Netcode Explained
By $uCkY-p|aYeR
Oh no you say, another netcode explained. Yes it is but it seems each one
is different and not all agree with the right settings. I am doing this
to show where the other guides are wrong, to prove why the settings should be a
certain way, and to let you the player learn and figure this out for
yourself. I am also going to provide information to the
server administrators. In the end they have the final say in how we can
set our settings. Between the client and the server administrators we can
produce almost perfect hit registration that the internet will allow. There are
several more settings that some think to be very important I will not be
covering these settings. I find it hard to test those other settings and
be able to come to a exact conclusion. I have
read many guides even old HL guides, which is where a
lot of the new hl2 guides got there information. All of the information I
have used is common knowledge. The information that
isnt common knowledge I tested thoroughly with having access to a server and
opening all settings so nothing is forced. I also filled up the
server with a lot of action. Because many of the things I discuss you wont see in a empty server.
FPS - Frames per Second.
fps_max - Sets an upper limit on the frames per second the
server or client runs at.
sv_maxrate - The Maximum amount of data in Bytes per Second the
Client can request from the Server.
sv_minrate - The Minimum amount of data in Bytes per Second the
Client can request from the Server.
sv_maxupdaterate - The Maximum amount of Updates per Second the Client
can request from the Server.
sv_maxupdaterate - The Minimum amount of Updates per Second the Client
can request from the Server.
sv_maxcmdrate - The Maximum amount of Updates per Second the Client
can send from the Server.
sv_mincmdrate - The Minimum amount of Updates per Second the Client
can send from the Server.
rate - The Maximum amount of Bytes Per Second the Client
will request from the server.
cl_updaterate - The Maximum amount of Updates Per
Second the Client will request from the server.
cl_cmdrate - The Maximum amount of Updates Per
Second the Client will Send to the server.
updates Packets of
information about what is going on in the game such as: player position,
explosions, everything that happens in the game. You receive updates from
the server then you send updates back with what is going on, on your side.
Ticrate This determines the most updates the server will be
able to send and receive. 100tic = 100updates, 66tic = 66 updates.
TICRATE
Lets start with ticrate and work are way down.
This is something that server administrators and players should really
understand. The ticrate determines the most updates the server will be
able to send and receive. The highest ticrate a server can be is
100, the lowest is 33, and the most common is 66. So if a server
administrator and a player were really thinking they would use these settings
below:
|
Client settings |
Server administrators max settings |
|
cl_updaterate 100 |
sv_maxupdaterate 100 |
|
cl_cmdrate 100 |
sv_maxcmdrate 100 |
If the ticrate is ultimately going to determine what the server and client send
and receive for updates. There isnt any reason not to set those settings
to the highest setting you can have. With those settings above if
the ticrate of the server is 66 tic. You would
receive and send only 66 updates (because the ticrate of the server is 66 even
though your settings are 100). So why make it tough on figuring them out
or changing them according to ticrate. Waste of time if you ask me.
One setting for all makes it easier. I didnt put in the sv_minupdaterate or
sv_mincmdrate. That is because it would be up to the server administrator
for setting this. I feel it is preference. I would set the min
values to 100 also but again my opinion (explained later in my
conclusion).
CL_UPDATERATE
I wont spend too much time on updaterate since I
pretty much explained it above with ticrate. Updaterate is determined on
the clients machine by sv_maxupdaterate,
sv_minupdaterate, ticrate and cl_updaterate. Updaterate is the amount of
updates you want the server to send you per second. The server will send
whatever you want as long as there isnt a rule telling it not to for
example. If I set cl_updaterate 100 then the server will send me 100
updates a second unless ticrate is less then 100 or sv_maxupdaterate is set
lower than 100 by server administrators(note if you dont have sv_maxupdaterate
in your server config then default is 60). Other than those
settings only choke and loss will play a factor in how many updates you get
from a server. This is explained later on.
CL_CMDRATE AND FPS
Let
me explain, probably the two most overlooked things that cause poor hit
registration. Besides seeing the actual true position of the player you
are aiming at. What do you think needs to register correctly to actually
hit that person? What needs to register, is your shot, you know when you
actually press the mouse button to shoot. The amount of updates you send
the server is very important. Since it tells the server that you shot
your gun and where you shot at. These settings below control what you
send the server.
|
Client side settings |
Server side settings |
|
Cl_cmdrate |
Sv_mincmdrate |
|
Ticrate |
Sv_maxcmdrate |
|
FPS |
|
Earlier I said to set cl_cmdrate to 100 since you will never be able to send
more updates then the highest ticrate a server can be which is 100. There
is one thing that will lower the amount of updates you send to the server no
matter how high the ticrate nor how high your cl_cmdrate. That is your
FPS. You cant send more updates to the server
then what frames you actually render on your end. So if you are in
a 100 ticrate server and you have cl_cmdrate 100, but your fps is only staying
around 50 then you only send 50 updates a second or whatever you fps during
that second of play. Seeing how fps is the end factor on what
updates you send the server on your shots fired and where you were aimed.
