WO2019120058A1

WO2019120058A1 - Methods and devices for phy management in flexe network

Info

Publication number: WO2019120058A1
Application number: PCT/CN2018/118439
Authority: WO
Inventors: Jun Deng; Jinfeng Zhao
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2017-12-20
Filing date: 2018-11-30
Publication date: 2019-06-27
Also published as: CN111357248B; CN111357248A

Abstract

A method for PHY management is provided. The method is implemented by a local network device in a communication network. The local network device is communicatively connected to a remote network device in the communication network. The method may comprise receiving a PHY membership indication for a remote PHY from the remote network device; obtaining a PHY membership indication for a local PHY in a FlexE group of the local network device, wherein the local PHY is paired with the remote PHY; determining the state of the local PHY in the FlexE group based on the PHY membership indications for the local PHY and the remote PHY; and transitioning the state of the local PHY in the FlexE group according to a trigger event.

Description

METHODS AND DEVICES FOR PHY MANAGEMENT IN FLEXE NETWORK

TECHNICAL FIELD

The present disclosure generally relates to Flexible Ethernet (FlexE) network, and more specifically to methods and devices for PHY management in FlexE network.

BACKGROUND

The FlexE defined by Optical Interworking Forum (OIF) provides a generic mechanism for supporting a variety of Ethernet Media Access Control (MAC) rates that may or may not correspond to any existing Ethernet Physical layer (PHY) rate. This includes MAC rates that are both greater than (through bonding) and less than (through sub-rate and channelization) the Ethernet PHY rates used to carry FlexE.

Conventionally, the general capabilities supported by the FlexE network include (i) bonding of Ethernet PHYs, e.g., supporting a 200G MAC over two bonded 100GBASE-R PHYs, (ii) sub-rates of Ethernet PHYs, e.g., supporting a 50G MAC over a 100GBASE-R PHY, and (iii) channelization within a PHY or a group of bonded PHYs, e.g., support a 150G and two 25G MACs over two bonded 100GBASE-R PHYs. Note, combinations are also contemplated, for example, a sub-rate of a group of bonded PHYs, for example, a 250G MAC over three bonded 100GBASE-R PHYs. A FlexE group refers to a group including 1 to n bonded Ethernet PHYs. When one or more of the PHYs of the FlexE group has failed, the traffic of all clients on the FlexE group will be broken.

SUMMARY

It is an object of the present disclosure to address at least one of the problems mentioned above, thereby improving the accuracy of clock synchronization.

According to a first aspect of the present disclosure, there is provided a method implemented at a local network device in a communication network. The local network device is communicatively connected to a remote network device in the communication network. The method may comprise receiving a PHY membership indication for a remote PHY from the remote network device; obtaining a PHY membership indication for a local PHY in a FlexE group of the local network device, wherein the local PHY is paired with the remote PHY; determining the state of the local PHY in the FlexE group based on the PHY membership indication for the local PHY and the remote PHY; and transitioning the state of the local PHY in the FlexE group according to a trigger event.

According to a second aspect of the present disclosure, a network device is provided in a communication network. The network device communicatively coupled to another network device in the communication network. The network device may comprise a processor and a memory communicatively coupled to the processor. The memory may be adapted to store instructions which, when executed by the processor, cause the network device to perform steps of the method according to the above first aspect.

According to the third aspect of the present disclosure, there is provided a non-transitory machine-readable medium having a computer program stored thereon. The computer program, when executed by a set of one or more processors of a network device, causes the network device to perform steps of the method according to the above first aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be best understood by way of example with reference to the following description and accompanying drawings that are used to illustrate embodiments of the present disclosure. In the drawings:

Fig. 1 is a diagram illustrating a general structure of FlexE network;

Fig. 2 schematically illustrates an exemplary flow diagram for PHY management implemented by a network device according to one or more embodiments of the present disclosure;

Fig. 3 schematically illustrates an exemplary flow diagram for determining the state of the local PHY in the FlexE group according to one or more embodiments of the present disclosure;

Fig. 4 is a state transition diagram illustrating the states transition between the states of the PHY in the FlexE group according to one or more embodiments of the present disclosure;

Fig. 5 is a diagram illustrating an implementation of the PHY membership indication according to one or more embodiments of the present disclosure; and

Fig. 6 is a block diagram illustrating a network device according to some embodiments of the present disclosure.

