FastDL

Source supports the download of custom content (maps, skins, sounds, and so on) from a HTTP server (ie: webserver) when connecting, instead of downloading directly from the game server itself.
HTTP downloading has three major benefits:
*There is no impact on the game server when downloading custom content, as a completely separate HTTP content server does the transfer.
*Players will download custom content at their maximum transfer rate, resulting in much faster downloads.
*Players downloading custom content do not take up a player slot on the server while waiting.
==Server with Custom Content: User Experience==
When a player connects to a server utilizing custom content, one of two things will occur:
*If the server is not configured for HTTP download, the game server will use the normal trickle download mechanism.
*If the server is configured for HTTP downloading, the player will see an enhanced download dialog and much faster downloads. While this content is downloading, they are not connected to the game server. Once the download finishes, they are automatically reconnected to the game server and ready to play.
== Set Up FastDL Server ==
Use Web program(such as XAMPP，Apache，Nginx) set up a webpage，Then make sure the webpage is accessible，Then find a way(Use FTP or another way) to put the files player need to download to wwwroot(Website root directory Not necessarily wwwroot)
== Configuring your server to use fast HTTP Downloading ==
1.Make a list of all the custom files (bsp, wav, mdl, etc) used on your server.
2.Put those files on a HTTP server (ie: webserver), keeping the folder layout intact.
3.Optional: To display a banner image to players that download content, place a 340x56 pixel image in the file <custom content directory>/gfx/banner.gif.(only Goldsource Maybe other Source games also support But CS:S and CS:GO are definitely not supported)
4.Set the sv_downloadurl cvar to .
Example:
Your server uses the non-standard map de_generic, which requires the following files:
C:\Program Files\Steam\SteamCache\[account name]\Counter-Strike\cstrike\maps\de_generic.map
C:\Program Files\Steam\SteamCache\[account name]\Counter-Strike\cstrike\de_generic.wad
C:\Program Files\Steam\SteamCache\[account name]\Counter-Strike\cstrike\sound\ambience\de_generic_a.wav
C:\Program Files\Steam\SteamCache\[account name]\Counter-Strike\cstrike\sound\ambience\de_generic_b.wav
C:\Program Files\Steam\SteamCache\[account name]\Counter-Strike\cstrike\sound\ambience\de_generic_c.wav
You have web space (perhaps through your ISP) with the URL http://www.turtlerockstudios.com/~matt that you will use to host your custom content.
Copy the files needed for de_generic to your webspace, placing them in a folder called my_cstrike; in your webspace top-level directory, keeping their directory layout intact.
You now have the following files in your webspace:
http://www.turtlerockstudios.com/~matt/my_cstrike/maps/de_generic.map
http://www.turtlerockstudios.com/~matt/my_cstrike/de_generic.wad
http://www.turtlerockstudios.com/~matt/my_cstrike/sound/ambience/de_generic_a.wav
http://www.turtlerockstudios.com/~matt/my_cstrike/sound/ambience/de_generic_b.wav
http://www.turtlerockstudios.com/~matt/my_cstrike/sound/ambience/de_generic_c.wav
You now set the sv_downloadurl cvar on your game server to http://www.turtlerockstudios.com/~matt/my_cstrike/
Players who then connect to your server will automatically download the map de_generic and its required files from your webspace when they connect, unless they already have it.
=== Technical Details ===
*The maximum length of the sv_downloadurl is 127 characters.
*A username and password can be specified for the HTTP server by embedding them in the sv_downloadurl like so:
http://username:password@www.somewhere.com/
*If a connecting player has an existing file of the same name, it will not be overwritten. The download file will be skipped.
Certain game-crtical and/or dangerous files cannot be downloaded (ie: *.exe, *.vbs, *.src script dll etc)
*FastDL allows downloads for normal and BZ2-compressed files that are over 150MB in size.
== summary ==
The command you enter into the server is:
sv_downloadurl "http://<yoururl>/valve/"
use quotemarks on either side of the string and include the final "/".
(valve = hldm, cstrike = counterstrike, csgo = counter-strike Global Offensive )
Then you create folders for gfx/env, maps, overviews, sound, sprites and models and populate them with the respective resource and in the "valve" directory exactly the way you would populate your server normally, including the WAD files.
If the client has ANY of the files already (including the WAD) it will not be overwritten, there is no way to do that, the client must delete the out of date or offending resource himself.