Socket number limitation in Windows

I don't think the limit is 1024 sockets... You're probably thinking about the lowest available port for use by non-kernel/system processes.

I'm just guessing here, but I think the limit, in number of sockets, is based upon available memory/resources. A socket is just a handle or a reference to some internal data structure that represents a tcp or udp connection (for instance dst_ip+port and src_ip+port)... this tuple takes about 4+2+4+2 = 10 bytes (10 bytes / socket). The internal structure probably holds some other data as well... Have a look in the Linux source code (haven't looked myself, i'm a Windows-guy :) )