System for expanding a parameter encoding field in a message to allow additional parameters to be added while maintaining compatibility with existing parameter encodings

摘要

A system for expanding a parameter encoding field in a new communications protocol that is compatible with an old protocol. An unused command parameter in an old protocol is used to indicate an expanded parameter encoding field in a new protocol. Parameter encodings from the old protocol are unchanged in the new protocol. A system communicating using the old protocol recognizes all parameters from the old protocol and ignores parameters from the new protocol. A system communicating using the new protocol recognizes parameters from both the old and new protocols.