QoS-specified Traffic Grooming Algorithm in WDM Mesh Networks

1. QoS-specified Traffic Grooming Algorithm in WDM Mesh Networks Bing Xiang, Hongfang Yu, Sheng Wang, Lemin Li Communications, Circuits and Systems, 2004. ICCCAS 2004. 2004 International Conference onVolume 1, 27-29 June 2004 Page(s):633 - 637 Vol.1

2. Abstract • In WDM network, the bandwidth request of a traffic stream is usually much lower than the capacity of a wavelength. • Traffic grooming can aggregate low-rate connections into high-capacity lightpaths to make efficient use of the bandwidth. • Authors propose a QoS-specified traffic grooming algorithm named BMST considering both the hops of lightpath and load balance in the network.

3. Introduction(1/5) • A WDM network consists of WDM switches (OXCs) connected by fiber optical links. • In each link, multiple wavelengths are available. OXCs enable space-switching of wavelengths from one port to another and help in establishuig circuit-switched connections called lightpaths between the nodes. • This enables optical passthrough at the WDM layer and eliminates the need to electronically process all the traffic at the node

4. Introduction(2/5) • Usually we can setup lightpaths using designate RWA in WDM networks ,but for the RWA, there exist an assumption that every connection required a full wavelength. • The network may be required to support traffic connections at rates that are much lower than the full wavelength capacity. • For networks of practical size, the number of available wavelengths is still lower than the number of source to destination connections that need to be made.

5. Introduction(3/5) • Traffic grooming can aggregate low-rate connections onto high-capacity lightpaths to make efficient use of the wavelength capacity. • Most of the researches related to traffic grooming focused on WDM/SONET ring networks while fewer studies of traffic grooming in WDM mesh network such as [12] are presented to maximize the network throughput. • The basic idea in Literature [12] can be described as follow: • set up the single-hop lightpaths as much as possible subject to the network resources. • use the single hop work lightpaths to construct virtual topology. • low-rate connections can be groomed in the virtual topology accordingly.

6. Introduction(4/5) • In the studies list above, no consideration hasaddressed on QoS based traffic grooming. • The QoS-specified RWAalgorithms proposed in [13]only suggest to setup three kinds of lightpath to support different QoSlevels, those areDedicated lightpath, Shared lightpath 'and Multi-hop lightpath respectively, But the traffic grooming is not considered. • Since the load distribution of network can exercise great influenceon the average transmission delay of traffic, load balance of network traffic can improve network performance efficiently.

7. Introduction(5/5) • In this paper authors proposea QoS-specified traffic grooming algorithm named BMST, Balanced Maximizing Single-Hop Traffic grooming Algorithm, considering both the hop of lightpath and load balance in WDM mesh networks.

8. References • [12] K.Y. Zhu, B. Mukherjee, “Traffic Grooming in an Optical WDM Mesh Network”, IEEE J. Select. Areas Co’mm., Vol. 20, N. 1, pp122-133, January 2002. • [13] Y. Qin, K. Sivalingam, B. Li, “QoS for Virtual Private Networks over Optical WDM Networks”, SPIE/ACM/IEEE Opticomm conference at Dallas, TX, October 2000.