Networking, Lag Compensation, and Hit Detection

[iAmMoDBoX]

I DID NOT WRITE THIS - IT IS FROM HERE BUT I THOUGHT IT WAS AN IMPORTANT READ.

 

KEEP IN MIND THIS IS OLD INFORMATION, BUT THE BASIC PRINCIPLES STILL APPLY TODAY WITH DEDICATED SERVERS AND LAG.

 

In not so recent developments, lag has taken the number one spot as a scapegoat for a lot of players' deaths. So much so that people completely made up explanations as to how "lag comp screws you over" or whatever. On top of that, this shit is actually considered common knowledge in some places (gamefaqs, reddit, official forums, youtube, etc.). I'm sure that most of you have seen Den's quick post on lag compensation/anti-lag, but I'm going to expand upon that. I'm just trying to dispel some of the stuff surrounding that for the sake of this forum since I'm sure a good number of our users come from those sites i mentioned. Now keep in mind that we obviously do not have any networking source code. This is going over the basics of a listen server alongside more gameplay related issues such as hit detection. It's important to note that while Treyarch and IW split off from each other at CoD4 (as in, both MW2 and WAW were modded from CoD4 and they've been modding their own game since then) there isn't really any evidence of them having changed the core networking mechanics beyond deciding hosts and organizing matches*. THAT BEING SAID, this is a fairly long read. The important points of each section will be printed in gold and key terms will be in green* for those of you who don't really care all that much.

*black ops 2 has shown to have networking issues as far as artificial delays go, however there is no evidence as to why this happens, nor any discernable reason as to why it could be included. It is likely a mistake. It will covered further down.

*I apologize to the colorblind people who may have some trouble skimming because I picked green for keywords

Table of Contents
[1.0] How does networking work?

• [1.1] Network Structure
• [1.2] Transferring Data

[2.0] How does lag affect me?

• [2.1] Latency, Jitter, Three bars, etc.
• [2.2] Input Prediction
• [2.3] Hit Detection and Lag Compensation
• [2.4] Interpolation and Artificial Delays
• [2.5] Packet Loss

[3.0] How does this come into play?

• [3.1] Connection Discrepancies pt.1
• [3.2] Connection Discrepancies pt.2
• [3.3] Killcams

[4.0] Matchmaking

• [4.1] Sorting players
• [4.2] Hosts and Migrations

[5.0] NAT

• [5.1] What is NAT?
• [5.2] Opening your NAT

[1.0] How does networking work?

[1.1] Network Structure

Obviously multiplayer games need a system that is capable of transferring data between the players. Virtually all modern multiplayer videogames utilize Client-Server networking or Peer-to-peer networking. In the case of Call of Duty, it uses a certain type of Client-Server based network called a Listen Server. This differs from the standard Dedicated Server (The PC versions of BO2, CoD4, and WAW use this) in that a listen server hosts both the server and client in the same location. Listen servers are generally inferior to dedicated servers in every way except for price, because it is more stressful on a single system and is limited by the host's internet connection. To simply put it, Clients send data to the server, which then organizes it and sends it out to all of the clients simultaneously, which then use that data to generate the world. Here's a slightly closer look using the Quake 3 networking model:*


*The IW engine is based off of the Quake 3 engine along with countless other shooters. They have their distinctions but the basics are pretty standard.

THE SYSTEM WORKS AS SUCH:
So the Server or Host has a Master Gamestate. This is the "official" state of the game at any given time. The host will attach a sequence number and a timestamp onto it and send it out to the clients. This is called a Snapshot. When the client receives this data. It makes a copy of the master gamestate and saves it in its memory. The client will then compare the snapshots in memory to generate a game state. If the client doesn't have any "valid" snapshots in history (either the last timestamp was too long ago due to lag issues or it just has connected and hasn't received data yet) the client will compare the snapshot with the dummy snapshot, which has every value equal to zero. The client will at the same time send inputs from the player or game (movement, hit detection, etc.) to the Server. The client will also acknowledge that it has received the previous snapshot and tell that to the server. When the server receives this data from the clients it utilizes it to create a new master gamestate, and acknowledges each client that it received the data. Lather, rinse, repeat. *

[1.2] Transferring Data
The biggest setback of online gaming is that it has to obey the laws of physics. That being, data does not travel instantly. This causes major discrepancies in the actual game, but we'll get to that later (or skip to 2.1 if you don't give a fuck about how it works).

Now all games typically choose to use TCP or UDP for data transfer. In short, TCP is very reliable at getting the information in its entirety and order from one location to another. However, the manner in which it does this is slow for various reasons. This is far too slow of a process in multiplayer games but it is perfectly fine for organizing matches, stat tracking, or pretty much anything that can afford to take more than half a second. UDP basically send the packet out with a destination stamped onto it and hopes it gets there; and it does that pretty well. The main issues with UDP is that packets tend to arrive out of order and it's quite prone to packet loss (an estimated 1-5% of the data likely won't arrive, this can of course vary with how matchmaking has places you relative to the server/host). A good layman's comparison of the two can be found here (and it goes into more detail in the following articles).

So while TCP works fine for untimely things such as playlist information or end-game stat tracking, UDP is neccessary in-game for speed reasons. So developers have to find ways to get past its faults. Now for the first issue, which is packets arriving in the wrong order, the server assigns a sequence number to outgoing data. On the client side, if any data received has a sequence number less than that of the current sequence number, the data is trashed. This effectively keeps things in order. Packet Loss is handled by each packet containing an ACK or acknowledgement. The client and server use ACKs to tell one another that they have received each other's data. Obviously any important data that wasn't sent (and needs to be) is resent.

[2.0] How does lag affect me?

