Hi all, I'm in the process of developping a game engine to build a demo out of it. I'm now looking at the networking sub-system. I've red alot posts and tuts and a few questions are poping out in my mind, that i need answered first, before digging into the design of the sub-system. My game-engine is based upon C# and MDX, and since DirectPlay is being deprecated i'm turning to System.Net.Socket namespace to build the networking sub-system. Also, i dont wanna use another lib, since i'm doing this as "on-the-side" research project for my university courses. So, 1. Would it be necessary to have 1 socket on the server to listing up to connection request from clients. Then, create a new socket for each "connected" client. I saw that a few times... Or just 1 socket would be ok for both? Or maybe 1 socket for listing connection request and 1 socket for game processing of messages, this one seems to be just enought to me. 2. I've also seen posts talking about "channels" when referring to UDP sockets. What are they, can't find anything related to this in MSDN. In thoses posts they were talking of a limit of 32ips by channel and 32channels per socket!?. Per msdn, it's seem that you can send udp packet to an unlimitted numbers of ips since the protype of the methode is Socket.SendTo(IPAddress address, byte[] data). 3. As udp is a connection-less protocol and it's unreliable. If you want to be able to guarante delivery we need to implement a Syn/Ack "paradigm" as in TCP. This pop a little question. When you send a udp packet flagged "Guaranteed Delivery", the receiver simply answer with a Ack packet with the sequence number. This ack packet cannot be a "Guaranteed Packet" because that could create a "infinite loop" of ack? right? So if that ack packet get lost, the sender will simply resend the packet to the client. I'm thinking that this could cause problems when you get high packet lost ratio... maybe i'm overlooking something... 4. Another thing of udp is the "out-of-sequence" problem that may arise. Is simply ignoring the packet that is out of sequence is enought when you send absolute game update (meaning, no delta-compression, relative-updates? 5. The network message / packet structures. In my preliminary design i'm making distinctions between packet and game message. A packet is a container(seq, ack, lenght, payload) to move game message back and forth between client/server. My game message would be structures identifiable by an ID, maybe and enumeration. Is this a normal design, effective design, there is other solutions or design to this ? 6. And last, but not the least, to encode/decode the packet/game-message to an array of byte, since SendTo needs an array of byte, is there a miracle method somewhere ;) BinaryFormatter is adding alot of overhead to the byte array (more then 50%). And writing a encoder/decoder for each message type using a StreamWriter/StreamReader, even if this seem to be the best solution, involve alot of work (alot of overhead on my side :) ) Thanks in advance for your patience... Jonathan

Thanks for your reply...

That's confirming my firsts thoughts...

So, now, let begin/finalyse that sub-system

Have a nice day,
Jonathan

Yes it really cool, but it almost all new to me... I know alot about network, i've worked in the field for 3 years.

If you wish, i would be put to design here, so maybe we can shares some ideas?

a+
Jonathan

Quote:Original post by LowRad
6. And last, but not the least, to encode/decode the packet/game-message to an array of byte, since SendTo needs an array of byte, is there a miracle method somewhere ;) BinaryFormatter is adding alot of overhead to the byte array (more then 50%). And writing a encoder/decoder for each message type using a StreamWriter/StreamReader, even if this seem to be the best solution, involve alot of work (alot of overhead on my side :) )

If you're using C#, I recommend taking advantage of the built in conversions...




From Byte Array to string

byte[] m_ary = System.Text.Encoding.ASCII.GetBytes("Testing")

From string to Byte array

string final = System.Text.Encoding.ASCII.GetString(m_ary)