35 Replies Latest reply on Sep 28, 2013 4:50 PM by rlbl RSS

    Listen Servers Explained (Warning: Wall of Text)


      I would like to thank Maccabi for helping in the right direction. I've been wanting to post this for a really long time but didn't quite know where to start on my research. So a big thank you Mac



      Now on to the juicy stuff you really want to know



      What is a Listen Server?



      Basically its a Dedicated Server that runs off the client's hardware instead of a fully supported server. This system is far cheaper requires little software to support. Its important to note that a Listen Server communicates the knowledge found on the game's disc as its only form of understanding as opposed to a Dedicated Server having an entire HDD loaded with information. Unlike a peer-to-peer (P2P) system, a host is still in charge of handling all the information. P2P set-ups are more like a spider-web of information where each client sends info to every other client.



      Pros of Listen Servers



      As mentioned above there is very little software needed for this type of server. Only the limited data used on a game's disc is used and aside from specific requests from the game's server (ie. Activision or Treyarch for stats and match making) there's really no other contact with anyone else. This means all bandwidth comes from the players as well as all other performance related functions



      Cons of Listen Servers



      The list is long so I'll try to be brief but concise. Listen Servers fully rely on the host for being able to perform all the necessary functions to host a match. Residential bandwidth often doesn't have the capacity to handle such needs. The upload limitations for your typical household are far less than what's required. However, if a lobby is made up then the person with the best upload will be picked regardless of their qualifications. This leads to lag, and any Google search will show that Listen Servers are notorious for lag no matter the game and that games internet requirements



      Another downside is that the host ends the game anytime they leave a match. Because the host is only catalyst between players, if the host leaves there no way for players to communicate with each other. Also, theoretically, if all is working as efficiently as possible the host will have a massive advantage over all other players. However, if the game is not performing efficiently, the host will receive the worst amount of lag as their bandwidth cannot facilitate the demands Listen Servers require



      Hosting via Listen Servers


      Herein lies 99% of all the lag issues. Because the host is trying to facilitate all the packets of information we have problems between what match making is forcing the host to do and what the host can actually accomplish. Anything over 16.87 milliseconds (60hz) starts to become noticeable to average human. Its at that point that we can sense a disturbance in the force and lag becomes perceived. The host basically has to transfer information to 11 people in less than 17ms in order for people to play fluently without even noticing that lag exists. It's at around 50ms that lag starts making a negative impact on a game. Once you start hitting ping above 100ms that's where anger will begin to set in.



      Match making however does not always allow this to happen. Depending on who you can get pair up with, the minimum latency between one person could be anywhere from 5ms (if that player lives with the same state as you) to 150ms (cross country or international). Now take the above paragraph and try to wrap your head around that. If the average person is experiencing negatives results from lag at 50ms and the host is unable to talk with just one person within 150ms you can easily see how the game can turn South in a hurry



      Lag Compensation and Listen Servers



      Here's where a lot of myths are going to be nixed. The host often doesn't have enough time to communicate with everyone effectively as you so clearly saw above. Any latency over the 17ms can easily become unnoticeable with the help of lag comp. By quickly processing the difference and correcting the discrepancies between the time an act was performed and the time act was communicated to all players, lag comp helps soften the blow 150ms can make



      However, like everything in life, there's a equally opposite disadvantage of lag compensation. If the lag is over the plausible limits of lag comp either lag comp will stop making accurate compensations or lag comp will fail to work altogether. What happens so often in matches is that the lag compensation between players 1-10 will be nearly perfect but player 11 will have such a high latency that it drags the whole lobby down with them



      Lag Switching and Listen Servers



      Because the host is prime source of information they can easily manipulate this to their advantage. If the lobby has a decent connection that doesn't push the match into high pings forcing the game to pick a new host, the host can momentarily cease all transferring of information and move about freely while everyone else is stuck in limbo grasping for a lifeline to the host. Note that Lag Switching is only possible on Listen Servers and cannot be done via P2P or Dedicate Servers



      Unstable Hosts



      Because Listen Servers are relying on a host who most likely has your normal, average bandwidth there lies massive potential for an unstable connection. Most people don't dedicated a sufficient amount of bandwidth to play Call of Duty or any other online game. Its a no-hold-bar for bandwidth in the average home.


