Cut Saturation for p-cycle Design

Khalid Al-SnaieElectronics Dept., College of Technology

Riyadh, Saudi Arabia

Dale R. Thompson*Department of Computer Science & Computer Engineering (CSCE)

University of Arkansas

Ring vs. Mesh

Two Enemies of Fiber

Four-fiber Bidirectional Line-Switched Ring (BLSR), no failure

Four-fiber BLSR, span switching

Four-fiber BLSR, ring switching

Wavelength-Division Multiplexing

Red

Green

Blue

Wavelength Path #1

S1

S2

S3

D1

D3

D2

1

2

1

Wavelength Path #2

S1

S2

S3

D1

D3

D2

1

2

2

Virtual Wavelength Path (VWP)

S1

S2

S3

D1

D3

D2

1

2

2

One preconfigured protection cycle (p-cycle), no failures

One p-cycle, on-cycle span failure

One p-cycle, straddling span failure

SCP vs JCP in p-cycles

• Spare capacity placement (SCP)– Route demand using shortest paths– Apply capacity algorithm to find set of p-cycles

that minimize spare capacity cost

• Joint capacity placement (JCP)– Apply capacity algorithm to find working

routes and set of p-cycles that minimize spare capacity cost.

Cut Saturation

0 .4

0 .40 .9

0 .30 .8

0 .3

0 .2

0 .6

0 .7

0 .8

0 .5

0 .30 .5

0 .6

C o m po ne nt N 2C o m po ne nt N 1

L i nk de l e te d

Satur ate d c ut

L i nk adde d

p-cycle Cut Saturation (PCUT)

Load topology and traffic demand.do {

Route traffic with JCP or with shortest path algorithm if using SCP.

Sort spans by load in descending order.Remove spans one at a time until the network

separates into two disconnected components N1 and N2. Add a new span between one of the lowest degree nodes in N1

and one of the lowest degree nodes in N2.Replace deleted spans.Find p-cycles with SCP or JCP.Calculate spare-to-working capacity ratio.

} while (spare-to-working capacity ratio is greater than a threshold)

NSF Network

5

4

1

0

62

3

1 4

9

8

7

1 1

1 2

1 3

1 0

1 9

1 7

1 8

2 1

2 3

2 2

1 5

2 0

1 6 2 5

2 4

2 7

2 6

S1 9S2 S9

S1 3

S7 S1 1

S6 S1 2

S3

S2 1S3 0

S1 5 S2 2

S2 6

S2 4

S27

S3 9

S4 2

S45

1 7

26

3 8

4 1

2 9

5 8

6 0

4 2 5 3

54

6 2

4 5

4

2 2

1 7

8 6

4

1

4 5

Add span #1 (N0 to N9)

5

4

1

0

62

3

1 4

9

8

7

1 1

1 2

1 3

1 0

1 9

1 7

1 8

2 1

2 3

2 2

1 5

2 0

1 6 2 5

2 4

2 7

2 6

S2 0

1 6S 1

S2 S1 0S1 4

S8 S1 2

S7 S1 3

S4

S2 2 S3 1S 5

S 6

S 1 5

S1 6 S2 3

S 1 8

S2 7

S2 5

S 2 4

S 1 7

S9

S 11

S 19

S 21

S 2 6

S28

S 2 9

S30

S 3 2

S 3 3

S 3 4

S 3 5

S36

S 37

S 3 8

S 3 9

S4 0

S 4 1

S 4 2

S4 3

S 4 4

S 4 5

S46

1 7

1 3

12

1 8

3 8

2 7

15

2 42 9

5 8

4 6

5 5

4 2 5 3

54

6 2

4 5

3 8

2 3

4

1 2

2 2

2 5

2 4

4 3

1 7

9

1 3

30

2 7

2 1

26

8 6

2 3

2 3

1 7

2 2

4

2

2 2

1

2 6

4 5

2 7

S3

14

Add span #2 (N7 to N14)

5

4

1

0

62

3

1 4

9

8

7

1 1

1 2

1 3

1 0

1 9

1 7

1 8

2 1

2 3

2 2

1 5

2 0

1 6 2 5

2 4

2 7

2 6

S2 1

1 6S 1

S2 S1 0S1 4

S8 S1 2

S7 S1 3

S4

S2 3 S3 2S 5

S 6

S 1 6

S1 7 S2 4

S 1 9

S2 8

S2 6

S 2 5

S 1 8

S9

S 11

S 20

S 22

S 2 7

S29

S 3 0

S31

S 3 3

S 3 4

S 3 5

S 3 6

S37

S 38

S 3 9

S 4 0

S4 1

S 4 2

S 4 3

S4 4

S 4 5

S 4 6

S47

1 7

1 3

12

1 8

3 8

2 7

14

2 3

3 0

5 8

4 5

5 0

4 0 5 2

53

6 3

4 1

3 3

2 1

5

1 1

2 2

2 5

2 1

3 9

1 7

9

1 3

30

2 7

2 1

26

8 6

2 3

2 3

1 7

2 2

4

2

2 21

2 6

4 5

2 7

S3

14

S 1 55

Add span #3 (N15 to N24)

