Number Of Routing Table Entries Research Articles

On Hierarchical Routing in Doubling Metrics

We study the problem of routing in doubling metrics and show how to perform hierarchical routing in such metrics with small stretch and compact routing tables (i.e., with a small amount of routing information stored at each vertex). We say that a metric ( X , d ) has doubling dimension dim(<i<X</i<) at most α if every ball can be covered by 2 α balls of half its radius. (A doubling metric is one whose doubling dimension dim(<i<X</i<) is a constant.) We consider the metric space induced by the shortest-path distance in an underlying undirected graph G . We show how to perform (1 + τ)-stretch routing on such a metric for any 0 < τ ≤ 1 with routing tables of size at most (α/τ) O (α) log Δlog δ bits with only (α/τ) O (α) log Δ entries , where Δ is the diameter of the graph, and δ is the maximum degree of the graph G ; hence, the number of routing table entries is just τ − O (1) log Δ for doubling metrics. These results extend and improve on those of Talwar (2004). We also give better constructions of sparse spanners for doubling metrics than those obtained from the routing tables earlier; for τ > 0, we give algorithms to construct (1 + τ)-stretch spanners for a metric ( X , d ) with maximum degree at most (2 + 1/τ) O(dim(X)) , matching the results of Das et al. for Euclidean metrics.

All-optical router with pulse-position modulation header processing in high-speed photonic packet switching networks

In future high-speed photonic packet switching networks, it is highly desirable to carry out robust all-optical header recognition to provide high-throughput routing. The authors present a pulse-position modulation header processing (PPM-HP) scheme, offering significantly reduced routing table size and employing a single bit-wise AND operation to carry out correlation of the packet header with the entire routing table entries. The downsized routing table also offers multiple transmission modes (unicast, multicast and broadcast) in the optical layer and improves core network scalability where the number of core/edge nodes could be altered without the need for changing the number of routing table entries. The authors present modelling and simulation of the packet switching router based on PPM-HP. Noise propagation and crosstalk incurred in a multiple-hop routing scenario are investigated. The simulation results are presented and compared with the theoretical calculations.

All-to-all disjoint multipath routing using cycle embedding

In this paper, we evaluate the performance of disjoint multipath routing approaches for all-to-all routing in packet-switched networks with respect to packet overhead, path length, and routing table size. We develop a novel approach based on cycle embedding to obtain two node-disjoint paths between all source-destination pairs with reduced number of routing table entries maintained at a node (hence the reduced lookup time), small average path length, and less packet overhead. We study the trade-off between the number of routing table entries maintained at a node and the average length of the two disjoint paths by: (a) formulating the cycle-embedding problem as an integer linear program; and (b) developing a heuristic. We show that the number of routing table entries at a node may be reduced to at most two per destination using cycle-embedding approach if the average length of the disjoint paths are allowed to exceed the minimum by 25%.

라우팅 테이블의 크기를 고려한 랑데부 라우터 선정 알고리즘

공유형 트리(Shared Tree)를 구성하여 멀티캐스트 서비스를 제공하는 CBT(Core Based Tree)와 PIM-SM(Protocol Independent Multicast-sparse Mode) 프로토콜에서는 랑데부 라우터(RP: Rendezvous Point)의 위치에 따라 전체 네트워크의 효율성이 결정된다. 본 논문에서는 멀티 캐스트 데이터 전송을 위하여 필요한 라우팅 테이블의 크기(테이블 내 entries의 수)를 최소화하고, 소스-멤버 사이의 비용을 일정한 범위 내로 관리할 수 있는 새로운 RP 선정 알고리즘을 제안한다. 성능분석 결과, 비용만을 고려하는 기존의 방법에 비하여 총비용은 5.37%, 라우팅 테이블의 크기는 13.35%까지 줄일 수 있음을 알 수 있다. Depending on the location of the rendezvous point (RP), the network efficiency is determined in the core based tree (CBT) or protocol independent multicast-sparse mode (PIM-5M) multicasting protocol to provide the multicast services based on the shared tree. In this paper, a new algorithm to allocate the RP using the estimated values of the total cost and the size(number of entries) of the routing tables is proposed for efficiently controlling the cost and the number of routing table entries. The numerical results show that the proposed algorithm reduces the total cost in 5.37%, and the size of routing tables in 13.35% as compared to the previous algorithm.

