an efficient recovery a pproach for protection lsp supervisor professor : 林振緯 speaker : ...

An Efficient Recovery Approach for Protection LSP

 Supervisor Professor : 林振緯

Speaker : 蘇文宏

Computer Science and Information Engineering Department

Fu Jen Catholic University

•Abstract•Introduction-MPLS Recovery Mechanisms •Recovery Time Model•My New Efficient Recovery Approach•Conclusion and Future Work•Reference

Outline

Abstract

• A next generation backbone architecture.• “Fault Recovery” has become an important research in

MPLS.• IETF has made strict definitions for MPLS Recovery in

RFC 3469 in February,2003.• The paper propose An Efficient Recovery Approach t

o handle fault recovery,we finally compare other approachs and demonstrate our proposed approach by several experiments is better.

Introduction-MPLS Recovery Mechanisms

There are three options for the “Initiation of the recovery path setup[1]:”

1.Pre-Established.

2.Pre-Qualified.

3.Established-on-Demand.

Introduction-MPLS Recovery Mechanisms(cont.)

Recovery path type Recovery path setup point

pros cons

Pre-EstablishedBefore fault

斷線恢復時間短 •資源可用率差•備用路徑不見得是最佳路徑

Pre-QualifiedBefore fault

資源可用率比 Pre-Established 高

•斷線恢復時間比 Pre-Established 稍長•備用路徑不見得是最佳路徑

Established-on-Demand

After fault

•資源可用率最好•備用路徑也是斷線時的最佳路徑

斷線恢復時間長

Introduction-MPLS Recovery Mechanisms(cont.)

There are two main options for the “Topology of recovery”[1]:

1.Local Repair.

2.Global Repair.

Introduction-MPLS Recovery Mechanisms(cont.)

1.Local Repair(Link Recovery or Node Recovery).

0 1

2

4

3

6

7

9 10Break

0 1

2

4

3

6

7

9 10Break

Link Recovery

Node Recovery

Introduction-MPLS Recovery Mechanisms(cont.)

2.Global Repair.

0 1

2

4

3

6

7

9 10Break

POR/PSL

(Ingress)

PML

(Egress)

FISBreak

Introduction-MPLS Recovery Mechanisms(cont.)

Local-to-Egress Repair[2]

0 1

2

4

3

6

7

9 10Break Break

Introduction-MPLS Recovery Mechanisms(cont.)

There are two options for the “Recovery Model”[1]:

1.Rerouting.• Recovery by rerouting is defined as establishing new paths or path

segments on demand for restoring traffic after the occurrence of a

fault.

2.Protection Switching.• pre-establish a recovery path or path segment, the recovery path may

or may not be link and node disjoint with the working path, a fault is detected, the protected traffic is switched over to the recovery path(s) and restored.

Introduction-MPLS Recovery Mechanisms(cont.)

Recovery model

Recovery path type

Recovery path setup point

Recovery time

Resource utiltization

Reliability

Rerouting Pre-qualified

Establish-on-demand

After fault 3

4

1

1

3

3

Protect switching

Pre-e

Stabli 1 + 1

Shed

1:1,1:n,

m:n

Beforce fault

1

2

3

2

1

2

Introduction-MPLS Recovery Mechanisms(cont.)

Proposed approach presently:• Haskin Approach[3].• Makam Approach[4].• Das Approach[5].• Hundessa Approach[6].• RSVP Approach[7].• Yoon Approach[8].• Dynamic Approach[9].

Introduction-MPLS Recovery Mechanisms(cont.)

• Haskin Approach.

0 1

2

4

3

6

7

9 10Break

POR/PSL

(Ingress)

PML

(Egress)

Break

Introduction-MPLS Recovery Mechanisms(cont.)

• Makam Approach.

0 1

2

4

3

6

7

9 10Break

POR/PSL

(Ingress)

PML

(Egress)

FIS

Introduction-MPLS Recovery Mechanisms(cont.)

• Das Approach.

0 1

2

4

3

6

7

9 10Break

POR/PSL

(Ingress)

PML

(Egress)

FIS

FIS

FISFIS

FIS

6

Temporary backup path

Introduction-MPLS Recovery Mechanisms(cont.)

• Hundessa Approach(Improve Haskin Approach).

