Difference between revisions of "Network Protocol"

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This page describes the '''network protocol''' used by [[Mario Kart Wii]]. It is very incomplete at this moment.
+
{{under-construction}}
  
 +
== Overview ==
 +
This article describes the '''network protocol''' used by [[Mario Kart Wii]].
  
__TOC__
+
=== Terminology ===
 +
The following terms are commonly used when explaining the game's network protocol.
  
 +
{| class="textbox grid sortable alt"
 +
|+ Game Features
 +
! Term
 +
! Description
 +
|-
 +
| ARP
 +
| [[wikipedia:Address Resolution Protocol|Address Resolution Protocol]], a network routing protocol.
 +
|-
 +
| cfc
 +
| The console friend code. It is displayed as 16 digits in the format "XXXX-XXXX-XXXX-XXXX".
 +
|-
 +
| Client
 +
| A [[Wii]] system that takes part in a race, with either one or two players.
 +
|-
 +
| fc, fc8
 +
| The [[friend code]] of the first user of a client. Sometimes it is extended by ".1" or ".2" to identify the user of the client. A friend code is displayed as 12 digits using format "XXXX-XXXX-XXXX".
 +
|-
 +
| [[GPCM]]
 +
| The client server.
 +
|-
 +
| [[GPSP]]
 +
| The server that retrieves friends.
 +
|-
 +
| Guest
 +
| All non-host clients.
 +
|-
 +
| Home client
 +
| The observed client where the network traffic comes from.
 +
|-
 +
| Host
 +
| The client who has opened the room.
 +
|-
 +
| [[MASTER]]
 +
| The master matchmaking server.
 +
|-
 +
| Mii
 +
| The Mii avatar of a user.
 +
|-
 +
| [[MS]]
 +
| The matchmaking retrieving server.
 +
|-
 +
| [[Network Protocol/Server|N-server]]
 +
| One of [[Nintendo]]'s servers.
 +
|-
 +
| [[NAS]], [[NASWII]]
 +
| The login server.
 +
|-
 +
| [[NATNEG]]
 +
| The server that enables client to client connections behind firewalls. It stands for '''N'''etwork '''A'''ddress '''T'''ranslation '''NEG'''otiation.
 +
|-
 +
| Packet
 +
| A packet is a technical network packet. [[Mario Kart Wii]] uses ARP, TCP and UDP (including name resolution) packets.
 +
|-
 +
| Player
 +
| A player that takes part in a race, with a maximum of 12.
 +
|-
 +
| Player ID
 +
| An alternative name for [[Profile ID]].
 +
|-
 +
| Profile ID, pid, fc4
 +
| The Profile ID is a short version of the friend code with only the lowest 4 bytes (32 bit). It acts as a unique identifier for each player.
 +
|-
 +
| TCP
 +
| [[wikipedia:Transmission Control Protocol|Transmission Control Protocol]], a network protocol.
 +
|-
 +
| Record
 +
| A packet can be split into logical records. Each record has its own meaning and its own data structure.
 +
|-
 +
| UDP
 +
| [[wikipedia:User Datagram Protocol|User Datagram Protocol]], a network protocol.
 +
|-
 +
| User
 +
| A player at the console. Each client supports 1 or 2 users. The users of the client are numbered 1 and 2.
 +
|}
  
{{textbox|red center|In Progress|This article is managed by [[Wiimm]] and will grow slowly. Feel free to edit typos and grammatical or speech issues. If you have additional information, please complete this page.}}
+
== Description ==
 
+
[[Mario Kart Wii]]'s network traffic begins with some domain name resolutions. The game then connects to various servers through TCP connections to check for server availability, perform the login process and queue for matchmaking among other things. In a friend room or while racing, consoles communicate directly with each other using UDP connections. While in a match, "keepalive" records are sent to the servers in order to maintain connectivity.
 
 
== Introduction ==
 
 
 
The analysis of the data is done with the tool
 
[[Wiimms mkw-ana (tool)|mkw-ana]]. So the naming of mkw-ana for objects
 
(records, stages, ...) is used here.
 
Because of the very early phase of the analysis,
 
names and structures may completely change.
 
 
 
You can discuss this topic at [http://www.mariokartwii.com/f101/mkw-ana-mario-kart-wii-network-protocol-109421.html mariokartwii.com].
 
