Re: [glob2-devel] Alpha 20 Preperations

[Bradley Arsenault]

On 7/16/06, Stéphane Magnenat <address@hidden> wrote:
> Exactly. With UDP, we are able to sustain some packet loss without affecting
> the game speed (as every order is sent twice in packet N an packet N+1). This
> won't be possible with TCP. Any packet loss will stall the game. Furthermore,
> as I said before, UDP is required to trick NAT and firewalls, look at that
> article for a scientific analysis :
> http://pdos.csail.mit.edu/papers/p2pnat.pdf
>
> So switching to TCP is not impossible, but it is a huge change and should
> definitively not happen before 1.0, and even after I think that, for today's
> network model, UDP is much better suited for the task. Now, I don't say we
> should not write a clean and well documented lib based on the previous
> article to encapsulate the UDP complexity and allow syntetic testing of
> network layer alone. Such a lib would be very usefull.
>
> Steph
Remember that packet loss isn't common thing. It would probably happen
several times throughout a game, but recovery is generally quick.

Anyway, all of the people I've talked to agree a switch to TCP would
be good, adding allot of reliability.

Your article also talks about TCP hole punching, saying its just as
fast and reliable as UDP hole punching.

I understand a switch to TCP is a very large amount of changes,
probably more than I want to do. So, instead, we need to fix this
0-checksum bug a different way. I'll investigate it some more,hopefull
tutning up better results.

The 0-checksum only appears when one player is signifigantly lagged
compared to the other players, in which he recieves a checksum of 0
and crashes.


--
Start and finish, Bradley Arsenault