I decided on another table to explain this.
|
|
Good hit registration |
Bad hit registration |
|
100 ticrate server |
100fps steady or higher |
Fluctuating fps under
100fps |
|
66 ticrate server |
66fps steady or higher |
Fluctuating fps under 66fps |
|
33 ticrate server |
33fps steady or higher |
Fluctuating fps under 33fps |
Good hit registration and Bad hit registration may not be seen by some people,
but having fluctuating fps under the ticrate of the server can cause it even if
you dont see it. If anything else the person with higher steady fps than
the ticrate will have an advantage over the low fps player. So all those
people that say you can play HL with low fps true you can cause
lag compensation will compensate for the updates you dont receive and make it
feel like really smooth play. But youre going to have
more times where you miss then a person pegging at a higher fps.
RATE The common cause of
choke and loss.
Rate the biggest problem with server administrators and players. This
setting is probably the main thing every single netcode guide has got
wrong. Why is this? Most of the netcode guides came from old CS 1.6
players. Who already knew what settings worked in old CS but didnt
realize they would ever need to set these settings higher. Even
Rate is merely a cap saying dont send more than 30000
bytes/second (I used 30000 as an example). Tell me this if you were
downloading mp3s would you want to say dont send me more than 30000
bytes/second which = 234kbits per second. I guess you would if you had
dsl because it is about that fast. We spend so much money on fast
download speeds yet in half life because someone said put this setting in. This
is the optimal setting you should use and we believe it. I say dont
believe them or me follow what they say and see if it works. Tests
settings they said dont use and see what happens. Here is a breakdown of
common internet speeds that I converted into bytes.
|
Internet speeds |
Converted to bytes/what your rate could be set at |
|
Dsl 256kbits download |
32768 |
|
1mb |
131072 |
|
2mb |
262144 |
|
3mb |
393216 |
|
6mb |
786432 |
Obviously you dont want to set your rate at 786432 lol. But I put that on there to show you how much your rate could be and you would still be able to handle the traffic. Because how many times have you heard 25000 is lan setting or 30000 is lan setting. That is funny I guess my 6mbit download speed is as fast a lan, lol, not. A lan setting could be as low as 10mbits for old lans and 1 GB for newer lans. So a rate setting of 1310720 would be a lan setting.
CHOKE AND LOSS
Choke and Loss can happen if this setting isnt set correctly. Loss happens when your internet cant handle the amount of bytes being sent that second or problems with hops between you and the server. I am not going to explain hops. But to control you loss and keep it to a minimum make sure your rate setting isnt set higher than your download speed. Its hard for me to test this since I have a 6mb connection.
Choke happens when a rule set by you or the server administrator tells the
server to stop sending updates. So the server then holds on too them tell
it can send them. I know who would say stop sending updates. You
dont actually say that to the server. What happens is we set our rate
settings to low sometimes or the server forces us to a low rate setting.
Here is an example I already used: You are
suppose to get 100 updates per second from the server each update is around 400
bytes. That is 40000 bytes per second but you have your rate set to
30000 that means after you receive 75 updates you wont
receive 25 updates that second. So your choke will be 25. So to
avoid this in the example I just wrote you would have had to set your rate to
40000 and you wouldnt have choked at all.
Well that is easy enough so I set my rate setting higher and my choke will be
gone. Yes it is that easy, but it isnt so easy to make server
administrators all across HL2 understand that there sv_maxrate setting is a big
problem. In that same scenario you could set your rate to 40000 and get
rid of choke but if the server set sv_maxrate 30000(which I bet 60-80% do) then
you will still choke cause the server will force you to a rate of 30000.
So the only way to get rate to work correctly we need the server administrator
to change there settings as well so we dont choke. Choke is like the one
thing we can control and together it is possible to rid most of these servers
of choke. Below are some rates for clients and some recommendations for
server administrators.
|
Internet speed |
Rate setting |
|
256kbit dsl |
32768 |
|
1mbit download speed or
higher |
100000 or higher if you choke |
|
Recommended server settings |
|
sv_maxrate 100000 |
|
sv_minrate 20000 |
I would be very surprised if
anyone ever choked at rate 100000 that is why I picked that setting. If
servers set that maxrate then we could get rid of our own choke and we couldnt
blame the servers anymore.
