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Compact Formulation of Network Entropy Maximization
Dahai Xu
46th Annual Conference on Information Sciences and Systems (CISS),
2012.
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[BIB]
IEEE Copyright
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. , 2012-03-21
{Any min-cost multi-commodity flow can be realized with a link-state routing protocol, PEFT, using uneven traffic splitting. PEFT was derived from a new convex optimization problem, Network Entropy Maximization (NEM), which involves an infinite number of variables. In this paper, we present the compact and equivalent formulation of the NEM problem.}
SRLG-Diverse Routing of Multiple Circuits in a Heterogeneous Optical Transport Network
Dahai Xu, Guangzhi Li, Byrav Ramamurthy, Angela Chiu, Dongmei Wang, Robert Doverspike
International Workshop on Design of Reliable Communication Networks (DRCN) 2011,
2011.
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[BIB]
IEEE Copyright
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 International Workshop on Design of Reliable Communication Networks (DRCN) 2011. , 2011-10-12
{Network planners are often requested to provision multiple physically-diverse high-speed circuits over a large carrier's core (inter-city) DWDM network, which consists of multiple layers and heterogeneous vendor systems. Optimally provisioning such circuits while avoiding shared risk link group (SRLG) failures is an NP-hard problem. In this paper, we propose a novel hybrid two-step approach: pre-processing with Integer Linear Programming (ILP) for diverse routing and post-processing for regenerator placement and wavelength assignment. This approach has been implemented in a prototype network planning tool. According to our experiments, most of the cases for a typical large carrier's core transport network can be solved within 1 minute, even with tens of thousands of binary decision variables, which allows interactive use by network planners.}
Network architecture for joint failure recovery and traffic engineering
Dahai Xu, Robert Doverspike, David Johnson, Martin Suchara, Jennifer Rexford
Sigmetrics 2011,
2011.
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ACM Copyright
(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 ACM SIGMETRICS , 2011-06-07.
{Today's networks typically handle traffic engineering (e.g., tuning the routing-protocol parameters to optimize the flow of traffic) and failure recovery (e.g., pre-installed backup paths) independently. In this paper, we propose a unified way to balance load efficiently under a wide range of failure scenarios. Our architecture supports flexible splitting of traffic over multiple precomputed paths, with efficient path-level failure detection and automatic load balancing over the remaining paths. We propose two candidate solutions that differ in how the routers rebalance the load after a failure, leading to a trade-off between router complexity and load-balancing performance. We present and solve the optimization problems that compute the configuration state for each router. Our experiments with traffic measurements and topology data (including shared risks in the underlying transport network) from a large ISP identify a "sweet spot" that achieves near-optimal load balancing under a variety of failure scenarios, with a relatively small amount of state in the routers. We believe that our solution for joint traffic engineering and failure recovery will appeal to Internet Service Providers as well as the operators of data-center networks.}
Proactive Network Management of IPTV Networks
Rakesh Sinha, Kadangode Ramakrishnan, Robert Doverspike, Dahai Xu, Jorge Pastor, Aman Shaikh
2010.
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[BIB]
{Consumer communications and entertainment services, including broadcast TV and VoIP require service providers to meet stringent availability and latency constraints. When a packet technology, such as IP, is used to transport these services, this also poses stringent packet loss requirement on the network. This aspect of IPTV, where impairments have consumer-visible impact and potential public relations consequences, creates new challenges in protocol design, as well as network management. The key to operating an effective network is to expand beyond the typical ?reactive? network management approach to be able to anticipate and manage potential network problems. This paper describes network management techniques deployed in a production IPTV network with over 2 million customers. }
Method And Apparatus For Providing Redundancy For An Access Network,
Tue May 17 16:05:09 EDT 2011
A method and apparatus for providing redundancy for an access network are disclosed. For example, the method receives an access network structure, and removes one or more unnecessary 2D edges or 3D edges from a simplex cover for the access network structure. The method then performs a search on the simplex cover; and, generates a new access network structure that includes the redundancy.