 
 
=== Terms and definition ===
 
 
 
{{MKWii Network Terms}}
 
 
 
== General description ==
 
 
 
The [[Mario Kart Wii]] traffic starts with some name resolutions.
 
Then it will use only UDP packets.
 
 
 
First it connects Nintendos servers (N-server).
 
In a room or while racing, all Wiis communicate directly to each other.
 
In a race, only some ''alive'' records are send to a N-server.
 
  
=== Connecting Nintendo servers ===
+
=== Connecting to Servers ===
 
+
When connecting to the [[Nintendo Wi-Fi Connection]], the console runs various DNS queries to obtain the IP addresses of the following servers:
If entering the Mario Kart WFC, the Wii started with DNS queries to find out the IP addresses of the following servers:
 
 
* gpcm.gs.nintendowifi.net
 
* gpcm.gs.nintendowifi.net
 
* gpsp.gs.nintendowifi.net
 
* gpsp.gs.nintendowifi.net
Line 46: Line 99:
 
* mariokartwii.gamestats2.gs.nintendowifi.net
 
* mariokartwii.gamestats2.gs.nintendowifi.net
 
* mariokartwii.ms19.gs.nintendowifi.net
 
* mariokartwii.ms19.gs.nintendowifi.net
 +
* naswii.nintendowifi.net
 +
Private servers generally follow the same naming scheme, while replacing "nintendowifi.net" with their own domain. More details about each server's purpose can be found [[Network Protocol/Server|here]].
  
<spoiler text="IP Addresses">
+
=== Point to Point Communication ===
IP addresses of the servers above, valid at 2013-12-29
+
The [[Wii]] uses a frequency of 59.94Hz ([[NTSC]]) as its time base. Clients send a status update to one of the other clients every other frame, which is approximately 1/30th of a second.
<pre>
 
69.10.30.242 gpcm.gs.nintendowifi.net
 
69.10.30.241 gpsp.gs.nintendowifi.net
 
69.10.30.240 gamestats.gs.nintendowifi.net
 
69.10.30.234 gamestats2.gs.nintendowifi.net
 
69.10.30.248 mariokartwii.available.gs.nintendowifi.net
 
69.10.30.254 mariokartwii.natneg1.gs.nintendowifi.net
 
69.10.30.253 mariokartwii.natneg2.gs.nintendowifi.net
 
69.10.30.252 mariokartwii.natneg3.gs.nintendowifi.net
 
69.10.30.248 mariokartwii.master.gs.nintendowifi.net
 
69.10.30.240 mariokartwii.gamestats.gs.nintendowifi.net
 
69.10.30.234 mariokartwii.gamestats2.gs.nintendowifi.net
 
69.10.30.247 mariokartwii.ms19.gs.nintendowifi.net
 
</pre>
 
</spoiler>
 
Then it starts the [[MKWii_Network_Protocol/Nintendo_servers|communication with nintendos servers]] and the first packet goes to ''mariokartwii.available.gs.nintendowifi.net''.
 
  
=== Point to point communication ===
+
For instance, if client A is in a room with two other clients B and C, the latter will receive an update from A every 1/15th of a second. This delay increases with the number of players, reaching up to about 1/3rd of a second with a full room of 12 clients. This latency is the primary cause of lag in larger rooms.
  
The Wii use a frequency of 59.94Hz (based on NTSC, about 1/60s) as time base.
+
The average packet length is approximately 220 bytes, resulting in a total traffic of about 7 KB/s in both directions, independent of the number of clients.
All clients send every second pulse (~1/30s) a status packet to one of the other clients.
 
If there for example 3 clients A, B and C, then A sends first a packet to B and then, 1/30s later, a packet to C, and again 1/30s later, the next packet to B. this means, that the individual status update is done only every 1/15s. This update time is reduced to 11/30s (~1/3s), if 12 clients are playing. And that's the reason for the many lagging effects if playing with many players.
 
  
The average packet length is about 220 bytes, so the the total traffic is about 6.6 KB/s (52.8 KBit/s) in both directions, independent of the number of clients.
+
== Race Packets ==
 +
[[RACE]] packets are sent from each client to all other clients in the room. The packet is split into multiple records, which act as logical units. The packet header includes a CRC32 checksum to detect corrupted packets. The following table shows the packet structure and the different records.
  
== Records ==
+
{| class="wikitable"
 
+
! Name
Each UDP packet can be split in records. Records are logical units. The following table shows:
+
! Size
* A name used by [[mkw-ana]].
+
! Description
* Value of the first 4-6 bytes (Record ID, big endian, hex).
+
|-
* Length of the record.
+
| [[HEADER]] || 0x10
* Description.
+
| The packet header.
 