NETGRAPH
Now that you got somewhat of an understanding of that stuff. Here is a
way to monitor everything I have explained above with a tool so much of us dont
use. It is called net graph. It will tell you what your fps, ping,
loss, choke, how many updates you are actually receiving and sending, and how
big each update is. You can enable this graph by pulling down console and
typing net_graph 3. there is other types of
net_graph but this one has the important information we are looking
for. You can also position it along the right, center, or left on
the bottom of the screen. Just type net_graphpos 1(right), 2(center), 3(left).
I use 1 it seems more out of my way.
1 = fps what a that particular second your fps is.
2 = ping not really true ping but close
3 = how big the packet size of the update you
just received and sent. In being what you
received, out being what you sent.
4 = How fast the information is going. Not real important.
5 = The top number is how many updates
per second you are actually receiving (cl_updaterate
or ticrate). The bottom number is how many updates you are actually
sending (cl_cmdrate, ticrate,
or fps).
6 = number of packets that you sent that got lost or dropped.
7 = number of updates you didnt receive from the server.
So now you can use this tool to figure out what is happening on your end and
see where you need to make adjustments. With this picture you can see no
loss and no choke that is great. Looking at section 5 tells us that
we are playing in a 100 tic server since we are receiving 102.4/s. But
the problem is that we are only sending 78.6/s. We should be sending
around 100 updates to the server as well. Well the problem is that we are
not getting 100fps look at area 1 we are only getting 79fps which is right
about what our updates we are sending is. So according to this graph we
would get pretty decent hit registry but to achieve the best hit registry we
would need fps to go up and stay at 100fps. So we are sending and
receiving the most updates the server will allow.
Lets take this same graph and imagine we are in a 66
tic server. With fps at 79 which is above 66 both the numbers in area 5
would read around 66 steady all the time unless fps dropped under 66 or we
started to choke/loss. I hope you get the idea on how we can use this and
understand how to tell what tic the server you are in is. Plus understand
how fps dropping can cause poor hit registry
EXTRA INFORMTION FOR TESTING THIS
Here are some key things you should know before going out and testing these
youre self. One servers most of the time force settings lower than what
you might want to set them at. To see what your setting is for any of the
client commands simply pull down console and type the command with nothing
after it and hit enter. If your setting is under the forced setting then
you will see what your setting is set at. If your setting is higher than
what the server is forcing you will see something in red saying your setting is
this but the server temporarily is setting it to something. You will see
this a lot with rate setting so when you set rate 100000 go into the server and
type rate and hit enter you will see almost 80% of all servers will force it to
30000.
Second you will see this in a lot of 66tic servers and above. The
administrator doesnt put a sv_maxupdaterate in the server.cfg thinking that it
will open it up and can be however high you want it. It in fact defaults
to 60. So in a 66 tic server or above if you see in area 5 the top number
stuck at 60 this is something that is the problem the server administrator did.
By not putting sv_maxupdaterate 66 or 100 in the
server.cfg. Well maybe valves fault for not making default higher.
CONCLUSION
So
with all the information I gave on how to adjust your settings, what the
settings mean and how they all work together. I hope you come to the same
conclusion as I did on what settings to have. Below is
what I set my settings at and what servers administrators should set
them. So that we can all have really good hit registration as well as
little to no choke.
|
Clients settings |
Server Settings |
|
rate
70000-100000 |
sv_maxrate
100000 |
|
cl_updaterate
100 |
sv_maxupdaterate
100 |
|
|
sv_minupdaterate
30-100 |
|
cl_cmdrate
100 |
sv_maxcmdrate
100 |
|
|
sv_mincmdrate
30-100 |
If
the client and the server are setup like this the only thing that will affect
persons hit registration will be there FPS and Loss. This is something
the server administrator cant help with. FPS is
basically revolves around you having a good video card and good cpu. Loss is usually caused by slow download speeds if
you have a dsl 256kbit line try finding an ISP that offers 1mbit or higher.
You could also lower your rate setting to fix loss in the end you might end up
choking. If you have a slow download speed and you lower your rate down
tell the loss is gone. You could then lower cl_updaterate until your choke
is gone. This is only if you have slow ISP and cant
do what I explained
in this article.