[2.1] Latency, Jitter, Three bars, etc.
Alright, back to a more macro-scale of networking. So we know that the main limit to online gaming is the sheer fact that data takes time to get from point A to point B. Latency is the time delay between these points. One way latency is the time taken to get from source to destination, while round trip latency is of course the time taken for data to go from the source, to the destination, back to the source. This is the combination of numerous delays involved in the creation and transmission of a packet, but the most significant is the travel time of the packet, which is mainly what I'll focus on. Jitter or Packet Delay Variation is the standard deviation in latency from the mean latency. Ping is a network utility for accurate determining latency, in which either a client or server sends a message to the other and awaits a response. The Latency Bars (or ping bars, whatever) display the results from one's most recent ping test to the host. It's a really simple system, really:

4 Bars = less than 100 ms of latency
3 bars = 100-200 ms of latency
2 bars = 200-300 ms of latency
1 bar = over 300 ms of latency

Now in a game like CoD, 100 ms of ping is a lot. When combined with interpolation (discussed in 2.4) and short kill times yields a significant delay in what a person does. Now that's not to say it isn't still accurate, (as far as hit detection goes, CoD is fucking fantastic for a shooter) just that poor connection has a huge influence on one's performance. Due to CoD's short TTKs, connection issues are VERY apparent and have a tendency to look a lot less fair than they really are.

[2.2] Input Prediction
Alright imagine the following scenario: You press the button that makes you move forward. Notice how your character instantly responds and moves forward himself. But how? After all, that data hasn't reached the server yet. This is the effect of Input Prediction. Input prediction realizes what the player will do before the information reaches the server and back to the client, and applies it instantly in order to smooth gameplay. Basically, Input prediction executes local commands instantaneously. The alternative here is for one to input a forward move, send that info to the server, which would send it back in the next snapshot, and then you would move. You'd be a clear split second behind everything you tried to do. This system allows the game to run fluidly for every individual client while having the side effect of one's commands being asynchronous with what the server is sending out in snapshots* (which will be more obvious in a bit).

*Of course you wouldn't be synchronized with the server anyway due to latency; however, without prediction you would receive your own inputs in the same manner that everyone else is getting them.

[2.3] Hit Detection and Lag Compensation
So, we know that input prediction makes the client asynchronous with the server, but how does that effect gameplay? Well the first major issue is with hit detection. Hit detection or hit authentication is the game's way of telling whether or not you've managed to actually hit your enemy. There are two main forms of doing this: Client Side Hit Authentication and Server Side Hit Authentication.

Client Side Hit Authentication means that each individual client keeps track of when it hits an enemy, and simply send the data of it being a hit to the server. The primary benefit of Client Side hit detection is that it is 100% accurate for the player shooting. The downside is that it's incredibly weak to lagswitches and hacking. It's entirely possible for a player to use a third party program to send a "hit" to the host without seeing a player or even firing your gun. Any player would be capable of using a lagswitch to its fullest extent.*

*at the moment, only the host can truly utilize a lagswitch because they are the ones sending data to the clients. If you're platinum or higher in league then you've likely seen this in action. It is also important to note that a host can specifically block the IPs of other players in order to kick them out of games, which is another common issue at high level ranked matches.

Server Side Hit Authentication is far more complicated. Let's take the following scenario:


You shoot at the guy on the left, because that's what you see. However the target is moving to the right. You aim, and shoot. Your console/PC sends your position, direction, and the fact that you shot to the server. Now lets say that you have a latency of something nuts like 200 ms. By the time that your command reaches the host/server, the target has moved to the spot on the right. But if the game utilizes the data exactly as you sent it, then it would register as a miss because there's no player there now. This is where Lag Compensation comes into play. Lag compensation effectively "rewinds time." It digs through its memory and determines a game state that matches the client's information and implements it under those conditions. This accounts for latency, interpolation, and anything else that creates a time delay that the game can manage to quantify. The benefits of Server side lag compensation are that it is virtually immune to things such as lagswitches and various hacks (however things such as god mode hacks and aimbotting would still work). The downside of course is that it's flat out not perfect. Modern day lag compensation is very accurate for what it's worth, but CoD sends data from each client at 30 states a second all the while running at close (or more in the PC version's case) to 60 FPS on each client. Small precision errors can still occur and have very unfavorable results.

There are other methods of lag compensation, however Jon Shiring AKA slothy (Ex Infinity Ward now Respawn employee) has effectively confirmed that The IW Cods used rewind time compensation in here. It's a fairly safe assumption that the 3arc installments follow the same route, but I suppose there isn't any confirmation of that. That thread linked had some nice information in general, so it's worth looking through if you're interested.

On the server side, hit detection is accurate and lenient. Rest assured that if you shoot someone, then it will register as a hit. There are two exceptions to this rule, however. First, if the host receives information at any time that a player has been killed, then any more data it receives from that presumably dead player will not be sent to the other clients. Of course, due to latency, the server will realize that you are dead before you do. And if you were shooting someone, you are sending that information to the host. You can continue sending that information until that you receive notice from the host that you are, in fact, dead. This means that you can effectively tell the server that you have shot the enemy after the server knows that you've been killed. This would frequently result in players both killing one another due to cod's short ttks, so as a result, the server will cut off all input that it receives from you until you respawn again. If someone plays halo online then they're probably familiar with two players killing each other simultaneously. However do to the quick-dying nature of cod, this would happen in nearly every head on encounter. This will be visualized later in 3.2. The second exception to the rule involves packet loss, which will be discussed in 2.5.

[2.4] Interpolation and Artificial Delays
One thing many players will notice when looking closer at connection issues is that players have artificial delays applied to them.*This is caused by interpolation. Interpolation stores snapshots and renders them a split second later in order to keep movement fluid. Take a look at the following graph:


The line represents the timeline of the game, with each segment depicting the time delay between snapshots. It is important to know that Real Time (Server), Real time (Client), and Current Rendering Time are all occurring simultaneously, but are all at different spots on the game's timeline. Starting from the right the server sends out a snapshot. As we know, there is a delay between when it is sent and when it is received by the client. When the client receives the snapshot, it stores it in memory. It does not render the snapshot instantly. More specifically it does not render that snapshot until it has another snapshot to compare it to. However then we have to remember that we are using UDP to transfer data. If we are only using the past two snapshots, then any packet loss whatsoever would cause choppy movement as the game would need to predict where enemies are heading in order to maintain a moving picture. Thus it is standard to have interpolation span at least three snapshots, or a 100ms "lerp" it is often called. The server sends data to the clients at about about 20 snapshots/second (and 30 packets/second from client to server), which means this creates an artificial delay of roughly 100 ms.

