GUIDE Relay Server

Relay Server – Setup, Usage, Advantages and Limitations

The Relay Server allows supported multiplayer games to connect through an intermediary server instead of requiring a direct connection between the host and the joining player.

This is especially useful when the host cannot open ports, is behind CGNAT, uses mobile internet, or has a router that does not support port forwarding correctly.

Supported games

The Relay Server is only available for games marked with the green:

Relay Server available

tag in the IPX Web Lobby.

Not every game supports the same networking method. Some games use IPX Wrapper, DOSBox IPX, IPX NullModem, Direct IP, or other compatibility tools.

Always check the green requirement tags shown for the selected game.

What the Relay Server does

Without a relay, the joining player connects directly to the host.

With a relay, both players connect to the relay server. The relay server then forwards the required multiplayer traffic between them.

This can help when:

• the host cannot configure port forwarding;
• the host is behind CGNAT;
• the router blocks incoming connections;
• the players are on different network types;
• a direct connection does not work reliably.

Important: Edit base_url.txt

Before using the Relay Server, both the host and the joining player must manually edit the base_url.txt file included with the lobby launcher or connection package.

Open:

base_url.txt

Find this line:

https://www.siljo-planet.net

Replace it with:

https://www.siljo-planet.net/?relay=relay.siljo-planet.net

Save the file before starting the HOST or JOIN launcher.

The final content of base_url.txt must be exactly:

https://www.siljo-planet.net/?relay=relay.siljo-planet.net

Do not add spaces, quotation marks, or extra lines.

Both players must use the Relay Server URL. If one player uses the normal URL and the other uses the relay URL, the connection may not work.

Requirements

Before starting, make sure that:

• both players edited base_url.txt correctly;
• both players use the same game version;
• both players use the correct HOST or JOIN package from the lobby;
• all required compatibility tools are installed;
• the game is allowed through Windows Firewall;
• antivirus software is not blocking the launcher or networking tools;
• both players select the same game in the lobby.

Some games may additionally require:

• IPX Wrapper;
• DOSBox or DOSBox SVN;
• DOSBox Daum;
• IPX NullModem Server;
• Npcap;
• cnc-ddraw;
• DxWnd;
• dgVoodoo2;
• DDrawCompat;
• IndirectSound;
• Chat Overlay.

The lobby displays the correct requirements for each game.

Host instructions

1. Open the IPX Web Lobby.
2. Select the game you want to play.
3. Check that the game has the Relay Server available tag.
4. Download the HOST package.
5. Extract the downloaded archive into the correct game directory.
6. Open base_url.txt.
7. Replace:

https://www.siljo-planet.net

with:

https://www.siljo-planet.net/?relay=relay.siljo-planet.net

1. Save base_url.txt.
2. Allow the launcher, game executable and networking tools through Windows Firewall.
3. Start the HOST launcher.
4. Wait until the relay connection is established.
5. Start or create the multiplayer game.
6. Send the required room code, address or connection information to the joining player.

Keep the HOST launcher open while the multiplayer session is active.

Join instructions

1. Open the IPX Web Lobby.
2. Select the same game as the host.
3. Download the JOIN package.
4. Extract the archive into the correct game directory.
5. Open base_url.txt.
6. Replace:

https://www.siljo-planet.net

with:

https://www.siljo-planet.net/?relay=relay.siljo-planet.net

1. Save base_url.txt.
2. Allow the launcher, game executable and networking tools through Windows Firewall.
3. Start the JOIN launcher.
4. Enter the room code, relay address or host information provided by the host.
5. Wait until the relay connection is established.
6. Start the game.
7. Join the multiplayer session from the game’s network menu.

Windows Firewall

Even when using a relay server, Windows Firewall can still block the game or launcher.

When Windows asks for network access, allow the application on:

• Private networks;
• Public networks, if required for your connection.

You may need to allow:

• the game executable;
• the HOST or JOIN launcher;
• DOSBox;
• IPX Wrapper tools;
• the relay client;
• the IPX NullModem server;
• any additional compatibility tool used by the game.

A Firewall Fix package may also be available in the lobby.

Advantages

The main advantages of using the Relay Server are:

• no manual router port forwarding in many cases;
• better compatibility with CGNAT connections;
• easier setup for inexperienced users;
• useful for mobile internet and restricted networks;
• the joining player does not need the host’s real public IP address;
• easier connection testing;
• one consistent connection method for supported games.

Limitations

The Relay Server also has some limitations:

• it only works with supported games;
• both players must use compatible launcher files;
• both players must configure base_url.txt correctly;
• the relay server must be online and reachable;
• latency may be slightly higher than with a direct connection;
• connection quality depends on the internet connection of both players and the relay server;
• some games may still require specific firewall rules;
• antivirus software may block older tools or modified launchers;
• different game versions, patches or executables may prevent players from seeing each other;
• the relay cannot fix game-specific networking bugs;
• the relay cannot guarantee a stable session if one player has packet loss or an unstable connection.

Direct connection or Relay Server?

Use a direct connection when:

• the host has a public IP address;
• port forwarding works correctly;
• both players have stable connections;
• the game performs better with lower latency.

Use the Relay Server when:

• direct hosting does not work;
• the host is behind CGNAT;
• router configuration is unavailable;
• port forwarding is too complicated;
• players need a simpler connection method.

To return to normal direct connection mode, change the content of base_url.txt back to:

https://www.siljo-planet.net

Troubleshooting

The relay launcher does not connect

Check:

• that base_url.txt contains exactly:

https://www.siljo-planet.net/?relay=relay.siljo-planet.net

• that there are no spaces or quotation marks in the file;
• that both players use the relay URL;
• that the relay server is online;
• that the selected game supports Relay Server mode;
• that Windows Firewall allows the launcher;
• that antivirus software is not blocking the connection;
• that both players use the latest HOST and JOIN packages.

The players cannot see each other

Check:

• both players configured base_url.txt correctly;
• both players selected the same game;
• both players use the same game version;
• both players use the same network mode;
• the host created the multiplayer session correctly;
• the joining player entered the correct connection information;
• required IPX, DOSBox or compatibility tools are installed.

The game starts, but multiplayer does not work

Check:

• the correct multiplayer protocol is selected inside the game;
• IPX is selected when required;
• the correct DOSBox configuration file is being used;
• the HOST launcher is still running;
• the game executable is allowed through the firewall;
• no VPN or security software is interfering with the connection.

The connection is slow or unstable

Try:

• closing downloads and streaming applications;
• using a wired connection instead of Wi-Fi;
• restarting the relay launcher;
• reconnecting both players;
• using a direct connection if port forwarding is available;
• selecting a relay server closer to both players, if multiple relay servers are available.

Security and privacy

The Relay Server forwards multiplayer traffic required for the supported game.

It does not provide complete anonymity and should not be treated as a VPN.

Do not share passwords, personal files or sensitive information through game chat or third-party multiplayer tools.

Only download HOST, JOIN and compatibility packages from the official website.

Final notes

The Relay Server is intended to make older multiplayer games easier to play on modern networks.

Because these games use many different network systems, some titles may require additional setup.

Always remember to configure base_url.txt, check the requirement tags for the selected game, and follow the game-specific forum instructions when available.