.1.250:5060>
Via: SIP/2.0/UDP 10.10.1.2:5060;branch=z9hG4bK-d87543-b6777511fb20a408-1--d87543
-;rport
User-Agent: Excel_CSP/83.10.66
Content-Length: 0
8 -SENT To 10.10.1.2:5060 at 4393
SIP/2.0 200 OK
To: <sip:11111@10.10.1.250:5060>;tag=93631126
From: "Subbu"<sip:20597@10.10.1.250:5060>;tag=390e7401
Call-ID: 3a06fa30fe30dd43@c3JhamVuZHJhLWlibS5Db3JwLnhsLmNvbQ..
CSeq: 2 INVITE
Contact: 11111<sip:11111@10.10.1.250:5060>
Supported: timer
Session-Expires: 1800; refresher=uas
Via: SIP/2.0/UDP 10.10.1.2:5060;branch=z9hG4bK-d87543-b6777511fb20a408-1--d87543
-;rport
User-Agent: Excel_CSP/83.10.66
Content-Type: application/sdp
Content-Length: 131
v=0
o=sip 1155656630 1155656630 IN IP4 10.10.1.250
s=SIP_Call
c=IN IP4 10.10.1.191
t=0 0
m=audio 16068 RTP/AVP 0
a=sendrecv
9 -RECEIVED From 10.10.1.2:5060 at 4393
ACK sip:11111@10.10.1.250:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.2:5060;branch=z9hG4bK-d87543-316c255f587e511b-1--d87543
-;rport
Max-Forwards: 70
Contact: <sip:20597@10.10.1.2:5060>
To: <sip:11111@10.10.1.250:5060>;tag=93631126
From: "Subbu"<sip:20597@10.10.1.250:5060>;tag=390e7401
Call-ID: 3a06fa30fe30dd43@c3JhamVuZHJhLWlibS5Db3JwLnhsLmNvbQ..
CSeq: 2 ACK
User-Agent: eyeBeam release 3010n stamp 19039
Content-Length: 0
10-RECEIVED From 10.10.1.2:5060 at 4395
11-RECEIVED From 10.10.1.2:5060 at 4396
REFER sip:11111@10.10.1.250:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.2:5060;branch=z9hG4bK-d87543-011a1e4f53392f2d-1--d87543
-;rport
Max-Forwards: 70
Contact: <sip:20597@10.10.1.2:5060>
To: <sip:11111@10.10.1.250:5060>;tag=93631126
From: "Subbu"<sip:20597@10.10.1.250:5060>;tag=390e7401
Call-ID: 3a06fa30fe30dd43@c3JhamVuZHJhLWlibS5Db3JwLnhsLmNvbQ..
CSeq: 3 REFER
User-Agent: eyeBeam release 3010n stamp 19039
Refer-To: <sip:12345@10.10.1.250:5060>
Referred-By: <sip:20597>
Content-Length: 0
12-SENT To 10.10.1.2:5060 at 4396
SIP/2.0 202 Accepted
To: <sip:11111@10.10.1.250:5060>;tag=93631126
From: "Subbu"<sip:20597@10.10.1.250:5060>;tag=390e7401
Call-ID: 3a06fa30fe30dd43@c3JhamVuZHJhLWlibS5Db3JwLnhsLmNvbQ..
CSeq: 3 REFER
Contact: 11111<sip:11111@10.10.1.250:5060>
Via: SIP/2.0/UDP 10.10.1.2:5060;branch=z9hG4bK-d87543-011a1e4f53392f2d-1--d87543
-;rport
User-Agent: Excel_CSP/83.10.66
Content-Length: 0
13-RECEIVED From 10.10.1.2:5060 at 4397
BYE sip:11111@10.10.1.250:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.2:5060;branch=z9hG4bK-d87543-97128e3806547b59-1--d87543
-;rport
Max-Forwards: 70
Contact: <sip:20597@10.10.1.2:5060>
To: <sip:11111@10.10.1.250:5060>;tag=93631126
From: "Subbu"<sip:20597@10.10.1.250:5060>;tag=390e7401
Call-ID: 3a06fa30fe30dd43@c3JhamVuZHJhLWlibS5Db3JwLnhsLmNvbQ..
CSeq: 4 BYE
User-Agent: eyeBeam release 3010n stamp 19039
Content-Length: 0
14-SENT To 10.10.1.2:5060 at 4397
SIP/2.0 200 OK
To: <sip:11111@10.10.1.250:5060>;tag=93631126
From: "Subbu"<sip:20597@10.10.1.250:5060>;tag=390e7401
Call-ID: 3a06fa30fe30dd43@c3JhamVuZHJhLWlibS5Db3JwLnhsLmNvbQ..
CSeq: 4 BYE
Via: SIP/2.0/UDP 10.10.1.2:5060;branch=z9hG4bK-d87543-97128e3806547b59-1--d87543
-;rport
User-Agent: Excel_CSP/83.10.66
Content-Length: 0