 
{| class="textbox alt headline grid"
 
|+ List of Records
 
! Name !! Record ID !! Length !! Description
 
 
|-
 
|-
| [[MKWii Network Protocol/CHECKSUM|CHECKSUM]] || 0000.0000 || 0x08
+
| [[RACEHEADER_1]] || 0x28
| A checksum record used for the most data records.
+
| A basic race data record.
 
|-
 
|-
| [[MKWii Network Protocol/USER|USER]] || 0000.000x || 0xc0
+
| [[RACEHEADER_2]] || 0x28
| A user information including a FC and 2 Miis for both users of the client. '''x''' is 1 for 1 player or 3 for 2 players.
+
| A game mode-dependent race data record.
 
|-
 
|-
| [[MKWii Network Protocol/ANNOUNCE|ANNOUNCE]] || 1000.0000 || 0x08 or 0xc8
+
| [[ROOM]] || 0x04
| Announce a new user by sending it's FC4. This record is send by a Nintendo Server to the host and the new guest. After receiving an announce, both clients start with a little handshake.
+
| Friend room lobby message record. The first byte decides the record type:
 +
* 1: Event start message (GP, Team, Balloon or Coin Battle).
 +
* 2: A player registered another player as their friend.
 +
* 3: A player joined the room.
 +
* 4: Regular room message (online chat).
 
|-
 
|-
| ''unknown'' || 1000.0000.xxxx || ?
+
| [[SELECT]] || 0x38
| ?
+
| This record is sent between matches to set up the next race. One byte decides the phase.
 +
* 0: Match setup.
 +
* 1: Course selection.
 +
* 2: Voting lottery.
 
|-
 
|-
| [[MKWii Network Protocol/ROOM|ROOM]] || 1000.0004 || 0x0c
+
| [[RACEDATA]] || 0x40 (per player)
| A [[MKWii Network Protocol/ROOM|ROOM]] record is always placed before an [[MKWii Network Protocol/USER|USER]] record. The byte at offset 8 decides the sub type:
+
| Race data record, containing player position, inputs and other miscellaneous info.
* '''0:''' ''unknown''
+
|-
* '''1:''' Send by host: Start an event (GP, Team, Ballon or Coin).
+
| [[USER]] || 0xC0
* '''2:''' ''unknown''
+
| User record, including friend code and one Mii for each player.
* '''3:''' ''unknown''
 
* '''4:''' Send a room message (online chat).
 
Room records are only sent in room events. There is a prefix record "GLOBAL" for non-room-events.
 
 
|-
 
|-
| [[MKWii Network Protocol/SELECT|SELECT]] || 1000.0038 || 0x40
+
| [[ITEM]] || 0x08 (per player)
| This record is send while selecting driver and track. It is always placed before an [[MKWii Network Protocol/USER|USER]] record. The byte at offset 0x3d decides the phase:
+
| Record containing each player's item status.
* '''0:''' Prepare the race.
+
|-
* '''1:''' Before first race: Driver selection. All races track selection by user.
+
| [[EVENT]] || &ge; 0x18
* '''2:''' Track lottery. Before start of the lottery, the host sends to all clients the winning user and track.
+
| Record containing item events, such as throwing an item or dropping one.
 +
|}
 +
 
 +
=== Additional Records ===
 +
The following table shows additional records, which are not necessarily present in every race packet.
 +
 
 +
{| class="wikitable"
 +
! Name
 +
! Magic
 +
! Length
 +
! Description
 
|-
 
|-
| [[MKWii Network Protocol/RACE|RACE]]<br/>[[MKWii Network Protocol/RACEDATA|RACEDATA]]<br/>[[MKWii Network Protocol/ITEM|ITEM]]<br/>[[MKWii Network Protocol/EVENTHEAD|EVENTHEAD]]<br/>[[MKWii Network Protocol/EVENTDATA|EVENTDATA]]
+
| [[SLOT]] || <tt>46.FC.57.0X</tt> || 0x08
| 1028.2800 || 0x58<br/>+U*0x40<br/>+U*0x08<br/>+0x18<br/>+N
+
| The message following this record is to be forwarded to client slot '''X'''. If a client has bandwidth problems, it can use another client as a proxy to reduce its own traffic during a match. Such indirect packets are also prefixed by a [[SLOT]] record.
| Record send during race and battle. The content of race and battle records are different.
 
