QoS aware traffic grooming and integrated routing on IP over WDM networks

Abstract

In this article, we consider traffic grooming and integrated routing in IP over WDM networks. The challenges of this problem come from jointly considering traffic grooming, IP routing, and lightpath routing and wavelength assignment (RWA). Due to the high bandwidth of optical fiber, there exists a mismatch between the capacity needed by an IP flow and that provided by a single lightpath. Traffic grooming is therefore used to increase the network utilization by aggregating multiple IP flows in a single lightpath. However, traffic grooming incurs additional delays that might violate Quality-of-Service (QoS) requirements of IP users. In this work, the tradeoff between traffic grooming and IP QoS routing is well-formulated as a mixed integer and linear optimization problem, in which the revenue from successfully provisioning IP paths is to be maximized. Problem constraints include IP QoS, routing, optical RWA, and the WDM network capacity. We propose a novel Lagrangean relaxation (LGR) algorithm to perform constraint relaxation and derive a set of subproblems. The Lagrangean multipliers are used in the proposed algorithm to obtain a solution in consideration of grooming advantage and resource constraints simultaneously. Through numerical experiments and comparisons between the proposed algorithm and a twophase approach, LGR outperforms the two-phase approach under all experimental cases. In particular, the improvement ratio becomes even more significant when the ratio of IP flow to the wavelength capacity is smaller.

Reformulation and decomposition approaches for traffic routing in optical networks

“…Moreover, these bounds are not better than the trivial combinatorial bound that can be computed a priori on the number of required optical hops: indeed, given wavelength capacity, the number of optical hops is at least k t k D k /U . (6)(7)(8)(9)(10)(11), and from both (26)(27)(28)(29)(30) and (35)(36)(37)(38)(39) where the term φ(y) is omitted, are all equal to the trivial dual bound k∈K t k D k /U.…”

“…Actually, if a request was routed over a two-hop aggregate lightpath, port installation cost would be incurred at the intermediate node. As formulation (35)(36)(37)(38)(39) is a relaxation of (26-30), itself a relaxation of the [OC] formulation given in (6)(7)(8)(9)(10)(11), its LP solution k∈K t k D k /U is also a lower bound for the [OC] formulation. Thus, to obtain the bound result for the [OC] formulation, it is enough to exhibit an LP solution reaching that bound.…”

Investigations on combined XPM and FWM effects on optical pulse propagation in dynamic IP traffic over WDM networks

“…Furthermore, voice, video, and real-time multimedia applications require more QoS support [2]. Some service models and mechanisms as well as applications of IP over WDM were addressed, such as integrated services (IntServ), differentiated services (Diffserv), and generalized multiprotocol label switching (GMPLS), which were proposed by the Internet Engineering Task Force (IETF) to fulfill the requirements of QoS [3].…”

“…With the rapid development of optical transmission technologies, the 40 Gbps single-wavelength system is commercially available. Without circuit grooming of the conventional SONET/SDH layer, traffic grooming must be fully performed in IP routers at the packet level [2]. To maximize network utilization, both IP routing and optical lightpaths provisioning need to be jointly considered to meet the desired QoS requirement.…”

An Intelligent Static Traffic Grooming Scheme in IP over DWDM Internet

“…In [2], traffic grooming and integrated routing in IP over WDM networks are studied. The tradeoff between traffic grooming and IP QoS routing is well-formulated as a mixed integer and linear optimization problem, and a novel Lagrangean relaxation algorithm is proposed to solve the problem.…”