There is another artificial delay added to the host. Since CoD4 there has always been a (reported) 20-40ms artificial delay added to the host and clients*. If 51% of the clients have a ping higher than 100ms, then the average ping of all players will be added to the host.* Robert Bowling said that this was changed so that the host's latency was equal to that of the next lowest latency player, so take that as you will.

*going off toysrme's word here and don't have any variables/dvars/values for that. However testing in CoD4 and MW2 showed this to be true. This also occurs on local splitscreen.

It is also important to note that there's been pretty good evidence of artificial delays in black ops 2. As shown here one can see that there is a major delay on splitscreen in BO2. It measures to be roughly 150ms compares to a little under 50ms for mw2/cod4. Theoretically there is absolutely no reason to have any delay on splitscreen, however that requires some reworking of game mechanics. Ignoring that there are various possibilities that could lead to a delay like this, such as interpolation having values unnecessarily high for local multiplayer or a flat delay for hosting platforms. Regardless it is worth noting that it exists and that Treyarch refused to acknowledge it during the game's lifespan.

There's another mechanic called extrapolation which predicts how the game will flow in a situation where too many snapshots were missed in a row to render a fluid scene. This is much less reliable for fluid movement and is rarely used for more than a fraction of a second in any game (if you have to extrapolate for over 250 ms then your connection's out of whack and there's no point).

[2.5] Packet Loss
Since a real time shooter like CoD is forced to use UDP, it is inherantly prone to packet loss. Now, as said earlier, data is sent from the server to the client 20 times each second and 30 times a second from client to server. Due to interpolation, missing one of these packets won't cause issues when rendering your in-game world. However, issues arrive when the exact packet containing information of a hit is dropped.

Now as said in 1.2, in order to compensate for potential packet loss, each packet sent must be confirmed by the receiver. Upon receiving information, the client or server will send out a response with an ACK to confirm that the previously sent information has reached them. If the ACK is not given within a certain period of time, then the important information from that lost packet is added onto the new one. While this system does a good job of making sure missing information goes through, it is unfortunately not very fast. It will take at least the length of one's round trip latency before the client/server knows that a packet did not get through, and in many shooters, that's often too late.

While it is certainly possible for data to get lost on the way to its destination, bandwith can be a major factor in packet loss (and is also the only factor that you can do anything about). When there is not enough room for an incoming packet to be stored or transmitted, that packet will be dropped. While CoD doesn't use too much bandwith, having multiple appliances on the same internet connection can ovwerwhelm and stifle connection from your videogame, especially if those applications primarily use a TCP connection.

[3.0] How does this come into play?

[3.1] Connection Discrepancies pt.1
Input prediction and lag will cause players to be out of sync with each other. More specifically, each client will see the other players significantly behind themselves. The difference will basically be Time it takes for the data to reach the server + Time taken from snapshot to reach another client + The time delay caused by interpolation. This stacks up to make a pretty big difference. When mixed with the fact that hit detection is designed to work properly from the shooter's perspective, this causes some wacky effects. The first major one comes from coming in and out of cover. In both these pictures: You are Red (your perspective), the enemy is Blue (his perspective), and the place where you see the enemy is on your end is a blue shadow.

Running into cover


In this situation, we have an enemy who is running away from you as you are shooting him. On his end, he has turned the corner, safe from your view. However, due to lag, the last snapshot to be rendered on your system was when he was a split second behind. due to the fact that you can act instantly and that hit detection is client side, your shots will register shooting him even though in real time on his client, he is out of your view. If you've been on the bad end of this (and you almost certainly have) you'd notice that you can actually travel a fair distance behind cover. This isn't as "bullshit" as it seems simply because for half of this time, you were already dead, your client just hadn't gotten word of it and thus input prediction allowed you to move because as far as it was concerned, you were still alive.* In actuality the difference is more reasonable and it just looks worse because the information had to get back to you.

It's important to note that this is simply dependent on a connection discrepancy. It doesn't matter who has the better connection on either side because the latencies of the players involved stack together. You do need to acknowledge the fact that in CoD, if either you or the opponent is lagging, then they have a window of opportunity after you take cover to kill you.

*it ends up being the time to send your location at time of death to server + latency between server and client + interpolation + sending it back to server + sending it back to you. Long time. Very silly. Looks weird. will visualize in 3.2

Coming out from cover


In this scenario, you are camping. Enemy comes around the corner and starts shooting you. On your end of the spectrum, he hasn't come around the corner yet. Basically, he sees you before you see him simply because he is moving into the room and you're already there. Once again, hit detection favors the attacker in this engagement; and once again, the significance is a result of the two players' combined latencies. When playing, especially on a poor connection, it's important to remember that you can manipulate this fault in networking to your advantage. However it's not consistent or reliable so it's not some be-all end-all trick either.

[iAmMoDBoX]

[3.2] Connection Discrepancies pt.2
Now I'm going to show what happens in a head on engagement, not involving cover. Let's assume that me, aidsaidsaids, and kirbyderby are all playing a free for all match; and for the sake of this, we're going to assume that there is no interpolation and that the following values are realistic (interpolation et. all would add more frames to the scenario and the point gets across without it).

Alright, so Kirb is the Host. Aids has a latency of 100ms and Mousey has a latency of 200ms. For the sake of the example this is one way latency. Review the following silly drawing:


In this, Mousey and Aids have come across one another. Mousey has started to attack aids a little earlier than vice versa, and the server has recognized this.



