多重協定標籤交換網路(MPLS)是IETF 所計畫的一種標籤交換傳遞技術，非常適合作為下一代網際網路骨幹。MPLS 的優點為改善網路層路由性能且增加網路可靠性 。為使MPLS網路達到可靠的傳遞服務，每個標籤交換路由器（LSRs）在發生斷線後的快速恢復機制是必需的。同時也被要求支援斷線偵測，斷線通知，和保護機制，使完成 LSP支援工作的配置和路徑保護。因此，在先前的文獻中對工作路徑發生斷線時已有不同的恢復機制提議以提昇MPLS 網路可靠度。
在這篇論述中，我們的重心集中在三個比較出名的恢復機制，分別是Makam、Haskin、Hundessa方法，我們主要關心的藉由探討發生斷線點位置的差異對各種TCP性能方面的影響，尤其在不同的 TCP 版本之下。併使用MPLS 網路模擬器(MNS)模擬探討結果，在模擬器中我們應用TCP Tahoe, TCP Reno, TCP New-Reno and TCP Sack等四種 TCP 版本。
從模擬所得結果，清楚地觀察到各種 TCP 版本的壅塞控制的特性。沒有使用快速重傳和快速恢復的TCP Tahoe，平均傳輸量是少於其它TCP 版本。除此之外，在斷線瞬間有多個封包以上被遺失時，將會降低平均傳輸量的性能，使TCP New-Reno與 Reno性能無所差別。從 Makam 方式中我們發現，當斷線的位置比較靠近入口端節點的時候，平均傳輸量性能是比較佳。

Multi-Protocol Label Switching (MPLS), a label swapping and forwarding technology proposed by IETF, is very suitable for the backbone of the next-generation Internet. MPLS has the advantages in improving the performance of network-layer routing and increasing network scalability as well. To provide more reliable delivery in MPLS networks, it is necessary for every label switch router (LSR) to perform a fast recovery mechanism after link failures. It is also required for an LSR to support the functions of failure detection, failure notification, and protection mechanisms in each label switched path (LSP). Therefore, different kinds of recovery schemes in previous literatures have been proposed to enhance the reliability of MPLS networks when a link failure occurs in the primary LSP.
In this thesis, we focus on the comparisons of three famous recovery mechanisms, Makam, Haskin, and Hundessa approach. By investigating different locations of link failure, the influences of the three approaches individually on the TCP performance are our major concerns, especially under different TCP versions. Finally, we use the MPLS Network Simulator (MNS) to verify our observations. Four different TCP versions, including TCP-Tahoe, TCP-Reno, TCP-NewReno, and TCP-SACK, are employed in our simulator.
From the simulation results, the characteristics of congestion control when using different TCP versions are discussed. Without applying fast retransmission and fast recovery, the average throughput of TCP-Tahoe is the smallest, as compared to that of other TCP versions. In addition, multiple packet losses in the period of link failures would largely downgrade the performance of average throughput, no matter which TCP version (TCP-NewReno or TCP-Reno) is employed. Using Makam approach, we found out that the average throughput becomes better when the location of link failures is close to the ingress node.

目錄
第一章 導 論
1-1 研究動機 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 1
1-2 研究方向與方法 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 2
1-3 論文架構 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 4
第二章 MPLS網路重繞機制與TCP版本的介紹 ‥‥‥‥‥‥‥ 5
2-1 MPLS 網路相關名詞簡介 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 5
2-2 MPLS 網路斷線重繞機制介紹 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 6
2-2-1 Makam Approach ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 7
2-2-2 Haskin Approach ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 8
2-2-3 Hundessa Approach ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 9
2-3 TCP版本的相關介紹 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 11
2-3-1 Tahoe TCP ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 11
2-3-2 Reno TCP ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 12
2-3-3 New-Reno TCP ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 13
2-3-4 SACK TCP ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 14
第三章 模擬網路的構思與探討 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 16
3-1 模擬網路架構的設計 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 16
3-1-1 模擬網路拓樸的設計 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 16
3-1-2 模擬機制與流量量測的設計 ‥‥‥‥‥‥‥‥‥‥‥‥‥ 17
3-2 斷線點差異性的設計 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 18
3-3 網路負載影響的設計 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 19