5

4

1

0

62

3

1 4

9

8

7

1 1

1 2

1 3

1 0

1 9

1 7

1 8

2 1

2 3

2 2

1 5

2 0

1 6 2 5

2 4

2 7

2 6

S2 1

1 8S 1

S2 S1 0S1 4

S8 S1 2

S7 S1 3

S4

S2 3 S3 3S 5

S 6

S 1 6

S1 7 S2 4

S 1 9

S2 8

S2 6

S 2 5

S 1 8

S9

S 11

S 20

S 22

S 2 7

S29

S 3 1

S32

S 3 4

S 3 5

S 3 6

S 3 7

S38

S 39

S 4 0

S 4 1

S4 2

S 4 3

S 4 4

S4 5

S 4 6

S 4 7

S48

1 9

1 1

12

1 8

3 6

2 7

14

2 33 2

5 6

4 5

5 0

4 2 6 2

43

6 3

4 1

3 3

2 1

5

1 1

2 2

2 5

2 9

3 9

1 7

9

1 3

30

2 7

2 1

26

6 6

2 3

2 3

1 7

2 2

4

2

1 6

7

1 2

3 9

2 7

S3

14

S 1 55

S3 02 0

Add span #4 (N10 to N23)

5

4

1

0

62

3

1 4

9

8

7

1 1

1 2

1 3

1 0

1 9

1 7

1 8

2 1

2 3

2 2

1 5

2 0

1 6 2 5

2 4

2 7

2 6

S2 1

1 9S 1

S2 S1 0S1 4

S8 S1 2

S7 S1 3

S4

S2 4 S3 4S 5

S 6

S 1 6

S1 7 S2 5

S 1 9

S2 9

S2 7

S 2 6

S 1 8

S9

S 11

S 20

S 23

S 2 8

S30

S 3 2

S33

S 3 5

S 3 6

S 3 7

S 3 8

S39

S 40

S 4 1

S 4 2

S4 3

S 4 4

S 4 5

S4 6

S 4 7

S 4 8

S49

2 1

1 1

11

1 8

3 6

2 6

14

2 33 4

5 6

4 4

5 0

4 4 5 9

40

5 2

4 2

3 4

2 1

5

1 2

2 2

2 3

2 9

4 0

1 7

9

1 3

29

2 7

1 9

25

6 3

2 3

2 1

1 6

1 9

4

2

1 6

7

1 2

3 9

2 4

S3

13

S1 55

S3 12 0

S2 25

Final Answer (N0 to N9, N7 to N14, N15 to N24, N10 to N23)

5

4

1

0

62

3

1 4

9

8

7

1 1

1 2

1 3

1 0

1 9

1 7

1 8

2 1

2 3

2 2

1 5

2 0

1 6 2 5

2 4

2 7

2 6

S2 1

1 9S 1

S2 S1 0S1 4

S8 S1 2

S7 S1 3

S4

S2 4 S3 4S 5

S 6

S 1 6

S1 7 S2 5

S 1 9

S2 9

S2 7

S 2 6

S 1 8

S9

S 11

S 20

S 23

S 2 8

S30

S 3 2

S33

S 3 5

S 3 6

S 3 7

S 3 8

S39

S 40

S 4 1

S 4 2

S4 3

S 4 4

S 4 5

S4 6

S 4 7

S 4 8

S49

2 1

1 1

11

1 8

3 6

2 6

14

2 3

3 4

5 6

4 4

5 0

4 4 5 9

40

5 2

4 2

3 4

2 1

5

1 2

2 2

2 3

2 9

4 0

1 7

9

1 3

29

2 7

1 9

25

6 3

2 3

2 1

1 6

1 9

4

2

1 6

7

1 2

3 9

2 4

S3

13

S1 55

S3 12 0

S2 25

Spare-to-working capacityLocation of new spans

Avg Node Degree

S/W

SCP (%)

S/W

JCP (%)

S/W

Bound (%)Original network

3.21 82 60 45

N0 to N9 3.28 76 52 44

N0 to N9, N7 to N14 3.36 72 51 42

N0 to N9, N7 to N14, N15 to N24 3.43 69 50 41

N0 to N9, N7 to N14, N15 to N24, N10 to N23

3.50 66 48 40

Contact Information

Dale R. Thompson, P.E., Ph.D.Department of Computer Science and Computer

EngineeringUniversity of Arkansas311 Engineering HallFayetteville, Arkansas 72701Phone: +1 (479) 575-5090FAX: +1 (479) 575-5339E-mail: d.r.thompson@ieee.orgWWW: http://csce.uark.edu/~drt/