If i send 1000 bytes in TCP, does it guarantee that the receiver will get the entire 1000 bytes \"togther\"? or perhaps he will first only get 500 bytes, and later he\'ll re
As other answers indicated, TCP is a stream protocol -- every byte sent will be received (once and in the same order), but there are no intrinsic "message boundaries" -- whether all bytes are sent in a single .send call, or multiple ones, they might still be received in one or multiple .receive calls.
So, if you need "message boundaries", you need to impose them on top of the TCP stream, IOW, essentially, at application level. For example, if you know the bytes you're sending will never contain a \0, null-terminated strings work fine; various methods of "escaping" let you send strings of bytes which obey no such limitations. (There are existing protocols for this but none is really widespread or widely accepted).