ODU path protection in a disaggregated OTN switching system
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.
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.