Xin Jin will present his research seminar/general exam on Monday April 29 at 2:30PM in Room 401 (note room!). The members of his committee are: Jennifer Rexford (advisor), Michael Freedman, and Kai Li. Everyone is invited to attend his talk, and those faculty wishing to remain for the oral exam following are welcome to do so. His abstract and reading list follow below. ----- Original Message ----- The title is "SoftCell: Taking Control of Cellular Core Networks". Existing cellular networks suffer from inflexible and expensive equipment, and complex control-plane protocols. To address these challenges, we present SoftCell, a scalable architecture for supporting fine-grained policies for mobile devices in cellular core networks. The SoftCell controller realizes high-level service polices by directing traffic over paths that traverse a sequence of middleboxes, optimized to the network conditions and user locations. To ensure scalability, the core switches forward traffic on hierarchical addresses (grouped by base station) and policy tags (identifying paths through middleboxes). This minimizes data-plane state in the core switches, and pushes all fine-grained state to software switches at the base stations. These access switches apply fine-grained rules, specified by the controller, to map all traffic to the appropriate addresses and tags. SoftCell guarantees that packets in the same connection traverse the same sequence of middleboxes in both directions, even in the presence of mobility. Our characterization of real LTE workloads, micro-benchmarks on our prototype controller, and large-scale simulations demonstrate that SoftCell improves the flexibility of cellular core networks, while enabling the use of inexpensive commodity switches and middleboxes. [1] L. L. Peterson and B. S. Davie, Computer networks: a systems approach. Morgan Kaufmann, 2007. [2] J. H. Saltzer, D. P. Reed, and D. D. Clark, “End-to-end arguments in system design,” ACM Transactions on Computer Systems (TOCS), vol. 2, no. 4, 1984. [3] M. Casado, M. J. Freedman, J. Pettit, J. Luo, N. Gude, N. McKeown, and S. Shenker, “Rethinking enterprise network control,” IEEE/ACM Trans. Networking, vol. 17, August 2009 . [4] N. McKeown, T. Anderson, H. Balakrishnan, G. Parulkar, L. Peterson, J. Rexford, S. Shenker, and J. Turner, “OpenFlow: Enabling innovation in campus networks,” SIGCOMM Computer Communications Review, vol. 38, no. 2, 2008. [5] A. R. Curtis, J. C. Mogul, J. Tourrilhes, P. Yalagandula, P. Sharma, and S. Banerjee, “DevoFlow: Scaling flow management for high-performance networks,” in ACM SIGCOMM, August 2011 . [6] A. Greenberg, J. R. Hamilton, N. Jain, S. Kandula, C. Kim, P. Lahiri, D. A. Maltz, P. Patel, and S. Sengupta, “VL2: A scalable and flexible data center network,” in ACM SIGCOMM, August 2009 . [7] R. Niranjan Mysore, A. Pamboris, N. Farrington, N. Huang, P. Miri, S. Radhakrishnan, V. Subramanya, and A. Vahdat, “PortLand: a scalable fault-tolerant layer 2 data center network fabric,” in ACM SIGCOMM, August 2009 . [8] D. Joseph, A. Tavakoli, and I. Stoica, “A policy-aware switching layer for data centers,” in ACM SIGCOMM, August 2008 . [9] Z. Wang, Z. Qian, Q. Xu, Z. Mao, and M. Zhang, “An untold story of middleboxes in cellular networks,” in ACM SIGCOMM, August 2011 . [10] M. Z. Shafiq, L. Ji, A. X. Liu, and J. Wang, “Characterizing and modeling internet traffic dynamics of cellular devices,” in ACM SIGMETRICS, June 2011 . [11] K.-K. Yap, R. Sherwood, M. Kobayashi, T.-Y. Huang, M. Chan, N. Handigol, N. McKeown, and G. Parulkar, “Blueprint for introducing innovation into wireless mobile networks,” in ACM VISA Workshop, August 2010 .