The record is followed by 1 or 2 extensions ([[MKWii Network Protocol/RACEDATA|RACEDATA]], each 0x40 bytes) for 1 or 2 users of the client.
 
After the user extensions a list with items and events is appended.
 
 
|-
 
|-
| [[MKWii Network Protocol/SLOT|SLOT]] || 46fc.570x || 0x08
+
| [[STATUS]] || <tt>BB.49.CC.4D</tt> || &ge; 0x14
| The following message is related to client slot '''x''' (default: for the sender). This is mainly used in combination with ANNOUNCE and USER to tie information to specific client slots.
+
| A status record with various purposes. Byte 0x08 describes the record type. For example, it can be used to allow or deny access to a room.
If a client has bandwidth problem, it can use another client as proxy to reduce its own traffic during the race. Such indirect packets are also prefixed by a SLOT record.
 
 
|-
 
|-
| [[MKWii Network Protocol/STATUS|STATUS]] || bb49.cc4d || 0x14+N
+
| [[HANDSHAKE]] || <tt>FD.FC</tt> || &ge; 0x14
| A status record with 5 different extensions. Byte 9 describes the extension length '''N''' and is 0, 4, 8, or 16. One task is to select and advice client slots to clients.
+
| [[NATNEG]] records. Type CONNECT_PING is sent through peer-to-peer, while all other types are routed through the NATNEG servers.
 
|-
 
|-
| [[MKWii Network Protocol/HANDSHAKE|HANDSHAKE]] || fdfc.1e66 || 0x14+N
+
| [[QUIT]] || <tt>FE.FE.68</tt> || 0x03
| Different handshake records with different length. At the moment an announce of Nintendo (with ip+port) and a little handshake between host and guest are known.
+
| This record is sent when a client leaves a room. It is not prefixed by a CHECKSUM record.
 
|}
 
|}
  
== Stages ==
+
== States ==
 +
This section describes what data is transmitted between clients during specific stages of gameplay.
 +
 
 +
=== Joining a Room ===
 +
==== Friend Room ====
 +
When a client wants to join a friend room, it sends a "GPCM90" type 1 message to the [[MASTER]] server. This asks the server for permission to enter the room, which will either be answered with a type 2 message (access granted) or a type 3 message (access denied). If access is granted, the new client and the host begin exchanging [[NATNEG]] messages to establish a peer-to-peer connection.
 +
 
 +
After completing NATNEG, the two clients send each other an empty race packet ([[ANNOUNCE]]) to indicate a successful connection.
 +
 
 +
The new player then appears in the room and starts doing NATNEG with all the other clients. Because NATNEG is very slow and does not run in threads, only one client can join a room at a time. Additionally, starting a match as soon as every client is in the room will cause significant delays, as the peer-to-peer mesh network (which can involve up to 66 connections with 12 clients) is incomplete.
 +
 
 +
==== Worldwide ====
 +
As soon as a client has found a room through [[MS|matchmaking]], it sends an "asking for entrance" status message. If the room host is in the client's friend list, GPCM90 messages are used; otherwise, the [[STATUS]] messages are proxied through MS and/or [[MASTER]].
 +
 
 +
Then, similarly to friend rooms, [[NATNEG]] is performed and an empty record ([[ANNOUNCE]]) is exchanged to mark the completion of the handshake.
 +
 
 +
During live view, only part of the main records are sent.
  
=== Room ===
+
=== Friend Room Start ===
=== Table ===
+
When the room host wishes to start playing, they send a [[ROOM]] message to indicate the beginning of an event. Each player chooses their character and vehicle, and the match setup begins. The setup has three phases:
=== Prepare a race ===
+
* '''Prepare''': The waiting phase before players can interact with the game to view their rating or vote for a track. In this phase, the game is working in the background to synchronize the time, race settings and various other information across clients.
=== Count down ===
+
* '''Voting''': The voting phase, which lasts until every player has voted.
=== First finished ===
+
* '''Lottery''': The lottery that determines the track to play. While the winning track is already decided before the lottery even begins, the game uses this time to preload the track and finish synchronizing all the necessary information.
=== All finished ===
 
  
== Links ==
+
=== Countdown ===
 +
Before the countdown begins, the host sends a "ready?" request to all clients. While waiting for the clients to respond, the loading icon will appear in the bottom right corner of the screen. Once every client is synchronized, the match can start.
  
