Compact routing on the Internet AS-graph

Compact routing algorithms have been presented as candidates for scalable routing in the future Internet, achieving near-shortest path routing with considerably less forwarding state than the Border Gateway Protocol. Prior analyses have shown strong performance on power-law random graphs, but to better understand the applicability of compact routing algorithms in the context of the Internet, they must be evaluated against real- world data. To this end, we present the first systematic analysis of the behaviour of the Thorup-Zwick (TZ) and Brady-Cowen (BC) compact routing algorithms on snapshots of the Internet Autonomous System graph spanning a 14 year period. Both algorithms are shown to offer consistently strong performance on the AS graph, producing small forwarding tables with low stretch for all snapshots tested. We find that the average stretch for the TZ algorithm increases slightly as the AS graph has grown, while previous results on synthetic data suggested the opposite would be true. We also present new results to show which features of the algorithms contribute to their strong performance on these graphs

Randomness for Reduced-State Inter-Domain Forwarding

The rate of growth of forwarding state at core Internet routers has prompted some concern about the scalability of the Internet in the future. This growth is affected by two factors: the number of prefixes advertised, and the densit

Deterministic, reduced-visibility inter-domain forwarding

Inter-domain forwarding state is growing at a super-linear rate, rendering older routers obsolete and increasing the cost of replacement. A reduction of state will alleviate this problem. In this paper, we outline a new reduced-state inter-domain forwarding mechanism. We carefully drop portions of the advertised forwarding state using a utility measure for prefixes based on the length of the prefix and the path length to its origin. A deterministic forwarding algorithm uses the resulting partial view. The graph of connections between autonomous systems is shallow, offering many viable paths for data flows, a property we aim to use to achieve minimal detrimental effect on delay and AS path stretch

Harnessing Internet Topological Stability in Thorup-Zwick Compact Routing

Thorup-Zwick (TZ) compact routing guarantees sublinear state growth with the size of the network by routing via landmarks and incurring some path stretch. It uses a pseudo-random landmark selection designed for static graphs, and unsuitable for Internet routing. We propose a landmark selection algorithm for the Internet AS graph that uses k-shells decomposition to choose landmarks. Using snapshots of the AS graph from 1997–2010, we demonstrate that the ASes in the kmax-shell are highly-stable over time, and form a sufficient landmark set for TZ routing in the overwhelming majority of cases (in the remainder, adding the next k-shell suffices). We evaluate path stretch and forwarding table sizes, and show that these landmark sets retain low average path stretch with tiny forwarding tables, but are better suited to the dynamic nature of the AS graph than the original TZ landmark selection algorithm

Wide-area SMC interaction, implementation and emulation

The primary components in a Self Managed Cell (SMC) -- the event bus, the policy management service, and the discovery service -- are required regardless of the scale of the SMC. However, the behaviour of core services may necessarily be altered to suit the environment within which an SMC operates. This paper discusses the design of core services (primarily, the event bus and discovery service) in wide- area SMCs. Delay-tolerant networking between SMCs is also discussed, as is the implementation of core services leading to an emulated network of SMCs. As the basis for a 'healthmap' capable of representing patient data across a geographic region, the discussion on wide-area SMCs leads into cursory discussion of geographical imaging and visualisation systems