RFC 3439 (rfc3439) - Page 2 of 28
Some Internet Architectural Guidelines and Philosophy
Alternative Format: Original Text Document
RFC 3439 Internet Architectural Guidelines December 2002
5. Packet versus Circuit Switching: Fundamental Differences . . 13
5.1. Is PS is inherently more efficient than CS? . . . . . . . 13
5.2. Is PS simpler than CS? . . . . . . . . . . . . . . . . . . 14
5.2.1. Software/Firmware Complexity . . . . . . . . . . . . . . 15
5.2.2. Macro Operation Complexity . . . . . . . . . . . . . . . 15
5.2.3. Hardware Complexity. . . . . . . . . . . . . . . . . . . 15
5.2.4. Power. . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.2.5. Density. . . . . . . . . . . . . . . . . . . . . . . . . 16
5.2.6. Fixed versus variable costs. . . . . . . . . . . . . . . 16
5.2.7. QoS. . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.2.8. Flexibility. . . . . . . . . . . . . . . . . . . . . . . 17
5.3. Relative Complexity . . . . . . . . . . . . . . . . . . . 17
5.3.1. HBHI and the OPEX Challenge. . . . . . . . . . . . . . . 18
6. The Myth of Over-Provisioning. . . . . . . . . . . . . . . . 18
7. The Myth of Five Nines . . . . . . . . . . . . . . . . . . . 19
8. Architectural Component Proportionality Law. . . . . . . . . 20
8.1. Service Delivery Paths . . . . . . . . . . . . . . . . . . 21
9. Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . 21
10. Security Considerations . . . . . . . . . . . . . . . . . . 22
11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 23
12. References. . . . . . . . . . . . . . . . . . . . . . . . . 23
13. Authors' Addresses. . . . . . . . . . . . . . . . . . . . . 27
14. Full Copyright Statement. . . . . . . . . . . . . . . . . . 28
1. Introduction
RFC 1958 [RFC 1958] describes the underlying principles of the
Internet architecture. This note extends that work by outlining some
of the philosophical guidelines to which architects and designers of
Internet backbone networks should adhere. While many of the areas
outlined in this document may be controversial, the unifying
principle described here, controlling complexity as a mechanism to
control costs and reliability, should not be. Complexity in carrier
networks can derive from many sources. However, as stated in
[DOYLE2002], "Complexity in most systems is driven by the need for
robustness to uncertainty in their environments and component parts
far more than by basic functionality". The major thrust of this
document, then, is to raise awareness about the complexity of some of
our current architectures, and to examine the effect such complexity
will almost certainly have on the IP carrier industry's ability to
succeed.
The rest of this document is organized as follows: The first section
describes the Simplicity Principle and its implications for the
design of very large systems. The remainder of the document outlines
the high-level consequences of the Simplicity Principle and how it
should guide large scale network architecture and design approaches.
Bush, et. al. Informational