Method and apparatus for routing traffic using asymmetrical optical connections

Patent metadata

Field	Value
Publication number	US-9413640-B2
Application number	US-201514984759-A
Country	US
Kind code	B2
Filing date	Dec 30, 2015
Priority date	Dec 2, 2013
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

A method, computer-readable storage device and apparatus for routing traffic in a reconfigurable optical add-drop multiplexer layer of a dense wavelength division multiplexing network are disclosed. For example, the method determines the reconfigurable optical add-drop multiplexer layer has asymmetric traffic, and routes the asymmetric traffic in the reconfigurable optical add-drop multiplexer layer over a plurality of asymmetrical optical connections, wherein the plurality of asymmetrical optical connections is provided with only uni-directional equipment in the reconfigurable optical add-drop multiplexer layer.

First claim

What is claimed is:

1. A method for routing traffic in a reconfigurable optical add-drop multiplexer layer of a dense wavelength division multiplexing network, the method comprising:
determining, by a processor, the reconfigurable optical add-drop multiplexer layer has asymmetric traffic; and
routing, by the processor, the asymmetric traffic in the reconfigurable optical add-drop multiplexer layer over a plurality of asymmetrical optical connections, wherein the plurality of asymmetrical optical connections is provided with only uni-directional equipment in the reconfigurable optical add-drop multiplexer layer, wherein the asymmetric traffic is determined by a symmetry ratio of an entire network being below a threshold.

2. The method of claim 1 , wherein the reconfigurable optical add-drop multiplexer layer is in communication with an internet protocol layer and an optical transport network layer.

3. The method of claim 1 , wherein the symmetry ratio is calculated by an equation of,

ρ
network

=

∑
i

⁢

[

min
⁡

(

t
⁡

(

A
i

→

Z
i

)

,

t
⁡

(

Z
i

→

A
i

)

)

]

∑
i

⁢

[

max
⁡

(

t
⁡

(

A
i

→

Z
i

)

,

t
⁡

(

Z
i

→

A
i

)

)

]

wherein ρ network is the symmetry ratio of the entire network, t(Z i →A i ) is an amount of traffic in bits per second traveling from node Z to node A for each link i and t(A i →Z i ) is an amount of traffic in bits per second traveling from node A to node Z for each link i.

4. The method of claim 1 ,
wherein the uni-directional equipment is for replacing bi-directional equipment; and
wherein the replacing comprises:
determining a required bandwidth of each direction supported by the bi-directional equipment; and
determining a maximum bandwidth supported by the uni-directional equipment; and
deploying a number of the uni-directional equipment for each direction supported by the bi-directional equipment based upon the required bandwidth of each direction supported by the bi-directional equipment and the maximum bandwidth supported by the uni-directional equipment.

5. The method of claim 4 , wherein the bi-directional equipment comprises a transceiver.

6. The method of claim 1 , wherein the routing comprises:
changing, by the processor, a route of the asymmetric traffic in one direction from travelling directly from an internet protocol layer to the reconfigurable optical add-drop multiplexer layer by by-passing an optical transport network layer to travelling from the internet protocol layer to the reconfigurable optical add-drop multiplexer layer via the optical transport network layer.

7. A non-transitory computer-readable storage device storing a plurality of instructions which, when executed by a processor, cause the processor to perform operations for routing traffic in a reconfigurable optical add-drop multiplexer layer of a dense wavelength division multiplexing network, the operations comprising:
determining the reconfigurable optical add-drop multiplexer layer has asymmetric traffic; and
routing the asymmetric traffic in the reconfigurable optical add-drop multiplexer layer over a plurality of asymmetrical optical connections, wherein the plurality of asymmetrical optical connections is provided with only uni-directional equipment in the reconfigurable optical add-drop multiplexer layer, wherein the asymmetric traffic is determined by a symmetry ratio of an entire network being below a threshold.

8. The non-transitory computer-readable storage device of claim 7 , wherein the reconfigurable optical add-drop multiplexer layer is in communication with an internet protocol layer and an optical transport network layer.

9. The non-transitory computer-readable storage device of claim 7 , wherein the symmetry ratio is calculated by an equation of,

ρ
network

=

∑
i

⁢

[

min

Assignees

• At & T Ip I Lp

Inventors

• Bathula Balagangadhar G
• Chiu Angela L
• Feuer Mark David
• Sinha Rakesh Kumar
• Strand John Lester
• Woodward Sheryl Leigh
• Zhang Weiyi

Classifications

• H04L45/22 Primary

  Alternate routing · CPC title

• H04J14/021 Primary

  Reconfigurable arrangements, e.g. reconfigurable optical add/drop multiplexers [ROADM] or tunable optical add/drop multiplexers [TOADM] · CPC title

• H04Q2011/0086

  Network resource allocation, dimensioning or optimisation · CPC title

• H04Q11/0066

  Provisions for optical burst or packet networks · CPC title

• H04Q2011/0073

  Provisions for forwarding or routing, e.g. lookup tables · CPC title