IL (network protocol) explained

The Internet Link protocol or IL is a connection-based transport-layer protocol designed at Bell Labs originally as part of the Plan 9 operating system and is used to carry 9P. It is assigned the Internet Protocol number of 40. It is similar to TCP but much simpler.

Its main features are:

• Reliable datagram service
• In-sequence delivery
• Internetworking using IP
• Low complexity, high performance
• Adaptive timeouts

As of the Fourth Edition of Plan 9, 2003, IL is deprecated in favor of TCP/IP because it doesn't handle long-distance connections well.^[1]

See also

• Fast Local Internet Protocol

Further reading

• Web site: The IL protocol . Dave Presotto . Dave Presotto . Phil Winterbottom . Phil Winterbottom . —The original paper describing IL

Notes and References

1. Web site: Plan 9 — Fourth Edition Release Notes . . June 2003 . August 3, 2018 . We are phasing out the IL protocol since it doesn’t handle long-distance connections well (and long-distance networks don't handle it well, either). IL is still used by fs(4) but TCP has become the standard protocol for all other services. .