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BLOPS III & MTU


Omega

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I have made an interesting find that when lowering your mtu in this game, even a marginal change goes a long way. I remember trying this back in the BLOPS II days with mixed results.  However, when lowering my mtu from the default 1500 to the XBL minimum of 1384 it has been night and day. I thought it was a placebo effect, so I went ahead and pushed it back up to 1500. Same old nonsense getting oneshotted across map with guns I know have no business killing that fast from that range. So, I dropped it back down to 1384 and the problems once again subsided. Now, I don't want to make it seem like this is a cure all. You will still get occasional lag as their servers are overloaded and most likely not the highest quality in the first place. However, for someone like myself who rushes constantly, I can tell the difference. I went 21-0 my first game after changing it and 35-4 the second. Please look into this people as it may too help you. More importantly, and the reason I came here, Duma team, would you be able to provide insight as to why this is occurring.

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I have found when running tests that whenever I do a test and then enter the lower value for mtu the next test I do gives an even lower figure.

If your talking about the cmd prompt ping test, you're only supposed to run that test once BEFORE you make any changes to your default mtu value. For example, if your mtu in your router settings defautls to 1500 and you run that test, it should indicate that 1472 is the highest payload without fragmentation. This is due to the fact that there is a 28 byte overhead on each packet. 1500-28=1472. But thats not my problem in the first place. I ran this test and it returned that 1472 value which would lead one to believe my mtu was at its optimal value. WRONG! I don't know why which is why I'm coming here, but I do know that dropping the MTU, for the most part, cures those phantom lag comp issues.

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I'll give it a try, though there are three MTU's involved in my setup (modem-->R1-->PS4) which is 1500,automatic and automatic respectively. 

What is the value I am supposed to enter in each device?

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I'll give it a try, though there are three MTU's involved in my setup (modem-->R1-->PS4) which is 1500,automatic and automatic respectively. 

What is the value I am supposed to enter in each device?

 

I'm not sure whether changing from auto to manual on the PS4 makes a difference but it's worth a shot if all else fails. Now, when you say modem do you mean a gateway (modem/router) or a docsis 3 cable modem? If the former, you will probably want to change the mtu to be reflective of the value you will input into the router. If the latter, I can't say exactly as I haven't messed with the modem directly. For the router mtu value, I don't know PSN's minimum mtu requirement, though I believe it is in the same ballpark as XBL's 1384. If you want you could use a nice easy value of 1400 if you'd like. After you make these changes in the router be sure to reboot the router and console for good measure. Report back with any questions.

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in wan and lan on the router?

Yes. The key with mtu is that everything on a packet's path is uniform. My guess, though highly speculative, is that there are hops along the path that have a lower mtu than our default ones causing fragmentation (critical time) or just being dropped (worst case scenario).

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I have made an interesting find that when lowering your mtu in this game, even a marginal change goes a long way. I remember trying this back in the BLOPS II days with mixed results.  However, when lowering my mtu from the default 1500 to the XBL minimum of 1384 it has been night and day. I thought it was a placebo effect, so I went ahead and pushed it back up to 1500. Same old nonsense getting oneshotted across map with guns I know have no business killing that fast from that range. So, I dropped it back down to 1384 and the problems once again subsided. Now, I don't want to make it seem like this is a cure all. You will still get occasional lag as their servers are overloaded and most likely not the highest quality in the first place. However, for someone like myself who rushes constantly, I can tell the difference. I went 21-0 my first game after changing it and 35-4 the second. Please look into this people as it may too help you. More importantly, and the reason I came here, Duma team, would you be able to provide insight as to why this is occurring.

If you set it to low you will start to get packet fragmentation thus causing you to lag as you packets will try and be resent. Check your MTU with THIS and it will tell you your optimal setting then if different from your current value change in your router and console.

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Iain is paraphrasing but in the words of John Carmack, MTU hasn't been an issue since 1997. It's extremely unlikely that putting it to anything under your optimum would result in such a big improvement game wise. If you're getting good games that is the most important thing though.

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If you set it to low you will start to get packet fragmentation thus causing you to lag as you packets will try and be resent. Check your MTU with THIS and it will tell you your optimal setting then if different from your current value change in your router and console.

I believe you have it backwards. If you set it too high say 1500, and you send a 1500 byte packet to a hop with mtu of 1400, that packet is going to be fragmented. Fragmenting itself means to break into smaller pieces.

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Iain is paraphrasing but in the words of John Carmack, MTU hasn't been an issue since 1997. It's extremely unlikely that putting it to anything under your optimum would result in such a big improvement game wise. If you're getting good games that is the most important thing though.

This is the response I expected, yet it makes no sense to me as to why it made such a drastic difference.

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Iain is paraphrasing but in the words of John Carmack, MTU hasn't been an issue since 1997. It's extremely unlikely that putting it to anything under your optimum would result in such a big improvement game wise. If you're getting good games that is the most important thing though.

Right I dont care how it works or why it works as long as it works!

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I believe you have it backwards. If you set it too high say 1500, and you send a 1500 byte packet to a hop with mtu of 1400, that packet is going to be fragmented. Fragmenting itself means to break into smaller pieces.

Im sure it works both ways Low/High either way it will fragment as you said but then will try to resend therefore causing the lag.

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If you set it to low you will start to get packet fragmentation thus causing you to lag as you packets will try and be resent. Check your MTU with THIS and it will tell you your optimal setting then if different from your current value change in your router and console.

 

^^

this is what happened

packet fragmentation

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If you set it to low you will start to get packet fragmentation thus causing you to lag as you packets will try and be resent. Check your MTU with THIS and it will tell you your optimal setting then if different from your current value change in your router and console.

^^

this is what happened

packet fragmentation

I think I understand what you mean. You are running the online mtu test via the hyperlink. I can't run the test right now to see what you mean, but I will try it when I get home at 4EST.

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I think I understand what you mean. You are running the online mtu test via the hyperlink. I can't run the test right now to see what you mean, but I will try it when I get home at 4EST.

Run this TOOL  it will give you exact number to input.

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I am guessing it will be fine to use your PC, set everything to auto then run the test. I believe that the test sites run the test to your router not any particular device.

 

 

 

Taken from here, http://www.letmecheck.it/mtu-test.php
"Online MTU test allows you to test the maximum MTU size from our host to your destination. To check your MTU, simply provide your IP or DNS hostname. We will test the PMTU (Path Maximum Transfer Unit) aka maximum MTU size (unfragmented) between our host and your destination, most likely the outside of your router or firewall."

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My understanding is that it should be as high as possible without defragmentation. Testing to your router is pointless. In gaming your pipeline is to the host. 1500 to your router maybe fine but your almost gaurenteed it will pass some line that its not optimal. With that said, 1500 is a no go for almost everyone. That would also include the 28 removal. So, the next possible level below 1472 is the highest anyone should have. Those are my thoughts, im no expert though. It should be highest underneath the smallest bottleneck.

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