C Gateway

The C Gateway was a multi-protocol router (one of the first two ever done), originally written at the MIT Laboratory for Computer Science, and later a product for Proteon and other organizations.

The MIT version supported several internetworking layer protocols:

• IP
• PUP
• Chaosnet

which could be included in any combination. A number of physical networks were supported, including:

• ARPANET
• MIT Experimental 1Mbit/second ring
• Experimental Ethernet
• Chaosnet
• Proteon 10 Mbit/second ring
• Ethernet
• Asynchronous serial line

again, in essentially any configuration. The Address Resolution Protocol was implemented for use on the Ethernet.

It ran under the MOS operating system, and was written in C (hence the name; the 'Gateway' is because it predates the adoption of the term 'router'). The code used a set of macros for type definitions which allowed it to later be easily made portable.

The C Gateway originally ran on QBUS PDP-11's; initially the LSI-11/2. It was later enhanced to use the KDF11-A CPU, and in particular use the PDP-11 Memory Management available on that machine to support more packet buffers, and leave all the low memory available for use by the C Gateway's code and data. It was eventually moved to run on the Intel 80286; the Proteon product ran on the Motorola MC68000, and later the AMD 29000.

External links

• 545 Technology Square Internet Status - lists the first C Gateways at MIT
• Internetworking: Emergence 1985-1988 - cover the Proteon connection, but gets some of the details wrong