CN102684838B - A kind of LOF detection method, device and Maintenance Entity end points - Google Patents
A kind of LOF detection method, device and Maintenance Entity end points Download PDFInfo
- Publication number
- CN102684838B CN102684838B CN201210162728.5A CN201210162728A CN102684838B CN 102684838 B CN102684838 B CN 102684838B CN 201210162728 A CN201210162728 A CN 201210162728A CN 102684838 B CN102684838 B CN 102684838B
- Authority
- CN
- China
- Prior art keywords
- frame
- mep
- eth
- time
- last
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Data Exchanges In Wide-Area Networks (AREA)
Abstract
A kind of LOF detection method, device and MEP, the method comprises: a MEP will periodically send message notice the 2nd MEP of the predetermined delivery time of ETH-LM frame; One MEP sends the ETH-LM frame carrying Tx to the 2nd MEP at each predetermined delivery time, receive the ETH-LM frame carrying Tx ' and Rx ' that the 2nd MEP sends; Tx ' in the ETH-LM frame that one MEP sends at the predetermined delivery time of nearest secondary according to the 2nd MEP received from the 2nd MEP and Rx ', the LOF carrying out far-end detects.Present invention also offers the LOF checkout gear for realizing said method and corresponding MEP.According to the present invention, between reciprocity MEP, delivery time is arranged, under the prerequisite not increasing hardware, make transmitting time window identical with time of reception window size and relative time delay more reasonable, thus more adequately carry out LOF detection.
Description
Technical Field
The present invention relates to an ethernet loss measurement function (ETH-LM), and more particularly, to a frame loss detection method, apparatus, and maintenance entity group endpoint (MEP).
Background
In a network requiring frame exchange, communication between devices is required due to service requirements, and it is necessary to transmit a data frame related to maintaining a service. This is related to maintaining the normal operation of the service, which requires good performance between the links, thereby reducing the frame loss rate as much as possible and maintaining the normal operation of the entire communication network.
The frame loss rate is one of the important performance indexes for measuring the network link quality, and can be understood as follows: and in a specified time range, the difference value between the total number of the data frames received by the receiving end and the total number of the data frames sent by the sending end and the ratio value between the total number of the data frames sent by the sending end are determined between specific devices and between given data links. To calculate the frame loss rate, the total number of data frames sent by the sending end and the total number of data frames received by the receiving end need to be detected.
In the ITU-TY.1731 recommendation approved by the International telecommunication Union, telecommunication standardization sector, the following is disclosed:
the ETH-LM is used to collect the value of the counter, which is applied to the service frames at ingress and egress. The counter maintains a count of transmitted and received data frames between a pair of MEPs.
ETH-LM is implemented by sending frames with ETH-LM information to its peer MEPs, and similarly receiving frames with ETH-LM information from peer MEPs. Each MEP performs near-end and far-end frame loss detection. For a MEP, a near-end frame loss refers to a frame loss associated with an ingress data frame, while a far-end frame loss refers to a frame loss associated with an egress data frame.
In a point-to-point Maintenance Entity (ME) to be loss detected, the MEP will maintain the following two local counters for each peer MEP and each priority level to be monitored:
TxFCl: a counter for non-superscalar data frames destined to a peer MEP.
RxFCl: a counter for non-superscalar data frames received from peer MEPs.
ETH-LM can be performed in two ways: a double ended ETH-LM and a single ended ETH-LM.
Double ended ETH-LM
In this case, in a point-to-point ME, each MEP periodically sends double ended frames with ETH-LM information to its peer MEPs to facilitate frame loss detection at the peer MEPs. Each MEP terminates a double ended frame with ETH-LM information and performs near end and far end loss detection.
When configured for active loss detection, the MEP periodically sends a connectivity check information (CCM) frame with the following information elements:
TxFCf: the value of the local counter TxFCl at the time of CCM frame transmission.
RxFCb: the value of the local counter RxFCl when the last CCM frame is received from the peer MEP.
TxFCb: the value of TxFCf in the last CCM frame received from a peer MEP.
The transmission of the CCM Protocol Data Unit (PDU) has a period value equal to the CCM transmission period configured by the transmitting MEP according to the performance monitoring application.
The MEP, upon receiving a CCM frame, will perform near-end and far-end loss detection using the following values:
of received CCM framesThe value of TxFCf, RxFCb, TxFCb and the value of the local counter RxFCl at the time of receipt of the CCM frame. These values are denoted as TxFCf [ t [ ]c]、RxFCb[tc]、TxFCb[tc]And RxFCl [ tc]Here tcIs the time of receipt of the current frame.
The value of TxFCf, RxFCb, TxFCb of the previous CCM frame and the value of the local counter RxFCl at the time of receipt of the previous CCM frame. These values are denoted as TxFCf [ t [ ]p]、RxFCb[tp]、TxFCb[tp]And RxFCl [ tp]Here tpIs the time of receipt of the previous frame.
The corresponding calculation formula is:
FrameLostfar-end＝|TxFCb[tc]-TxFCb[tp]|-|RxFCb[tc]-RxFCb[tp]|
FrameLostnear-end＝|TxFCf[tc]-TxFCf[tp]|-|RxFCl[tc]-RxFCl[tp]|
among them, FrameLostfar-endRepresents tpTo tcThe number of data frames lost at the far end in a time period, and the FrameLostnear-end represents tpTo tcThe number of data frames lost by the near end in the time period.