      So before a lobby starts a player might have more than enough upload and download to be a host and so a lobby will center around this person and his connection. The players will be picked accordingly and everything will seem fine. However, once the match starts there's an endless number of events that could happen and this host might lose available bandwidth and no longer has the capacity to effectively host a match. Since the mitigation for preventing catastrophic lag is set to take place at such a high ping, the game will continue to play out even though the 50ms threshold noticeable lag has been breached


      How Listen Servers Can Work



      This form of hosting matches is not 100% broken. As long as the host is able to make rounds to every player in a reasonable amount of time this can work quite well. Matching players based on the following factors can lead to premium playability:


      Reliability/StabilityGrade given to a player's connection based on the history of their connection. Positive grades are given for consistency
      Physical LocationPlayer's physical geographical location to the host
      Maximum PingThe amount of time it takes for a player to communicate with all other players in a lobby (in milliseconds)
      Maximum BandwidthThe maximum capacity in for both upload and download (in kb/s)



      If all 12 players in a lobby can fit this criteria then we will certainly see a improvement in the quality of matches. Listen Servers can work, I'm sure all of us have had a match that played just fine and it was probably one of our most memorable matches. The first step towards progress is fixing match making and tightening the requirements for who gets to play with who




      Listen Servers also force the issue of how "involved" the game can be before it is self defeating. The more intense a game is with heavy gun fire and lots of action taking place over a shorter period of time the worse lag will be because lag comp is constantly having to work to compensate all players to more pieces of action.


      Imagine you're a photographer and you're taking pictures of two events. A graduation speech and a rave. Considering you understand lag comp and how it works, how much harder would lag comp have to work if it were helping you capture all the moments of a rave vs a grad speech?

        • Re: Listen Servers Explained (Warning: Wall of Text)

          My head hurts, lol.


          Well your solution at the end sounds fine but will people want to wait that extra time?

          • Re: Listen Servers Explained (Warning: Wall of Text)

            Long Post ..But Good

            I does give me a better understanding of why Lag is such a ***** at times

            If our search features allowed us to search for a connections that best matchaed ours in Bandwidth and Ping/Lat. then Lag might be elimanated for the most part.....But playing with ones freinds or clan mates might become impossible


            I know there is not a fix that will work for everyone, because of so many variables and some of these variables changes with the weather.....and i mean literally with the weather......as our connections can be infulenced by factors we cannot control.....My Old Internet provider (Century Link) gave me a good solid connection.....until we got rain......on rainy days my Bandwith and ping tests would drop to 60% of what i had on a nice dry sunny day........

            • Re: Listen Servers Explained (Warning: Wall of Text)

              Thanks. Macc is always good to go with this info. Yet, I want to know and will never know, why I am being put on probation for the unstable, undesirable effects that THEY provide.

                • Re: Listen Servers Explained (Warning: Wall of Text)

                  My guess is that the rule is very black and white and doesn't take into consideration the possibility that not everyone leaves a match under their own free will.


                  If player A leaves a match X amount of times within a span of Y they receive a ban of Z time


                  Not thinking the these lobbies are growing more and more unstable to the point that matches end without warning because the host pulls the plug or ping hits such a high amount the lobby is forced to disband. As I stated above, the mitigation for preventing a full breakdown in lobbies is set so high that often times it is unable to recover



                  This can be proven by the amount of time a lag switcher can roam the map while communication is at a complete halt

                • Re: Listen Servers Explained (Warning: Wall of Text)

                  Holy wall of text!

                  • Re: Listen Servers Explained (Warning: Wall of Text)

                    Excellent and informative post G'


                    Thanks for taking the time to write that.

                    • Re: Listen Servers Explained (Warning: Wall of Text)

                      Sounds like a great idea.

                      • Re: Listen Servers Explained (Warning: Wall of Text)

                        So the real question is..... What the hell did they do to this matchmaking system since MW2 (which ran 1000 times better) that completely broke COD. All of these problems started with Black Ops. It seems as though they tweaked the lag balancing settings to make things run a bit better for the 10 percent of people with horrible pings in remote areas with terrible Internet like Mexico. In the process of trying to make things run a little better for the minority of players they ruined the game for the other 90 percent.


                        There is absolutely no reason I should ever have to play against somebody with a high ping when I live in the middle of that big bright part of the cod map yet my lobbies are usually half full of Mexican players. At least give us back a working local only option. I shouldn't have my game ruined just to give somebody who shares their Internet with their whole village a better experience.

                        • Re: Listen Servers Explained (Warning: Wall of Text)

                          Nice one Ghammora.  Bottom line is what you, I and a few others have been saying repeatedly.


                          Improved matchmaking = improved gameplay.

                          • Re: Listen Servers Explained (Warning: Wall of Text)

                                 So, in theory, if all 11 other people in the lobby are sharing a <50 ms ping, the game should run pretty flawlessly? 


                                 The problem is that it only takes ONE player to screw the whole thing up.  They give us 3 search preference options.  ANY should take you to a match very quickly.  This is what you should select if you are impatient and wish to be put in a match immediately.  BEST should be just that, everyone with under 50 ms ping. 


