A Simple Approximation to Minimum-Delay Routing

Abstract

The conventional approach to routing in computer networks consists of using a heuristic to compute a single shortest path from a source to a destination. Single-path routing is very responsive to topological and link-cost changes; however, except under light traffic loads, the delays obtained with this type of routing are far from optimal. Furthermore, if link costs are associated with delays, single-path routing exhibits oscillatory behavior and becomes unstable as traffic loads increase. On the other hand, minimumdelay routing approaches can minimize delays only when traffic is stationary or very slowly changing.We present a "near-optimal" routing framework that offers delays comparable to those of optimal routing and that is as flexible and responsive as single-path routing protocols proposed to date. First, an approximation to the Gallager's minimum-delay routing problem is derived, and then algorithms that implement the approximation scheme are presented and verified. We introduce the first routing algorithm based on link-state information that provides multiple paths of unequal cost to each destination that are loop-free at every instant. We show through simulations that the delays obtained in our framework are comparable to those obtained using the Gallager's minimum-delay routing. Also, we show that our framework renders far smaller delays and makes better use of resources than traditional single-path routing.

Robust load balancing under traffic uncertainty—tractable models and efficient algorithms

“…Hence, in many cases it is desirable to separate the path calculations from the load balancing and distribute the traffic over precalculated paths. An approximation of Gallagher's algorithm is introduced by Vutukury and Garcia-Luna-Aceves [36] where the traffic is balanced on a set of pre-computed paths. Elwalid et al [9] introduces MPLS Adaptive Traffic Engineering (MATE).…”

Multipath routing and rate-controlled video encoding in wireless video surveillance networks

“…According to this algorithm each node, thanks to a distance-vector algorithm, knows the distance from the Internet through each path in the Mesh network, and forwards packets, in a round-robin fashion, through all the paths having the same minimum cost to reach the Internet, whatever the destination Gateway node. The distance-vector multipath network-balancing routing algorithm is used for two reasons: first it is able to reduce delay [25,35,36]; secondly, thanks to its multipath peculiarity, it increases the robustness of the architecture to external attacks and interceptions. In fact, if a path is shielded (maliciously or not), or its quality is temporally degraded, all the packets flowing through it are lost; however, the application of the multipath network-balancing routing algorithm guarantees that a high percentage of packets are able to reach the Video Decoder block, and therefore frames can be decoded, by applying an error concealment video decoding algorithm [37][38][39].…”

Improving the efficiency of multipath traffic via opportunistic traffic scheduling

“…A significant literature addresses protocol design for computing multiple routes and their associated weights to minimize delay and optimize use of network resources; see for example [16,17] and the references therein. Such work is complimentary to OMS as OMS presupposes a control-path protocol to set up the routes: such a protocol may be a simple hop-count protocol with equal splitting [1] or more sophisticated distributed optimizations as in [16,17].…”

“…Such work is complimentary to OMS as OMS presupposes a control-path protocol to set up the routes: such a protocol may be a simple hop-count protocol with equal splitting [1] or more sophisticated distributed optimizations as in [16,17].…”