You are here: CSP Developer’s Guide: Internet Protocol > 5 Session-Initiation Protocol (SIP) Software > SIP Referred By Mechanism
Overview
This feature supports the insecure refer technique using the Referred-By mechanism. This mechanism supports Call Agent Mode (CAM) and non-CAM configurations. The Referred-By header is disabled by default.
There are applications of the REFER where it is desirable to provide the refer target with the information about the referrer. The refer target can use this information when deciding whether to admit the referenced request. This feature provides the refer target with the SIP URI of the referrer.
Pertinent Specification
RFC 3892
Description
This feature allows the host to instruct the CSP SIP stack to insert the Referred-By header in the outbound REFER request. By default the CSP SIP stack does not include the Referred-By header. The Referred-By header is then reported to the host by the CSP receiving the REFER request (Referee) within the PPL Event Indication to report receipt of REFER message.
The host can use this Referred-By header data in either the Outseize Control (0x002C) or Route Control (0x00E8) message to instruct the CSP SIP stack to include Referred-By header in the INVITE request to the Refer Target (another CSP). The Refer target reports the Referred-By header in the INVITE to the host with in the RFS.
API Messages Used
• PPL Event Request (0x0044)
• PPL Event Indication (0x0043)
• Outseize Control (0x002C)
• Route Control (0x00E8)
• Request For Service with Data (0x002D)
These messages support the following TLVs.
• 0x2929 - SIP Referred By Header URI TLV
• 0x292A - SIP Referred By Header Parameters TLV
API and CSA Configuring and Querying
This feature can be configured either using the API or CSA.
API Configuring and Querying
By default CSP does not report the Referred-By header, if it is present in the received REFER request or INVITE request message. To enable this feature, set bit 18 in the 0x027F - SIP Message Information Mask TLV and send it within the VoIP Protocol Configure (0x00EE) message.
See 0x027F - SIP Message Information Mask TLV
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 Referred by Header in Refer and Invite.
Call Flow - Insecure Refer
The call flow below shows the insecure Refer scenario.
Notes
• The call flow assumes that Referrer and Referee are in answered state.
• All CSPs have the Referred-By header reporting enabled.
• The PPL ER for REFER to Referrer instructs CSP SIP stack to include Referred-By mechanism in the REFER request.
• The referee receiving the REFER request reports the Referred-by header to the host in the PPL Event Indication used to report the receipt of REFER message.
• The host uses this Referred-By header data received in the PPL Event Indication, within the Outseize Control message to instruct the CSP SIP stack to include the Referred-By header in the INVITE message.
• The Refer Target receiving the INVITE, reports the Referred-By header to host in the Request for Service message.
Message Trace
Below is the API and SIP trace for the call flow above but the Refer target in the trace is an Eyebeam softphone not a CSP.
CSP1:
H->X
