proto_ws Module

Table of Contents

1. Admin Guide
1.1. Overview
1.2. Dependencies
1.2.1. OpenSIPS Modules
1.2.2. External Libraries or Applications
1.3. Exported Parameters
1.3.1. ws_port (integer)
1.3.2. ws_send_timeout (integer)
1.3.3. ws_max_msg_chunks (integer)
1.3.4. trace_destination (string)
1.3.5. trace_on (int)
1.3.6. trace_filter_route (string)
1.3.7. require_origin (int)
1.4. Exported MI Functions
1.4.1. ws_trace
2. Frequently Asked Questions
3. Contributors
3.1. By Commit Statistics
3.2. By Commit Activity
4. Documentation
4.1. Contributors

List of Tables

3.1. Top contributors by DevScore(1), authored commits(2) and lines added/removed(3)
3.2. Most recently active contributors(1) to this module

List of Examples

1.1. Set ws_port parameter
1.2. Set ws_send_timeout parameter
1.3. Set ws_max_msg_chunks parameter
1.4. Set trace_destination parameter
1.5. Set trace_on parameter
1.6. Set trace_filter_route parameter
1.7. Set require_origin parameter

Chapter 1. Admin Guide

1.1. Overview

The WebSocket protocol (RFC 6455) provides an end-to-end full-duplex communication channel between two web-based applications. This allows WebSocket enabled browsers to connect to a WebSocket server and exchange any type of data. RFC 7118 provides the specifications for transporting SIP messages over the WebSocket protocol.

The proto_ws module is transport module that provides communication over the WebSocket protocol. This module is fully compliant with the RFC 7118, thus allowing browsers to act as SIP clients for the OpenSIPS proxy.

The current implementation acts both as WebSocket server and client, thus it can accept connections from WebSocket clients and can also initiate connections to another WebSocket server. After the connection is established, messages can flow in both directions.

OpenSIPS supports the following WebSocket operations:

  • text and binary - can both send and receive WebSocket messages that contain text or binary body

  • close - messages used to safely close the WebSocket communication using a 2-messages handshake

  • ping - responds with pong messages. There is no mechanism to trigger ping messages.

  • pong - sent when a ping message is received. OpenSIPS, absorbes the pong messages received.

Once loaded, you will be able to define WebSocket listeners in your script. To add a listener, you have to add its IP, and optionally the listening port, after the mpath parameter, similar to this example:

socket=ws:		# change with the listening IP
socket=ws:	# change with the listening IP and port

1.2. Dependencies

1.2.1. OpenSIPS Modules

The following modules must be loaded before this module:

  • None.

1.2.2. External Libraries or Applications

The following libraries or applications must be installed before running OpenSIPS with this module loaded:

  • None.

1.3. Exported Parameters

1.3.1. ws_port (integer)

The default port to be used for all WS related operation. Be careful as the default port impacts both the SIP listening part (if no port is defined in the WS listeners) and the SIP sending part (if the destination WS URI has no explicit port).

If you want to change only the listening port for WS, use the port option in the SIP listener defintion.

Default value is 80.

Example 1.1. Set ws_port parameter

modparam("proto_ws", "ws_port", 8080)

1.3.2. ws_send_timeout (integer)

Time in milliseconds after a WebSocket connection will be closed if it is not available for blocking writing in this interval (and OpenSIPS wants to send something on it).

Default value is 100 ms.

Example 1.2. Set ws_send_timeout parameter

modparam("proto_ws", "ws_send_timeout", 200)

1.3.3. ws_max_msg_chunks (integer)

The maximum number of chunks in which a SIP message is expected to arrive via WebSocket. If a received packet is more fragmented than this, the connection is dropped (either the connection is very overloaded and this leads to high fragmentation - or we are the victim of an ongoing attack where the attacker is sending very fragmented traffic in order to decrease server performance).

Default value is 4.

Example 1.3. Set ws_max_msg_chunks parameter

modparam("proto_ws", "ws_max_msg_chunks", 8)

1.3.4. trace_destination (string)

Trace destination as defined in the tracing module. Currently the only tracing module is proto_hep. Network events such as connect, accept and connection closed events shall be traced along with errors that could appear in the process. For each connection that is created an event containing information about http request and reply belonging to web socket protocol handshake and network layer information shall be sent.

WARNING: A tracing module must be loaded in order for this parameter to work. (for example proto_hep).

Default value is none(not defined).

Example 1.4. Set trace_destination parameter

modparam("proto_hep", "hep_id", "[hep_dest];transport=tcp;version=3")

modparam("proto_ws", "trace_destination", "hep_dest")

1.3.5. trace_on (int)

This controls whether tracing for ws is on or not. You still need to define trace_destinationin order to work, but this value will be controlled using mi function ws_trace.

Default value is 0(tracing inactive).