DETAILED DESCRIPTION

The following detailed description describes methods and apparatuses for FlexE PHY management in FlexE network. In the following detailed description, numerous specific details such as logic implementations, types and interrelationships of system components, etc. are set forth in order to provide a more thorough understanding of the present disclosure. It should be appreciated, however, by one skilled in the art that the present disclosure may be practiced without such specific details. In other instances, control structures, circuits and instruction sequences have not been shown in detail in order not to obscure the present disclosure. Those of ordinary skill in the art, with the included descriptions, will be able to implement appropriate functionality without undue experimentation.

As used herein, the terms “first” , “second” and so forth refer to different elements. The singular forms “a” , “an” , and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” as used herein, specify the presence of stated features, elements, and/or components and the like, but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof. The term “according to” is to be read as “at least in part according to” . The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment” . The term “another embodiment” is to be read as “at least one other embodiment” .

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meanings as commonly understood. It will be further understood that a term used herein should be interpreted as having a meaning consistent with its meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Bracketed text and blocks with dashed borders (e.g., large dashes, small dashes, dot-dash, and dots) may be used herein to illustrate optional operations that add additional features to embodiments of the present disclosure. However, such notation should not be taken to mean that these are the only options or optional operations, and/or that blocks with solid borders are not optional in certain embodiments of the present disclosure.

An electronic device stores and transmits (internally and/or with other electronic devices over a network) code (which is composed of software instructions and which is sometimes referred to as computer program code or a computer program) and/or data using machine-readable media (also called computer-readable media) , such as machine-readable storage media (e.g., magnetic disks, optical disks, read only memory (ROM) , flash memory devices, phase change memory) and machine-readable transmission media (also called a carrier) (e.g., electrical, optical, radio, acoustical or other form of propagated signals -such as carrier waves, infrared signals) . Thus, an electronic device (e.g., a computer) includes hardware and software, such as a set of one or more processors coupled to one or more machine-readable storage media to store code for execution on the set of processors and/or to store data. For instance, an electronic device may include non-volatile memory containing the code since the non-volatile memory can persist code/data even when the electronic device is turned off (when power is removed) , and while the electronic device is turned on, that part of the code that is to be executed by the processor (s) of that electronic device is typically copied from the slower non-volatile memory into volatile memory (e.g., dynamic random access memory (DRAM) , static random access memory (SRAM) ) of that electronic device. Typical electronic devices also include a set of or one or more physical network interfaces to establish network connections (to transmit and/or receive code and/or data using propagating signals) with other electronic devices. One or more parts of an embodiment of the present disclosure may be implemented using different combinations of software, firmware, and/or hardware.

A network device is an electronic device that communicatively interconnects other electronic devices on the network (e.g., other network devices, end-user devices) . Some network devices are “multiple services network devices” that provide support for multiple networking functions (e.g., routing, bridging, switching, Layer 2 aggregation, session border control, Quality of Service, and/or subscriber management) , and/or provide support for multiple application services (e.g., data, voice, and video) .