[00 83 00 2c 00 00 01 00 01 0d 03 00 64 1f 02 03 00 1e 00 0f 00 02 01 16 00 02 00 00 01 1a 00 03 00 00 00 03 00 33 00 5d 00 09 27 7e 00 03 08 00 00 29 19 00 06 32 32 32 32 32 00 29 1b 00 0c 31 30 2e 31 30 2e 31 2e 32 35 32 00 29 1c 00 04 00 00 13 c4 29 23 00 06 31 31 31 31 31 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 27 92 00 04 0a 0a 01 bf 27 93 00 04 00 00 10 7c]
X->H
[00 07 00 2c 00 00 01 00 10]
X->H
[00 20 00 43 00 09 01 00 01 0d 03 00 64 1f 00 a7 00 24 01 03 00 33 00 0a 00 01 29 4a 00 04 00 00 00 00]
H->X
[00 05 00 43 00 09 01]
H->X
[00 05 00 43 00 09 01]
X->H
[00 58 00 43 00 0a 01 00 01 0d 03 00 64 1f 00 a7 00 20 01 03 00 33 00 42 00 03 29 2b 00 06 32 32 32 32 32 00 29 2d 00 06 32 32 32 32 32 00 29 ff 00 28 2a 0e 00 04 0a 0a 01 ab 2a 01 00 1c 2a 03 00 01 00 2a 07 00 04 00 00 3d 7c 2a 13 00 01 00 2a 02 00 06 2a 08 00 02 00 02]
H->X
[00 05 00 43 00 0a 01]
H->X
[00 05 00 43 00 0a 01]
H->X
[00 48 00 44 00 00 01 00 01 0d 03 00 64 1f 00 a7 00 27 01 03 00 33 00 32 00 05 29 1e 00 06 32 32 32 32 32 00 29 20 00 0c 31 30 2e 31 30 2e 31 2e 32 35 32 00 29 21 00 04 00 00 13 c4 29 29 00 00 29 2a 00 06 70 61 72 61 6d 00]
X->H
[00 07 00 44 00 00 01 00 10]
X->H
[00 1e 00 43 00 0b 01 00 01 0d 03 00 64 1f 00 a7 00 27 01 03 00 33 00 08 00 01 29 15 00 02 00 ca]
H->X
[00 05 00 43 00 0b 01]
H->X
[00 05 00 43 00 0b 01]
X->H
[00 25 00 43 00 0c 01 00 01 0d 03 00 64 1f 00 a7 00 28 01 03 00 33 00 0f 00 02 29 15 00 02 00 64 29 48 00 03 02 00 00]
H->X
[00 05 00 43 00 0c 01]
H->X
[00 05 00 43 00 0c 01]
X->H
[00 30 00 43 00 0d 01 00 01 0d 03 00 64 1f 00 a7 00 28 01 03 00 33 00 1a 00 02 29 15 00 02 00 c8 29 48 00 0e 00 00 00 6e 6f 72 65 73 6f 75 72 63 65 00]
H->X
[00 05 00 43 00 0d 01]
H->X
[00 05 00 43 00 0d 01]
H->X
[00 11 00 08 00 00 01 00 02 0d 03 00 64 1f 0d 03 00 64
1f]
X->H
[00 07 00 08 00 00 01 00 10]
X->H
[00 57 00 69 00 02 01 00 01 0d 03 00 64 1f 02 02 1e 2a 00 05 01 04 00 04 00 00 00 00 01 05 00 04 00 00 01 14 01 11 00 04 00 00 01 15 01 10 00 04 00 00 ac 80 01 12 00 04 00 00 ad 20 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 10 7c]
H->X
[00 05 00 69 00 02 01]
H->X
[00 05 00 69 00 02 01]
2
Printing all SIP messages
1 -RECEIVED From 10.10.1.2:5060 at 490
2 -SENT To 10.10.1.252:5060 at 494
INVITE sip:22222@10.10.1.252:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.250
To: 22222<sip:22222@10.10.1.252:5060>
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
Contact: 11111<sip:11111@10.10.1.250:5060>
User-Agent: Excel_CSP/83.10.15
Supported: timer
Session-Expires: 1800
Min-SE: 300
CSeq: 1 INVITE
Content-Type: application/sdp
Content-Length: 100
v=0
o=sip 0 0 IN IP4 10.10.1.250
s=SIP_Call
c=IN IP4 10.10.1.191
t=0 0
m=audio 4220 RTP/AVP 0
3 -RECEIVED From 10.10.1.252:5060 at 494
SIP/2.0 100 Trying
To: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 1 INVITE
Contact: 22222<sip:22222@10.10.1.252:5060>
Via: SIP/2.0/UDP 10.10.1.250
User-Agent: Excel_CSP/83.10.15
Content-Length: 0
4 -RECEIVED From 10.10.1.252:5060 at 494
SIP/2.0 180 Ringing
To: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 1 INVITE
Contact: 22222<sip:22222@10.10.1.252:5060>
Via: SIP/2.0/UDP 10.10.1.250
User-Agent: Excel_CSP/83.10.15
Content-Length: 0
5 -RECEIVED From 10.10.1.252:5060 at 495
SIP/2.0 200 OK
To: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 1 INVITE
Contact: 22222<sip:22222@10.10.1.252:5060>
