- Create a TCP socket:
int s; // Descriptor index. s = socket(AF_INET, SOCK_STREAM, 0); // Creates a TCP socket in the per-process descriptor table // Returns the index in the per-process descriptor table
- TCP socket:
- TCP socket =
a end point of
communication
using the
TCP protocol
- Unlike UDP, the TCP protocol does not only use the TCP socket to identify a programming communication endpoint
- TCP socket =
a end point of
communication
using the
TCP protocol
- TCP connection:
- TCP connection =
a communication link between
2 network programs that
uses TCP sockets
- Network programs communicate with one another using TCP connections
- A
TCP connection is
uniquely identified by:
(srcIP, srcPort#, destIP, destPort#)
- TCP connection =
a communication link between
2 network programs that
uses TCP sockets
- Fact:
- Because:
- A TCP connection
(= communication pathway between
2 network programs))
is identified by:
(srcIP, srcPort#, destIP, destPort#)it is possible to form the following different TCP connections:
TCP connection 1: ( IP1, port1, IP2, port2 ) TCP connection 2: ( IP1, port1, IP3, port3 )
using the same (IP1, port1)
Graphically:
This is the situation where a web-server running on the host IP1 is servicing 2 web clients:
- One client running on host IP2
- One client running on host IP3
- A TCP connection
(= communication pathway between
2 network programs))
is identified by:
In other words:
- One TCP port in the Operating System kernel can support multiple TCP connections for the same IP address
- Because: