Optimizing flow control for buffered switches

Dong

2011

IEEE Trans. Commun.

Abstract-Combined input-crosspoint buffered (CICB) switches can achieve high switching performance without speedup. However, the dedicated crosspoint buffers in a CICB switch may not be efficiently used, and throughput degradation may occur. This throughput degradation is especially observable under flows with high data rates and long distances between the line cards and the buffered crossbar. This paper introduces two load-balanced CICB switches: the load-balancing CICB switch with full access (

Section: Related Workmentioning

confidence: 99%

Load-Balanced Combined Input-Crosspoint Buffered Packet Switches

Dong

2011

IEEE Trans. Commun.

“…Another approach focused on increasing the efficiency of the flow control mechanism, to decrease the dependency in memory [15]. Furthermore, the implementation of input arbiters placed at the buffered crossbar was then proposed [19].…”

mentioning

confidence: 99%

Throughput analysis of shared-memory crosspoint buffered packet switches

Dong

2012

IET Commun.

This paper presents a theoretical throughput analysis of two buffered-crossbar switches, called shared-memory crosspoint buffered (SMCB) switches, in which crosspoint buffers are shared by two or more inputs. In one of the switches, the sharedcrosspoint buffers are dynamically partitioned and assigned to the sharing inputs, and memory is sped up. In the other switch, inputs are arbitrated to determine which of them accesses the shared-crosspoint buffers, and memory speedup is avoided. SMCB switches have been shown to achieve a throughput comparable to that of a combined input-crosspoint buffered (CICB) switch with dedicated crosspoint buffers to each input but, with less memory than a CICB switch. The two analyzed SMCB switches use random selection as the arbitration scheme. We model the states of the shared crosspoint buffers of the two switches using a Markov-modulated process and prove that the throughput of the proposed switches approaches 100% under independent and identically distributed uniform traffic. In addition, we provide numerical evaluations of the derived formulas to show how the throughput approaches asymptotically to 100%.

“…As the buffered crossbar switch can be physically located far from the input ports, actual round trip times (R 0 ) can be non-negligible. Nonnegligible round trip delays have been considered in [4], [5], for practical implementations.…”

Section: Introductionmentioning

confidence: 99%

Analysis of a flow control system for a combined input-crosspoint buffered packet switch

Guo

HPSR. 2005 Workshop on High Performance Switching and Routing, 2005.

-A flow control mechanism is used in combined input-crosspoint buffered (CICB) switches to avoid buffer overflow and underflow. Credit-based flow control is widely used in CICB switches to reduce the required crosspoint-buffer size. For simplification, we analyze an flow control mechanism with active queue management (AQM) and a proportional controller. We show that the flow control mechanism is stable for small crosspoint buffer sizes and non-negligible round-trip times. In addition, we observe the effect of an input shaper combined with a proportional controller. We show that the input shaper reduces the response time of the flow control mechanism.