Editing Chaosnet (section)

==Chaosnet protocol==
The Chaosnet protocol identifies hosts by 16-bit addresses, 8 bits of which identify the subnet, 8 bits of which identify the host within the subnet.<ref>{{harvnb|Moon|1981|p=10}}</ref> The basic protocol was a full-duplex reliable packet transmission between two user processes. The packet contents could be treated as bytes of 8 or 16 bits, with support for other word sizes provided by higher-level protocols. The connection was identified by a combination of the 16-bit addresses of each host and a 16-bit "connection index" assigned by each host to maintain uniqueness. "Controlled" packets within a connection were identified by a 16-bit packet number, which was used to deliver controlled packets reliably and in order, with re-transmission and flow control.  "Uncontrolled" packets were not retransmitted, and were used at a lower level to support the flow-control and re-transmission. Chaosnet also supported "BRD" broadcast packets to multiple subnets.<ref>{{harvnb|Moon|1981}}</ref>

Initial establishment of the connection was made using "contact names." These names identified the network service and higher-level protocol. For example, "STATUS" was the contact name which requested basic network statistics from a host. "TELNET" was a contact name for the Arpanet TELNET protocol. "FILE" was a contact name for the Lisp Machine network file service. Other contact names included "SUPDUP", "MAIL", "NAME" for the Arpanet Finger protocol, "TIME", "SEND" for interactive messaging, "ARPA" for a gateway service to Arpanet. "DOVER" was the contact name for sending print jobs to Chaosnet hosts with a [[Xerox Dover]] printer attached (an early [[laser printer]]).<ref>{{harvnb|Moon|1981}}</ref> Developers could easily experiment with new protocols by inventing new contact names. In [[Incompatible Timesharing System|ITS]], a new server for that protocol could be installed by creating a link to the program in the location DSK:DEVICE;CHAOS <cname> where <cname> was up to six letters of the contact name.

Simple transactions could be completed by a single "RFC" packet containing a contact name, answered by a single "ANS" packet with the relevant information. For example, an RFC to contact name "TIME" would result in a single ANS packet containing a 32-bit number indicating the time.<ref>{{harvnb|Moon|1981}}</ref>
 
The original [[GNU Manifesto]] mentioned that it aimed to, among other things, support the Chaosnet protocol.

[[Symbolics]], a maker of the [[Lisp machine]]s, licensed the [[MIT]] Chaosnet hardware and software implementation from the [[Lisp machine|CADR]] computer design.