The Birth of the Internet - RFC 6, A Conversation on Early Network Protocols

RFC 6, penned by Steve Crocker from UCLA on April 10, 1969, captures a pivotal conversation with Bob Kahn from BB&N. It’s a glimpse into the technical discussions that shaped the early days of network communication. Let’s break down the key points and implications of this early RFC.

Robert (Bob) Kahn is credited with the development of the TCP/IP protocol suite, which is the foundation of the modern internet.

So, what was the main focus of RFC 6?

RFC 6 is essentially a summary of a technical discussion between Crocker and Kahn, focusing on several critical aspects of network communication, particularly around code conversion and HOST-IMP interactions.

Code Conversion: What’s the big deal?

Code conversion was a major topic in their conversation. BB&N planned to handle different character codes by converting them into 8-bit ASCII for transmission. This was a significant step because it allowed for more standardized communication between different systems. They discussed converting 6, 7, 8, or even 9-bit codes into 8-bit ASCII, which was a common standard at the time.

What about the technical specifics?

BB&N proposed a one-to-one conversion scheme with unique tables for each HOST. This means that each HOST would have its own conversion table to ensure accurate translation of characters. Crocker suggested adding case shifting for 6-bit codes, which could lead to overflow issues if too many shifts were required. Kahn acknowledged this but noted that such cases were rare and an overflow indication could be a practical solution.

HOST-IMP Communication: What’s the setup? The conversation also delved into the HOST-IMP communication setup. Here’s a breakdown of the important components discussed:

• Five-bit Link Field and Conversion Indicators: They talked about using a five-bit link field and a bit to indicate whether conversion is needed. Additionally, a 2-bit conversion indicator was proposed to handle conversion before sending and after receiving messages. This allowed for more control and flexibility in managing data conversion. What could a HOST send to an IMP?

The HOST had several options for communication with the IMP, including:

• Tracing and Conversion Information: Requesting tracing or specifying conversion needs.
• Message Handling: Indicating whether a message was for the destination IMP or HOST.
• RFNM (Receiver Not Ready): Sending requests related to RFNM.
• System Status: Reporting HOST status, synchronization issues, format errors, and requesting status information.

And what could an IMP send to a HOST?

Similarly, the IMP could communicate the following to the HOST:

1. Conversion Status: Information about conversion and whether RFNM had arrived.
2. System Status: Reporting IMP status, synchronization issues, and format errors.
3. Error Handling: Notifying if the called HOST was not responding.

Crocker also summarized Network Notes 1, 2, and 3 for Kahn, providing an overview of previous discussions and developments. This summary would help ensure that both parties were on the same page regarding ongoing network protocol work.

RFC 6 is crucial because it captures the early thought processes and technical considerations that went into network protocol development. It shows how foundational issues like code conversion and communication protocols were tackled to ensure smooth data transmission across different systems.

What Else was Happening?

• Harley J. Earl, American automobile designer (1st head of design at General Motors), died at 75. He was a pioneer in automotive design and was responsible for the design of many iconic cars.
• The song “Dizzy” by Tommy Roe was the number one song on the Billboard Hot 100 chart. This song became a major hit and a cultural touchstone of the time.