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5. Designing a complete VideoLAN solution

This section talks about how to organise the servers needed for VideoLAN in order to stream on a Local Area Network (LAN), or a Wide Area Network (WAN). These are not precise technical procedures but suggestions taken from our own experience.

5.1 The VideoLAN Servers

You can have as many VideoLAN Servers (vls) on your network as you want. vlms should only be used for testing purposes. You may want to specialise your VideoLAN Servers. For example, on our campus, we have three VideoLAN servers located in three different places :

If you want to stream multiple DVDs (we suppose that you have the legal right to do so) from the same machine, you may want to have big disk drives instead of multiple DVD drives. You can copy the DVDs on the hard drives and tell vls to read from the hard drive instead of the DVD drive.

If you want to stream satellite channels (we again suppose that you have the legal right to do so), you need a satellite card for every transponder. On one transponder, you have up to around 10 channels. If you want to stream 5 channels that are on 3 different transponders, you will need 3 satellite cards inside the machine. We don't care if those 3 transponders are on 3 different satellites, that's your problem ! A satellite stream is around 4 Mbit/s. You will then stream 5 x 4 = 20 Mbit/s : a 100 Mbit/s Ethernet connection will be needed. If you have want to stream channels from more transponders that PCI slot available in the machine... you will need to find a second computer !

If you want to do Video On Demand with a lot of potential clients, you may want to set up a server specialized for VOD. This server would have very fast disk access and be located in a technical room with a fast network connection available. For example, you could set up a SAN with disk drives connected in fibre channel and multiple 100 Mbit/s Ethernet connections or a Gigabit connection to the network.

5.2 The VideoLAN Channel Servers

Multicast solution

If your network supports multicast, you will have to install a miniVLCS in order to enable the clients to easily go from a channel to another. This program doesn't need much resources in term of computer power or network connection. Therefore, you can install it on a old machine running Linux, or on one of your VideoLAN Servers.

Multicast allows you to stream a video to multiple machines on a Wide Area Network (WAN). The network hardware of the WAN will need to have a full multicast support. If it doesn't, you can link multicast islands from one to another through IP tunnels. This is how the MBone (a Multicast Backbone on the Internet) works.

VLANs solution

With the VLANs solution, you will only be able to stream on a LAN where all the switches support VLANs. You will not be able to stream on a WAN. With this solution, we advise you to have a Linux machine dedicated to hosting the mini VLAN server. This machine is critical in term of security because it will have in it's configuration files the MIBs of all the switches of you LAN.

If your router is a bad router (i.e. you can't configure it so as to let the different VLANs communicate but without letting the streams broadcasted by vls in a VLAN go to the other VLANs), you may want to set up a VLANbridge or buy a new router. If you want to set up a VLANbridge and you have an Ethernet network, you need to have a Linux machine with as many network cards as VLANs used. This machine will be located in a place where you have a switch with as many ports available as VLANs used. You will plug each network card to a port in each VLAN used, and your VLANbridge will enable the different VLANs to communicate but without letting the video streams go from a VLAN to another. If you want to set up a VLANbridge and you have an ATM backbone (like on our old network), the VLANbridge machine only needs one ATM card connected to the ATM backbone : this card will enable the VLANbridge to have an interface in every VLAN.

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