In this you can see that Aids and Kirb and responding fairly quickly to one another. The host has recognized that Aids started to aim and aids has acknowledged Mousey beginning to knife.



Now let's assume that both Mousey and Aids killed one another simultaneously in real time. On both of their screens they have gotten a killing blow, but neither of that information has reached the host yet, so they will still be seeing (and executing commands) that they receive from the other players until the host has acknowledged this. Input prediction does not predict another player's death (obviously) so the server must confirm it. Also, neither players would receive a hitmarker on these hits until the server confirms it; Mousey would hear the sound of the knife stabbing, however.



Kirb receives the information from Aids saying that Mousey is dead. His system would immediately stop sending any information it receives from Mousey (including the upcoming knife) until she respawns. Neither Mouse nor Aids has received this confirmation that Mousey is dead and thus they are still alive on each other's clients.



Aids receives information that Mousey is dead and he stops shooting. Kirb is still receiving information from Aids that he is shooting (as he was until the death was confirmed). Mousey is just now receiving information that aids is shooting, which looks silly and weird after he has been knifed.



Mousey now receives the info that Aids has killed her. She immediately warps back to the place of death as it was on the server. The death would have seemed awkward and unusual. If she had been shooting, then there would have been a period of where it appeared that bullets were hitting Aids but without hitmarkers to confirm them, simply because of how significant the delay is. The host would stop confirming that information the moment it acknowledges someone having killed her. Mousey would also have never received a hitmarker from the knife, as the host would never have confirmed the hit. Being on the bad end of a laggy connection will give you a serious disadvantage in all head on fights (but I'm sure you already knew that ).

[3.3] Killcams
Alright, so we saw that little frame by frame silliness that would show how it would appear from each player's perspective. Now let's see that in gif form.



The killcam that Mousey would see would be from the host's perspective of what happened. You may notice that while it doesn't seem like much of a laggy mess as Mousey's perspective, it seems fairly quick for what it's worth because it doesn't have the delay that aids really saw due to latency. Killcams also do not show precise readings of where people shot or were looking at. They are shown at most 20 states per second and thus are being rendered on your client on a fraction of the information present from the shooter's perspective. Any video you see that is using killcams as an example for anything is worthless information (unless of course, they are trying to show that killcams are inaccurate).

[4.0] Matchmaking
[4.1] Sorting players
The matchmaking and hosting systems are the two networking elements that IW and Treyarch has actually put some serious effort into making better. As far as finding games, it's supposedly been really simple in the past (starting with mw2, when it comes to cod4 nobody knows how the hell it decided hosts and such).

Starting in MW2, a client searches for available games that reveal a ping of under 50ms. Your system then searches those games and deems if you're suitable to join or not (through whatever criteria are in place). If no suitable games were found, then it would increase the threshold by 10ms and search again. It has a cap so that you'll never be put into a game that reads 800ms, but that's pretty high up there. It seems to work this way up through MW3 but I'm unsure.

Not too long ago, Activision released an article on how public matchmaking puts players into games. The system basically boils down to:

1. Find "suitable" games within a certain proximity
2. Eliminate games that are outside the player's skill bracket
3. Choose the one with the lowest ping.

According to the article, the game puts a lower priority in getting you into a game with the best connection than previous titles did. Take that as you will (or read the article at least).

Black Ops 2 includes search preferences as well. I do not know what the specifics of each option are (though "Best," "Normal," and "Any" are pretty straightforward) Vond has mentioned in a tweet that sorting by "best" places an upper cap on what the matchmaking system will find to be an acceptable latency for you (though the context tweet no longer exists).

[4.2] Hosts and Migrations
The hosting system is the other thing that the devs actually put some effort into regarding networking.

According to posts by toysrme (the default values for many variables are present in these), CoD4 and World at War use an unknown system to determine host. Since then, the systems works as such:

Cod4 and onward:
The host will constantly be pinging its clients. A player is "unhappy" if their ping shows to be above 400ms. In order for a host to change, at least three players must be in a game, and more than 51% of the clients need to show that they need to be unhappy. If this yields true for 300 network frames (at 20 snapshots/second this means for 15 seconds), then the game will be dropped (WAW) or the host will be migrated* (MW2 and onward).

*if someone is lagswitching and a migration occurs, then they suck at lagswitching

MW2:
MW2 introduced host migrations. The first host is chosen with a bandwidth race (see toys's post for specifics). This is done every time the host changes, which is done every time the old host leaves, a lobby merges, or if the host is not "suitable" for the game. Any time that the game would be dropped in CoD4, MW2 forces a host migration. If a migration takes longer than 40 seconds, the game is ended.

Black Ops:
Black Ops is nearly the same as MW2, however it runs the bandwidth test every time you sign into matchmaking to save time.

Could not find anything on MW3 or BO2. Feel free to shed some light if you know.

[5.0] NAT
This subject came up in a separate thread and I've decided to add my response to this.

[5.1] What is NAT?
First off let me get out of the way that different NAT types aren't going to affect latency or whatever unless you have some crazy multi-layered shit going on and you probably don't.

NAT is a technique that most routers these days are inherently capable of. It serves two major purposes:

 

• Combine multiple devices on a network into a single external IP address to save space
• Conceal the local address of each device by masking the IP under their own

When a machine tries to connect to the outside world through an NAT router, the router allocates a port for that device and sends the data to its destination as though itself were the original sender. Then when it receives a response, it will remember the device that the port is allocated to, and then forward the information to it. NAT will block information that's coming from an unrecognized location, and will not forward any incoming data if the port isn't allocated to anything either.

Forwarding ports is the method of taking all data sent to the router and sending it to a specific machine. The plus side as you may guess is uninterrupted connection, the downside is that you lose security. Opening specific ports for a game is totally safe. DMZ on a home network is kinda like forwarding all of your ports. It's basically easy mode but shouldn't do anything that forwarding the right ports should not. Its dangerous if you don't have any sort of firewall. On the other hand NAT is outdated as a form of security compared to typical firewall software. As long as you have something like that going, then you don't have to worry about any security issues resulting from DMZ or port forwarding.