Require: timer
Supported: timer
Session-Expires: 1800; refresher=uas
Via: SIP/2.0/UDP 10.10.1.250
User-Agent: Excel_CSP/83.10.15
Content-Type: application/sdp
Content-Length: 131
v=0
o=sip 1152893505 1152893505 IN IP4 10.10.1.252
s=SIP_Call
c=IN IP4 10.10.1.171
t=0 0
m=audio 15740 RTP/AVP 0
a=sendrecv
6 -SENT To 10.10.1.252:5060 at 495
ACK sip:22222@10.10.1.252:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.250
To: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 1 ACK
Content-Length: 0
7 -SENT To 10.10.1.252:5060 at 497
REFER sip:22222@10.10.1.252:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.250
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
To: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 2 REFER
Max-Forwards: 70
Contact: 11111<sip:11111@10.10.1.250:5060>
Refer-To: <sip:22222@10.10.1.252:5060>
Referred-By: <sip:11111@10.10.1.250:5060>;param
User-Agent: Excel_CSP/83.10.15
Content-Length: 0
8 -RECEIVED From 10.10.1.252:5060 at 497
SIP/2.0 202 Accepted
To: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 2 REFER
Contact: 22222<sip:22222@10.10.1.252:5060>
Via: SIP/2.0/UDP 10.10.1.250
User-Agent: Excel_CSP/83.10.15
Content-Length: 0
9 -RECEIVED From 10.10.1.252:5060 at 497
NOTIFY sip:11111@10.10.1.250:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.252
To: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
From: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 3 NOTIFY
Event: refer
Contact: 22222<sip:22222@10.10.1.252:5060>
Subscription-State: active
Content-Type: message/sipfrag;version=2.0
Content-Length: 20
SIP/2.0 100 Trying
10-SENT To 10.10.1.252:5060 at 497
SIP/2.0 200 OK
To: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
From: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 3 NOTIFY
Via: SIP/2.0/UDP 10.10.1.252
User-Agent: Excel_CSP/83.10.15
Content-Length: 0
11-RECEIVED From 10.10.1.2:5060 at 499
12-RECEIVED From 10.10.1.252:5060 at 500
NOTIFY sip:11111@10.10.1.250:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.252
To: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
From: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 4 NOTIFY
Event: refer
Contact: 22222<sip:22222@10.10.1.252:5060>
Subscription-State: terminated;reason=noresource
Content-Type: message/sipfrag;version=2.0
Content-Length: 16
SIP/2.0 200 OK
13-SENT To 10.10.1.252:5060 at 500
SIP/2.0 200 OK
To: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
From: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 4 NOTIFY
Via: SIP/2.0/UDP 10.10.1.252
User-Agent: Excel_CSP/83.10.15
Content-Length: 0
14-SENT To 10.10.1.252:5060 at 500
BYE sip:22222@10.10.1.252:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.250
To: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 3 BYE
User-Agent: Excel_CSP/83.10.15
Content-Length: 0
15-RECEIVED From 10.10.1.252:5060 at 500
SIP/2.0 200 OK
To: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 3 BYE
Via: SIP/2.0/UDP 10.10.1.250
User-Agent: Excel_CSP/83.10.15
Content-Length: 0
CSP2:
X->H
