att_abstract={{SIP server clusters provide scalability and high availability for SIP applications.  The nature of telecommunications services dictates requirements for these capabilities that generally exceed what is necessary in the domain of web applications. There are a number of clustering solutions available to address these requirements, but due to significant differences in architecture and the lack of common terminology, the solutions are difficult to compare.  In this paper, we propose system requirements that are necessary to achieve scalability and high availability.  We then propose an abstract cluster architecture containing four common architectural elements.  Solutions from three different vendors are described in terms of these abstract elements.  The solutions are compared based on an evaluation framework that includes a number of criteria, such as robustness to failures of different types and numbers, overhead required to manage failures, and scaling efficiency.}},
	att_authors={gb2191, ec1916, ts2732},
	att_copyright_notice={{(c) ACM, 2011. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in IPTComm 2011 {{, 2011-08-01}}.
	att_tags={SIP,  high availability,  fault tolerance,  scalability,  application server},
	author={Gregory Bond and Eric Cheung and Thomas Smith and Jong Yul Kim},
	institution={{IPTComm 2011}},
	title={{An Evaluation Framework for Highly Available and Scalable SIP Server Clusters}},