ODU path protection in a disaggregated OTN switching system

• US 10,462,543 B2
• Filed: 01/30/2017
• Issued: 10/29/2019
• Est. Priority Date: 04/21/2016
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Cai, Biaodong, Dunsmore, Richard, Naphan, Rod, Lisle, Sam, Patel, Deepak, Syed, Iqbal
• Primary Examiner(s): Cors, Nathan M
• Application Number:
  US15/419,751
• Publication Number:
  US 20170310387A1
• Time in Patent Office: 1,002 Days
• CPC Class Codes: H04B 10/032 using working and protection systems H04J14/0287 takes precedence
• CPC Class Codes: H04J 2203/0012 Switching modules and their interconnections
• CPC Class Codes: H04J 2203/0026 Physical details
• CPC Class Codes: H04J 2203/0085 Support of Ethernet
• CPC Class Codes: H04J 3/1652 Optical Transport Network [OTN]
• CPC Class Codes: H04L 12/40 Bus networks
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04L 41/0659 by isolating or reconfiguring faulty entities
• CPC Class Codes: H04L 41/0677 Localisation of faults
• CPC Class Codes: H04L 41/08 Configuration management of networks or network elements address allocation H04L61/50
• CPC Class Codes: H04L 41/0895 Configuration of virtualised networks or elements, e.g. virtualised network function or OpenFlow elements
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering
• CPC Class Codes: H04L 45/7452 Multiple parallel or consecutive lookup operations lookup operation involving Bloom filters H04L45/7459
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/70 Virtual switches
• CPC Class Codes: H04L 61/5038 for local use, e.g. in LAN or USB networks, or in a controller area network [CAN]
• CPC Class Codes: H04Q 11/00 Selecting arrangements for multiplex systems multiplex systems H04J
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 11/0062 Network aspects
• CPC Class Codes: H04Q 11/0066 : Provisions for optical burst or packet networks
• CPC Class Codes: H04Q 2011/0073 : Provisions for forwarding or routing, e.g. lookup tables

Abstract

Methods and systems for optical data unit (ODU) path protection in a disaggregated optical transport network (OTN) switching system that include using plug-in universal (PIU) modules each having multiple ports for OTN to Ethernet transceiving and an Ethernet fabric as a switching core are disclosed. An OTN over Ethernet module in each of the PIU modules may enable various OTN functionality to be realized using the Ethernet fabric which may include multiple Ethernet switches. An egress PIU module may receive Ethernet packets via the Ethernet fabric from a working ODU path. In response to determining that a protection switch using a protection ODU path may be performed on the working ODU path, the egress PIU module may receive the Ethernet packets via the Ethernet fabric from the protection ODU path.

Claims

1. An optical transport network (OTN) comprising:

a first OTN switch connected to a working optical data unit (ODU) path and a protection ODU path from a second OTN switch, the first OTN switch comprising;

a first ingress plug-in module receiving ODUs from the second OTN switch via the working ODU path, converting the ODUs to corresponding Ethernet packets, and transmitting the Ethernet packets to an Ethernet fabric included in the first OTN switch;

a second ingress plug-in module receiving the ODUs from the second OTN switch via the protection ODU path and converting the ODUs to corresponding Ethernet packets, the second ingress plug-in module connected to the Ethernet fabric; and

a first egress plug-in module receiving the Ethernet packets from the Ethernet fabric;

the first OTN switch, in response to determining, by the first ingress plug-in module, an event indicating that a protection switch using the protection ODU path is to be performed on the working ODU path, enabled to perform the protection switch to;

set, at the first ingress plug-in module, a status of the working ODU path of Ethernet packets to indicate the event prior to transmitting Ethernet packets to the Ethernet fabric,

transmit, from the second ingress plug-in module, a keep alive Ethernet packet indicating the status of the protection ODU path to the Ethernet fabric, and

upon receipt, by the first egress plug-in module, of one or more Ethernet packets having the status of the working ODU path and a keep alive Ethernet packet indicating the status of the protection path,

determine that a protection switch is to be performed on the working ODU path, and

receive the Ethernet packets via the Ethernet fabric from the second ingress plug-in module from the protection ODU path.

