Recursive Internetwork Architecture: Difference between revisions

Revision as of 10:02, 27 July 2015

Revision as of 12:45, 27 July 2015

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'''1986. [[Congestion collapse]] takes the Internet by surprise'''. Despite the fact that the problem of congestion control in datagram networks had been known since the very beginning (in fact there had been several publications during the 70s and early 80s,<ref>D. Davies. Methods, tools and observations on flow control in packet-switched data networks. IEEE Transactions on Communications, 20(3): 546–550, 1972</ref><ref>S. S. Lam and Y.C. Luke Lien. Congestion control of packet communication networks by input buffer limits - a simulation study. IEEE Transactions on Computers, 30(10), 1981.</ref>) the congestion collapse in 1986 caught the Internet by surprise. What is worse, it was decided to adopt the [[congestion avoidance]] scheme from [[Ethernet]] networks with a few modifications, but it was put in TCP. The effectiveness of a congestion control scheme is determined by the time-to-notify, i.e. reaction time. Putting congestion avoidance in TCP maximizes the value of the congestion notification delay and its variance, making it the worst place it could be. Moreover, congestion detection is implicit, causing several problems: i) congestion avoidance mechanisms are predatory: by definition they need to cause congestion to act; ii) congestion avoidance mechanisms may be triggered when the network is not congested, causing a downgrade in performance.

'''1992. Second opportunity to fix addressing missed'''. In 1992 the [[Internet Architecture Board]] (IAB) produced a series of recommendations to resolve the scaling problems of the [[IPv4]] based Internet: address space consumption and routing information explosion. Three types of solutions were proposed: introduce CIDR ([[Classless Inter-Domain Routing]]) to mitigate the problem, design the next version of IP (IPv7) based on [[CLNP]] (ConectionLessConnectionLess Network Protocol) and continue the research into naming, addressing and routing.<ref>Internet Architecture Board. IP Version 7 ** DRAFT 8 **. Draft IAB IPversion7, july 1992</ref> CNLP was an OSI based protocol that addressed nodes instead of interfaces, solving the old multi-homing problem introduced by the [[ARPANET]], and allowing for better routing information aggregation. CIDR was introduced but the [[IETF]] didn't accept an IPv7 based on CLNP. IAB reconsidered its decision and the IPng process started, culminating with [[IPv6]]. One of the rules for IPng was not to change the semantics of the IP address, which continues to name the interface perpetuating the multi-homing problem.<ref name="IPv6"/>

There are still more wrong decisions that have resulted in long-term problems for the current Internet, such as: