Possible solution to COOP "lag" or desync

Hi,

I've been playing the COOP campaign with a friend and we have mainly been doing most of our game play in the Razor Two mission since a number of bugs/crashes and script errors kept us restarting.

However its been a lot of fun :)

One particular bug we had was what seemd to be "lag" upon "resuming" or loading a previous save game. My friend is the host and I'm the client joining his COOP game.

When we die and he loads the last save, my game seems to "lag" behind by about 10 or more seconds... if he is driving a car down the road for example I will see him driving in circles and off the road, then the car will jump back on the road etc...

The only way to fix this is to click "Esc" > "Abort" > "disconnect" > "ok" and join the game back again. Once this is done the game is ok until the next resume.

Now today we finished the Razor Two mission and are now playing Manhattan... or trying to!

At the start of Manhattan this "lag" bug seems to be very strong, to the point where I cant see him moving... even the AI soldiers simply walk in 1 place... animation moving them but not changing postion.... then suddenly eveyrhting will move and then lag again....

This time the exit fix does not work.. making Manhattan unplayable.

As I have a dual screen setup, I can monitor many things on my system on the second monitor, including my network usage (up and down).

I noticed when this lag is occurring in Manhattan, my download speed is 40kb/sec... now this is actually the maximum my friends ADSL connection can upload.

After trying a number of things I suggested we try Hamachi to see if that fixes it... by playing using the "Lan" mode.

Indeed after joining his LAN game the Manhattan mission is working perfectly, I am downloading at about 30kb/sec and have no lag... its perfect.

So if your having problems in the COOP campaign, give Hamachi and LAN a try... it worked for us.

There must be some bug in the net code I guess? The game shouldn't require more than 30kb/sec upload as that would make it unusable on many Aussie connections as we get our uploads capped at either 25kb/sec, 40kb/sec or 100kb/sec.

Yapa

I had the same experince. Desynchronization started to appear in Razor Two and got really bad in Manhattan. We even had several situation where the hosting player was involved in a firefight, but the clients couldn't see him firing (nor was there any enemies on the map). The exit fix id not solve the problem. Hence I'm very anxious to find a working solution. But I simply don't udnerstand what you are saying. What is Hamachi?

Hamachi is basically a VPN over the net... LAN over net.

It creates a VPN for you and others, secured and encrypted.

Basically once you and your friends are on the same "channel" your computers are connected over the net as if they were in a Local Area Network (LAN).

More info here:

https://secure.logmein.com/products/hamachi/vpn.asp?lang=en

yapa

See you can disable Hamachi encryption, in theory you should gain some speed.

It's been years since I tried Hamachi, the prob I seen was it opening up all your pc info to others connected.

Has that been cured?

Security is good, not sure how it was years ago as I've only been using Hamachi for about 2 or 3 years.

Always practice safety measures and if you have a software firewall on the PC within your network you will be fine.

Also if you play with friends you shouldn't have to worry unless they are untrust worthy! ;)

Yapa

Nevertheless I think that you made an important discovery. If the campaign plays significantöly better in LAN than over the Internet, then there is bound to be a problem with ArmA2's netcode. And that is something that can be fixed in a future patch. Hope they see this. Did you add your discovery to the Community Bug Tracker?

I'm sorry to say but after playing againt just now... the game is still bugged and I'm getting UNPLAYABLE lag in COOP campaign, with LAN or without....

Honestly I'm over this BETA f game.... cant even play something you pay for? Sick of waiting for patches...

I was patient and loved the game, but this is just too much.

Yapa

Try running without mods,face or anything not Vanilla.

Do a tracert to your friends IP.

Running a 100% vanilla game, we hate mods until we finish the Vanilla campaign.

I'll do a tracert tomorrow but it shouldnt be a lag problem as we play other games together without problem, our pings to each other are below 40ms.

Does anyone else get this problem?

After the last angry post we decided to let me host while my friend joins my game... hopefully fixing our issue. This did not work, my friend kept on desyncing and lagging....

I have a 1mbit upload connection and it never went past 24kb/sec... so plenty of room to move.

Yapa

Just out of curiousity... are either of you on Wireless connections?

If so, that's the likely cause. (google Vista NoLag for the wireless fix, bare in mind that it only works with about 5% of network cards)

Thanks for the suggestions.

We are both on cable LAN so thats not it.

Bulldogs, your COOP campaign runs without lags/desync?

I would also like to add that normal multiplayer runs without any lag.

I must admit when playing Coop Campaign with my brother that we were getting lag problems frequently. Pings varied but were from 20 to 90.

The cars doing circles and then jumping back on the road momentarily were frequent. Frequently saw the orange and red link symbols. He lives about 25km's away and we are both using the same ISP with both of us are on 1500/256kb contracts.

