att_abstract={{Abstract— Shared Risk Link Groups (SRLGs) have been investigated during the past 10 years due to optical network innovation and deployment. Dense Wavelength Division Multiplexing (DWDM) technology has significantly increased the data transmission capability per fiber. Service providers build their overlay networks, such as IP networks, on top of optical networks and all optical networks are built over some combination of DWDM equipment and fibers. If there is a single DWDM system outage or fiber outage, the set of overlay network links dependent on the failed resource would all fail at the same time. The set of links failed by a common resource outage is called a shared risk link group (SRLG). SRLGs have been designed and implemented in many network planning tools and some network routing protocols. A single SRLG represents one potential outage (or failure mode) and a large service provider’s network could easily contain tens of thousands of failure modes. The greater the number of SRLGs, the more difficult it is to attain good performance from planning tools (like routers) whose computations are dependent on the number of SRLGs. For some routing protocols using SRLG information, the situation becomes even worse because a routing protocol may have space constraints to hold a limited number of SRLGs. These issues create a challenge to optimize the SRLG calculations such that the SRLG-related functions are not impacted or the impacts to the SRLG-related functions are limited. This paper takes a closer look at the SRLG optimization issue and proposes algorithms for how to reduce the number of SRLGs for different applications. }},
	att_authors={gl1464, dw6462, tg2424, rd2518},
	att_categories={C_CCF.8, C_NSS.9, C_NSS.12},
	att_copyright_notice={{This version of the work is reprinted here with permission of IEEE for your personal use. Not for redistribution. The definitive version was published in 2012  {, Volume $vol}}{{, 2012-09-13}}
	att_tags={Shared Risk Link Group,  Optimization,  Algorithm,  Case Study},
	author={Guangzhi Li and Dongmei Wang and Timothy Gallivan and Robert Doverspike},
	institution={{Journal of optical communication networks}},
	title={{On Shared Risk Link Group Optimization (Invited)}},