2. The OTN of claim 1, wherein the event comprises one of:

a fault condition associated with the working ODU path;

an OTN command to perform the protection switch;

a cessation of ODU transmission over the working ODU path;

an impairment of ODU transmission over the working ODU path; and

an expiration of a keep alive delay associated with the protection ODU path.

3. The OTN of claim 1, wherein

after the protection switch, the first ingress plug-in module stops transmission of the Ethernet packets via the Ethernet fabric to the first egress plug-in module.

4. The OTN of claim 1, wherein the first OTN switch transmits the ODUs to a third OTN switch, and further comprising:

a second egress plug-in module at the first OTN switch receiving the Ethernet packets via the Ethernet fabric from the first ingress plug-in module from the working ODU path; and

in response to an indication that the first ingress plug-in module has a fault condition and the protection switch is to be performed, perform the protection switch to;

receive the Ethernet packets via the Ethernet fabric from the second ingress plug-in module from the protection ODU path.

5. The OTN of claim 1, further comprising:

the first OTN switch connected to a second working ODU path and a second protection ODU path from the second OTN switch;

a second egress plug-in module receiving second Ethernet packets via the Ethernet fabric from the first ingress plug-in module from the second working ODU path;

the first OTN switch performing the protection switch further to;

receive the second Ethernet packets via the Ethernet fabric from the second ingress plug-in module from the second protection ODU path.

6. A method for optical data unit (ODU) path protection, the method comprising:

in a first optical transport network (OTN) switch connected to a working optical data unit (ODU) path and a protection ODU path from a second OTN switch,

receiving, by a plug-in module, ODUs from the second OTN switch via the working ODU path, converting the ODUs to corresponding Ethernet packets, and transmitting Ethernet packets to an Ethernet fabric included in the first OTN switch;

receiving, by a second ingress plug-in module, the ODUs from the second OTN switch via the protection ODU path and converting the ODUs to corresponding Ethernet packets, the second ingress plug-in module connected to the Ethernet fabric;

receiving, by a first egress plug-in module, the Ethernet packets from the Ethernet fabric; and

in response to determining, by the first ingress plug-in module, an event indicating that a protection switch using the protection ODU path is to be performed on the working ODU path,

performing, for the first OTN switch, the protection switch, including;

setting, at the first ingress plug-in module, a status of the working ODU path of Ethernet packets to indicate the event prior to transmitting Ethernet packets to the Ethernet fabric,

transmitting, from the second ingress plug-in module, a keep alive Ethernet packet indicating the status of the protection ODU path to the Ethernet fabric, and

upon receipt, by the first egress plug-in module, of one or more Ethernet packets having the status of the working ODU path and a keep alive Ethernet packet indicating the status of the protection path,

determine that a protection switch is to be performed on the working ODU path, and

receiving the Ethernet packets via the Ethernet fabric from the second ingress plug-in module from the protection ODU path.

7. The method of claim 6, wherein the event comprises one of:

a fault condition associated with the working ODU path;

an OTN command to perform the protection switch;

a cessation of ODU transmission over the working ODU path;

an impairment of ODU transmission over the working ODU path; and

an expiration of a keep alive delay associated with the protection ODU path.

8. The method of claim 6, further comprising:

stopping, by the first ingress plug-in module, after the protection switch, transmission of the Ethernet packets via the Ethernet fabric to the first egress plug-in module.

9. The method of claim 6, further comprising:

transmitting, by the first OTN switch, the ODUs to a third OTN switch;

receiving, by a second egress plug-in module at the first OTN switch, the Ethernet packets from the working ODU path; and

in response to an indication that the first ingress plug-in module has a fault condition and the protection switch is to be performed, performing the protection switch including receiving the Ethernet packets via the Ethernet fabric from the second ingress plug-in module from the protection ODU path.

10. The method of claim 6, wherein the first OTN switch is connected to a second working ODU path and a second protection ODU path from the second OTN switch, and further comprising:

receiving, by a second egress plug-in module, second Ethernet packets via the Ethernet fabric from the first ingress plug-in module from the second working ODU path; and

performing, for the first OTN switch, the protection switch including;

receiving the second Ethernet packets via the Ethernet fabric from the second ingress plug-in module from the second protection ODU path.