Context:

The future of Internet depends on meeting ever-increasing capacity needs while curbing the energy consump- tion’s uncontrolled growth in data networks and reducing the end-to-end latency of mobile networks. Optical functionalities (OFs), such as wavelength conversion, all-optical regeneration and optical packet switching, have a tremendous potential to solve these challenges by reducing the required number of optical-to-electronic (O-E) conversions and leveraging the lower energy cost per bit of optical transmissions. Unfortunately, such OFs that ought to be “killer applications” have never gained any significant market share, because they don’t easily fit the conventional layered network model.

Our team is currently working on new ways to handle OFs[1, 2], notably Optical and Hybrid Opto- electronic Packet Switching (OPS, HOPS), which have been shown in simulation to boost the performance and energy efficiency of data center networks, especially when coupled with TCP congestion control algorithms (CCAs).

Problem statement:

The aim of this project is study the buffer occupancy of the switches in the HOPS data center network. Till the moment, we have studied the HOPS network of the 8-ary 3 level fat-tree topology[3], it is known that the buffer occupancy of each level of switches vary and influence the overall latency of a datacenter network, which is crucial in a data center network.

The students will undertake simulations of the HOPS data center networks and study the effect of buffer occupancy of switches of each level and find their influence on the network performance. If time permits, the students are encouraged to propose a TCP CCA taking into account said buffer occupancy, based on Explicit Congestion Notification (ECN)[4]. The simulations will be performed by the simulator developed (C++) in Telecom ParisTech.

References

1. A. Minakhmetov, C. Ware, and L. Iannone. “TCP Congestion Control in Datacenter Optical Packet Net- works on Hybrid Switches”. In: vol. 10. 7. OSA, July 2018, B71–B81. DOI: 10.1364/JOCN.10.000B71.URL: http://jocn.osa.org/abstract.cfm?URI=jocn-10-7-B71.
2. A. Minakhmetov, H. Chouman, L. Iannone, M. Lourdiane, and C. Ware. “Network-level strategies for best use of optical functionalities”. In: Int. Conference on Transparent Optical Networks (ICTON). Tu.B1.3. July 2018.
3. M. Al-Fares, A. Loukissas, and A. Vahdat. “A Scalable, Commodity Data Center Network Architecture”. In: Proceedings of the ACM SIGCOMM 2008 Conference on Data Communication. SIGCOMM ’08. Seat- tle, WA, USA: ACM, 2008, pp. 63–74. ISBN: 978-1-60558-175-0. DOI: 10.1145/1402958.1402967.
4. K. Ramakrishnan, S. Floyd, and D. Black. The Addition of Explicit Congestion Notification (ECN) to IP. RFC 3168. http://www.rfc-editor.org/rfc/rfc3168.txt. RFC Editor, Sept. 2001. URL:http://www.rfc-editor.org/rfc/rfc3168.txt.