Stream relay guide

This is guide is meant to explain how to set up a relay of the AssemblyTV broadcast. There will be separate instructions for just viewing the stream. The VideoLAN streaming howto is recommended additional reading. By setting up a relay for your network, you can lower the external load of your internet connection if you have multiple viewers. Additionally you can provide multicast if your network supports it.

System requirements

You will need a networked computer running VLC 0.8.2. Older versions will not work. You will also need the ability to open necessary ports on your firewall.

Accessing the stream

The are two ways to access the stream.
The first is to open the desired stream normally from any of our relays using MMSH or RTP just like all clients do. This is simple, but has the downside that your relay will probably stop if there is an interruption in the stream and you will have to restart it manually.
The necessary input line is simply the stream MRL in question (eg. mmsh://server:port or rtsp://server:port/link).

The second way is to request a UDP uplink from our stream splitter. You will need to open the UDP ports corresponding to the streams you wish to receive for input from our splitter in the Assembly Organizing netblock 85.188.32.0/24 (exact IP coming). The list of stream specifications and port numbers which we are using will be added here shortly. We prefer using standard port numbers for each stream, but will try to accommodate requests for other port numbers as well.
In order to request the UDP uplink, send an email to with the subject "Stream relay request for x" where x is the name of your network or organization. Give a general description of your target network (name of the organization and the amount of users). Specify the address of your relay as well as the stream or streams you would like to receive. If you wish to use other ports than the defaults, specify those as well. We will get back to you as soon as possible.
Additionally we can possibly provide you with our internal 2Mbps stream via the UDP uplink if you would like to distribute it. This is subject to the availability of our uplink bandwidth.
The necessary input line for UDP uplinks is:

• udp:<your relay ip>:<port>

or simply

• udp:@:<port>

if you don't have multiple interfaces or don't mind the relay following all of them.

Distributing the stream

You can use any of the valid VLC output modules to distribute the stream, but some of them may not work together using the duplicate command. This can of course be overcome by receiving multiple copies of the stream via different UDP ports and configuring separate relays for each port. The limitations for valid output modules are set by our stream formats (WMV2+MP3 and MP4V+AAC) and are listed on the VLC streaming features page. We do not recommend transcoding to overcome these limitations as it will cause quality loss.

If you use the same configurations as we do, you can also use our stream viewing guide (work in progress). You may also copy and adapt our stream viewing guide for your use as long as the source of the original document is mentioned.

The output line for MMSH is of the following format:

• #standard{acccess=mmsh,mux=asfh,url=<relay ip>:<port>} (eg. 83.145.216.1:9000)
  

For HTTP (with ts mux, our recommendation) the format is similar:

• #standard{acccess=https,mux=ts,url=<relay ip>:<port>}

If you omit the port mumber, VLC will use port 8080.

For RTP with RTSP requests the format is:

• #rtp{sdp=rtsp://<relay ip>:<port>/<path>} (eg. 83.145.216.1:554/test.sdp)

554 is the most common port for RTSP requests, but you can use any port. The actual RTP stream will be sent via UDP from ports in the range 16384-32767. There is no need to open these ports for incoming traffic.

For UDP (with ts muxing) the format is:

• #standard{access=udp,mux=ts,url=<target ip>:<port>}

Note that UDP streaming as a single target ip. This can be a single machine (unicast) or a multicast ip if your network supports this. If you omit the port number, VLC will use port 1234.
Targetted RTP streaming is also possible with:

• #rtp{dst=<target ip>,sdp=http://<relay ip>:<port>/<path>}

Additionally you can specify the first port with port=<port>, but the number must be even. The sdp file can also be exported as a file. The target ip can be a multicast group.

Refer to the VLC streaming howto for more instructions.

Distributing multiple streams

The easy way to distribute multiple streams is to use the VLC manager interface via telnet. First start VLC with

• VLC --intef telnet --telnet-port <port> --telnet-password <password>

Then telnet to <port> and enter the password. Remember to close this port from external access in your firewall as telnet is inherently insecure. We run both VLC and telnet under the screen program to allow easy detaching and reattaching as well as placing control in a single terminal session.
After entering the telnet interface you can download our relay configuration (coming soon) and edit it to suit your environment. Then either use load <config> and control <stream> start for each stream to start things in the manager interface or type the file in one line at a time.

Limiting access

There is no access limiting functionality built into VLC. You can limit access by using a firewall to control access to the stream request ports.

Using other media servers

In theory it should be possible to use other media servers to relay the streams, but have not tested this and cannot support it. If we have spare time (unlikely), we can try to give speculative advice. Specifically it may be possible to configure Helix Universal Server so that RealOne Player can use RTP by retrieving the SDP file and setting up the RTSP relay feature.

Contact

Please contact for more information !