[01 6e 00 2d 00 02 02 00 01 0d 03 00 c8 02 00 33 01 03 00 33 01 5a 00 1a 27 4e 00 02 00 05 27 7e 00 03 08 00 00 29 19 00 06 32 32 32 32 32 00 29 1b 00 0c 31 30 2e 31 30 2e 31 2e 32 35 32 00 29 1c 00 04 00 00 13 c4 29 23 00 06 31 31 31 31 31 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 06 31 31 31 31 31 00 29 2d 00 06 31 31 31 31 31 00 29 2f 00 0c 31 30 2e 31 30 2e 31 2e 32 35 30 00 29 30 00 04 00 00 13 c4 29 33 00 01 01 27 18 00 08 02 00 00 00 05 11 11 10 27 17 00 06 02 00 05 22 22 20 29 16 00 01 01 29 54 00 06 32 32 32 32 32 00 29 55 00 0c 31 30 2e 31 30 2e 31 2e 32 35 32 00 29 56 00 04 00 00 13 c4 29 50 00 24 45 58 43 45 4c 2d 43 53 50 31 2e 31 30 31 66 2e 34 39 34 2e 31 38 30 40 31 30 2e 31 30 2e 31 2e 32 35 30 00 29 51 00 0c 34 31 32 37 32 36 38 32 31 65 65 00 29 52 00 08 32 36 38 32 31 65 62 00 2a 0e 00 04 0a 0a 01 bf 29 9a 00 1a 29 9b 00 02 00 22 29 9c 00 10 29 5e 00 0c 31 30 2e 31 30 2e 31 2e 32 35 30 00 29 4a 00 04 00 00 00 01 29 ff 00 23 2a 0e 00 04 0a 0a 01 bf 2a 01 00 17 2a 03 00 01 00 2a 07 00 04 00 00 10 7c 2a 02 00 06 2a 08 00 02 00 02]
H->X
[00 0c 00 2d 00 02 02 00 01 0d 03 00 c8 02]
H->X
[00 0c 00 2d 00 02 02 00 01 0d 03 00 c8 02]
H->X
[00 11 00 bf 00 00 02 00 02 0d 03 00 c8 02 0d 03 00 c8
02]
X->H
[00 07 00 bf 00 00 02 00 10]
H->X
[00 0d 00 ba 00 00 02 00 01 0d 03 00 c8 02 01]
X->H
[00 07 00 ba 00 00 02 00 10]
X->H
[00 77 00 43 00 04 02 00 01 0d 03 00 c8 02 00 a7 00 21 01 03 00 33 00 61 00 07 29 2b 00 06 31 31 31 31 31 00 29 2d 00 06 31 31 31 31 31 00 29 19 00 06 32 32 32 32 32 00 29 1b 00 0c 31 30 2e 31 30 2e 31 2e 32 35 32 00 29 1c 00 04 00 00 13 c4 29 29 00 1b 73 69 70 3a 31 31 31 31 31 40 31 30 2e 31 30 2e 31 2e 32 35 30 3a 35 30 36 30 00 29 2a 00 06 70 61 72 61 6d 00]
H->X
[00 05 00 43 00 04 02]
H->X
[00 05 00 43 00 04 02]
H->X
[00 1e 00 44 00 00 02 00 01 0d 03 00 c8 02 00 a7 00 20 01 03 00 33 00 08 00 01 29 4b 00 02 00 64]
X->H
[00 07 00 44 00 00 02 00 10]
H->X
[00 a6 00 2c 00 01 02 00 01 0d 03 00 c8 1f 02 03 00 1e 00 0f 00 02 01 16 00 02 00 00 01 1a 00 03 00 0d 00 03 00 33 00 80 00 0b 27 7e 00 03 08 00 00 29 19 00 06 32 30 35 39 37 00 29 1b 00 0a 31 30 2e 31 30 2e 31 2e 32 00 29 1c 00 04 00 00 13 c4 29 23 00 06 32 32 32 32 32 00 29 25 00 0c 31 30 2e 31 30 2e 31 2e 32 35 32 00 29 26 00 04 00 00 13 c4 27 92 00 04 0a 0a 01 ac 27 93 00 04 00 00 20 8c 29 29 00 17 31 31 31 31 31 40 31 30 2e 31 30 2e 31 2e 32 35 30 3a 35 30 36 30 00 29 2a 00 06 70 61 72 61 6d 00]
X->H
[00 07 00 2c 00 01 02 00 10]
X->H
[00 20 00 43 00 05 02 00 01 0d 03 00 c8 1f 00 a7 00 24 01 03 00 33 00 0a 00 01 29 4a 00 04 00 00 00 00]
H->X
[00 05 00 43 00 05 02]
H->X
[00 05 00 43 00 05 02]
X->H
[00 5b 00 43 00 06 02 00 01 0d 03 00 c8 1f 00 a7 00 20 01 03 00 33 00 45 00 02 29 2d 00 06 32 30 35 39 37 00 29 ff 00 35 2a 0e 00 04 0a 0a 01 02 2a 01 00 29 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]
H->X
[00 05 00 43 00 06 02]
H->X
[00 05 00 43 00 06 02]
H->X
[00 1e 00 44 00 00 02 00 01 0d 03 00 c8 02 00 a7 00 20 01 03 00 33 00 08 00 01 29 4b 00 02 00 c8]
X->H
[00 07 00 44 00 00 02 00 10]
X->H
[00 57 00 69 00 02 02 00 01 0d 03 00 c8 02 02 02 1e 2a 00 05 01 04 00 04 00 00 00 00 01 05 00 04 00 00 01 13 01 11 00 04 00 00 01 20 01 10 00 04 00 00 ab e0 01 12 00 04 00 00 b4 00 03 00 33 00 18 00 03 27 4e 00 02 00 10 27 92 00 04 0a 0a 01 ab 27 93 00 04 00 00 3d 7c]
H->X
[00 05 00 69 00 02 02]
H->X
[00 05 00 69 00 02 02]
H->X
[00 11 00 08 00 00 02 00 02 0d 03 00 c8 1f 0d 03 00 c8
1f]
X->H
[00 07 00 08 00 00 02 00 10]
X->H
