A distributed LSP scheme to reduce spare bandwidth demand in MPLS networks

Abstract

A preplanned path-protection scheme with sufficient spare bandwidth is appropriate for real-time fault restoration in multiprotocol label switching (MPLS) networks. In this case, however, it is important to reduce the amount of spare bandwidth to prevent degradation of network efficiency. A distributed label switched path (D-LSP) scheme is proposed to reduce the amount of spare bandwidth required for protecting against network faults in MPLS networks. The main idea of the proposed D-LSP scheme is to partition traffic into multiple LSPs, each of which is established on a distinct link-disjoint route between each pair of end nodes. The D-LSP scheme is evaluated in terms of the reduction ratio of total network cost in comparison with the conventional LSP scheme. Traffic partitioning in the D-LSP scheme can decrease the statistical multiplexing gain (SMG) obtained by aggregating IP packet flows into an LSP. The tradeoff between spare bandwidth reduction and degradation of SMG due to traffic partitioning is also investigated. The numerical results show that the proposed D-LSP scheme yields the network cost-reduction ratio (NCRR) of at least 29%, 27%, and 15% for the networks where average node degrees are 4.6, 4.4, and 3.2, respectively. The D-LSP scheme shows the similar performance of NCRR in both Markovian traffic and self-similar traffic environments. Index Terms-Distributed label switched path (D-LSP), label switched path (LSP) partitioning, network cost-reduction ratio (NCRR), spare bandwidth reduction, statistical multiplexing gain (SMG).

Calculation of routing value in MPLS network according to traffic fractal properties

“…Lets consider the case where each edge router LER is both a source and a receiver. LSR can not be the recipient of traffic that has arrived to it from an adjacent network [8]. It is assumed that set of QoS traffic channels indicated Y (in one link m may be a plurality of channels y Y  ), and that they have the following attributes:…”

“…Thus, the entire amount of intensive computing falls on edge area, and high-performance switching is performed in core, which allows efficient optimization of MPLS device configuration depending on their location in the network [8].…”

“…Lets consider the case where each edge router LER is both a source and a receiver. LSR can not be the recipient of traffic that has arrived to it from an adjacent network [8].…”

“…The definition of the burst level can also help in the marking of traffic flows, for example, in cases where higher priority traffic for a long time prevents the flow of lower priority streams. In [8], an approach is proposed to increase the amount of free bandwidth and the total cost of the network; when determining the path for traffic transmission and necessary bandwidth, self-similar traffic parameters are taken into account.…”