1 Break2

Tag

BufferPOR/PSL

(Ingress)

Tag

Working path

Backup path

Introduction-MPLS Recovery Mechanisms(cont.)

• RSVP Approach.

0 1

2

4

3

6

7

9 10Break

POR/PSL

(Ingress)

PML

(Egress)

Introduction-MPLS Recovery Mechanisms(cont.)

• Yoon Approach.

0 1

2

4

3

5

6

7

8

9

10

11

Break

POR/PSL

(Ingress)

PML

(Egress)

Introduction-MPLS Recovery Mechanisms(cont.)

• Dynamic Approach.

0 1

2

4

3

6

7

9 10Break

Introduction-MPLS Recovery Mechanisms(cont.)

Recovery Methods

Pros. Cons. Local repair

Global repair

Haskin •Packet loss 少•Switch backup fast

Reorder 較嚴重 * *

Makam •幾乎沒有 Reorder 問題 Packet loss 較多 *

Das •Packet loss 少 FIS 傳送路徑長，恢復時間長

*

Hundessa •Packet loss 少•不會有 reorder 情況

LSR 負擔較大，成本較高， buffer overflow 問題

*

RSVP •Packet loss 少•不會有 reorder 情況•Switch backup fast

Backup path 可能會發生頻寬不足的問題

*

Yoon 能取得較佳路徑 LSR 資料維護量較大，負擔重

*

Dynamic •高頻寬使用效率•低負載

服務中斷時間較長 *

Recovery Time Model

[9]

Recovery Time Model(cont.)

[9]

[9]

Recovery Time Model(cont.)

(4)

(5)

(6)

(1)

(2)

(3)

[9]

My New Efficient Recovery Approach

0 1

2

4

3

5

6

7

8

9

10

11

Break

POR/PSL

(Ingress)

PML

(Egress)

Conclusion and Future Work(cont.)

Future work(Schedule)

時程 進度

暑假 完成 NS2 模擬

研二 ( 上 ) 目標：發表一篇 Conference paper

研二 ( 下 ) 論文

Reference

1.V.Sharma, F.HellstrandAndersson, , “Framework for Multi-Protocol Label Switching (MPLS)-based Recovery”, RFC 3469, February 2003.

2. A. Autenrieth and A. Kirstadter, “Engineering End-to-End IP Resilience Using Resilience-Differentiated QoS,” IEEE Communication Magazine, Volume 40,Issue 1, January 2002, pp.50-57.

3. D. Haskin and R. Krishnan, “A Method for Setting an Alternative Label Switched Paths to Handle Fast Reroute,” Internet-Draft(draft-haskin-mpls-fast-reroute-05.txt), November 2000.

4.S.Makam, V.Sharma, K.Owens, and C.Huang, “Protection/Restoration of MPLS Networks,” Internet-Draft (draft-makam-mpls-protection-00.txt), October 1999.

5.S.K. Das and P. Venkataram, “A method of Designing a path restoration scheme for MPLS based network”, High Speed Networks and Multimedia Communications 5th IEEE International Conference on, 2002, pp.218-222.

Reference(cont.)

6.L. Hundessa and J. D. Pascual, “Fast Rerouting Mechanism for Protected Label Switched Path”, IEEE Computer Communications and Networks, 2001.Proceedings. Tenth International Conference on 2001, pp.527-530.

7.Ping Pan, Der-Hwa Gan, George Swallow, Jean Philippe Vasseur, Dave Cooper,Alia Atlas and Markus Jork, “Fast Reroute Extensions to RSVP-TE for LSP “,Internet draft <draft- ietf-mpls-rsvp- lsp- fastreroute-02.txt>, work in progress.

8.Sangsik Yoon, Hyunseok Lee, Deokjai Choi, Youngcheol Kim, Gueesang Lee and Lee M., “An efficient recovery mechanism for MPLS-based protection LSP”,IEEE International Conference on, 2001, pp. 75-79.

9.G. Ahn, and W. Chun, “Simulator for MPLS Path Restoration and Performance Evaluation”, IEEE, 2001.

Reference(cont.)

10.Achim Autenrieth,”Recovery Time Analysis of Differentiated Resilience in MPLS”,Design of Reliable Communication Networks(DRCN)2003,Banff,Alberta,Canada,October 19-22,2003