* [[Wiimms mkw-ana (tool)]]
+
=== Race Finish ===
* [http://www.mariokartwii.com/f101/mkw-ana-mario-kart-wii-network-protocol-109421.html Discussion at mariokartwii.com]
+
As soon as the race leader reaches the finish line, their completion time is sent to all the other players, who then have a limited time to complete the race. When the race is finished by either everyone crossing the finish line, the [[Online Time Limit|maximum race time limit]] being reached or the aforementioned limited time running out, the "finish" phase is activated. The rankings will be displayed and the next race will begin.
  
<br/>
+
{{Network Protocol}}
{{MKWii Network Protocol}}
+
[[Category:File Format/MKW]]
[[category:File Format]]
+
[[Category:Network Protocol|!]]
[[category:Network Protocol|!]]
 

Latest revision as of 17:15, 28 January 2024

Under Construction
This article is not finished. Help improve it by adding accurate information or correcting grammar and spelling.

Overview

This article describes the network protocol used by Mario Kart Wii.

Terminology

The following terms are commonly used when explaining the game's network protocol.

Game Features
Term Description
ARP Address Resolution Protocol, a network routing protocol.
cfc The console friend code. It is displayed as 16 digits in the format "XXXX-XXXX-XXXX-XXXX".
Client A Wii system that takes part in a race, with either one or two players.
fc, fc8 The friend code of the first user of a client. Sometimes it is extended by ".1" or ".2" to identify the user of the client. A friend code is displayed as 12 digits using format "XXXX-XXXX-XXXX".
GPCM The client server.
GPSP The server that retrieves friends.
Guest All non-host clients.
Home client The observed client where the network traffic comes from.
Host The client who has opened the room.
MASTER The master matchmaking server.
Mii The Mii avatar of a user.
MS The matchmaking retrieving server.
N-server One of Nintendo's servers.
NAS, NASWII The login server.
NATNEG The server that enables client to client connections behind firewalls. It stands for Network Address Translation NEGotiation.
Packet A packet is a technical network packet. Mario Kart Wii uses ARP, TCP and UDP (including name resolution) packets.
Player A player that takes part in a race, with a maximum of 12.
Player ID An alternative name for Profile ID.
Profile ID, pid, fc4 The Profile ID is a short version of the friend code with only the lowest 4 bytes (32 bit). It acts as a unique identifier for each player.
TCP Transmission Control Protocol, a network protocol.
Record A packet can be split into logical records. Each record has its own meaning and its own data structure.
UDP User Datagram Protocol, a network protocol.
User A player at the console. Each client supports 1 or 2 users. The users of the client are numbered 1 and 2.

Description

Mario Kart Wii's network traffic begins with some domain name resolutions. The game then connects to various servers through TCP connections to check for server availability, perform the login process and queue for matchmaking among other things. In a friend room or while racing, consoles communicate directly with each other using UDP connections. While in a match, "keepalive" records are sent to the servers in order to maintain connectivity.

Connecting to Servers

When connecting to the Nintendo Wi-Fi Connection, the console runs various DNS queries to obtain the IP addresses of the following servers:

  • gpcm.gs.nintendowifi.net
  • gpsp.gs.nintendowifi.net
  • gamestats.gs.nintendowifi.net
  • gamestats2.gs.nintendowifi.net
  • mariokartwii.available.gs.nintendowifi.net
  • mariokartwii.natneg1.gs.nintendowifi.net
  • mariokartwii.natneg2.gs.nintendowifi.net
  • mariokartwii.natneg3.gs.nintendowifi.net
  • mariokartwii.master.gs.nintendowifi.net
  • mariokartwii.gamestats.gs.nintendowifi.net
  • mariokartwii.gamestats2.gs.nintendowifi.net
  • mariokartwii.ms19.gs.nintendowifi.net
  • naswii.nintendowifi.net

Private servers generally follow the same naming scheme, while replacing "nintendowifi.net" with their own domain. More details about each server's purpose can be found here.

Point to Point Communication

The Wii uses a frequency of 59.94Hz (NTSC) as its time base. Clients send a status update to one of the other clients every other frame, which is approximately 1/30th of a second.

For instance, if client A is in a room with two other clients B and C, the latter will receive an update from A every 1/15th of a second. This delay increases with the number of players, reaching up to about 1/3rd of a second with a full room of 12 clients. This latency is the primary cause of lag in larger rooms.

