Strange networking issue possibly regarding Windows 10

[Zinx777]

Well looks like it also happens on WIndows 10 now.
So I dont think its an OS thing anymore but a router thing that somehow gets resolved by either using a VPN or using a non-adhocmatching game (for real like 90% chance it will work there).
I tried to play with someone and he tried both Android and Win10 and he still got me to get the incorrect source port issue on both platforms lol with a adhocmatching game (but not non-adhocmatching).

[AdamN]

There are Win10 updates recently while adhoc haven't been updated for... months may be (i don't even remembered when was the last PR), so if newer OS updates is starting to get this issue.. may be it's the correct socket's binding behavior that got fixed recently by OS devs, but i haven't found any documentation how to trigger this (may be PPSSPP's netcode accidentally triggering this for a long time but because not many OS fixed it it somehow worked fine in the past)

Also, the only reason you won't be seeing this "incorrect port" message on non-adhocmatching games, is because it's only shown on adhocmatchng games, it won't be shown on non-adhocmatchin games even when they had this issue too.
It's not like i didn't want to show it, it's because non-adhocmatching games are using custom port, so i don't know what are the correct port suppose to be (without customizing it for each games), thus unable to report it as "incorrect" without knowing the correct one.

[Zinx777]

Yeah you say the message does not appear but every time I play a non adhocmatching game and host it it works while other games do not.
So if it does work there consistently almost it might be good to look at it maybe.
This is not including GameMode games though as it could also happen there.
In conclusion:
Not working with Adhocmatching
Not working with GameMode
Working with other games as long as the player that does not have the issue hosts.

[AdamN]

Both AdhocMatching and GameMode are using PDP/UDP socket under-the-hood where the lobbying/matchmaking are managed by AdhocMatching/GameMode library provided by Sony, while non-adhocmatching/non-gamemode can using PDP/UDP/PTP/TCP socket directly and have their own matchmaking/lobbying (custom-made by the game developer or using a third-party matchmaking library)

Current AdhocMatching implementation is unreliable, and GameMode implementation is still lacking.

[Zinx777]

Your implementations are still impressive.
I can't get most of the games on xlink to even work lol while they work on PPSSPP.
I think that with a bit more work it could be great.
I wish I got a PS3 but meh not worth it and even some games work on PPSSPP still lol.

[AdamN]

Hmm.. after reading this https://stackoverflow.com/questions/3177...erver-recv
It seems there are cases where received source port to be different than the sender port, and it was something todo with port re-mapping done by router or ISP.

Quote:Some further information. Your approach is logical, RTSP is indeed doing similar things. However, that also caused trouble when ISP and your router start doing port re-mapping, for RTSP they have special port arrangement and RTSP-aware NAT is actually watching the TCP communication and special handle those port. But for custom protocol you should do the complicated way.

In this case, i should probably remove the code that checked the source port and always assume it as valid port.
However, if there are games that checked the port too, those games may consider it as invalid port, hopefully there are no games that does this, at most probably only 3rd-party library used by the game who have a possibility to check the port.

[Zinx777]

I knew it''s something router related lol.
It looks like it less affects games that dont use adhocmatching but also games that use infrastructure mode in addition to adhocmatching.
Thats kinda a rare combination though.

Shame that the problem seems to be prevelant in a lot of games though and not so few...

This also seems to validate what you said : https://serverfault.com/questions/485150...158#485158

Isn't this all connected to how proadhoc cant use more then one device on a LAN over the internet/public ip?

As I understood from Linblow , the client socket source port js ignored over on that implementation.

So it wont matter if you checked or not.

[AdamN]

Ugh.. on a second thought, always assuming the source port to be valid won't fix this issue entirely...
because the way AdhocMatching worked is, when someone created a room they will broadcasts that room data to all members in the same group, and when that member received this room data they will show it on screen.
However, this broadcast is using a predefined port (initialized by the game when creating AdhocMatching) and all players supposed to use the same port, but due to this "incorrect port" issue some players might not be able to received this room data, because it will be getting a random port and other players won't know the port (not even the player that had this issue know which port they're actually using, because trying to retrieved the binded port will show the predefined port, which normally to be correct but may no longer correct due to this issue)

So, basically, always assuming the source port to be valid will only increase the possibility for AdhocMatching to work, but not entirely fix this issue, because the issue is on the router side, and we don't know what's triggering this behavior on LAN... may be enabling UPnP when playing on LAN causing some router to get confused.
But even if we can fix this on LAN (ie. by disabling UPnP options, that is if UPnP causes some router to get confused), people who use UPnP over the internet will also have a possibility to get the same issue due to port re-mapping done by the router or ISP (which is normal over public IP, but not supposed to happen on LAN IP)

PS: GameMode is also using a single predefined port to be used for sending & receiving data (as i remembered), thus will have similar issue to AdhocMatching.

[Zinx777]

I don't know why Metal Gear Solid Peace Walker/Phantasy Star Portable 2 seems to be the worst offender of this.
I have a feeling this is related to how many ports the game uses or opens (at least for Peace Walker)..
The more ports the game uses the more chance you gonna get the incorrect port issue.
At least Peace Walker I know opens 4 ports on versus but I don't know on coop.
At least you didn't say that the proadhoc/ProOnline implementation is lacking because it ignores the source port lol.
I wonder what VPNs do to make the issue go away...
Also it doesn't seems to be UPNP fault I think because I got it with it being disabled and enabled with someone...
TBH i never got it on LAN once tho.
I know you dont like people reporting issues about using public IP but what could you do when its basically the default option on PPSSPP currently lol (uses socom.cc now).
I think that main issue is either ISP or NAT changing port remappings though..
I guess adenovan found this behavior as early as 2017: https://i.ibb.co/547NRQ6/image.png
https://github.com/hrydgard/ppsspp/issue...-347817114

[AdamN]

I've updated my test builds on my signature to handle "incorrect port" (now written as "unknown port") issue better by keeping track the new port for further communication.
However, keeping track of the port will only work if the player were able to receive a data on the "correct" port in order to get the sender port (which might be re-mapped), which mean the player who supposed to receive the data for the first time must not have their port being re-mapped.

Edit: You can also get the artifacts from this PR https://github.com/hrydgard/ppsspp/pull/14870

Please this those test builds to see whether they're better or not, because i'm having difficulty trying to reproduce the "incorrect port" issue on my end.
Please also test the "UseOriginalPort" thing with this, in case the issue why it didn't work before was because the port were different and being ignored by AdhocMatching.

I'm planning to do the same for GameMode (ie. keeping track the port) which potentially have similar issue to AdhocMatching, but i never tried to show a warning on screen, thus we never saw reports about it on GameMode.

PS: Players who had the warning shown on their screen are not the one who had their port being re-mapped, since they're able to receive data on the "correct" port.

[Zinx777]

Just saying but I got the message on a GameMode befoe this so..
You will get this there because the game uses AdhocMatching in the lobby anyway.

[AdamN]

I've updated the test builds on my signature with this PR for GameMode https://github.com/hrydgard/ppsspp/pull/14880