Pity as coop play was a big seller for both of us.

Edited August 18, 2009 by mlenser

It could be the campaign. I only play the campaign on LAN, haven't tried online yet.

I'm participating in the dev-heaven system and will be submitting some files to the dev's later this week to try and find the source of the problem.

COOP was also our main reason for buying the game, apart from it being a great game :)

Thanks,

We are experiencing similar problem on wireless LAN. It lags after resume if you travel via Starforce. Then it seems to hang midair upon landing for clients, they cannot disembark. If they manage to get out, host+his AI is not moving/lagging like hell (20-30sec lags)

ping=9ms, desync=0, bandwidth=350 (strange isnt it ?)

BUT - after save&exit and resume it stops lagging until next heliflight ! It seems like it gets all wrong when your travel fast (chopper)

There are SO MANY bugs in the campaign COOP that its become unplayable.

Manhattan is totally lagging out, its basically unplayable. I have submitted some save files to see if they can find the problem.

Today I tried to play with two other friends, all on fast connections. We played mission "Harvest Red" and "Razor Two".....

Harvest Red never bugged or lagged for us in 1.02, but now we are getting lag, desync, crashing and logs of bugs like cannot heal and people who can only crawl. Then there is the bug where everyone is floating in the air!

Its just crazy... absolutely crazy! After like 5 attempts we finally managed to get a bug free and lag free game... we completed Harvest Red but it did not open up Razor Two for me the host so we could not continue.

Another friend had to host who had already gone into Razort Two in SP... very unplayable.

Yapa

.. we completed Harvest Red but it did not open up Razor Two for me the host so we could not continue.

Another friend had to host who had already gone into Razor Two in SP

I had the same problem after completing coop Badlands, we had to change hosts because the host hadn't completed the mission in SP as well as in coop? I cant find anywhere if this is the way it was programmed or a bug? I would have thought that we can complete the complete campaign in coop without first completing it in single player - right?

Yes this is a bug and seems there is no way for us to continue without having to cheat and advance the missions that way.... which we dont want to do!

Patch 1.04 seems to be mainly about fixing mouse lag and performance, as much as I welcome the performance improvements I would really like to be able to play the campaign in COOP.

Yapa

I was unable to play Coop Manhattan with my friends over the internet. Totally unplayable. Lag and lag and more lag. Our host had a fast quad core and a 10-megabit in/out connection.

What did you end up doing? Or did you give up?

I have opened a bug report at the community issue tracker and its being looked at.

I encourage anyone who wants to play COOP and has the same issue to register (its simple) at the CIT and vote for the topic and provide their own examples/files.

here is the bug report:

http://dev-heaven.net/issues/show/3680

Yapa

Edited August 19, 2009 by Yapab
extra info

Well we tried to play again using the latest beta patch.... I have to say the desync/lag issue was less than before and the game was playable.

However the jumping/lag issue was still present and in some cases I didnt even know we were under attack because the game so desynced... in my game nothing was happening while my friend was fighting and killing 2 or 3 guys!

Then suddenly the game would "sync" back and I would see the dead bodies and messages!

Very annoying and still not a lot of fun for the client.

Yapa

I wonder how much his upload speed was causing?

Desync is caused by two things..

1) Initial connection/reconnection to a game that's already running. Widely established problem with the game which settles a short while after connection. I had this very thing occur with my own server when a friend joined, to test it. We had the red disconnect flag up and desync was at 10000 but after 20 secs or so the desync dropped to 0 and the red flag disappeared.

2) Desync is very very likely when you have a lot of AI going at it. This explains why some small CO-OP maps tend to be fine due to the limited amounts of AI running and why larger scale CO-OP scenarios such as CTI and Dom, which can spawn shedloads of AI as the game progresses tend to get desync'd. The faster the machine hosting (in terms of CPU) the longer it will take before desync kicks in.

His upload speed is max 40kb/sec... if the game requires more than that they might as well remove the COOP campaign as many connections around the world still offer less!

Here in Australia the fastest upload connection available to normal customers is 118kb/sec.... this is the connection I have and ARMA2 was using 140+kb/sec .... so there is definitely a problem! The game should not try to use this much bandwidth after the initial handshake and data sync.

The desync issues does not "settle down".... it continues and is not fixable, there is no workaround we could find. Pings are low.

The desync occurred in campaign mission Razor Two, which does not have many AI going at it... and its more evident in Manhattan which has more AI. The desync occurs at the very start when there is no fighting and only a few AI in the base.

The Host is on a 4ghz Dual Core, cant really get faster than that without going i7.... its WAY above recommended specs :)

Yapa