Multicast scheduling of wavelength-tunable, multiqueue optical data center switches
Journal article, 2018

The all-optical switching of multicast flows using star couplers and tunable transceivers is a promising solution for emerging cloud data center applications. However, the limited tuning range of optical components on one hand and the buffer management challenges for multicast traffic delivery on the other pose a significant impact on the performance of optical multicast scheduling algorithms. Using only one queue per input port results in head-of-line (HOL) blocking and limits the throughput, especially for bursty traffic patterns. As the number of possible multicast destinations grows exponentially with the switch size, allocating one queue per destination is not a feasible solution. To resolve HOL blocking, in this paper we consider only a handful of queues per switch input port and devise scalable scheduling algorithms that take into account transceiver tunability constraints. According to our Monte Carlo analysis of a switch with 64 ports and operating under bursty traffic, it is possible to improve the maximum achievable throughput by 44% when the number of queues per port is increased from one to eight. We show that the performance gains due to an increase in the queue count depend on the availability of the spectral resources. With the scarcity of wavelengths, an increase in the number of queues leads to diminishing returns.

Multicast traffic

Data center

Star coupler

Scheduling

Multiqueue switch

Optical packet switching

Tunability

Author

Kamran Keykhosravi

Chalmers, Electrical Engineering, Kommunikationssystem, informationsteori och antenner, Communication Systems

Houman Rastegarfar

University of Arizona

Erik Agrell

Chalmers, Electrical Engineering, Kommunikationssystem, informationsteori och antenner, Communication Systems

Journal of Optical Communications and Networking

1943-0620 (ISSN)

Vol. 10 4 -364

Subject Categories

Telecommunications

Communication Systems

Computer Systems

DOI

10.1364/JOCN.10.000353