I can't exactly find how the distinction between strict and moderate is made or what causes it and there are way too many shitty NAT guides for me to wade through to figure that out. An Open NAT, however, means that no connection to any potential hosts are being blocked, and should improve matchmaking for players by increasing the number of compatible games.

[5.2] Opening your NAT
UPnP Method:
UPnP stands for Universal Plug and Play, it is a set of networking protocols and its purpose is basically to let the console open whatever Foxtroting ports it wants. Ideally, if everything between your console and the internet is capable of UPnP, then enabling it should do the trick. To do so:

• Log into your router, you do this by typing in your default gateway into a web browser and then entering the login info. There are tons of way to find your default gateway and it can vary between OS so just look it up.
• Find an enable UPnP (this can vary between router so again look it up)
• Restart your console

Port Forwarding:
If the above didn't work because your router cant do UPnP, then port forwarding is the next step. This involves checking for when data is sent to a specific location and then automatically forwarding that to a specific machine on the network:

• Make sure the console has a static IP address. This can vary for console I'm guessing. On 360 you manually can set the local IP address. It should be in a specific range specified by your router, but if you know how to easily find your computers local IP address (e.g. ipconfig in windows) then you can just change the last number to something that's not already used on the network.
• Log into your router and open the specific ports for your console or game

 

OR

 

• Enable DMZ on the router

Just look up what ports you need. Xbox one's is easy to find, as is 360, but I can't say the same for PS4. TCP/UDP 3074 shouldn't be necessary for Playstation users because its Microsoft's official XBL port. 3075 is registered by Activision for blops 3. 3071 for blops 1.

Pegasusactual brought up that there isn't much reason for XBL to need certain ports forwarded, such as 53 or 80, despite the documentation. I don't have an xbox anymore but if someone wants to fiddle around with shit and see which ports seem to make a difference it would be appreciated.

Other Issues:
Some things can prevent an open NAT despite doing everything right.

• You can't use multiples of the same console at the same time if your port forward. You can do so with UPnP.
• Double NATing. Namely, connecting to a modem through a router or something of the sort. Both may be NAT devices but you're only fixing the issue on one. There should be a way to put the router into bridge mode (hardware dependent) or to put the router in the Modem's DMZ to redirect all traffic there. Using a computer as a bridge can also cause this issue.
• If using a static IP, only the last number should vary between it and any other devices on the network. If you change IP for some reason (new router, moved somewhere, took Xbox to a friends house) then you will need to update the IP manually.

Other Things:
According to some thread on neogaf i just came across, Xbox One has problems maintaining an open NAT over time, and does not fix it until the console is reset.

It's important to have realistic expectations. CoD runs on an old engine with network rates that became obsolete a decade ago. People die quickly. Lag is erratic and unreliable. She'll tell you she loves you and then kick your dog. It will help you and it will hurt you. It's gonna be there and there is nothing you can do to change that. Of course there are things you can do to mitigate connection issues, and it's particularly easy in the earlier PC versions, but that's a whole different topic.


EDIT: I couldn't find anywhere to explicitly fit this into this post, but here is a thread with information of the subject

[A7Legit]

I remember reading this on another forum.

 

I only disagree with a few points because the original author bases what he knows from COD4 and isn't as familiar with the changes made after BO1.

[ColonicBoom]

i'm getting through this but it's a lot of info. my attention span is not so goo...

[ColonicBoom]

i was rooting for the mouse

[Omega]

This surely wasn't the first time I've seen this topic, and I'm certain it won't be the last. You know what I notice more than anything when I play BO3? The more unstable the connection, the better the gameplay. I've played this game quite a bit being a part of multiple first page teams on GB. I've done much tinkering from series to series, game to game, sometimes even death to death. What I can tell you is that when I put the Netduma into preemptive, eliminating any buffer bloat (added latency), the gameplay I receive is laughable. It's the age old tale of getting obliterated before the blink of an eye. And I fought this notion since it goes against any common sense. But, after setting to reactive with sliders at 100% and seeing bufferbloat add on as much as 500 ms of latency, the gameplay is significantly better. Seems a bit counter-intuitive right? I've researched this topic for many years, dating back to the MW3 days. It's been five years and I can honestly say I have found no fix to this. What I said helped me is not a fix because all it does is make it inconsistent, as opposed to consistently bad. This makes the game random, and thus less competitive. The current state of CoD is sad, and the next release of Infinite Warfare surely won't address this growing trend of randomness. In fact, I expect it to only get worse. Just look at the random loot system employed, one that forces those who really want something in a game they purchased to shell out money for what is essentially a raffle ticket . If that doesn't sum up CoD, I don't know what does. The problem does begin with the community, though. With Youtubers like Ali-A, who are surely in the deep pockets of Activision, posting video after video of massive supply drop openings. Yet, he never addresses how inconsistent the gameplay is. Hmmm. Odd since everyone I play with complains about the inconsistency on a daily basis. Luckily, I'm 24 years old, and my playing days are nearing an end as it is rather difficult to manage video games and adult life (can't believe I actually said it). But, for the teens out there, you guys are getting a raw deal. You're paying more for incomplete games, as Activision lines its pockets with your money. It's the harsh reality that is the current state of the industry.

[A7Legit]

Whilst I can understand and even put some respeck on your frustration I don't agree with you on the matter, actually, I can't from my own experiences in Call of Duty titles I still play and others.

 

I have BO3 on both the PS4 and XB1 and the game plays nicely 90% of the time, that's pretty consistent for me, I have bad games when the dedicated servers have issues or I do something dumb in my games like run out in front of 2-3 people and try to contest them, heck sometimes I even get away with it, mostly I do not.

