ATCP Specification
From MudStandards
TELNET is the protocol used to connect to MUDs, however it is often not expressive enough for some of the functionality that a server may want to provide. For this reason, a separate protocol was designed that will piggy-back on top of normal TELNET (negotiated on and off like any other option) and allow a channel of communication between client and server that the user doesn’t necessarily have to see. This is commonly used to provide supplemental information or hints to the client by the server (and for the server to query capabilities and information from the client).
For instance, if a custom client was written to display vital character information in a separate window (or subwindow), then the server could send messages to the client encoding this character information. This could be done both invisible to the user and in a very efficient manner (to ease parsing, etc).
The content passed (as well as its format) is completely up to a system implementor. (With the one caveat that is explained below.)
Transport Protocol
This protocol needed to be compliant and invisible to existing TELNET standards because the primary client of choice is still simply a TELNET-compatible one (such as zMUD). So, the following format was designed:
- ATCP Enabling
- ATCP Sending Messages
- ATCP Message Format
- ATCP Message Module Negotiation
- ATCP Modules
