Advanced telnet is a very slightly modified telnet protocol that was invented by AICS Research, Inc. for its QCTerm terminal emulator in order to make world-wide telnet communications not only feasible but pleasant.

As with all forms of communication protocols, the protocol must be implemented on both the host and client simultaneously if it is to be of any value. The Commercial Systems Division of Hewlett-Packard, with the very able and enthusiastic cooperation of Jeff Bandle of HP CSY networking, was the first large-scale vendor to implement the protocol. It is now in general release among all HP3000 MPE/iX operating system users.

Advanced telnet was extensively tested before it was released into the general population of HP3000 users. It has never been found to have a problem. Moreover, it has proven itself to be very mode stable. A user can switch between "standard" and "advanced" telnet modes as often as he wishes and never generate any form of confusion between the two modes.

More information on the advanced telnet protocol can be obtained from the following:

A Brief History of Terminal Communications

The relationship between the various forms of serial communications modes and the reasons for the evolution of advanced telnet are discussed.

The First Business Use of Advanced Telnet

Although the focus of the article concerns the evolution of an Application Services Provider in Cape Town, South Africa, the value of the advanced telnet protocol to the ASP is prominently featured in the text.

The IETF Draft RFC for Suppress Local Echo

"Advanced" telnet is nothing much more than a re-invocation of a thirty year-old idea: half-duplex communications. Indeed, this is the protocol under which NVT's (network virtual terminals) were originally expected to operate, even though full-duplex communications later became the norm.

In order to properly implement half-duplex communications, without having to institute a much more complex line buffering mode of operation, a simple client-local echo suppress option needed to be added to the telnet protocol. This new option is Option 45, Suppress Local Echo, of the telnet protocol and is explained in detail in the referenced text.

The complete list of telnet options is available from the Internet Assigned Numbers Authority.