公平佇列通常需要維持狀態(state)，管理緩衝(buffer)，執行每條資料流排班。但藉由降低這些複雜，核心無狀態機制變的較可擴充。然而它們在核心路由器時需要重新標記每個封包。在這篇論文，我們提出了一個核心無狀態公平頻分配系統，這系統不需要在核心路由器維持每個資料流的狀態。而且，它不需要像現存核心無狀態機制需重新標記封包。只有在網路的入口才根據此封包所屬資料流的特性標記它。用我們提出的系統，不論TCP或是UDP資料流可以得到它們的公平共享速率。還有這個系統在核心路由器估計動態資料流的數目。這估計可被用來計算公平共享頻寬且不用維每條資料流的狀態。若資料流的速率超過測估計的公平共享速率，它所屬的封包就會被丟棄。這個創新的系統稱做核心無狀態標記公平(CSLF)。我們將會提出及討論在不同情形下時所做模擬的效能。

Core-stateless mechanisms achieve better scalability by reducing the complexity of fair queuing, which usually needs to maintain states, manage buffers, and perform flow scheduling on a per-flow basis. However, they require per-packet re-labeling in the core routers. In this paper, we propose a core-stateless fair bandwidth allocation scheme without maintaining per flow state in core routers. Furthermore, it does not need re-labeling, which is commonly used in existing core-stateless schemes. Packets are labeled only once in the entrance of the network according to the characteristics of the flow to which the packets belong. No matter TCP or UDP flows can get their fair share rate by the proposed scheme. Moreover, the scheme employs an estimation of number of active flows in the core routers. The estimation can be used to provide fair share rate without maintaining per flow states. The packets belonging to the flows whose rates exceed the estimated fair share rate are dropped. The novel scheme is called core-stateless labeling fairness (CSLF). We present and discuss simulations on the performance under different traffic scenarios.

[1] Clerget and W. Dabbous, “TUF:Tag-based Unified Fairness” in IEEE INFOCOM 2001

[2] Z. Cao, Z. Wang and E. Zegura, “Rainbow Fair Queuing: Fair Bandwidth Sharing Without Per-Flow State,” In Proceedings of IEEE INFOCOM ’2000

[3] Sally Floyd and Kevin Fall, “Promoting the use of end-to-end congestion control in the internet,” IEEE/ACM Transactions on Networking, vol. 7, no. 4, pp. 458–472, Aug. 1999.

[4] W. Feng, D. Kandlur, D. Daha, K. Shin, “Stochastic Fair Blue: A Queue Management Algorithm for Enforcing Fairness”, in Proc. Of Infocom 2001, April 2001

[5] M. Nabeshima, T. Shimizu and I. Yamasaki, “Fair queuing with in/out bit in core stateless networks,” in Proceedings of the Eight IEEE/IFIP International Workshop on Quality of Service, 2000

[6] D. Lin and R. Morris, “Dynamic of Random Early Detection,” In Proceedings of ACM SIGCOMM ’97, pp 127-137, October 1997

[7] D. Lin and R. Morris, “Dynamics of Random Early Detection,” in Proceedings of ACM SIGCOMM’97, pp127-137, October 1997.

[8] Mankin A., Ramakrishnan K., Gateway Congestion Control Survey, RFC-1254, August 1991.

[9] M. Nabeshima, T. Shimizu and I. Yamasaki, “Fair queuing with in/out bit in core stateless networks,” IEEE ‘2000

[10] T. Ott, T. Lakshman, and L. Wong, “SRED: Stabilized RED,” In Proceedings of INFOCOM ’1999, pp 1346-1355, March 1999

[11] Jitendra Padhye, Victor Firoiu, Don Towsley, and Jim Kurose, “Modeling
tcp throughput: A simple model and its empirical validation,” in Proceedings of ACM SIGCOMM’ 98, 1998.

[12] M. Shreedhar and G. Varghese, “Efficient Fair Queuing using Deficit Round Robin,” in Proceedings of ACM SIGCOMM’95, pages 231-242, 1995.

[13] I. Stoica, S. Shenker, H. Zhang, "Core-Stateless Fair Queuing: A Scalable Architecture to Approximate Fair Bandwidth Allocations in High Speed Networks," in Proceedings of ACM SIGCOMM'98, August 1998.

[14] J. Widmer, R. Denda, and M. Mauve. A Survey on TCP-Friendly Congestion Control. IEEE Network, May 2001

[15] http://www.isi.edu/nsnam/ns/

[16] http://www-2.cs.cmu.edu/~istoica/csfq/

[17] Z. Cao, Z. Wang and E. Zegura, “Rainbow Fair Queuing: Fair Bandwidth Sharing Without Per-Flow State,” In Proceedings of IEEE INFOCOM ’2000

[18] Ion Stoica, Hui Zhang, Scott Shenker, “Self-verifying CSFQ” In Proceedings of IEEE INFOCOM ’2002

[19] Masayoshi Nabeshima, “adaptive CSFQ: a new fair queuing mechanism for SCORE networks” in IEEE HPSR 2002 , May 2002