[00 57 00 69 00 03 02 00 01 0d 03 00 c8 1f 02 02 1e 2a 00 05 01 04 00 04 00 00 00 00 01 05 00 04 00 00 00 6c 01 11 00 04 00 00 00 7f 01 10 00 04 00 00 43 80 01 12 00 04 00 00 4f 60 03 00 33 00 18 00 03 27 4e 00 02 00 10 27 92 00 04 0a 0a 01 ac 27 93 00 04 00 00 20 8c]
H->X
[00 05 00 69 00 03 02]
2
Printing all SIP messages
1 -RECEIVED From 10.10.1.250:5060 at 491
INVITE sip:22222@10.10.1.252:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.250
To: 22222<sip:22222@10.10.1.252:5060>
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
Contact: 11111<sip:11111@10.10.1.250:5060>
User-Agent: Excel_CSP/83.10.15
Supported: timer
Session-Expires: 1800
Min-SE: 300
CSeq: 1 INVITE
Content-Type: application/sdp
Content-Length: 100
v=0
o=sip 0 0 IN IP4 10.10.1.250
s=SIP_Call
c=IN IP4 10.10.1.191
t=0 0
m=audio 4220 RTP/AVP 0
2 -SENT To 10.10.1.250:5060 at 491
SIP/2.0 100 Trying
To: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 1 INVITE
Contact: 22222<sip:22222@10.10.1.252:5060>
Via: SIP/2.0/UDP 10.10.1.250
User-Agent: Excel_CSP/83.10.15
Content-Length: 0
3 -SENT To 10.10.1.250:5060 at 492
SIP/2.0 180 Ringing
To: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 1 INVITE
Contact: 22222<sip:22222@10.10.1.252:5060>
Via: SIP/2.0/UDP 10.10.1.250
User-Agent: Excel_CSP/83.10.15
Content-Length: 0
4 -SENT To 10.10.1.250:5060 at 492
SIP/2.0 200 OK
To: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 1 INVITE
Contact: 22222<sip:22222@10.10.1.252:5060>
Require: timer
Supported: timer
Session-Expires: 1800; refresher=uas
Via: SIP/2.0/UDP 10.10.1.250
User-Agent: Excel_CSP/83.10.15
Content-Type: application/sdp
Content-Length: 131
v=0
o=sip 1152893505 1152893505 IN IP4 10.10.1.252
s=SIP_Call
c=IN IP4 10.10.1.171
t=0 0
m=audio 15740 RTP/AVP 0
a=sendrecv
5 -RECEIVED From 10.10.1.250:5060 at 493
ACK sip:22222@10.10.1.252:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.250
To: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 1 ACK
Content-Length: 0
6 -RECEIVED From 10.10.1.250:5060 at 495
REFER sip:22222@10.10.1.252:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.250
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
To: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 2 REFER
Max-Forwards: 70
Contact: 11111<sip:11111@10.10.1.250:5060>
Refer-To: <sip:22222@10.10.1.252:5060>
Referred-By: <sip:11111@10.10.1.250:5060>;param
User-Agent: Excel_CSP/83.10.15
Content-Length: 0
7 -SENT To 10.10.1.250:5060 at 495
SIP/2.0 202 Accepted
To: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 2 REFER
Contact: 22222<sip:22222@10.10.1.252:5060>
Via: SIP/2.0/UDP 10.10.1.250
User-Agent: Excel_CSP/83.10.15
Content-Length: 0
8 -SENT To 10.10.1.250:5060 at 495
NOTIFY sip:11111@10.10.1.250:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.252
To: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
From: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 3 NOTIFY
Event: refer
Contact: 22222<sip:22222@10.10.1.252:5060>
Subscription-State: active
Content-Type: message/sipfrag;version=2.0
Content-Length: 20
SIP/2.0 100 Trying
9 -RECEIVED From 10.10.1.250:5060 at 495
SIP/2.0 200 OK
To: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
From: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 3 NOTIFY
Via: SIP/2.0/UDP 10.10.1.252