                                 Another issue though, the people in the "ANY" category, are going to need someone to host.  12 people with crappy connections aren't going to be able to do much of anything. 


                                 My personal opinion is people that take online gaming serious and have upgraded cable and fibre connections, shouldn't have as bad of a gaming experience as someone playing in a dorm room sharing a connection with 100 other people.

                              • Re: Listen Servers Explained (Warning: Wall of Text)

                                Highwayman0226 wrote:


                                     My personal opinion is people that take online gaming serious and have upgraded cable and fibre connections, shouldn't have as bad of a gaming experience as someone playing in a dorm room sharing a connection with 100 other people.

                                In match making's defense there's a lot of break down when selecting players for a lobby. You might have a few hundred people in your immediate area playing at the same time, sure. But when you sort out between playlist type, gamemode, generic rank (so you're not playing a full party of scrubs), and generic connections you're not left with much to choose from

                              • Re: Listen Servers Explained (Warning: Wall of Text)

                                Exceptional post G,


                                Thanks for taking the time, now the one thing you confused me was: Listen servers take little bandwidth, then you quote that players will probably have low bandwidth. I have a decent provider (comcast) and the bandwidth they provide for what I pay (second highest tier) is more than what is needed for gaming.


                                I played many years via wifi until this game when I connected my system to the coaxial cable and my gaming experience was improved incredibly.


                                I am curious what the next gen systems will provide in terms of quality gaming and hosting, if cloud computing will be great or just good or equal.

                                • Re: Listen Servers Explained (Warning: Wall of Text)

                                  At least someone understand the servers on this game.  I was wondering if you knew why sometimes when you die and get the killcam it freezes as soon as the killcam starts and freezes and soon as you are about to respawn taking about a total of 10 secs to respawn.  It doesn't happen all the time, but when it does I just leave because I end of missing valuable time playing the objective or it takes so long that it will lag people (and me) out of the game.  Is that anything to do with packet loss or just lag in general?

                                    • Re: Listen Servers Explained (Warning: Wall of Text)

                                      Play HC, no killcam, doesn't happen...


                                      What you describe sounds a bit weird, no idea why it would do that.

                                      • Re: Listen Servers Explained (Warning: Wall of Text)

                                        I believe it's packet loss. There's no real info out there so I can only theorize why this happens. I believe that it's a lot like a scratched CD. The killcam tries to reply a damaged or incomplete replay of what happened and it can't throwing you into limbo. High ping contributes to packet loss. The longer it takes for information to travel around the more information is lost. Since ping in Black Ops II gets so ridiculously high there's a lot of information dropped. .


                                        That or the game realizes how stupid your death was so to keep the truth of the BS from being seen it just skips through the killcam.

                                          • Re: Listen Servers Explained (Warning: Wall of Text)

                                            Those all sound like good possibilities, haha but seriously it has been happening a lot lately and it is quite annoying when it does happen.  You know you just lost a good 10 seconds of gameplay because of packet loss/bs death (I like that answer the best).  But man it has been bad today I left about 6 games because the killcams starting freezing and once that happens I always have troubles getting going again because I missed out on the flag/hardpoint/hq.

                                        • Re: Listen Servers Explained (Warning: Wall of Text)

                                          ive heard but im not quite sure of the truth of it all but is ghosts and ps4 going to have dedicated hosts? ive heard its going to which would solve this whole issue. Listening host also explains why they lag and weak lobbies have suddenly aroused as with the lack of players there is a lack of good hosts. No good host no good games!!

                                          • Re: Listen Servers Explained (Warning: Wall of Text)

                                            The issue is, the problems/cons won't be addressed or can't be without changing a lot.


                                            They could slow down the game.  Lower the run speed.  Increase map size.  But, it's too late.


                                            Most people have multiple machines on their connection.  Machines (pc, phones, tablets, neighbors equipment, etc) all loaded out with tons of malware and update checking software wasting what little upload we get.  Said things are usually not constant and cause spikes.


                                            Cheaters will cheat given any opportunity.  Cheating is rampant and socially acceptable to some.  They have yet to realize how much they are cheating themselves of challenge and entertainment.  The setup gives them opportunity.  They will take it.  Talking about host connection manipulation.


                                            Map packs will continue to flow, increase in number, and segregate players by which ones they have.  This will continue to limit possible good connection interaction that would otherwise be possible.  Matchmaking.


                                            They won't acknowledge or change what is able to be changed.  Cost of work vs profit from it.


                                            While you can blame the above factors on both sides, the design that allows them falls on the shoulders of the developers.