How Online Networks work in GT5...

Discussion in 'Gran Turismo 5' started by ScouserHUN, Jan 22, 2011.

  1. ScouserHUN


    First of all - as I've seen - we don't exactly know how online servers work in GT5. I've read the in-game manual and came to a conclusion:

    There are two modes:

    Open Lobby

    In an Open Lobby the most important thing you can set is the fixed room ownership. With this option ON there will be 1 host (creator of the room) who will host the game for all of the players. This player need very good connection, because he needs to send all of the information to everybody in the lobby. You can notice, that when you set the number of players to 16 you will have the recommended Race Quality lower, than when you set max players to 10. Of course with good host connection this is the best way to play the game. This network type is: Star Type Network

    When fixed room ownership is off, the game creates a network like torrents have. This is a Mesh Type Network. In this network every user is connected to all of the others and everyone is sharing information with the others. This means you should have better experience with the more people in the room, simply because there will be more information source for everyone. It's just like P2P protocol. This is why when the room creator leaves a room like this nothing happens, you can play on as normal. This network type has no host at all. There is a downside with this setting too, because there may be people who are not compatible to the network (for example NAT3 connections), so there might be problems due to these people.

    Private Lobby (My lounge)

    In private loby, you don't have the possibility to choose fixed room ownership, so you can only run a Mesh Type network.

    Of course there is a thing I would like to know:

    - Are we connected to any PD server when we are in these Mesh Type Networks?

    I've experienced a lot of disconnections lately, with the same people I used to have very long races. It is impossible, that 12 out of 16 friends suddenly has bad connection and disconnets during an endurance race. These people had no problem playing with me in the last 2 months, but in the last week we had serius problems.

    Please discuss, and sorry for the grammar mistakes.... Best regards from GT5 Community Hungary
    Last edited: Jan 22, 2011
  2. Devedander


    I highly doubt there are multiple protocals built into GT5 for how connections are handled.

    The fixed host does not change you from a mesh to star topology, I am pretty sure it's always the same (and that is a distributed star. which is the norm for console p2p). Setting fixed host means the same person always acts as the center of the star and remains in control.

    Setting to a non fixed host means the game tries to move the hosting responsibility to whoever has the bet connection and makes them the center of the star.

    A mesh network is pretty bad for online gaming as it massively increases the data transfer needed (everyone has to broadcast to everyone instead of only to one host wh then has to broadcast an "actual game state" back to everyone) and more importantly there is no set "real" environment for everone to sync against making netcode very difficult to impliment (when you have a star the center is the "real" world and what he sees is how it is which is why host ping advantage exists).

    To imagine why a mesh network is bad for something like GT5 network play imagine an army... they choose a leader, everyone talks to him, he tells everyone what to do. This is efficient and everyone is on the same page - HIS page. Now imagine they have no leader and everyone just shouts to each other... it's chaotic and difficult to bring everyone onto the same page at the same time.

    Mesh networks are good when you need to distribute the work load evenly however they are very poor for syncing up a shared environment over the internet where latency is both high and unpredictable.

    To continue the analogy, when you set "fixed host" you say "I am the leader of this army no matter what" and when you don't set fixed host you just become one of the crew and then whoever is best at being a leader is promoted to being the leadr (which might be you but mmight not).

    So while your idea is interesting, I think it's a case of seeing what's possible and thinking it must be. My studies and experience in networking communcation make me feel it's very unlikely it's anything but a star ever.

    As for your disconnects, there are numerous possibilities... problems could be at your end, could be in your country or could be with PD's servers. Remember a mesh network is far more fault tolerant than a star, a node dropping out of the mesh doens't hurt anyone because everyone is already and stilll talking to everyone else. In a star things are much more delicate and if the center drops out of the star, depending on how fast and well the code can find a new center, multiple people will suddenly have no connection to anyone.
    Last edited: Jan 22, 2011
  3. ScouserHUN


    I do understand what you say, but this is in the game manual in the game! If i remember correctly under 9.1. where it explains online play. It says, that when you don't set fixed host, then the network type will be Mesh Type.

    Just click on the yellow "?" in the main menu and search for it at 9.1.

    It would be interesting what you think afterwards.
  4. Devedander


    You are correct, it does say that. I am confused as to why PD would impliment the mesh type support as it's generally considered near useless in online gaming of this sort... not the first time PD has chosen to do something apparently pointless though...

    Either way, good find and if they really do as the help says, you are correct, there is a switch to mesh network model possible.
  5. ScouserHUN


    I was even very surprised to see, that when the room creator leaves the lobby in my lounge, the game does not try to find a new host as we could see in Modern Warfare for example. The crown jumps instantly to the next one in the queue, and there is not even a little time when the game tries to find a new host. This network must be Mesh Type.

    It would be interesting to know if the whole network connets to a PD server, as you can see with a torrent connecting to a tracker when downloading. When the tracker doesn't work, you can't connect to the other people and download the file you want.

    I sure we have no problem with our connection, as I've said we had no problem prior this week. And the most interesting thing is that people tend to disconnect separately, not in the same time.