User-Agent: Excel_CSP/83.10.15
Content-Length: 0
10-SENT To 10.10.1.2:5060 at 495
INVITE sip:20597@10.10.1.2:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.252
To: 20597<sip:20597@10.10.1.2:5060>
From: 22222<sip:22222@10.10.1.252:5060>;tag=412786241ef
Call-ID: EXCEL-CSP2.101f.495.990@10.10.1.252
Contact: 22222<sip:22222@10.10.1.252:5060>
User-Agent: Excel_CSP/83.10.15
Supported: timer
Session-Expires: 1800
Min-SE: 300
CSeq: 1 INVITE
Referred-By: <11111@10.10.1.250:5060>;param
Content-Type: application/sdp
Content-Length: 100
v=0
o=sip 0 0 IN IP4 10.10.1.252
s=SIP_Call
c=IN IP4 10.10.1.172
t=0 0
m=audio 8332 RTP/AVP 0
11-RECEIVED From 10.10.1.2:5060 at 496
SIP/2.0 180 Ringing
Via: SIP/2.0/UDP 10.10.1.252
Contact: <sip:20597@10.10.1.2:5060>
To: "20597"<sip:20597@10.10.1.2:5060>;tag=7204a018
From: "22222"<sip:22222@10.10.1.252:5060>;tag=412786241ef
Call-ID: EXCEL-CSP2.101f.495.990@10.10.1.252
CSeq: 1 INVITE
User-Agent: eyeBeam release 3010n stamp 19039
Content-Length: 0
12-RECEIVED From 10.10.1.2:5060 at 498
SIP/2.0 200 OK
Via: SIP/2.0/UDP 10.10.1.252
Contact: <sip:20597@10.10.1.2:5060>
To: "20597"<sip:20597@10.10.1.2:5060>;tag=7204a018
From: "22222"<sip:22222@10.10.1.252:5060>;tag=412786241ef
Call-ID: EXCEL-CSP2.101f.495.990@10.10.1.252
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: 187
v=0
o=- 87437649 87437674 IN IP4 10.10.1.2
s=eyeBeam
c=IN IP4 10.10.1.2
t=0 0
m=audio 8306 RTP/AVP 0
a=alt:1 1 : 1DE6CC47 0000007B 10.10.1.2 8306
a=rtpmap:0 pcmu/8000
a=sendrecv
13-SENT To 10.10.1.2:5060 at 498
ACK sip:20597@10.10.1.2:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.252
To: 20597<sip:20597@10.10.1.2:5060>;tag=7204a018
From: 22222<sip:22222@10.10.1.252:5060>;tag=412786241ef
Call-ID: EXCEL-CSP2.101f.495.990@10.10.1.252
CSeq: 1 ACK
Content-Length: 0
14-SENT To 10.10.1.250:5060 at 498
NOTIFY sip:11111@10.10.1.250:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.252
To: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
From: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 4 NOTIFY
Event: refer
Contact: 22222<sip:22222@10.10.1.252:5060>
Subscription-State: terminated;reason=noresource
Content-Type: message/sipfrag;version=2.0
Content-Length: 16
SIP/2.0 200 OK
15-RECEIVED From 10.10.1.250:5060 at 498
SIP/2.0 200 OK
To: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
From: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 4 NOTIFY
Via: SIP/2.0/UDP 10.10.1.252
User-Agent: Excel_CSP/83.10.15
Content-Length: 0
16-RECEIVED From 10.10.1.250:5060 at 498
BYE sip:22222@10.10.1.252:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.250
To: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 3 BYE
User-Agent: Excel_CSP/83.10.15
Content-Length: 0
17-SENT To 10.10.1.250:5060 at 498
SIP/2.0 200 OK
To: 22222<sip:22222@10.10.1.252:5060>;tag=26821eb
From: 11111<sip:11111@10.10.1.250:5060>;tag=412726821ee
Call-ID: EXCEL-CSP1.101f.494.180@10.10.1.250
CSeq: 3 BYE
Via: SIP/2.0/UDP 10.10.1.250
User-Agent: Excel_CSP/83.10.15
Content-Length: 0
18-SENT To 10.10.1.2:5060 at 500
BYE sip:20597@10.10.1.2:5060 SIP/2.0
Via: SIP/2.0/UDP 10.10.1.252
To: "20597"<sip:20597@10.10.1.2:5060>;tag=7204a018
From: "22222"<sip:22222@10.10.1.252:5060>;tag=412786241ef
Call-ID: EXCEL-CSP2.101f.495.990@10.10.1.252
