Hm? I've downloaded and uploaded often using a single port.
I bet you havent (with mirc), you might think you did but u used a seperate port for each one. identical remote ends port is irrelevent.
I've had many people asking about that in another forum who then got it fixed by changing their router settings. It might have been a NAT setting, now that I think of it.
More likely you mean a NAPT setting, in which a port used is routered to another port value, thus miss guiding some into believing the same port was in use, mirc well not use the same port number for two sends or gets, so even then the ports would still remain different. alot of NAPT settings well shift port values up to around 50,000. This is done correctly well be transparent to mirc as the router shifts them back down when forwarding on to the pc, such as a send goes like this, assume port sending on is
1234>>> sender -> MSG recivever dcc send filename IP
1234 filesize -> Router -> MSG recivever dcc send filename IP
50109 filesize -> irc server -> reciver
>>> reciver -> socket connects to [email:IP@port
50109]IP@port
50109[/email] -> router -> socketconnect to [email:PC@port
1234]PC@port
1234[/email]
* However in most routers this fails when a resume is requested, as the irc resume message trail looks like this,
>>> sender -> MSG recivever dcc send filename IP
1234 filesize -> Router -> MSG recivever dcc send filename IP
50109 filesize -> irc server -> reciver
>>> reciver -> MSG sender dcc resume "file"
50109 position -> irc server -> router -> sender *** sender rejects as no send on port
50109 ***
Essentially most routers dont intercept a dcc resume message correctly or at all.
Also, consider how many connections you have on IRC to port 6667
Interesting point, im not sure how this is achived at the irc servers end, its either a queued system based on ip's or its simply routed your connection to another IP, i think its the first since a irc server polls you to see if your still there rather than keeps an active connection alive, in fact under tcp/ip i dont really know if there is a "real" alive connection, its all just packets being sent, so you can receive packets from many ip's on one port but those packets have to make sence to what ever software is using that port, mirc expects a stream of data to be recieved if its opened a port to the sender, and i also beleive it well simply ignore any other data from anyone but the IP it conencted to on that port. Same as the sender just sits there and waits for the "receiver" to connect to it on what ever port it said it well send the file on, as a side note you well notice i put "" around reciever, as the person who gets the file nned not actuially be the reciever, any mirc can be made to recieve a file from someone who is attempting to send it, it would/is just simply a matter of knowing what IP and port to attempt a GET file to. You can even with the right script have USER1 on NETWORK1 send u a file, and you "forward" that send attempt to USER2 on NETWORK2, who gets the file dcc direct from USER1 (user1 does however think its u getting the file, as he knows no better who is connected to his Ip on the speced port)
or to websites on port 80 at the same time. You can socket multiple sites on port 80 at the same time without an issue, as an example.
your missed the point here, your not using 80 your contacting there 80 port, and websites can accept multiple into there 80 becuase they simply recieve the request and reply to it, and thats the end of the connection, even the "stay alive connections" are really just repeated sends to the server to say ya still around.
That said, there is a limit that SP2 in Windows XP does impose (it's something like 10, I think). It's meant to prevent viruses from spreading as badly. However, you can change that to a larger number with various patches that are available.
Damn never heard of that, is it xp home or xp in general, I use server far more than workstation so dont often encounter wierd limitaions imposed on workstation os's.
*** lol just read back all this, sorry for all the rambling ***