Example 1.5. Set trace_on parameter

modparam("proto_ws", "trace_on", 1)

1.3.6. trace_filter_route (string)

Define the name of a route in which you can filter which connections will be trace and which connections won't be. In this route you will have information regarding source and destination ips and ports for the current connection. To disable tracing for a specific connection the last call in this route must be drop, any other exit mode resulting in tracing the current connection ( of course you still have to define a trace_destination and trace must be on at the time this connection is opened.

IMPORTANT Filtering on ip addresses and ports can be made using $si and $sp for matching either the entity that is connecting to OpenSIPS or the entity to which OpenSIPS is connecting. The name might be misleading ( $si meaning the source ip if you read the docs) but in reality it is simply the socket other than the OpenSIPS socket. In order to match OpenSIPS interface (either the one that accepted the connection or the one that initiated a connection) $socket_in(ip) (ip) and $socket_in(port) (port) can be used.

WARNING: IF trace_on is set to 0 or tracing is deactived via the mi command ws_trace this route won't be called.

Default value is none(no route is set).

Example 1.6. Set trace_filter_route parameter

modparam("proto_ws", "trace_filter_route", "ws_filter")
/* all ws connections will go through this route if tracing is activated
 * and a trace destination is defined */
route[ws_filter] {
	/* all connections opened from/by ip will be traced
	   on interface listener)
	   all the other connections won't be */
	 if ( $si == "" && $sp == 8000 &&
		$socket_in(ip) == ""  && $socket_in(port) == 5060)

1.3.7. require_origin (int)

Controls whether the module should require the Origin header or not.

Default value is 1(require Origin header).

Example 1.7. Set require_origin parameter

modparam("proto_ws", "require_origin", no)

1.4. Exported MI Functions

1.4.1.  ws_trace

Name: ws_trace


  • trace_mode(optional): set ws tracing on and off. This parameter can be missing and the command will show the current tracing status for this module( on or off ); Possible values:

    • on

    • off

MI FIFO Command Format:

			opensips-cli -x mi ws_trace on

Chapter 2. Frequently Asked Questions


Can OpenSIPS act as a WebSocket client?

Yes, starting with OpenSIPS 2.2, it can act as a WebSocket client.


Does OpenSIPS support WebSocket message fragmentation?

No, WebSocket fragmentation mechanism is not supported.

Chapter 3. Contributors

3.1. By Commit Statistics

Table 3.1. Top contributors by DevScore(1), authored commits(2) and lines added/removed(3)

 NameDevScoreCommitsLines ++Lines --
1. Razvan Crainea (@razvancrainea)96484080823
2. Ionut Ionita (@ionutrazvanionita)2114609114
3. Bogdan-Andrei Iancu (@bogdan-iancu)171412336
4. Liviu Chircu (@liviuchircu)1186793
5. Vlad Patrascu (@rvlad-patrascu)859774
6. Maksym Sobolyev (@sobomax)4242
7. Vlad Paiu (@vladpaiu)4231
8. Nick Altmann (@nikbyte)3144
9. Peter Lemenkov (@lemenkov)3122
10. Julián Moreno Patiño3111

(1) DevScore = author_commits + author_lines_added / (project_lines_added / project_commits) + author_lines_deleted / (project_lines_deleted / project_commits)

(2) including any documentation-related commits, excluding merge commits. Regarding imported patches/code, we do our best to count the work on behalf of the proper owner, as per the "fix_authors" and "mod_renames" arrays in opensips/doc/ If you identify any patches/commits which do not get properly attributed to you, please submit a pull request which extends "fix_authors" and/or "mod_renames".

(3) ignoring whitespace edits, renamed files and auto-generated files

3.2. By Commit Activity

Table 3.2. Most recently active contributors(1) to this module

 NameCommit Activity
1. Razvan Crainea (@razvancrainea)Mar 2015 - Sep 2023
2. Maksym Sobolyev (@sobomax)Feb 2017 - Oct 2022
3. Vlad Patrascu (@rvlad-patrascu)May 2017 - Oct 2021
4. Nick Altmann (@nikbyte)May 2021 - May 2021
5. Bogdan-Andrei Iancu (@bogdan-iancu)Mar 2017 - Apr 2021
6. Liviu Chircu (@liviuchircu)Mar 2015 - Jan 2020
7. Peter Lemenkov (@lemenkov)Jun 2018 - Jun 2018
8. Ionut Ionita (@ionutrazvanionita)Jul 2015 - Apr 2017
9. Julián Moreno PatiñoFeb 2016 - Feb 2016
10. Vlad Paiu (@vladpaiu)Mar 2015 - May 2015

(1) including any documentation-related commits, excluding merge commits

Chapter 4. Documentation

4.1. Contributors

Last edited by: Vlad Patrascu (@rvlad-patrascu), Razvan Crainea (@razvancrainea), Bogdan-Andrei Iancu (@bogdan-iancu), Peter Lemenkov (@lemenkov), Liviu Chircu (@liviuchircu), Ionut Ionita (@ionutrazvanionita).

Documentation Copyrights:

Copyright © 2015