Fig. 1 is a diagram illustrating a logical structure of FlexE network 100. The logical structure of FlexE network 100 includes a FlexE group 110, one or more FlexE clients 120, and FlexE shims 130 at each end of the FlexE group. The FlexE group 110 refers to a group including 1 to n bonded Ethernet channels between the FlexE Shims 130. As used herein, a PHY is a component that operates at the physical layer of the OSI network model. Each PHY can be identified by a number, for example in the range [1-254] . The values of 0 and 255 are reserved. A PHY number may correspond to the physical port ordering on equipment, such as a network device, and the FlexE shim at any end of the FlexE group can identify each PHY in the group using the PHY number. Each PHY of the FlexE group is able to deliver a logically serial stream of 64B/66B encoded blocks from the FlexE mux to the FlexE demux. The FlexE group 110 can include one or more bonded 100GBASE-R PHYs as well as including other rates, including new, higher rates once those standards are complete. The one or more FlexE clients 120 are each an Ethernet flow based on a MAC data rate that may or may not correspond to any Ethernet PHY rate. The FlexE client 120 MAC rates supported by the OIF-FLEXE 1.0 are 10, 40, and m×25 Gb/s. The FlexE shim 130 is the layer that maps or demaps the FlexE clients 120 carried over the FlexE group 110. A FlexE mux refers to the transmit direction which maps the FlexE clients 120 over the FlexE group 110. The FlexE demux refers to the receive direction which demaps the FlexE clients 120 from the FlexE group 110. Therefore, a PHY described in this disclosure can be a network layer, when used in the context of network layers, a function entity, when used in FlexE group context, one-to-one mapping to port or optical transceivers, or a chip, when used in hardware design, which implements the functions of the PHY layer.

Currently, there are only two membership status for a PHY in the FlexE group, i.e. in the group or not in the group. As defined in OIF-FLEXE-1.0, a PHY bit map is specified to indicate whether a PHY is in the FlexE group or not. In the case that the PHY is failed, locked out for administration or there is misalignment of PHY bit map (due to PHY member add/delete) in the two ends of the FlexE group, the whole FlexE network would be out of service and all client’s traffic will be broken.

The present disclosure provides a method to isolate a PHY member from the FlexE group, such that the FlexE group will work with an isolated member in the group, thereby PHY fault, lock out for administration, temporarily misalignment of PHY bit map for the paired PHYs (due to PHY member add/delete) will not cause the whole FlexE group out of service. Besides the current two PHY membership status (in or not in the group) , a third PHY membership status is defined, i.e. isolated member. When a PHY is an isolated member in the FlexE group, no client traffic will be distributed to the PHY, although the PHY is still in the FlexE group, and the FlexE group will function regardless the status of the isolated PHY.

For the case that a PHY in the FlexE group is failed or broken, the PHY may be isolated as an isolated member in the FlexE group, until the fault is recovered, and such fault will not cause all the client’s traffic in the FlexE group broken. For the case that some PHYs are locked out, the PHYs may be isolated as isolated member for administration purpose. To add a PHY in the FlexE group, the PHY may be added as an isolated member first, and then become a PHY member of the FlexE group after being activated. To delete a PHY in the FlexE group, the PHY may be isolated as an isolated member in the FlexE group first and then be deleted from the FlexE group. Details of the method will be described in the following.

Fig. 2 schematically illustrates an exemplary flow diagram 200 for PHY management implemented by a network device according to one or more embodiments of the present disclosure.

Referring to Fig. 2, in step 201, a PHY membership indication for a remote PHY may be received from the remote network device. In step 202, a PHY membership indication for a local PHY in a FlexE group of the local network device may be obtained. According to the embodiments of the present disclosure, the local PHY is coupled to the remote PHY. In step 203, the state of the local PHY in the FlexE group may be determined based on the PHY membership indications for the local PHY and the remote PHY. In step 204, the state of the local PHY in the FlexE group may be transitioned according to a trigger event.

According to further embodiments of the present disclosure, an updated PHY membership indication may be sent to the remote network device, when a membership of the local PHY at the local network device is changed. As an example, the PHY membership indication may be sent to the remote network device once the membership status of the local PHY at the local network device is changed. As another example, the PHY membership indication may be sent to the remote network device periodically.

According to further embodiments of the present disclosure, the PHY membership indication may include a PHY Bit MAP and a PHY isolation indication. As an example, the PHY isolation indication may include an Isolation Bit MAP in the reserved bits of an overhead frame. As another example, the PHY isolation indication may include an Isolation PHY number list in management channel of an overhead frame. The implementation of the PHY membership indication according to one or more embodiments of the present disclosure may be described in more details below.

