Re: Log Out Issues
From: Arkady Frenkel (arkadyf_at_hotmailxdotx.com)
Date: 09/05/04
- Next message: Callum Winter: "Re: Log Out Issues"
- Previous message: hooway: "Get Adapter Name"
- In reply to: Alexander Nickolov: "Re: Log Out Issues"
- Next in thread: Callum Winter: "Re: Log Out Issues"
- Messages sorted by: [ date ] [ thread ]
Date: Sun, 5 Sep 2004 15:28:46 +0300
That's the case when you need multicasting/broadcasting
which possible with UDP. Here is game example but in NYSE broadcasting used
for rate's announcement e.g.
Arkady
"Alexander Nickolov" <agnickolov@mvps.org> wrote in message
news:ui2qdddkEHA.2140@TK2MSFTNGP15.phx.gbl...
> The reason UDP is preferred is because it does not implement
> connection throttling, e.g. it does not limit the bandwidth to prevent
> packet loss. However, there's no magic here - if you exceed your
> bandwidth, your perormance may be worse than TCP. The trick
> would be if your protocol anticipates packet loss and does not
> need to retransmit a small percentage of the packets altogether.
>
> Anyway, that's beyond your question. For connection termination,
> use TCP's half close and the fin wait / time wait connection states.
> See http://www.faqs.org/rfcs/rfc793.html page 36-37.
>
> --
> =====================================
> Alexander Nickolov
> Microsoft MVP [VC], MCSD
> email: agnickolov@mvps.org
> MVP VC FAQ: http://www.mvps.org/vcfaq
> =====================================
>
> "Callum Winter" <callum@REMOVE_THISwinter9999.fsnet.co.uk> wrote in
message
> news:%23IKmfFakEHA.3520@TK2MSFTNGP11.phx.gbl...
> > Hi Alex,
> >
> > I would be quite happy to use TCP to save headaches, but from every
source
> > ive read during my learning, UDP is the way to go for internet games.
> > Apparently the extra overhead in TCP can cause a lot more lag in your
> > game,
> > especially in the MMORPG variety where a mass of data passing is
required
> > to
> > keep everything running.
> >
> > If you can confirm that these comments are out of date then ill move
over
> > to
> > TCP, but I ask why do most top online games use UDP for their protocol
if
> > TCP were better.
> >
> > I already have reliable/ordered/multithreaded communication, I just need
> > help with this one logging out/message passing problem. I must at least
> > try
> > the fastest method before I give in and move to the simpler but slower
> > method of communication, as speed will effect the total number of
players
> > I
> > can have per hosting server.
> >
> > Do you know of any good resources that at least give some varied
solutions
> > to this problem.
> >
> > Your comments are appreciated.
> > Callum.
> >
> >
> > "Alexander Nickolov" <agnickolov@mvps.org> wrote in message
> > news:uCCMa9TkEHA.2664@TK2MSFTNGP11.phx.gbl...
> >> Any reason you are not using TCP instead of UDP? TCP handles
> >> all these details already. If you want, you can implement TCP's
> >> algorithms yourself of course, but what would be your gain from
> >> that? TCP is implemented in the kernel thus it will be much more
> >> efficient...
> >>
> >> --
> >> =====================================
> >> Alexander Nickolov
> >> Microsoft MVP [VC], MCSD
> >> email: agnickolov@mvps.org
> >> MVP VC FAQ: http://www.mvps.org/vcfaq
> >> =====================================
> >>
> >> "Callum Winter" <callum@REMOVE_THISwinter9999.fsnet.co.uk> wrote in
> > message
> >> news:%23PJ7Y4SkEHA.2340@TK2MSFTNGP11.phx.gbl...
> >> > Hi all, hope someone can help.
> >> >
> >> > I just started to learn winsock 2 a few weeks back, and ive already
> > wrote
> >> > code to send and receive user datagrams.
> >> > The code also performs ordering of incoming packets and sends ACKs
for
> >> > reliable messages.
> >> > so that messages are resent until ACKS are received in reliable
cases.
> >> >
> >> > Now all this works great but Ive come to a chicken and the egg
problem
> >> > with
> >> > logging out.
> >> >
> >> > Lets say the client sends a log out request to the server reliably.
The
> >> > server then gets this and sends a log out confirm message to the
client
> >> > and
> >> > delete that host from its local list.
> >> >
> >> > If the client receives the message all is well and the client cleans
up
> >> >
> >> > If the log out confirm gets lost, the client will hang forever
waiting
> > for
> >> > the server to send another, which will never happen cos the server
> > deleted
> >> > that host.
> >> >
> >> > Now i could make the server wait until it gets another reply back
from
> > the
> >> > client saying it got the logout confirm before it deletes, but then
how
> >> > does
> >> > the client know when to stop sending this info unless the server
> > responds
> >> > back which it wont do once it deletes that host, it will only send an
> > ACK
> >> > once. If that ACK doesnt get to the client, the client will send
> > forever.
> >> >
> >> > This silly loop goes on and on and on.
> >> >
> >> > The only solution i can think of is to have the client time out after
n
> >> > seconds if it doesnt receive a log out confirm. Problem here is that
> >> > the
> >> > reason it may not of received a log out confirm isa beacuse the
server
> >> > never
> >> > got the log out request in the first place.
> >> > So if the server never gets it and the client times out the server
will
> >> > still think they are logged in and never free up that slot in its
list.
> > So
> >> > then you have to have a timer on the server etc etc.
> >> >
> >> > This is all very messy. Does anyone have any comments on the best
> >> > method
> >> > for
> >> > a player wanting to log out and how far to take the message back and
> >> > forthing. In fact how has everyone else combatted this problem.
> >> >
> >> > Any ideas would be greatly appreciated.
> >> > Thanks in advance.
> >> > Callum.
> >> >
> >> >
> >>
> >>
> >
> >
>
>
- Next message: Callum Winter: "Re: Log Out Issues"
- Previous message: hooway: "Get Adapter Name"
- In reply to: Alexander Nickolov: "Re: Log Out Issues"
- Next in thread: Callum Winter: "Re: Log Out Issues"
- Messages sorted by: [ date ] [ thread ]
Relevant Pages
|