 

I've noticed the opposite of what you have, when I use Preemptive I get more round trip latency and with Reactive (also known FQ_Codel) my round trip latencies are improved which actually makes sense considering the purpose and success of FQ_Codel. In saying that, ISP implementation of how they deal with queues and bloat are different (if any at all for some ISP's).

 

Also I noticed that lowering jitter gives you an overall better experience in BO3 more so than any earlier 3arc or Infinity Ward (during and after West/Zampella era) title(s).

 

I've come to see many gamers not even bother with jitter but worry about 2-5ms of added latency (round trip) when every other second they see 5-15ms of line deviation.

 

Sadly we all will suffer from jitter to the dedicated servers (and all the people in the lobby will) but what will seperate us from the others will be how much internal jitter we have in our home networks as opposed to the others in our lobbies.

 

It might not be what people want to hear and I'm always seeing how people continue to dispute me on this but at the end of the day I continue to have success in this title (BO3) as well as older COD's (i.e. BO2, BO1, MW3, Ghosts) and other games such as BF4 (PC) & FIFA.

 

When settings and success spans over so many different titles and genres I just cannot accept that the bad internet excuse holds weight.

Don't get me wrong, I used to think that too but I learned from experience that it is not entirely accurate due to so many different variables each individual household has to put up with.

 

I look forward to Iain and Fraser making the next video to put this bad internet equals lag compensation favouring to rest.

[RobReapz]

Whilst I can understand and even put some respeck on your frustration I don't agree with you on the matter, actually, I can't from my own experiences in Call of Duty titles I still play and others.

 

I have BO3 on both the PS4 and XB1 and the game plays nicely 90% of the time, that's pretty consistent for me, I have bad games when the dedicated servers have issues or I do something dumb in my games like run out in front of 2-3 people and try to contest them, heck sometimes I even get away with it, mostly I do not.

 

I've noticed the opposite of what you have, when I use Preemptive I get more round trip latency and with Reactive (also known FQ_Codel) my round trip latencies are improved which actually makes sense considering the purpose and success of FQ_Codel. In saying that, ISP implementation of how they deal with queues and bloat are different (if any at all for some ISP's).

 

Also I noticed that lowering jitter gives you an overall better experience in BO3 more so than any earlier 3arc or Infinity Ward (during and after West/Zampella era) title(s).

 

I've come to see many gamers not even bother with jitter but worry about 2-5ms of added latency (round trip) when every other second they see 5-15ms of line deviation.

 

Sadly we all will suffer from jitter to the dedicated servers (and all the people in the lobby will) but what will seperate us from the others will be how much internal jitter we have in our home networks as opposed to the others in our lobbies.

 

It might not be what people want to hear and I'm always seeing how people continue to dispute me on this but at the end of the day I continue to have success in this title (BO3) as well as older COD's (i.e. BO2, BO1, MW3, Ghosts) and other games such as BF4 (PC) & FIFA.

 

When settings and success spans over so many different titles and genres I just cannot accept that the bad internet excuse holds weight.

Don't get me wrong, I used to think that too but I learned from experience that it is not entirely accurate due to so many different variables each individual household has to put up with.

 

I look forward to Iain and Fraser making the next video to put this bad internet equals lag compensation favouring to rest.

I agree with you for the most but do you not feel the need to throttle when u play the older cods ie MW3 because without throttling my game feels like a mess?

[Omega]

Whilst I can understand and even put some respeck on your frustration I don't agree with you on the matter, actually, I can't from my own experiences in Call of Duty titles I still play and others.

I have BO3 on both the PS4 and XB1 and the game plays nicely 90% of the time, that's pretty consistent for me, I have bad games when the dedicated servers have issues or I do something dumb in my games like run out in front of 2-3 people and try to contest them, heck sometimes I even get away with it, mostly I do not.

I've noticed the opposite of what you have, when I use Preemptive I get more round trip latency and with Reactive (also known FQ_Codel) my round trip latencies are improved which actually makes sense considering the purpose and success of FQ_Codel. In saying that, ISP implementation of how they deal with queues and bloat are different (if any at all for some ISP's).

Also I noticed that lowering jitter gives you an overall better experience in BO3 more so than any earlier 3arc or Infinity Ward (during and after West/Zampella era) title(s).

I've come to see many gamers not even bother with jitter but worry about 2-5ms of added latency (round trip) when every other second they see 5-15ms of line deviation.

Sadly we all will suffer from jitter to the dedicated servers (and all the people in the lobby will) but what will seperate us from the others will be how much internal jitter we have in our home networks as opposed to the others in our lobbies.

It might not be what people want to hear and I'm always seeing how people continue to dispute me on this but at the end of the day I continue to have success in this title (BO3) as well as older COD's (i.e. BO2, BO1, MW3, Ghosts) and other games such as BF4 (PC) & FIFA.

When settings and success spans over so many different titles and genres I just cannot accept that the bad internet excuse holds weight.

Don't get me wrong, I used to think that too but I learned from experience that it is not entirely accurate due to so many different variables each individual household has to put up with.

I look forward to Iain and Fraser making the next video to put this bad internet equals lag compensation favouring to rest.

Before I address your flawed argument, I will give you the benefit of the doubt because A. your dedication to this forum and B. I truly would like a solution to this issue.

 

You suggest using reactive if I read what you stated correctly. What do you put the sliders at? The same value or different bi-directionally? Do you use Hyper Lane? Do you configure the flower? If so with what values? I will mirror your setup with the hope that what your saying proves true. Just to address the dedicated server part of your argument, that proves null and void considering I only play competitive custom lobbies which I'm sure you're aware are P2P. With that said I hope you are right.

 

Thanks,

Dan

[A7Legit]

Before I address your flawed argument, I will give you the benefit of the doubt because A. your dedication to this forum and B. I truly would like a solution to this issue.

