Sylk Server

Sylk Server is packaged and ready to use on Debian and Ubuntu Linux. Alternatively, you can download its source code and build the package yourself, install it the python way or run it from its download directory without installing it system-wide.

Linux Packages

Linux installation instructions are available here. The package name is sylkserver.

sudo apt-get update
sudo apt-get install sylkserver

or to install with WebRTC gateway support:

sudo apt-get update
sudo apt-get install sylkserver-webrtc-gateway

Source Code

The source code is managed using darcs version control tool. The darcs repository can be fetched with:

darcs get

To obtain the incremental changes after the initial get run:

darcs pull -a

Alternatively, you can use our Github mirror.

Install the required dependencies:

To run Sylk Server in the foreground:

cd sylkserver/
./sylk-server --no-fork

To install Sylk Server manually on the system tree:

cd sylkserver/
sudo python install

Running the server

Set in /etc/default/syslkserver:


The software can work fine with the default settings. To overwrite the default settings edit the following files:







At least one XMPP domain must be configured in the file above and the DNS.



You may want to change the default TLS certificate and Janus api token.

Start the server:

sudo /etc/init.d/sylkserver start


Activity messages are logged to syslog.

SIP and MSRP protocol traces can be enabled in config.ini

Listening ports

Sylk Server must run on a public IP address reachable directly by the SIP clients. If Sylk Server is installed behind NAT using a private IP address, only clients from the same LAN can make use of it.

Sylk Server listens for incoming connections on the following ports:

Component Ports Transport
SIP signaling 5060 UDP, TCP
SIP signaling 5061 TLS
RTP media 50000:50500 UDP
MSRP media 2855 TLS
XMPP media 5269 TLS
WEB media random > 1024 TLS
WebRTC 10888 TLS

The server is also initiating outbound connections for both signaling and media.

Janus, an internal component used for WebRTC, is listening on web socket

SIP Proxy setup

To use SylkServer you need a SIP Proxy. You can install a pre-configured SIP Proxy as a start point, like OpenSIPS.

Installation instructions are available here.

OpenSIPS configuration debian package is available here.

The package name is opensips-config-light.

Sylk Pushserver

Sylk Pushserver was designed to act as a central dispatcher for mobile push notifications inside RTC provider infrastructures. Both the provider and the mobile application customer, in the case of a shared infrastructure, can easily audit problems related to the processing of push notifications.

Download instructions are similar to Sylk Server:

  • the package is called sylk-pushserver
  • The software requires Python 3

Sylk Desktop

Source Code

The source code is maintained using darcs version control tool. The darcs repository can be fetched with:

darcs get

To obtain the incremental changes after the initial get run:

darcs pull -a

Alternatively, you can use our Github mirror.

By default, the client requires no configuration to run by using the publicly available SIP2SIP service as a backend.

iIf you want to use Sylk Client with your own Sylk Server installation edit this file:


and rebuild the client as described in the file.

How to contribute

The original source code is maintained using darcs version control tool.

Darcs repository

If you want to help us fixing a bug that you found or if you want to contribute with a new feature you must be familiar with the darcs version control system from

First make sure you are using the latest version by doing a darcs pull. Then record your changes using darcs record. Follow the following guidelines for recording your changes:

Keep a patch name under 80 characters, so that a darcs changes in a 80 char console is consistent and readable. If you need to write more than that, use --edit-long-comment or do not specify -m "patch name" and it will automatically ask for a patch name and a long comment. Keep the long comment inside the 80 char frame. When you add a long comment, you have the patch name on the first line. After that, leave an empty line and then add the long comment starting from the 1st column. If you need to add bulleted entries in the long comment, use a dash (-) not an asterisk (*), to avoid confusion with the asterisk darcs places before every patch name. Record separate patches for each distinct changes you make. Do not mix different changes in a single record. Use darcs replace to rename tokens if possible instead of using a search and replace in your editor. It correctly handles cases where someone else still kept using the old name (it will automatically rename this uses of the old name when he pull the darcs replace patch, which a simple token rename done by the editor and recorded as a standard diff will never do, requiring further patches to rename the old tokens that the other developer added in his code while you were doing the renaming).

Finally, notify us on the SIP Beyond VoIP mailing list at:

After approval, submit the patch using:

darcs send --to


The darcs repository is mirrored on Github.

You may submit a Github pull request as usual. We will check the it and if approved by our developers, will apply it to the original darcs repository.