You are here: CSP Developer’s Guide: Internet Protocol > 5 Session-Initiation Protocol (SIP) Software > Support for Request URI Parameters in SIP INVITE Messages

Support for Request URI Parameters in SIP INVITE Messages

Overview

This feature allows host application developers to use the EXS API to write and access proprietary Request URI parameters that extend SIP messages for carrying application-specific information.

Description

SIP Request URI Parameter TLV (0x2958) supports this feature for Inbound and Outbound calls, as explained below.

Inbound Calls

The Request URI Parameters TLV (0x2958) carries all the Request URI parameters, received by the CSP SIP stack in the Request for Service with Data message (0x002D) to the host application.

To report this TLV to the host, you must program Bit 6 in the SIP Message Information Mask TLV (0x027F) used in the VoIP Protocol Configure message (0x00EE).

Example of Inbound Call

In the following example, the italic text in the SIP message represents the URI parameters contained in the Request for Service with Data message (0x002D).

X->H

[01 2a 00 2d 00 df 04 00 01 0d 03 03 fe 1d 00 33 01 03 00 33

01 16 00 18 27 4e 00 02 00 05 27 7e 00 03 08 00 00 29

19 00 05 31 31 31 31 00 29 1b 00 0c 31 30 2e 31 2e 32

30 35 2e 32 35 00 29 1c 00 04 00 00 13 c4 29 23 00 05

32 32 32 32 00 29 25 00 0c 31 30 2e 31 2e 32 30 35 2e

31 35 00 29 26 00 04 00 00 13 c4 29 2d 00 1a 32 32 32

32 3b 74 67 72 70 3d 22 6c 6f 63 61 6c 3d 74 67 31 32

33 34 35 22 00 29 2f 00 0c 31 30 2e 31 2e 32 30 35 2e

31 35 00 29 30 00 04 00 00 13 c4 29 33 00 01 01 27 18

00 07 02 00 00 00 04 22 22 27 17 00 05 02 00 04 11 11

27 94 00 04 0a 01 cd 4f 27 95 00 04 00 00 11 80 27 b0

00 02 00 02 27 b1 00 02 00 04 29 16 00 01 01 29 54 00

18 31 31 31 31 3b 74 67 72 70 3d 6c 6f 63 61 6c 3d 74

67 35 34 33 32 31 00 29 55 00 0c 31 30 2e 31 2e 32 30

35 2e 32 35 00 29 56 00 04 00 00 13 c4 29 35 00 17 22

6c 75 63 65 6e 74 3d 65 78 63 65 6c 3d 74 65 6c 65 63

6f 6d 22 00 29 53 00 02 01 00]

X->H

[00 45 00 43 00 9e 04 00 01 0d 03 03 fe 1d 00 a7 00 23 01 03

00 33 00 2f 00 02 29 53 00 02 02 01 29 58 00 23 74 67

72 70 3d 67 6c 6f 61 62 61 6c 3d 74 61 67 6c 75 63 65

6e 74 65 78 63 65 6c 73 69 70 35 30 30 30 00]

Received message:

INVITE sip:1111;tgrp=local=tg54321@10.1.205.25:5060;
tgrp=gloabal=taglucentexcelsip5000 SIP/2.0

Via: SIP/2.0/UDP 10.1.205.15

To: 1111<sip:1111@10.1.205.25:5060>

From: 2222<sip:2222@10.1.205.15:5060>;tag=204846324c0

Call-ID: EXCEL-CSP2.800.1216.60@10.1.205.15

Contact: 2222<sip:2222;tgrp="local=tg12345"@10.1.205.15:5060;"lucent=excel=telecom">

User-Agent: Excel_CSP/82.30.70

Supported: timer

Session-Expires: 65535

Min-SE: 65534

CSeq: 1 INVITE

Content-Type: application/sdp

Content-Length: 137

v=0

o=sip 0 0 IN IP4 10.1.205.15

s=SIP_Call

c=IN IP4 10.1.205.79

t=0 0

m=audio 4480 RTP/AVP 0 96

a=rtpmap:96 telephone-event/8000

Outbound Calls

Host application developers can use the Request URI Parameters 0x2958 TLV in the Route Control and Outseize Control messages to insert Request URI parameters in SIP INVITE messages.

Example of Outbound Call

In the following example, the italic text in the SIP message represents the URI parameters that the host application inserted using the Route Control message (0x00E8).

H->X

[00 71 00 e8 00 00 ff 00 01 29 02 ff fe 02 03 00 1e 00

19 00 04 00 13 00 02 00 08 00 08 00 02 00 65 00 0f 00

01 0b 00 65 00 02 00 00 03 00 33 00 42 00 04 27 7e 00

03 08 00 00 27 17 00 05 10 00 04 11 11 29 58 00 13 74

67 72 70 3d 6c 6f 63 61 6c 3d 74 67 35 34 33 32 31 00

29 35 00 15 74 67 72 70 3d 22 6c 6f 63 61 6c 3d 74 67

31 32 33 34 35 22 00]

SIP:

INVITE sip:1111@10.10.1.202:5060;tgrp=local=tg54321 SIP/2.0

Via: SIP/2.0/UDP 10.10.1.31

To: 1111<sip:1111@10.10.1.202:5060>

From: 00000000<sip:00000000@10.10.1.31:5060>;tag=17197953780

Call-ID: EXCEL-CSP1.6b7.1920.140@10.10.1.31

Contact: 00000000<sip:00000000@10.10.1.31:5060;tgrp="local=tg12345">

User-Agent: Excel_CSP/82.20.114

Supported: timer

Session-Expires: 1800

Min-SE: 300

CSeq: 1 INVITE

Content-Type: application/sdp

Content-Length: 99

v=0

o=sip 0 0 IN IP4 10.10.1.31

s=SIP_Call

c=IN IP4 10.10.1.37

t=0 0

m=audio 14876 RTP/AVP 0

Session-Initiation Protocol. A signaling protocol used for establishing sessions in an IP network. A session could be a simple, two-way telephone call, or it could be a collaborative multi-media conference session.
Tag-Length-Value block. A standardized block that allows data to inserted in a standard way into API messages.
Voice over Internet Protocol. The delivery of voice information in digital form in discrete packets rather than in the traditional circuit-committed protocols of the public-switched telephone network (PSTN).
Real-Time Transport Protocol. Supports transport of real-time data like interactive voice and video over packet-switched networks.
In PPL, a condition that, when met, drives a state machine (PPL Component) from one state to another, by invoking an associated Primitive. In PPL files, an Event is marked by an arrow and text.
A computer, attached to the Excel platform through an RS-232 or Ethernet link, from which you run the telecommunications application that controls the Excel platform.
Outgoing call setup during real-time call processing on a specific channel.