You suggest using reactive if I read what you stated correctly. What do you put the sliders at? The same value or different bi-directionally? Do you use Hyper Lane? Do you configure the flower? If so with what values? I will mirror your setup with the hope that what your saying proves true. Just to address the dedicated server part of your argument, that proves null and void considering I only play competitive custom lobbies which I'm sure you're aware are P2P. With that said I hope you are right.

Thanks,

Dan

I appreciate you giving me the benefit of the doubt Dan, at the end of the day we're all in this together my Netduma brother.

 

Reactive, sliders at 97%, speeds in my signature with a B bufferbloat at 100% and line quality at A+ without throttling or lowering CC.

 

My hyper-traffic: http://forum.netduma.com/topic/15657-preliminary-lag-compensation-experiment-findings/?do=findComment&comment=105001

 

I personally do not know anyone with my same hit detection across all the COD's (wow that sounds arrogant but it's true), 3-4 on point shots and the enemies drop, consistently.

People complain that 3arc has bad hit detection yet I have Ghosts hit detection in all COD's, so I don't need to validate what I say works (at least for me).

 

The game plays the same across the PS4 and XB1.

 

Just to prove this isn't a one off thing.

https://twitter.com/a7legit/status/750995975641059329

 

I've literally got plenty of these kinds of clips on Twitter, anyone who follows knows that my hit detection is crisp almost every game (9/10 times).

 

https://twitter.com/a7legit/status/750333643831201792

 

I agree with you for the most but do you not feel the need to throttle when u play the older cods ie MW3 because without throttling my game feels like a mess?

I used to throttle back in the day but after sorting my physical connection I don't need to anymore, it's a one size fits all right now.

[Zennon]

I personally do not know anyone with my same hit detection across all the COD's (wow that sounds arrogant but it's true), 3-4 on point shots and the enemies drop, consistently.

 

Dependent on gun and range my hit detection is what the guns stats say.

 

2 hit with the sheiva and one to the head with high cal, 3 shot with the MOW 3-4 with the KN-44 etc as it is for all players with good aim just a lot of people miss and blame hit detection.

 

It is all about recoil handling and arching the right stick to compensate or left to right arching if you are strafing.

[A7Legit]

Dependent on gun and range my hit detection is what the guns stats say.

 

2 hit with the sheiva and one to the head with high cal, 3 shot with the MOW 3-4 with the KN-44 etc as it is for all players with good aim just a lot of people miss and blame hit detection.

 

It is all about recoil handling and arching the right stick to compensate or left to right arching if you are strafing.

 

I need to use the Shieva more. 

[Zennon]

Its a beast, two shot anywhere on the map with long barrel , pop high cal on and its a one shot head shot.

 

It is great from about 8 foot onward but up close when you hip fire it has massive spread.

[A7Legit]

Its a beast two, shot anywhere on the map with long barrel , pop high cal on and its a one shot head shot.

 

It is great from about 8 foot onward but up close when you hip fire it has massive spread.

From what I'm reading the Shieva kinda reminds me of the FAL from BO2 but better!

 

Thanks, I'll be using it when I play next.

[iAmMoDBoX]

My hyper-traffic: http://forum.netduma.com/topic/15657-preliminary-lag-compensation-experiment-findings/?do=findComment&comment=105001

 

 

 

As for your hyper lane settings, according to the 3arc dev who reached out to me... There is no communication on port 3074 for the actual game. I don't know how true it is, but he said this... (green is me)

 

[A7Legit]

As for your hyper lane settings, according to the 3arc dev who reached out to me... There is no communication on port 3074 for the actual game. I don't know how true it is, but he said this... (green is me)

 

Source UDP:3074 1*8.6*.2**.132.choopa.net Destination UDP: 34050

Adelaide, South Australia, Choopa LLC dedicated server {PS4}.

 

I don't really want to go into too much detail here, but it is what it is.

[RoyDavis77]

I noticed when using an openwrt router, udp destination ports between 34000 and 34100 are used to communicate with the call of duty servers, udp 3074 is always source port and the 3074 destination port is used to communicate with the other players in the lobbey.

[A7Legit]

I noticed when using an openwrt router, udp destination ports between 34000 and 34100 are used to communicate with the call of duty servers, udp 3074 is always source port and the 3074 destination port is used to communicate with the other players in the lobbey.

This is why I add 3074 as the sole priority for packets first in and first out (Hyper-lane).

[RoyDavis77]

But as you rightly say Legit, if you port forward or prioritize the ports communicating with the server, it makes no difference to the game experience, also if you block udp 3074 sport or dport, you are disconnected from the game, so 3074 udp seems to be the main port, for the funtionability of call of duty.

[RoyDavis77]

The is speculation originating from a cod player claiming to be a network engineer that because cod servers delay data sent to all in game client machines, the only way to get in synch with game play in call of duty, is to reduce the response rate to the cod servers but i wouldnt know where to start, testing his theory

 

heres a link to his claim:

 

https://blog.activision.com/t5/Black-Ops-3-Support/Tier-2/td-p/9804177

 

Interesting read.

[A7Legit]

The is speculation originating from a cod player claiming to be a network engineer that because cod servers delay data sent to all in game client machines, the only way to get in synch with game play in call of duty, is to reduce the response rate to the cod servers but i wouldnt know where to start, testing his theory

 

heres a link to his claim:

 

https://blog.activision.com/t5/Black-Ops-3-Support/Tier-2/td-p/9804177

 

Interesting read.

I knew someone who was using his JTAG Xbox 360, he'd double the rate and then host p2p games for people, the games (MW3, BO1, BO2) would have far better hit registration, people weren't dying behind corners and when you were outgunned you could accept it because it looked legitimate. I had the pleasure of having a few games in his lobby whilst he hosted. It was better, but not perfect.

What I liked so much was he didn't enable any cheating BS, no aim bots or invincibility crap, so I believe the individual who had this idea either started the trend or was fortunate enough to play in such a lobby also.

