This project contains the RMBT Test Server for conducting measurements based on the RMBT protocol. Clients can communicate either directly via TCP sockets or based on the WebSocket protocol.

To simply run the server (with diabled token check!) with Docker, run:

docker run -v rmbtd-config:/config -p 8081-8082:8081-8082 lwimmer/rmbt-server

rmbt-client can be easily used as a CLI measurement client in Docker:

docker run lwimmer/rmbt-client -h <server hostname> -p <server port> -s ''

For more information see https://github.com/lwimmer/rmbt-client.

Needed packages:

• build-essential
• libssl-dev

Generate the random file, your secret key and the server executable using

> make random
> make key
> make all

For production use, an optimized build can be generated using make server-prod.

The server uses keys to authenticate clients, as specified in the RMBT protocol. These keys that are loaded from the secret.key file at startup. Each line in this file contains the key as well as a space-separated label, which will be sent to the syslog each time a client identifies using this key.

For running the server, either use the supplied /etc/systemd/system service scripts or the rmbtd executable.

Parameters:

==== rmbtd ====
command line arguments:

 -l/-L  listen on (IP and) port; -L for SSL;
        examples: "443","1.2.3.4:1234","[2001:1234::567A]:1234"
        maybe specified multiple times; at least once

 -c     path to SSL certificate in PEM format;
        intermediate certificates following server cert in same file if needed

 -k     path to SSL key file in PEM format; required

 -t     number of worker threads to run for handling connections (default: 200)

 -u     drop root privileges and setuid to specified user; must be root

 -d     fork into background as daemon (no argument)

 -D     enable debug logging (no argument)

 -w     use as http and websocket server (no argument)
 
 -v     behave as version (v) for serving older clients
        example: "0.3"

The server can be used in HTTP mode or in the legacy plain mode, depending on the usage of the -w parameter.

If the -w parameter is supplied when starting the server, the server will listen for HTTP GET requests on the specified TCP port. Clients can request a connection upgrade to either RMBT or websocket by sending a Connection: Upgrade header as specified in RFC 2616.

Clients can request an upgrade plain RMBT by adding a Upgrade: RMBT header. A sample communication is given below. Additionally, the client may add an RMBT-Version-header, indicating the most recent compatible server version.

Request from a client to the server

GET /rmbt HTTP/1.1
Connection: Upgrade
Upgrade: RMBT
RMBT-Version: 1.2.0

Response from the server

HTTP/1.1 101 Switching Protocols
Connection: Upgrade
Upgrade: RMBT

After this handshake is complete, the communication will continue using plain RMBT.

Clients can request RMBT communication wrapped in the WebSocket protocol. For this, a handshake as specified in RFC 6455 is used. A sample communication is given below.

Request from a client to the server

GET /rmbt HTTP/1.1
Connection: Upgrade
Upgrade: websocket
Sec-WebSocket-Version: 13
Sec-WebSocket-Key: 38VqBEsiw/GKJUPnSGNAUA==

Response from the server

HTTP/1.1 101 Switching Protocols
Connection: Upgrade
Sec-WebSocket-Accept: V8nixtUGE3Gfzy3Qix9R0svp05M=
Upgrade: websocket

After this handshake is complete, the communication will continue using RMBT wrapped in WebSocket frames.

If the server is started without the -w parameter, communication is done by relying on plain TCP sockets. As soon as the connection is established, the server will initiate the communication by sending the string RMBT<VERSION> whereas <VERSION> will contain the current version of the server software, e.g. v1.2.0.

• RMBT specification
• RMBTws Client
• RTR-Netztest/open-rmbt

• RTR-Netztest on the web

Copyright 2014-2017 Rundfunk und Telekom Regulierungs-GmbH (RTR-GmbH). This source code is licensed under the Apache license found in the LICENSE.txt file. The documentation to the project is licensed under the CC BY-AT 3.0 license.