kamailio/modules/qos

QOS Module

Ovidiu Sas

SOMA Networks, Inc.

Edited by

Ovidiu Sas

Copyright � 2008 SOMA Networks, Inc.
__________________________________________________________________

Table of Contents

1. Admin Guide

1. Overview
2. How it works
3. Dependencies

3.1. Kamailio Modules
3.2. External Libraries or Applications

4. Parameters

4.1. qos_flag (integer)

5. Functions
6. Statistics
7. MI Commands
8. Exported pseudo-variables
9. Installation and Running

2. Developer Guide

1. Available Functions

1.1. register_qoscb (qos, type, cb, param)

List of Examples

1.1. Set qos_flag parameter

Chapter 1. Admin Guide

Table of Contents

1. Overview
2. How it works
3. Dependencies

3.1. Kamailio Modules
3.2. External Libraries or Applications

4. Parameters

4.1. qos_flag (integer)

5. Functions
6. Statistics
7. MI Commands
8. Exported pseudo-variables
9. Installation and Running

1. Overview

The qos module provides a way to keep track of per dialog SDP
session(s).

2. How it works

The qos module uses the dialog module to be notified of any new or
updated dialogs. It will then look for and extract the SDP session (if
present) from SIP requests and replies and keep track of it for the
entire life of a dialog.

All of this happens with a properly configured dialog and qos module
and setting the dialog flag and the qos flag at the time any INVITE sip
message is seen. There is no config script function call required to
set the SDP session tracking mechanism. See the dialog module users
guide for more information.

A dialog can have one or more SDP sessions active in one of the
following states:
* pending - only one end point of the SDP session is known.
* negotiated - both end points of the SDP session are known.

An SDP session can be established in one of the following scenarios:
* INVITE/200ok - typical "INVITE" and "200 OK" SDP exchange.
* 200ok/ACK - "200 OK" and "ACK" SDP exchange (for calls starting
with an empty INVITE).
* 183/PRACK - early media via "183 Session Progress" and "PRACK" (see
rfc3959 for more information) - not implemented yet.

3. Dependencies

3.1. Kamailio Modules
3.2. External Libraries or Applications

3.1. Kamailio Modules

The following modules must be loaded before this module:
* dialog - dialog module and its decencies (tm).

3.2. External Libraries or Applications

The following libraries or applications must be installed before
running Kamailio with this module loaded:
* None.

4. Parameters

4.1. qos_flag (integer)

4.1. qos_flag (integer)

Keeping with Kamailio, the module will not do anything to any message
unless instructed to do so via the config script. You must set the
qos_flag value in the setflag() call of the INVITE you want the qos
module to process. But before you can do that, you need to tell the qos
module which flag value you are assigning to qos.

In most cases when ever you set the dialog flag you will want to set
the qos flag. If the dialog flag is not set and the qos flag is set, it
will not have any effect.

This parameter must be set of the module will not load.

Default value is "Not set!".

Example 1.1. Set qos_flag parameter
...
modparam("dialog", "dlg_flag", 5)
modparam("qos", "qos_flag", 7)
...
route {
...
if (method=="INVITE") {
setflag(5); # set the dialog flag
setflag(7); # Set the qos flag
}
...
}

5. Functions

There are no exported functions that could be used in scripts.

6. Statistics

There are no exported statistics for the qos module.

7. MI Commands

There are no exported MI functions for the qos module. Check the dialog
MI functions for a way to inspect the internals of a dialog.

8. Exported pseudo-variables

There are no exported pseudo-variables for the qos module.

9. Installation and Running

Just load the module and remember to set the flag.

Chapter 2. Developer Guide

Table of Contents

1. Available Functions

1.1. register_qoscb (qos, type, cb, param)

1. Available Functions

1.1. register_qoscb (qos, type, cb, param)

1.1. register_qoscb (qos, type, cb, param)

Register a new callback to the qos.

Meaning of the parameters is as follows:
* struct qos_ctx_st* qos - qos to register callback to. If maybe NULL
only for QOSCB_CREATED callback type, which is not a per qos type.
* int type - types of callbacks; more types may be register for the
same callback function; only QOSCB_CREATED must be register alone.
Possible types:
+ QOSCB_CREATED - called when a new qos context is created -
it's a global type (not associated to any qos).
+ QOSCB_ADD_SDP - called when a new SDP was added to the qos
context - it's a per qos type.
+ QOSCB_UPDATE_SDP - called when an existing SDP is updated -
it's a per qos type.
+ QOSCB_REMOVE_SDP - called when an existing SDP is removed -
it's a per qos type.
+ QOSCB_TERMINATED - called when the qos is terminated.
* qos_cb cb - callback function to be called. Prototype is: "void
(qos_cb) (struct qos_ctx_st *qos, int type, struct qos_cb_params
*params); "
* void *param - parameter to be passed to the callback function.