第四章 模擬結果與分析 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 20
4-1 Makam Approach 對TCP性能的影響 ‥‥‥‥‥‥‥‥‥‥‥‥ 20
4-2 Haskin Approach 對TCP性能的影響 ‥‥‥‥‥‥‥‥‥‥‥‥‥ 26
4-3 Hundessa Approach 對TCP性能的影響‥‥‥‥‥‥‥‥‥‥‥‥ 32
第五章 結論與未來展望 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 37
5-1 結論 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 37
5-2 未來展望 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 38
參考文獻 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 39
索引 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 42

圖表目錄

圖2-1 MPLS網路 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 5
圖2-2 Makam Approach 示意圖 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 7
圖2-3 Haskin Approach 示意圖 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 8
圖2-4 送出Tag記號封包，將後續封包儲存在Buffer內 ‥‥‥‥‥‥‥ 9
圖2-5 解除Tag記號，將儲存在Buffer內封包送出 ‥‥‥‥‥‥‥‥‥ 10
圖3-1 網路模擬拓樸 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 16
圖4-1 Makam Model 封包接收數量統計比較 ‥‥‥‥‥‥‥‥‥‥‥‥ 20
圖4-2 Makam Model 的封包遺失比較 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 22
圖4-3-a Makam Model 前端斷線之封包傳輸量示意 ‥‥‥‥‥‥‥‥‥‥ 22
圖4-3-b Makam Model 末端斷線之封包傳輸量示意 ‥‥‥‥‥‥‥‥‥‥ 23
圖4-4-a Makam Model 斷線之封包平均傳輸量與正常平均傳輸量比較 ‥‥ 24
圖4-4-b Makam Model 封包傳輸量利用率 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 25
圖4-5 Haskin Model 封包接收數量統計比較 ‥‥‥‥‥‥‥‥‥‥‥‥‥ 26
圖4-6 Haskin Model 的封包遺失比較 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 27
圖4-7- a Haskin Model 前端斷線之封包傳輸量示意 ‥‥‥‥‥‥‥‥‥‥ 28
圖4-7- b Haskin Model 末端斷線之封包傳輸量示意 ‥‥‥‥‥‥‥‥‥‥ 29
圖4-8-a Haskin Model 斷線之封包平均傳輸量與正常平均傳輸量比較 ‥‥ 30
圖4-8 -b Haskin Model 封包傳輸量利用率 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 30
圖4-9 Makam Model 封包接收數量統計比較 ‥‥‥‥‥‥‥‥‥‥‥‥ 32
圖4-10 Makam Model 的封包遺失比較 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 33
圖4-11-a Makam Model 前端斷線之封包傳輸量示意 ‥‥‥‥‥‥‥‥‥‥ 34
圖4-11- b Makam Model 末端斷線之封包傳輸量示意 ‥‥‥‥‥‥‥‥‥ 34
圖4-12- a Makam Model 斷線之封包平均傳輸量與正常平均傳輸量比較 ‥‥35
圖4-12- b Makam Model 封包傳輸量利用率 ‥‥‥‥‥‥‥‥‥‥‥‥‥ 36


表2-1 各種斷線恢復機制的優缺點 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 10
表2-2 TCP實作版本比較 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 15
表3-1 模擬使用的機制與量測流量設定 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 18
表3-2 發生斷線時間及位斷線點置設定 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 18
表3-3 背景訊務設定 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 19