According to the embodiments of the disclosure, there may be three membership status for a PHY in a FlexE group: member, isolated member and not a member. Member means that a PHY is in the FlexE group and is capable of carrying client’traffic. Isolated member means that a PHY is in the FlexE group, but isolated, thus no client traffic may be distributed to the PHY. Not a Member means that a PHY is not in the FlexE group.

According to further embodiments of the disclosure, the state of the local PHY in the FlexE group may be determined based on the membership indications for the local PHY and for the remote PHY. There may be at least five states for the PHY, including Out of Group (O) state, Maintenance (M) state, Working (W) state, Local Add (LA) state and Remote Add (RA) state.

Fig. 3 schematically illustrates an exemplary flow diagram 300 for determining the state of the local PHY in the FlexE group according to one or more embodiments of the present disclosure.

Referring to Fig. 3, in step 301, ifthe PHY membership indication for the local PHY indicates that the local PHY is a member in the FlexE group, and the PHY membership indication for the remote PHY indicates that the remote PHY is a member in the FlexE group, the state of the local PHY may be determined as W state. In step 302, if the PHY membership indication for the local PHY indicates that the local PHY is not a member in the FlexE group, and the PHY membership indication for the remote PHY indicates that the remote PHY is not a member in the FlexE group, the state of the local PHY in the FlexE group may be determined as O state. In step 303, if the PHY membership indication for the local PHY indicates that the local PHY is an isolated member in the FlexE group, and the PHY membership indication for the remote PHY indicates that the remote PHY is an isolated member in the FlexE group, the state of the local PHY in the FlexE group may be determined as M state. In step 304, if the PHY membership indication for the local PHY indicates that the local PHY is not a member in the FlexE group, and the PHY member indication for the remote PHY indicates that the remote PHY is an isolated member in the FlexE group, the state of the local PHY may be determined as RA state. In step 305, if the PHY membership indication for the local PHY indicates that the local PHY is an isolated member in the FlexE group, and the PHY member indication for the remote PHY indicates that the remote PHY is not a member in the FlexE group, the state of the local PHY may be determined as LA state.

Fig. 4 is a state transition diagram 400 illustrating the states transition between the states of the local PHY in the FlexE group according to one or more embodiments of the present disclosure.

According to the embodiment of the present disclosure, when the state of the local PHY is determined as W state, if an isolation trigger event to isolate the local PHY from the FlexE group is received, the membership status of the local PHY may be changed to isolated member, and the state of the local PHY may be transitioned to M state, as shown at 401. According to one or more embodiments of the present disclosure, the isolation trigger event may include detecting the local PHY is failed, locking out the local PHY, detecting a remote defect indication for the remote PHY, receiving an isolation instruction for the local PHY, or receiving an updated PHY membership indication indicating that the remote PHY is an isolated member from the remote network device. According to further embodiments of the present disclosure, after transitioning the state of the local PHY to M state, , the traffic on that PHY may be redistributed to other PHY which are at Working state in the FlexE group.

According to an embodiment of the present disclosure, when the state of the local PHY is determined as M state, if an activation trigger event to activate the local PHY in the FlexE group is received, the membership status of the local PHY may be changed to a member, and the state of the local PHY may be transitioned to W state, as shown at 402. According to one or more embodiments of the present disclosure, the activation trigger event may include detecting the fault clearing for the local PHY, clearing the lock out for the local PHY, and receiving an updated PHY membership indication indicating that the remote PHY is a member in the FlexE group from the remote network device. According to further embodiments of the present disclosure, when the state of the local PHY is determined as M state, if a delete trigger event to delete the local PHY from the FlexE group is received, the membership status of the local PHY may be changed to not a member, and the state of the local PHY may be transitioned to RA state, as shown at 403. According to one or more of the present disclosure, when the state of the local PHY is determined as M state, the state of the local PHY may be transitioned automatically to LA state, when receiving an updated PHY membership indication for the remote PHY from the remote network device, indicating that the remote PHY is not a member in the FlexE group, as shown at 404.

