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TCP/UDP Port question
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| i'm finally getting a handle on how well-known port numbers work.
but my question is....
i read somewhere that the TCP port# is 6 and the UDP port# is 17. what are these port numbers and how do they compare with well-known port numbers?
and what's a socket (winsock, etc.)??
thanks for any help | |
| depamo 2001-11-05, 9:33 pm |
| Don't want to go through all the typing again so here is the link to the thread where a lot of great guru's put in their input to TCP Ports and Sockets.
Should be pleanty of information to get it all straight.
http://www.examnotes.net/forums/sho...&threadid=25342
Hope that is enough for you to sink your teeth into on this subject!!
Dmaftei had an awesome explination of port/IP socket definition and port assignment. Check it out!! | |
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| yes, i already read that article about well-known port numbers. it is a good post - and it helped.
i was more curious about the TCP(6) and UDP(17) that i had come across somewhere, but wasn't sure what they were referring to.
now i think understand, though...
those are "protocol" numbers in the transport header, telling which transport protocol to use (TCP or UDP). they're not port numbers. | |
| dmaftei 2001-11-06, 6:26 am |
| quote:
Originally posted by lew
...those are "protocol" numbers in the transport header...
Protocol numbers in the IP header. | |
| depamo 2001-11-07, 11:35 am |
| TCP and UDP are different methods of communicating between the two IP network aware devices.
TCP (Transmission Control Protocol) guarantees delivery in the protocol stack through two way communications and windowing, sequence numbers so the application doesn't need to verify information or insure order of information.
UDP (User Datagram Protocol) does not guarantee delivery, order nor timelness of packets between two systems.
Since a TCP and UDP headers are different and IP doesn't provide ports, these two don't get confused, they go up two different stacks with IP (TCP/IP and UDP/IP) so the network portion of the OS can determine the difference of the ports, even when they overlap. It will just boil down to what the application calling the redirector chooses to send the traffic, UDP or TCP with IP. |
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