 

The devs are aware of this, but I remember reading someone from 3arc I believe saying to double the rates would mean upload and download rates would need to be in excess of 128kbps and that was not going to happen... So they basically said that they went going to improve the game because of bandwidth requirements needing to be faster than a measly 128kbps... It's mid 2016 and these devs are supposedly worried about upping the bandwidth requirements.

 

I have no more words lol

[ColonicBoom]

The is speculation originating from a cod player claiming to be a network engineer that because cod servers delay data sent to all in game client machines, the only way to get in synch with game play in call of duty, is to reduce the response rate to the cod servers but i wouldnt know where to start, testing his theory

 

heres a link to his claim:

 

https://blog.activision.com/t5/Black-Ops-3-Support/Tier-2/td-p/9804177

 

Interesting read.

 

I'm not able to input anything useful to the technical side of this discussion...

But like he said in that link, I cannot understand the match-making in this game at all.

 

Earlier this evening I had 8 out of 12 in the lobby with 3 to 1 bar connections, while my ping to the dedi was a steady 26ms.

They were from: 2 in Germany, 1 in Ukraine (I think), 1 in Southernmost Italy and 1 in Southernmost Spain, 1 in France, 1 in Finland, 1 in Turkey, 1 in Ireland and 2 in the UK. Needless to say, it was all over the place.

 

What kind of wonky matchmaking is this? On a Saturday evening when surely a lot of UK gamers are playing.

I'm starting to think that this game may have better matchmaking when dedis eventually get dropped and it becomes P2P (not at the moment of course as P2P seems to be reserved for torture-connections). It seems like it will throw anyone into a lobby and there is little effort in match-making as long as it can fill lobbies quickly. And it's not something I used to see very often on the P2P CoDs.

[Omega]

A7 Legit, after testing out your setup there is no difference whatsoever. To be completely honest, you should count your lucky stars because I haven't had a single game where my hit detection was that good lol. If I use my Nighthawk R7000 I get 500ms of added buffer latency. 500ms is half a second. So if I use the R1 and knock this buffer latency down to 5-10ms, one would expect to see a drastic difference. However, no difference is seen. This can only mean that there is some other factor at play. I'm mainly the M8 anchor player on my team. I've had games where I've recorded hitmarkers on 5 consecutive bursts with long barrel. Mind you it's a 4 bullet kill with the M8. This type of scenario should never happen. And yet in those same games where I'm 5 bursting players, I am getting melted as if I were a zombie and the humans picked up the insta kill powerup. My dslreports grades are all A+ . Quite frankly there is no explanation for this phenomenon which has been dubbed most commonly lag comp. I am at a loss as to what to do to make this game play anywhere near consistently.

[A7Legit]

A7 Legit, after testing out your setup there is no difference whatsoever. To be completely honest, you should count your lucky stars because I haven't had a single game where my hit detection was that good lol. If I use my Nighthawk R7000 I get 500ms of added buffer latency. 500ms is half a second. So if I use the R1 and knock this buffer latency down to 5-10ms, one would expect to see a drastic difference. However, no difference is seen. This can only mean that there is some other factor at play. I'm mainly the M8 anchor player on my team. I've had games where I've recorded hitmarkers on 5 consecutive bursts with long barrel. Mind you it's a 4 bullet kill with the M8. This type of scenario should never happen. And yet in those same games where I'm 5 bursting players, I am getting melted as if I were a zombie and the humans picked up the insta kill powerup. My dslreports grades are all A+ . Quite frankly there is no explanation for this phenomenon which has been dubbed most commonly lag comp. I am at a loss as to what to do to make this game play anywhere near consistently.

Ah well, I give up...

 

I keep getting told I'm lucky, when I too used to rage in BO3, I forced my connection to work and to optimise it for online gaming and VOIP. I think my R1 was bitten by the same spider that bit Peter Parker (Spider-Man).

 

I think I'll keep what I do to myself in future, sorry it didn't help you bro.

 

Cheers.

[ColonicBoom]

A7 Legit, after testing out your setup there is no difference whatsoever. To be completely honest, you should count your lucky stars because I haven't had a single game where my hit detection was that good lol. If I use my Nighthawk R7000 I get 500ms of added buffer latency. 500ms is half a second. So if I use the R1 and knock this buffer latency down to 5-10ms, one would expect to see a drastic difference. However, no difference is seen. This can only mean that there is some other factor at play. I'm mainly the M8 anchor player on my team. I've had games where I've recorded hitmarkers on 5 consecutive bursts with long barrel. Mind you it's a 4 bullet kill with the M8. This type of scenario should never happen. And yet in those same games where I'm 5 bursting players, I am getting melted as if I were a zombie and the humans picked up the insta kill powerup. My dslreports grades are all A+ . Quite frankly there is no explanation for this phenomenon which has been dubbed most commonly lag comp. I am at a loss as to what to do to make this game play anywhere near consistently.

 

He did say that it wouldn't necessarily work for everyone, in fact I'm sure he said somewhere that it might be a placebo and it might work for nobody else.

Bufferbloat only affects you when you connection is maxed out I think, BO3 will never max out anything but the very lowest bandwidth connections though.

I've had hitmarkers with 5 bursts of an M8 too but this isn't a hit detection problem, the fact that you got hit markers shows that the hits were detected and the damage was dealt to the enemy (enemies).

 

Ah well, I give up...

 

I keep getting told I'm lucky, when I too used to rage in BO3, I forced my connection to work and to optimise it for online gaming and VOIP. I think my R1 was bitten by the same spider that bit Peter Parker (Spider-Man).

 

I think I'll keep what I do to myself in future, sorry it didn't help you bro.

 

Cheers.

 

 

You sure YOU didn't get bitten by that spider mate?

Don't keep it to yourself, I've been trying some of your suggestions and so far I have nothing negative to report (I just haven't reported anything yet because your mailbox was full when I tried).

Keep up the experimenting and the beasting, the more people experiment then the more chance they have of finding their optimal settings.

Even if people just copy your play-style they will likely improve their performances.

Party on Wayne.