Hardware Implementation of Ports **What is the hardware implementation of a port and/or network socket?** I understand that, at the lowest level, x86 uses opcodes such as IN and OUT when the data resulting from the instruction execution is to be sent to a peripheral with a port-mapped I/O memory address. **Am I making an incorrect assumption that the port-mapped I/O memory addresses are synonymous with ports identified for networking?** Whenever I read about the use of ports, the application has been abstracted far past the physical layer and it is difficult to draw a connection between the host hardware and their use in networking.

There is no hardware implementation of a TCP or UDP port or a network socket. That is like asking for a hardware implementation of an IP address. Ports are layer-4 addresses, and they are conceptual. A port represents a software connection between a layer-4 protocol and an application. A network socket consists of a combination of source and destination layer-3 (e.g. IP) and layer-4 (e.g. TCP) addresses.