According to an embodiment of the present disclosure, when the state of the local PHY is determined as O state, if an add trigger event to add the local PHY into the FlexE group is received, the membership status of the local PHY may be changed to a member and the state of the local PHY may be transitioned to LA state as shown at 405. According to one or more of the present disclosure, when the state of the local PHY is determined as O state, the state of the local PHY may be transitioned automatically to RA state, when receiving an updated PHY membership indication for the remote PHY from the remote network device, indicating that the remote PHY is a member in the FlexE group, as shown at 406.

According to an embodiment of the present disclosure, when the state of the local PHY is determined as LA state, if a delete trigger event to delete the local PHY from the FlexE group is received, the membership status of the local PHY may be changed to not a member, and the state of the local PHY may be transitioned to O state, as shown at 407. According to one or more of the present disclosure, when the state of the local PHY is determined as LA state, the state of the local PHY may be transitioned automatically to M state, when receiving an updated PHY membership indication for the remote PHY from the remote network device, indicating that the remote PHY is an isolated member in the FlexE group, as shown at 408.

According to one or more of the present disclosure, when the state of the local PHY is at RA state, if an add trigger event to add the local PHY in the FlexE group is received, the membership status of the local PHY may be changed to a member, and the state of the local PHY may be transitioned to M state, as shown at 409. According to one or more of the present disclosure, when the state of the local PHY is at RA state, the state of the local PHY may be transitioned automatically to O state, when receiving an updated PHY membership indication for the remote PHY from the remote network device, indicating that the remote PHY is not a member in the FlexE group, as shown at 410.

Fig. 5 is a diagram illustrating an implementation of the PHY membership indication according to one or more embodiments of the present disclosure.

Referring to Fig. 5, there is a general structure of FlexE overhead frame and multiframe. The alignment of the data from the PHY of the FlexE group is accomplished by the insertion of FlexE overhead into the stream of 66B blocks carried over the group. As shown in Fig. 5, a PHY Bit Map may be carried in an overhead multiframe. Also, a PHY isolation Bit Map may be defined using 256 bit map in an overhead multiframe, and each bit has the same correlation to a PHY as the PHY Bit Map. As an example, for the PHY Bit Map, a bit=0 may mean that the PHY is not in the FlexE group; and a bit=1 may mean that the PHY is in the FlexE group, and vice versa. As an example, for the PHY isolation Bit Map, a bit=0 may mean that the PHY is not in the group or in the group but not isolated from the FlexE group; and a bit=1 may mean that the PHY is in the group and isolated from the FlexE group; and vice versa. Thus, the PHY membership indication may include "00" , i.e. the PHY is not a member in the FlexE group; "11" , i.e. the PHY is an isolated member in the FlexE group; and "10" , i.e. the PHY is a member in the FlexE group. The position of the PHY Bit Map is not limited to the 2nd block of each overhead frame, the PHY isolation Bit Map may be carried in other reserved bits of the overhead frame according to the implementation. The PHY isolation Bit Map may also be compressed according to one or more embodiments of the present disclosure, since the isolation may only happen on a few PHYs.

According to other embodiments of the present disclosure, the PHY isolation indication may include an Isolation PHY number list over management channel of an overhead frame. However, such structures are merely examples, the skilled person in the art may employ other structures for PHY membership indications according to different implementations.

Fig. 6 is a block diagram illustrating a network device 600 according to some embodiments of the present disclosure. It should be appreciated that the network device 600 may be implemented using components other than those illustrated in Fig. 6.

With reference to Fig. 6, the network device 600 may comprise at least a processor 601, a memory 602, an interface and a communication medium. The processor 601, the memory 602 and the interface are communicatively coupled to each other via the communication medium.

The processor 601 includes one or more processing units. A processing unit may be a physical device or article of manufacture comprising one or more integrated circuits that read data and instructions from computer readable media, such as the memory 602, and selectively execute the instructions. In various embodiments, the processor 601 is implemented in various ways. As an example, the processor 602 may be implemented as one or more processing cores. As another example, the processor 601 may comprise one or more separate microprocessors. In yet another example, the processor 601 may comprise an application-specific integrated circuit (ASIC) that provides specific functionality. In yet another example, the processor 601 provides specific functionality by using an ASIC and by executing computer-executable instructions.

