Performance Analysis of Flow-Based Label Switching: The Single IP Flow Model

Ling-Chih KAO  Zsehong TSAI  

IEICE TRANSACTIONS on Communications   Vol.E83-B   No.7   pp.1417-1425
Publication Date: 2000/07/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Fiber-Optic Transmission
flow,  label switch,  performance analysis,  

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A closed-loop queueing model of flow-based label switches, supporting label reservation protocols of different label-setup and release policies, is presented. This model can emulate the behavior of TCP under the label switch when the maximum window size has been achieved and the packet loss rate is negligible. The label-setup policy is that the IP controller does not start to set up a label until the accumulated packets of the same flow in the switch buffer have exceeded a triggering threshold. Meanwhile, the reserved bandwidth is released when the flow is detected idle and the label-release timer has expired. This policy can achieve higher channel utilization with minimal label processing overhead in spite of suffering from certain delay penalty. To avoid unnecessary TCP timeout or large packet delay under such policy, we also introduce a label-setup timer. Norton's theorem is applied to obtain approximate solutions of this queueing model. Although the analytical method is an approximate one, the simulation results show that the accuracy is high and this model can clearly illustrate how the label-setup and the lable-release timer affect the system performance. Besides, one can observe the trade-off between the throughput and the channel utilization.