Linear time distributed construction of colored trees for disjoint multipath routing

Disjoint multipath routing (DMPR) is an effective strategy to achieve robustness in networks where data is forwarded along multiple link- or node-disjoint paths. DMPR poses significant challenges in terms of obtaining loop-free multiple (disjoint) paths and effectively forwarding data over the multiple paths, the latter being particularly significant in datagram networks. One approach to reduce the number of routing table entries for disjoint multipath forwarding is to construct two trees, namely red and blue, rooted at a destination node such that the paths from a source to the destination on the two trees are link/node-disjoint. This paper develops the first distributed algorithm for constructing the colored trees whose running time is linear in the number of links in the network. The paper also demonstrates the effectiveness of employing generalized low-point concept rather than traditional low-point concept in the DFS-tree to reduce the average path lengths on the colored trees.

A Simple Data Transfer Technique Using Local Address for Networks-on-Chips

Networks-on-chips (NoCs) have been studied to connect a number of modules in a chip by introducing a network structure which is similar to that in parallel computers. Since embedded streaming applications usually generate predictable small-sized data traffic, the network structure can be customized to the target traffic. Accordingly, we develop a data transfer technique for simplifying routers for predictable small-sized communication in simple tile-based architectures. A data structure is split into single-flit packets, and a label is attached to each of them in order to route them independently. A label is transferred on dedicated wires beside data lines in a channel by taking advantage of relaxed pin count limitations of a channel. To reduce the wiring area for the label, the label is locally assigned according to a preanalysis of required communication pairs of nodes. Analysis results show that only a 3-bit local label is sufficient to route all data of evaluated streaming applications in the case of a 16-node 2D torus. The required amount of hardware for a router is reduced by 37 percent compared with that for a wormhole packet router with the same number of routing table entries

다중 인터넷 게이트웨이를 갖는 MANET의 부하 균등화 기법

이동 애드 혹 네트워크(Mobile Ad Hoc Network; MANET)는 유선 인프라 없이 구축된 무선 네트워크로 멀티 홉 통신을 수행할 수 있다. 인터넷 노드와 통신하고자 하는 MANET 노드에게 인터넷 연결을 가능하게 하는 방법이 요구되며 인터넷 연결은 인터넷과 MANET을 중계하는 인터넷 게이트웨이를 통해 지원된다. 신뢰성과 통신의 유연성을 지원하기 위해 다중 인터넷 게이트웨이들을 MANET에 배치하여 사용할 수 있다. 게이트웨이들 간의 부하를 잘 분배한다면 네트워크 성능 향상을 얻을 수 있으므로, MANET 내에 여러 개의 인터넷 게이트웨이가 존재할 경우 이들 간의 부하 균등화는 중요한 이슈이다. 본 연구에서는 부하 균등화 기법을 제어 메시지의 플러딩 방법과 인터넷 게이트웨이를 선택하는 주체에 따라 4가지로 분류하며, 부하 균등화 문제를 해결하기 위한 새로운 메트릭(metric)을 제안한다. 시뮬레이션을 통하여 흡 수와 라우팅 엔트리의 수를 메트릭으로 이용하는 새로운 기법의 성능이 기존 기법에 비하여 향상되었음을 보인다. A mobile ad hoc network (MANET) is an infrastructureless network that supports multi-hop communication. For the MANET nodes wishing to communicate with nodes in the wired Internet, the global Internet connectivity is required and this functionality can be achieved with the help of the Internet gateway. For the support of reliability and flexibility, multiple Internet gateways can be provisioned for a MANET. In this case, load-balancing becomes one of the important issues since the network performance such as the network throughput can be improved if the loads of the gateways are well-balanced. In this paper, we categorize the load-balancing mechanisms and propose a new metric for load-balancing. Simulation results show that our proposed mechanism using the hop distance and the number of routing table entries as a load-balancing metric enhances the overall network throughput.