The memory 602 includes one or more computer-usable or computer-readable storage medium capable of storing data and/or computer-executable instructions. It should be appreciated that the storage medium is preferably a non-transitory storage medium.

The communication medium facilitates communication among the processor 601, the memory 602 and the interface. The communication medium may be implemented in various ways. For example, the communication medium may comprise a Peripheral Component Interconnect (PCI) bus, a PCI Express bus, an accelerated graphics port (AGP) bus, a serial Advanced Technology Attachment (ATA) interconnect, a parallel ATA interconnect, a Fiber Channel interconnect, a USB bus, a Small Computing System Interface (SCSI) interface, or another type of communications medium. The interface could be coupled to the processor. Information and data as described above in connection with the methods may be sent via the interface.

In the example of Fig. 6, the instructions stored in the memory 602 may include those that, when executed by the processor 601, cause the network device 600 to implement the methods described with respect to Figs. 2, 3 and 4.

Some portions of the foregoing detailed description have been presented in terms of algorithms and symbolic representations of transactions on data bits within a computer memory. These algorithmic descriptions and representations are ways used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of transactions leading to a desired result. The transactions are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.

It should be appreciated, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the above discussion, it is appreciated that throughout the description, discussions utilizing terms such as "processing" or "computing" or "calculating" or "determining" or "displaying" or the like, refer to actions and processes of a computer system, or a similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system′sregisters and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.

The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the required method transactions. The required structure for a variety of these systems will appear from the description above. In addition, embodiments of the present disclosure are not described with reference to any particular programming language. It should be appreciated that a variety of programming languages may be used to implement the teachings of embodiments of the present disclosure as described herein.

An embodiment of the present disclosure may be an article of manufacture in which a non-transitory machine-readable medium (such as microelectronic memory) has stored thereon instructions (e.g., computer code) which program one or more data processing components (generically referred to here as a “processor” ) to perform the operations described above. In other embodiments, some of these operations might be performed by specific hardware components that contain hardwired logic (e.g., dedicated digital filter blocks and state machines) . Those operations might alternatively be performed by any combination of programmed data processing components and fixed hardwired circuit components.

In the foregoing detailed description, embodiments of the present disclosure have been described with reference to specific exemplary embodiments thereof. It will be evident that various modifications may be made thereto without departing from the spirit and scope of the present disclosure as set forth in the following claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.

Throughout the description, some embodiments of the present disclosure have been presented through flow diagrams. It should be appreciated that the order of transactions and transactions described in these flow diagrams are only intended for illustrative purposes and not intended as a limitation of the present disclosure. One having ordinary skill in the art would recognize that variations can be made to the flow diagrams without departing from the spirit and scope of the present disclosure as set forth in the following claims.

Claims

A method implemented in a local network device in a communication network, the local network device being communicatively connected to a remote network device in the communication network, the method comprising:

receiving a PHY membership indication for a remote PHY from the remote network device;

obtaining a PHY membership indication for a local PHY in a FlexE group of the local network device, wherein the local PHY is paired with the remote PHY;

determining state of the local PHY in the FlexE group based on the PHY membership indications for the local PHY and the remote PHY; and

transitioning the state of the local PHY in the FlexE group according to a trigger event.
The method of claim 1, wherein the PHY membership indication indicates membership of the PHY as one of: a member, an isolated member and not a member in the FlexE group.
The method of claim 2, wherein the state of the local PHY in the FlexE group includes any of: Out of Group (O) state, Maintenance (M) state, Working (W) state, Local Add (LA) state and Remote Add (RA) state;

wherein determining the state of the local PHY comprises:

if the PHY membership indication for the local PHY indicates that the local PHY is a member in the FlexE group and the PHY membership indication for the remote PHY indicates that the remote PHY is a member in the FlexE group, the state of the local PHY is determined as W state;

