==== Internet (TCP/IP) and other communications options ====

=== Communications hardware ===

  * TTY serial lines
  * NIA-20 ethernet interface
  * CI-20 cluster interface

=== Internet (TCP/IP) ===

IP version 4 is implemented in some distributions of tOPS-20.

== Addressing ==

=== Management operations ===

=== Applications ===

== Interactive remote login ==

  * TELNET

== User interaction ==

  * Mail

== File transfer ==

  * FTP

=== Programming ===

=== Protocols ===

== Connection-oriented end-to-end data streams (TCP) ==

  * Client end

  * Server end

== packet-oriented datagram transfer (UDP) ==

== Sockets ==

== Assembly level operations ==

=== DECnet ===

DECnet is the proprietary network protocol designedby Digital EquipmentCorporation for communication between diffrent hosts runnning operatingsytems such as TOPS-20, TOPS-10, VMS, RSX etc. Implementations exist also for other operating systems,such as Sun/Solaris and GNU/Linux.

== Addressing ==

== Management operations ==

  * OPR/NCP

== Applications ==

== Interactive remote login ==

  * SET HOST

== User interaction ==

  * MAIL

== File transfer ==

== Programming ==

  * Client end

  * Server end

== Assembly-level operations ==

=== ChaosNet ===

ChaosNet is an optional protocol designed primarily for communication with and between MIT CADR Lisp Machines. implementations (maybe experimental) may exist for some TOPS-20 distributions.