Systems and methods for detecting and propagating resizability information of oduflex connections

Patent metadata

Field	Value
Publication number	US-9917668-B2
Application number	US-201414341037-A
Country	US
Kind code	B2
Filing date	Jul 25, 2014
Priority date	Jun 13, 2014
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

A method, in a network element, for detecting and propagating resizability information of an Optical channel Data Unit flex (ODUflex) connection includes receiving resizability information in overhead associated with the ODUflex connection, wherein the resizability information indicates a number of available tributary slots and whether the ODUflex connection is symmetric; and adjusting the resizability information based on a change in the available tributary slots due to a bandwidth change at the network element. The systems and methods include a solution to communicate, in real time, the resizability information of an ODUflex connection utilizing the associated data path to carry it instead of the management/control plane.

First claim

What is claimed is:

1. A method, in a network element, for detecting and propagating resizability information of an Optical channel Data Unit flex (ODUflex) connection, the method comprising:
receiving resizability information in reserved bits of Resize Control Overhead (RCOH) associated with the ODUflex connection for advertisement thereof, wherein the reserved bits are designated for future standardization, wherein the resizability information in the reserved bits of the RCOH includes a number of available tributary slots and whether the ODUflex connection is resizable because it is symmetric;
adjusting the resizability information based on a change in the number of available tributary slots, due to a bandwidth change at the network element; and
transmitting the adjusted resizability information in the RCOH such that the adjusted resizability information is available in real time as the bandwidth change to client endpoint network elements.

2. The method of claim 1 , wherein the resizability information is monitored, at a client endpoint, to determine how much and whether the ODUflex connection can resize.

3. The method of claim 1 , wherein the number of available tributary slots is a lowest number of available tributary slots along a path of the ODUflex connection.

4. The method of claim 1 , wherein the resizability information indicates a number of tributary slots supported at the network element and preceding network elements, and wherein subsequent network elements determine if the ODUflex connection has an equal or greater number of tributary slots, and, if not, the resizability information is adjusted accordingly.

5. The method of claim 1 , wherein the resizability information is set to DEFAULT at an originating network element for the ODUflex connection, VALID with the number of available tributary slots set at subsequent network elements to a minimum of available bandwidth over all network elements in which the ODUflex connection traverses, or INVALID when the ODUflex connection is not resizable.

6. The method of claim 1 , further comprising:
checking the resizability information to determine if the number of available time slots from a preceding network element is greater than a number of tributary slots available locally at the network element, and if so, changing the resizability information to reflect the lower number of available tributary slots available locally; and
checking if the ODUflex connection is resizable, and if not, changing the resizability information to reflect that the ODUflex connection is not resizable.

7. The method of claim 1 , further comprising:
updating the resizability information whenever any link at the network element associated with the ODUflex connection has a change in bandwidth.

8. The method of claim 1 , wherein, at a client endpoint of the ODUflex connection, a hitless increase of the ODUflex connection is allowed or disallowed based on the resizability information.

9. A network element, comprising:
at least one port with a High Order (HO) Optical channel Data Unit (ODU) with an ODUflex connection thereon; and
a controller configured to:
if the network element is an endpoint to the ODUflex connection, set resizability information in reserved bits of Resize Control Overhead (RCOH) of the ODUflex connection to a default value for advertisement thereof, wherein the reserved bits are designated for future standardization, wherein the resizability information in the reserved bits of the RCOH includes a number of available tributary slots and whether the ODUflex connection is resizable because it is symmetric, and wherein the resizability information is adjusted in real time with any changes to the number of available tributary slots; and
if the network element is an intermediate point for the ODUflex connection, read the resizability information in the overhead and adjust its values based on local information related to the number of available tributary slots and whether the ODUflex connection is resizable, wherein a change in the adjusted resizability information is available in real time with the changes to the number of available tributary slots.

10. A network, comprising:
a plurality of network elements;
a plurality of links interconnecting the network elements; and
at least one Optical channel Data Unit flex (ODUflex) connection on a path over links between two endpoints of the plurality of network elements;
wherein resizability information is included in reserved bits of Resize Control Overhead (RCOH) associated with the ODUflex connection for advertisement thereof, wherein the reserved bits are designated for future standardization;
wherein the resizability information in the reserved bits of the RCOH includes a number of available tributary slots for resizing and whether the ODUflex connection is resizable because it is symmetric; and
wherein the resizability information is adjusted based on a change of the bandwidth available on the ODUflex connection path concurrently with a change of a connection map on any link along the path such that the adjusted resizability information is available in real time with the change to any client endpoint network element.

11. The network of claim 10 , further comprising:
a control plane;
wherein the resizability information is communicated through the RCOH associated with the ODUflex is communicated to the control plane.

12. The network of claim 10 , wherein the resizability information is set to DEFAULT at an originating network element for the ODUflex connection, VALID with the number of available tributary slots set at subsequent network elements to a minimum of all links in the path, or INVALID when the ODUflex connection is not resizable.

13. The network of claim 10 , wherein the hitless adjustment utilizes G.7044/Y.1347 (10/11) “Hitless adjustment of ODUflex (GFP)” (G.HAO), and wherein the ODUflex connection supports the hitless adjustment if the ODUflex connection has an equal number of tributary slots on all links.

Assignees

• Juneja Kapil
• Tuli Pallavi
• Sareen Jatin
• Khan Waseem Reyaz
• Kannan Rajagopalan
• Ciena Corp

Inventors

• Juneja Kapil
• Tuli Pallavi
• Sareen Jatin
• Khan Waseem Reyaz
• Kannan Rajagopalan

Classifications

• H04J3/1652 Primary

  Optical Transport Network [OTN] · CPC title

• H04J2203/006

  Fault tolerance and recovery · CPC title

• H04Q11/0062

  Network aspects · CPC title

• H04L45/62

  Wavelength based (optical switching H04Q11/0062) · CPC title