if the PHY membership indication for the local PHY indicates that the local PHY is not a member in the FlexE group and the PHY membership indication for the remote PHY indicates that the remote PHY is not a member in the FlexE group, the state of the local PHY in the FlexE group is determined as O state;

if the PHY membership indication for the local PHY indicates that the local PHY is an isolated member in the FlexE group and the PHY membership indication for the remote PHY indicates that the remote PHY is an isolated member in the FlexE group, the state of the local PHY in the FlexE group is determined as M state;

if the PHY membership indication for the local PHY indicates that the local PHY is not a member in the FlexE group, and the PHY member indication for the remote PHY indicates that the remote PHY is an isolated member in the FlexE group, the state of the local PHY is determined as RA state; or

if the PHY membership indication for the local PHY indicates that the local PHY is an isolated member in the FlexE group, and the PHY member indication for the remote PHY indicates that the remote PHY is not a member in the FlexE group, the state of the local PHY is determined as LA state.
The method of claim 3, when the state of the local PHY is determined as W state, transitioning the state of the local PHY in the FlexE group according to a trigger event comprises:

if receiving an isolation trigger event to isolate the local PHY from the FlexE group, the membership status of the local PHY is changed to an isolated member, and the state of the local PHY is transitioned to M state.
The method of claim 3, when the state of the local PHY is determined as M state, transitioning the state of the local PHY in the FlexE group according to a trigger event comprises:

if receiving an activation trigger event to activate the local PHY in the FlexE group, the membership status of the local PHY is changed to a member, and the state of the local PHY is transitioned to W state; or

if receiving a delete trigger event to delete the local PHY from the FlexE group, the membership status of the local PHY is changed to not a member, and the state of the local PHY is transitioned to RA state.
The method of claim 3, when the state of the local PHY is determined as O state, transitioning the state of the local PHY in the FlexE group according to a trigger event comprises:

if receiving an add trigger event to add the local PHY into the FlexE group, the membership status of the local PHY is changed to a member and the state of the local PHY is transitioned to LA state.
The method of claim 3, when the state of the local PHY is determined as LA state, transitioning the state of the local PHY in the FlexE group according to a trigger event comprises:

if receiving a delete trigger event to delete the local PHY from the FlexE group, the membership status of the local PHY is changed to not a member, and the state of the local PHY is transitioned to O state.
The method of claim 3, when the state of the local PHY is determined as RA state, transitioning the state of the local PHY in the FlexE group according to a trigger event comprises:

if receiving an add trigger event to add the local PHY in the FlexE group, the membership status of the local PHY is changed to a member, and the state of the local PHY is transitioned to M state.
The method of claim 4, wherein the isolation trigger event includes any of: detecting the local PHY is failed, locking out the local PHY, detecting a remote defect indication for the remote PHY, receiving an isolation instruction for the local PHY, or receiving an updated PHY membership indication indicating that the remote PHY is an isolated member from the remote network device.
The method of claim 5, wherein the activation trigger event includes any of: detecting the fault clearing for the local PHY, clearing the lock out for the local PHY, or receiving an updated PHY membership indication indicating that the remote PHY is a member in the FlexE group from the remote network device.
The method of claim 1, wherein the PHY membership indication including PHY Bit MAP or PHY isolation indication.
The method of claim 11, wherein the PHY isolation indication including Isolation Bit MAP in reserved bits of an overhead frame or Isolation PHY number list in management channel of an overhead frame.
The method of claim 4, after transitioning the state of the local PHY to M state, the method further comprising: redistributing traffic to other local PHYs which are at W state in the FlexE group.
The method of claim 1, further comprising: sending an updated PHY membership indication to the remote network device when the membership status of the local PHY at the local network device is changed.
A network device in a communication network, the network device communicatively coupled to another network device in the communication network, and comprising:

a processor; and

a memory communicatively coupled to the processor and adapted to store instructions which, when executed by the processor, cause the network device to perform steps of the method according to any one of the Claims 1-14.
A non-transitory machine-readable medium having a computer program stored thereon, which when executed by a set of one or more processors of a network device, causes the network device to perform steps of the method according to any one of the Claims 1-14.