The average packet length is approximately 220 bytes, resulting in a total traffic of about 7 KB/s in both directions, independent of the number of clients.

Race Packets

RACE packets are sent from each client to all other clients in the room. The packet is split into multiple records, which act as logical units. The packet header includes a CRC32 checksum to detect corrupted packets. The following table shows the packet structure and the different records.

Name Size Description
HEADER 0x10 The packet header.
RACEHEADER_1 0x28 A basic race data record.
RACEHEADER_2 0x28 A game mode-dependent race data record.
ROOM 0x04 Friend room lobby message record. The first byte decides the record type:
  • 1: Event start message (GP, Team, Balloon or Coin Battle).
  • 2: A player registered another player as their friend.
  • 3: A player joined the room.
  • 4: Regular room message (online chat).
SELECT 0x38 This record is sent between matches to set up the next race. One byte decides the phase.
  • 0: Match setup.
  • 1: Course selection.
  • 2: Voting lottery.
RACEDATA 0x40 (per player) Race data record, containing player position, inputs and other miscellaneous info.
USER 0xC0 User record, including friend code and one Mii for each player.
ITEM 0x08 (per player) Record containing each player's item status.
EVENT ≥ 0x18 Record containing item events, such as throwing an item or dropping one.

Additional Records

The following table shows additional records, which are not necessarily present in every race packet.

Name Magic Length Description
SLOT 46.FC.57.0X 0x08 The message following this record is to be forwarded to client slot X. If a client has bandwidth problems, it can use another client as a proxy to reduce its own traffic during a match. Such indirect packets are also prefixed by a SLOT record.
STATUS BB.49.CC.4D ≥ 0x14 A status record with various purposes. Byte 0x08 describes the record type. For example, it can be used to allow or deny access to a room.
HANDSHAKE FD.FC ≥ 0x14 NATNEG records. Type CONNECT_PING is sent through peer-to-peer, while all other types are routed through the NATNEG servers.
QUIT FE.FE.68 0x03 This record is sent when a client leaves a room. It is not prefixed by a CHECKSUM record.

States

This section describes what data is transmitted between clients during specific stages of gameplay.

Joining a Room

Friend Room

When a client wants to join a friend room, it sends a "GPCM90" type 1 message to the MASTER server. This asks the server for permission to enter the room, which will either be answered with a type 2 message (access granted) or a type 3 message (access denied). If access is granted, the new client and the host begin exchanging NATNEG messages to establish a peer-to-peer connection.

After completing NATNEG, the two clients send each other an empty race packet (ANNOUNCE) to indicate a successful connection.

The new player then appears in the room and starts doing NATNEG with all the other clients. Because NATNEG is very slow and does not run in threads, only one client can join a room at a time. Additionally, starting a match as soon as every client is in the room will cause significant delays, as the peer-to-peer mesh network (which can involve up to 66 connections with 12 clients) is incomplete.

Worldwide

As soon as a client has found a room through matchmaking, it sends an "asking for entrance" status message. If the room host is in the client's friend list, GPCM90 messages are used; otherwise, the STATUS messages are proxied through MS and/or MASTER.

Then, similarly to friend rooms, NATNEG is performed and an empty record (ANNOUNCE) is exchanged to mark the completion of the handshake.

During live view, only part of the main records are sent.

Friend Room Start

When the room host wishes to start playing, they send a ROOM message to indicate the beginning of an event. Each player chooses their character and vehicle, and the match setup begins. The setup has three phases:

  • Prepare: The waiting phase before players can interact with the game to view their rating or vote for a track. In this phase, the game is working in the background to synchronize the time, race settings and various other information across clients.
  • Voting: The voting phase, which lasts until every player has voted.
  • Lottery: The lottery that determines the track to play. While the winning track is already decided before the lottery even begins, the game uses this time to preload the track and finish synchronizing all the necessary information.

Countdown

Before the countdown begins, the host sends a "ready?" request to all clients. While waiting for the clients to respond, the loading icon will appear in the bottom right corner of the screen. Once every client is synchronized, the match can start.

Race Finish

As soon as the race leader reaches the finish line, their completion time is sent to all the other players, who then have a limited time to complete the race. When the race is finished by either everyone crossing the finish line, the maximum race time limit being reached or the aforementioned limited time running out, the "finish" phase is activated. The rankings will be displayed and the next race will begin.