    Problem 2: It happens sometimes, that some of the racers (normally 1 or 2 from 16) do not see everybody on the track. I don't know why this happens, but it could be solved, by knowing how the online network works exactly...
  6. TMN Racing

    TMN Racing

    The whole online thing is hosted on Sony's servers, have you ever noticed when you get a 'Dissconnected From Server' message while online? Its the only way to handle such a high load of players and data, we should be glad we dont have to pay for it.
  7. ScouserHUN


    No, it's not. Please read the manual.

    In a Star type network the host is the server, in a Mesh type network the whole network is the server.
  8. Sawin44


    So how fast of a connection would I need to host a room with a fixed host status with 16 players?
  9. Qxs-Storm


    Well, I monitored my bandwidth as non-fixed host in a 14 person nurb freerun.. and incoming was 100kbit/sec, outgoing was around 10kbit/sec.
    This kinda blew my mind for minute... but if it is some sort of mesh... then maybe not... I suspect that if I had been fixed host the outgoing would have been about 10x the kbit/s... 10kbit is ridiculously small imho.. seeing as my upload is capped at about 500kbit... it would have been interesting to see the bandwidth usage of everyone else in the game...

    Horribly CPU/RAM limited, could easily race 32 cars from a bandwidth point of view.. Daytona 500 would be absolutely wild...
  10. -raVer-


    I think in a non fixed room , the host opens a PD Server (center of the Star network)
    Only the host can remote the server.If the original host leaves the room the next in the queue gets the host.

    In a fixed room the PD server only acts as router.If the host pulls the plug all others get disconected (maybe)

  11. daics69


    this is a little unrelated but am curious to know if anyone knows if this is a flaw in the game, or if it's happened to anyone else.

    i've just got my brother into gt5 and we've tried numerous (dozens) times to play online together. now, if we join a random room together, no problems but if we open up our own room or become the host for the current, non-fixed room 1 of us either drops out or isn't able to join at all.

    quite frustrating and wondering whether anyone might have a solution for this or whether its a router problem or another glitch in the game.

    kind regards,


    error code - 0xffffffc8
  12. jjaisli

    jjaisli Premium

    United States
    Are you in the same house or internet connection? It could be an incompatibility caused from both of you logging in from the same subnet.
  13. knuckle


    I dont get this. I only recently bought a PS3, solely to play GT5. So I dont have alot of understanding on how PS3 runs their online games.

    Ive played PC games for 15 years (mostly FPS) and every single game uses the same online system. Players all dial into a server hosted somewhere else, owned either by the game company or individuals. The server (center of star) can be controlled by anyone with the proper access rights (a host). So being a "host" does not mean that you are the "server" where ppl dial into you, it just means that you have control of the server. Most games have the option to host a server on your local machine, but this way is unplayable online and no one runs servers that way. Its really only for running on your local network (LANS, etc.)

    Im with raver on the fact that the Star Type is actually a server run by PD and we all dial into it. The host is just the only one with access rights to change settings. If you read the manual closely it states "If room host is fixed, it cannot be transferred." To me, that is saying that control of the server cannot be passed on, not that you are the server. Its the term "host" that makes this all confusing.
  14. CJSpencer77


    The guy whos opened this thread actually has it bang on, its exactly how gt5's connections work, the problem when you dont have a fixed host room is if there 1 or 2 people with bad connections it can bring others around them down.

    There are no dedicated servers to link to,just those 2 pier to pier protocals, personally i think we could do with some real dedicated servers and then each player would be responsible for his own connection with other peoples connections having no bearing
  15. NotSoSilentBob



    Try setting 1 of the PS3s into the routers DMZ. Some games do not find a different port if it is taken, and that will cause 1 person to get kicked/unable to connect. The DMZ is setting the specified devise outside the firewall and thus you will not be using ports in the router. It does have its draw backs I would recommend doing some research online to see if you want to risk it.
  16. Korza

    Korza Premium

    New Zealand
    Does anybody know how much internet bandwidth an average online lobby on GT5 uses?
  17. chukabilly

    chukabilly Premium

    United States
    You are right on the money as far as setting the DMZ will assist daics69 in being able to race with his brother. We've been able to race up to six people off my one cable internet connection.

    I'm following this thread because it addresses the issue about internet connectivity and on-line racing flaws. There are entire on-line racing series being either canceled or modified because we can no longer race more than 10 people without serious glitches. Neither PD nor Sony have responded, but there are some of us who won't let it go.

    ScouserHUN, please keep going!!! :tup:
  18. DaPaperman


    Are you in the same house or internet connection? It could be an incompatibility caused from both of you logging in from the same subnet.:tdown:

    A house would not have subnets.. Not unless they they had a really high dollar Cisco box as well as a need for one.

    Some other things you can do to speed up your connection is set your PS3 in the DMZ of your router,turn on PnP on your Router and PS3.
    There's a wonderful tutorial on how do do this here:
    Last edited: Jan 28, 2012