參考文獻(References)
[1] Rosen, E., Viswanathan, A., and Callon, R., "Multiprotocol Label Switching Architecture", Work in Progress, Internet Draft <draft-ietf-mpls-arch-06.txt>, August 1999.
[2] V.Ed. Sharma, and F.Ed Hellstrand, "Framework for Multi-Protocol Label Switching (MPLS)-based Recovery", RFC3469, November 2000.
[3] R. Gallon, P. Doolan, N. Feidman, A. Frcdcttc, G. Swallow, and A. Viswanathan, "A framework for multiprotocol label switching," Internet draft<draft-ietf-mpls-framework-05.txt>,, September 1999.
[4] E. Rosen, A. Viswanathan, and R. Callon, " Multiprotocol label switching architecture," RFC 3031.. January 2001.
[5] D. Awduche, J. Malcolm, J. Agogbua, M. O'Dcll, and J. McManus, "Requirements for traffic engineering over mpls," RFC 2702,, September 1999.
[6] A. Juttner, B. Szviatovszki, A.Szentesi, D. Orincasy and J. Harmatos, ”On-demand optimijation of label switched paths in MPLS networks”, Computer Communications and Networks, 2000, pp.107-113.
[7] J. L. Marzo, E. Calle, C. Scoglio, T. Anjah, ”QoS online routing and MPLS multilevel protection: a surve”, Communications Magazine, IEEE , Volume: 41 , Issue: 10, Oct. 2003, pp: 126–132.
[8] S.Makam, V. Sharma, K. Owens, and C.Huang, “Protection/Restoration of MPLS Networks”, Internet draft < draft-chang-mpls-path-protection-03-txt>, October 1999.
[9] Ken Owens, et al, “A Path Protection/Restoration Mechanism for MPLS Networks”, IETF < draft-chang-mpls-path-protection-03-txt >, July 2001.
[10] D.Haskin and R.Krishnan, “A Method for Setting an Alternative Label Switched to Handle Fast Reroute”, Internet draft < draft-haskin-mpls-fast-reroute-05-txt>, November 2000.
[11] Gaeil Ahn and Woojik Chun, “Design and implementations of MPLS network simulator (mns) supporting QoS”, 2001. Proceedings. 15th International Conference on Information Networking, 2001, pp.694-699.
[12] Gaeil Ahn and Woojik Chun, “Simulator for MPLS path restoration and performance evalution”, 2001. Joint 4th IEEE International Conference on ATM (ICATM 2001) and High Speed Intelligent Internet Symposium, 2001, pp.32-36.
[13] L.Hundessa and J.D. Pascual, “ Fast Rerouting Mechanism for a Protected Label Switched Path”, , 2001. Proceedings. Tenth International Conference on IEEE Computer Communication and Networks, 2001 , pp.527-530.
[14] E. Rosen, D. Tappan, G. Fedorkow, Y. Rekhter, D. Farinacci, T. Li, and A. Conta, "Mpls label stack encoding," RFC3032,, January 2001.
[15] Stevens, W., "TCP Slow Start, Congestion Avoidance, Fast Retransmit, and Fast Recovery Algorithms", RFC 2001, Jan 1997
[16] Stevens, W., Allman, M. and V. Paxson, "TCP Congestion Control", RFC 2581, April 1999.
[17] M. Mathis, J. Mahdavi, S. Floyd, and A. Romanow, "TCP Selective Acknowledgment Options", RFC 2018, Oct, 1996
[18] V. Jacobson. “Congestion Avoidance and Control, ” SIGCOMM Symposium on Communications Architectures and Protocols, 1988 , pp.314–329.
[19] W. Richard Stevens. TCP/IP Illustrated, Volume 1: The Protocols. Addison Wesley,1994.
[20] V. Jacobson. “Modified TCP Congestion Avoidance Algorithm,”. Technical report, 30 Apr. 1990.
[21] Kevin Fall and Sally Floyd. "Simulation-based Comparisons of Tahoe, Reno, and Sack TCP", Computer Communication Review, Jul 1996
[22] B. Sikdar, S. Kalyanaraman, K.S. Vastola, “Analytic models for the latency and steady-state throughput of TCP Tahoe, Reno, and SACK”, IEEE/ACM Transactions on Networking, Vol.11 , Issue: 6 , Dec. 2003, pp.959–971.
[23] S. Floyd, ACIRI and T. Henderson “The NewReno Modification to TCP's Fast Recovery Algorithm”, RFC 2582, April 1999 .
[24] D. Borman, R. Braden, and V. Jacobson. “TCP Extensions for High Performance” , RFC 1323, May 1992.
[25] R. Braden. “T/TCP – TCP Extensions for Transactions Functional Specifi-cation”, RFC 1644, July 1994.
[26] A. Agarwal, R. Deshmukh,“Ingress failure recovery mechanisms in MPLS network”, MILCOM 2002. Proceedings , Vol. 2 , 2002 , pp. 1150 –1153.