CSeq: 2 BYE
User-Agent: Excel_CSP/83.10.15
Content-Length: 0
19-RECEIVED From 10.10.1.2:5060 at 500
SIP/2.0 200 OK
Via: SIP/2.0/UDP 10.10.1.252
Contact: <sip:20597@10.10.1.2:5060>
To: "20597"<sip:20597@10.10.1.2:5060>;tag=7204a018
From: "22222"<sip:22222@10.10.1.252:5060>;tag=412786241ef
Call-ID: EXCEL-CSP2.101f.495.990@10.10.1.252
CSeq: 2 BYE
User-Agent: eyeBeam release 3010n stamp 19039
Content-Length: 0
Call Flow - How to handle REFER with cid token (Secure REFER)
The call flow below provides an example how to inform the Referrer that the Referee does not support secure REFER. The Referred-By header in REFER request with "cid" token shall be reported to the host. The host is expected to parse and find out if this a secure ("cid" token present) or insecure REFER request. In case of secure REFER, the host can use PPL ER to generate NOTIFY with a message/sipfrag body indicating a final response of 501 "Not Implemented" to the Referrer. The host decides the final response to be used in the NOTIFY message body. Response 501 is an example:
Call Flow - How to handle 429 response for INVITE w/ Referred-By header
The call flow below shows an example of how to handle a 429 response for a INVITE w/ Referred-By header. If the INVITE message receives a 3xx-6xx response, the call is dropped and the channel is released. The channel-released API contains the response received for INVITE within the NPDI SIP Response Code TLV (0x2915). If the response is 429 "Provide Referrer Identity", then the refer target requires a valid Referred-By token to accept the INVITE request (Secure REFER). This is informed to the Referrer using NOTIFY with a message/sipfrag body indicating a final response of 429.
New TLVs
0x027F - SIP Message Information Mask TLV
Used in:
VoIP Protocol Configure message
VoIP Protocol Query message
|
Byte |
Description |
|
0, 1 |
Tag 0x027F |
|
2, 3 |
Length 0x0004 |
|
4-n |
Value[0-3] This field is a 32-bit mask. Each bit selects specific SIP message fields and is listed from LSB to MSB. Bit 18 - Selects reporting of Referred-By header in REFER and INVITE request |
0x2929 - SIP Referred By Header URI TLV
This TLV does the following:
• Instructs the CSP SIP stack to insert Referred-By header in the outbound REFER. In case no data is provided CSP SIP stack fills in the contact URI.
• Reports the URI in the Referred-By header, if present, in the received REFER or INVITE request.
• Writes the URI of the Referred-By header in the outbound INVITE request.
Used in:
Route Control
Outseize Control
Request For Service with Data
PPL Event Request
PPL Event Indication
|
Byte |
Description |
|
0, 1 |
Tag 0x2929 |
|
2, 3 |
Length Variable (Maximum is 100) |
|
4-n |
Value[0-3] Null Terminated ASCII string
|
0x292A - SIP Referred By Header Parameters TLV
This TLV does the following:
• Reports the Referred-By header parameters, if present, in the received REFER or INVITE request.
• Writes the parameters of the Referred-By header in the outbound REFER or INVITE request.
Used in:
Route Control
Outseize Control
Request For Service with Data
PPL Event Request
PPL Event Indication
|
Byte |
Description |
|
0, 1 |
Tag 0x292A |
|
2, 3 |
Length Variable (Maximum is 100) |
|
4-n |
Value Null Terminated ASCII string |