Ports
- ports extends the host-to-host communication service of the underlying network layer into a process-to-process communication service on the transport layer
- ports are identified by a 16-bit integer (~64K possible ports)
- a process on a host is identified by a ⟨port, host⟩ pair
- ways a client can figure out which port on server connect to:
- well-known ports - (e.g. HTTP=80, SMTP=25, etc)
- port-mapper - servers runs port-mapper at a well-know port then responds to clients which port they should talk to based on client’s request
Sockets
- sockets is tuple: IP Address/Port Number
- e.g. 192.168.86.1/8080
socket types:
- UNIX Socket
- TCP Socket