Experimental evaluation of a coarse-grained switch scheduler

ABSTRACT

Modern high performance routers rely on sophisticated interconnection networks to meet ever increasing demands on capacity. Previous studies have used a combination of analysis and idealized simulations to show that coarse-grained scheduling of traffic flows can be effective in preventing interconnect congestion while ensuring high utilization. In this work, we study the performance of a coarse-grained scheduler in a real router with a scalable architecture similar to those found in high performance commercial systems. Our results are obtained by taking fine-grained measurements within the router that provide a detailed picture of the scheduler's behavior under a variety of conditions, giving a more complete and realistic understanding of the short time-scale dynamics than previous studies could provide.

REFERENCES

• 1: Thomas E. Anderson , Susan S. Owicki , James B. Saxe , Charles P. Thacker, High-speed switch scheduling for local-area networks, ACM Transactions on Computer Systems (TOCS), v.11 n.4, p.319-352, Nov. 1993 [doi>10.1145/161541.161736]
• 2: Cisco Carrier Routing System. http://www.cisco.com/en/US/products/ps5763/index.html.
• 3: Krishna, P., N. Patel, A. Charny and R. Simcoe. "On the Speedup Required for Work-conserving Crossbar Switches," IEEE J. Selected Areas of Communications, 6/99.
• 4: Open Network Laboratory. http://www.onl.wustl.edu.
• 5: Pappu, P., J. Turner and K. Wong. "Work-Conserving Distributed Schedulers for Terabit Routers," Proceedings of SIGCOMM, 9/04.
• 6: Wiseman, C., J. Turner, K. Wong and B. Heller. "Experimental Evaluation of a Coarse-Grained Switch Scheduler", Washington University Computer Science and Engineering Technical Report, WUCSE-2007-51, 10/07.

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.1 Network Architecture and Design
          Subjects: Network communications

Additional Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.1 Network Architecture and Design
          Subjects: Packet-switching networks

General Terms:
Algorithms, Measurement, Performance

Keywords:
coarse-grained scheduling, distributed scheduling, high performance routers