1 / 17

# IP Restoration on WDM Optical Networks - PowerPoint PPT Presentation

IP Restoration on WDM Optical Networks. Hwajung Lee*, Hongsik Choi, Hyeong-Ah Choi The George Washington University Department of Computer Science. Contents. Terminology Problem Formulation Main Results Lemma 1 Lemma 2 Theorem Conclusion Further Work. IP WDM. Terminology.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## PowerPoint Slideshow about ' IP Restoration on WDM Optical Networks' - cynthia-warren

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### IP Restoration on WDM Optical Networks

Hwajung Lee*, Hongsik Choi, Hyeong-Ah Choi

The George Washington University

Department of Computer Science

• Terminology

• Problem Formulation

• Main Results

• Lemma 1

• Lemma 2

• Theorem

• Conclusion

• Further Work

WDM

Terminology

• WDM : Wavelength Division Multiplexing

• IP over WDM Optical Network

: Network structure with IP protocol as an upper

layer and WDM Optical Network as a lower layer.

• Lightpath : Transfer Path from Source to Sink in Optical Networks

• Given: IP Topology G, and WDM Topology G0

• Objective: To find mappings f and h, where f maps each vertex of V(G) into a vertex in G0 and h maps each link of E(G) into a lightpath in G0, which that, for any source-sink pair s and t, if G has two link-disjoint paths from s to t, there exist two sequences of link-disjoint paths from s to t in G0.

For any nodes u, vV(G),f(u)f(v) in any mapping f.

a

a

a

a

a

b

b

b

b

b

b

e

e

c

c

c

c

d

d

d

d

f

f

a

a

d

d

f

f

e

e

a

a

b

b

c

c

b

b

Example of the Problem

• Fault Propagation on IP over WDM

IP Layer

WDM Layer

a

a

b

b

b

e

c

c

a

d

d

b

f

a

d

f

e

a

b

c

b

Example of a Solution

IP Layer

a

b

WDM Layer

f

e

d

b

c

Vs.

• Lemma 1: Any vertex mappings are acceptable in case of 3-edge-connected.

• Lemma 2: Given G is 2-edge-connected, G is tolerant to single link faults of G0 iff edge cuts of size two of G are mapped with a vertex mapping f and an edge-to-path mapping h, under the condition of Lemma 2.

• Theorem: Given G is 2-edge-connected and G0 is a ring, G is tolerant to single link faults of G0.

• If G is 3-edge-connected, for any vertex mapping f:V(G)  V(G0), an edge-to-path mapping h: E(G)  P(G0) ensuring that G is tolerant to single link faults of G0.

 a mapping h of

MaxeE(G0){# of wavelengths on an edge}  2

There must be at least one live path in the case of single link faults causing at most 2 edge disable.

IP Layer

Y

X

a

a

d

Mw=2

Mw=3

WDM Layer

Mw=Maxe E(G0){# of wavelengths on an edge}

• Suppose G is 2-edge-connected.

Let f: V(G)  V(G0), and h: E(G) P(G0) be mappings such that G is tolerant to single link faults, iff, for any edge cuts of size two

{ei=(a, b), ej=(c,d)} in G if there exists any, ordering of vertices in G0 is not f(a)-f(c)-f(b)-f(d) in the clockwise or counterclockwise direction.

a

a

a

a

a

b

b

b

b

b

b

e

e

c

c

c

c

d

d

d

d

f

f

a

d

f

e

a

b

c

b

Example of Lemma 2

IP Layer

a

a

b

WDM Layer

f

e

d

b

c

• Given G is 2-edge-connected and G0 is a ring,G is tolerant to single link faults of G0.

 It is obtained based on the Lemma 1

and Lemma 2.

a

c

e

g

j

Mapping Example

IP Layer

i

a

k

c

e

l

d

g

j

b

h

f

WDM Layer

i

l

a

k

j

b

d

c

e

h

f

g

• Lemma 1: Any vertex mappings are acceptable in case of 3-edge-connected.

• Lemma 2: Given G is 2-edge-connected, G is tolerant to single link faults of G0 iff edge cuts of size two of G are mapped with a vertex mapping f and an edge-to-path mapping h, under the condition of Lemma 2.

• Theorem: Given G is 2-edge-connected and G0 is a ring, G is tolerant to single link faults of G0.

• Consider a mesh Topology as the underlying WDM structures.