Single ended ETH-LM
In this case, for loss detection, an MEP sends frames with ETH-LM request information to its peer MEP and receives frames with ETH-LM reply information from its peer MEP.
The PDU for a single-ended ETH-LM request is called a loss detection message (LMM). The PDU for a single-ended ETH-LM reply is called a lost message reply (LMR: Lossmeasurementreply). The frame carrying the LMMPDU is called an LMM frame, and the frame carrying the LMRPDU is called an LMR frame.
For loss detection on demand, the MEP periodically sends LMM frames in the following information units:
TxFCf: the value of the local counter TxFCl at the time of transmission of the LMM frame.
Whenever a MEP receives a valid LMM frame, an LMR frame is generated and sent to the requesting MEP. An LMR frame contains the following values:
TxFCf: the value of TxFCf copied from the LMM frame.
RxFCf: the value of the local counter RxFCl at the time of LMM frame reception.
TxFCb: the value of the local counter TxFCl at the time of transmission of the LMR frame.
Upon receipt of the LMR frame, the MEP will perform near-end and far-end loss detection using the following values:
the value of TxFCf, RxFCf, TxFCb of the received LMR frame and the value of the local counter RxFCl at the time the LMR frame was received. These values are denoted as TxFCf [ t [ ]c]，RxFCf[tc]，TxFCb[tc]And RxFCl [ tc]Here tcIs the time of receipt of the current reply frame.
The value of TxFCf, RxFCf, TxFCb of the previous LMR frame and the value of the local counter RxFCl at the time of receipt of this previous LMR frame. These values are denoted as TxFCf [ t [ ]p]、RxFCf[tp]、TxFCb[tp]And RxFCl [ tp]Here tpIs the time of receipt of the previous reply frame.
The calculation formula is as follows:
FrameLostfar-end＝|TxFCf[tc]-TxFCf[tp]|-|RxFCf[tc]-RxFCf[tp]|
FrameLostnear-end＝|TxFCb[tc]-TxFCb[tp]|-|RxFCl[tc]-RxFCl[tp]|
among them, FrameLostfar-endRepresents tpTo tcNumber of data frames lost at far end in time period, FrameLostnear-endRepresents tpTo tcThe number of data frames lost by the near end in the time period.
In the foregoing manner, during the transmission of a CCM frame or an LMM or LMR frame, only one frame is transmitted at a time, which may cause a loss, and also may cause a variation in the network state, and the actual transmission time of the frame fluctuates and greatly differs from the average transmission time of the data frame, so that the size of a time window (hereinafter, referred to as a transmission time window) on which the data frame is transmitted is different from the size of a time window (hereinafter, referred to as a reception time window) on which the data frame is received, or the time delay of the reception time window relative to the transmission time window differs greatly from the average transmission time of the data frame, thereby causing an error in frame loss detection.
Disclosure of Invention
The technical problem to be solved by the present invention is to provide a more accurate frame loss detection method, device and maintenance entity group end point.
In order to solve the above problem, the present invention provides a frame loss detection method applied to a system including a first and a second maintenance entity group end point (MEP) of each other, the method including:
the first MEP informs a second MEP of information of scheduled sending time of periodically sending Ethernet loss detection function (ETH-LM) frames;
the first MEP sends an ETH-LM frame carrying Tx to the second MEP at each scheduled sending time, receives an ETH-LM frame carrying Tx ' and Rx ' sent by the second MEP, wherein Tx in the ETH-LM frame is the value of a local sending counter of the MEP sending the ETH-LM frame at the scheduled sending time of the ETH-LM frame, and Tx ' in the ETH-LM frame is the peer MEP received by the MEP sending the ETH-LM frame from the peer MEP at the latest scheduled sending time tlastTx in transmitted ETH-LM frame, Rx' in ETH-LM frame is MEP at (t) where the ETH-LM frame is transmittedlast+ Δ t) the value of the local receive counter, Δ t being the link delay between the two MEPs;
and the first MEP performs far-end frame loss detection according to Tx 'and Rx' in the ETH-LM frame sent by the second MEP at the latest scheduled sending moment and received from the second MEP.
Preferably, the first and second liquid crystal films are made of a polymer,
the method comprises the steps that a first MEP and a second MEP carry out double-end ETH-LM, an ETH-LM frame is a communication check information (CCM) frame, the two MEPs send CCM frames carrying Tx, Tx 'and Rx' in the same mode at the same preset sending time, and frame loss detection is carried out in the same mode;
the first MEP schedules the second MEP at the latest scheduled transmission time t according to the second MEP received from the second MEPlastAnd tlast-1Tx in a transmitted CCM frame, and (t)last+ Δ t) and (t)last-1+ Δ t) time, the value Rx of the local reception counter, and performs frame loss detection at the near end.
Preferably, the first and second liquid crystal films are made of a polymer,
the method comprises the steps that a first MEP and a second MEP carry out single-ended ETH-LM, an ETH-LM frame sent by the first MEP is a loss detection message (LMM) frame, an ETH-LM frame sent by the second MEP is a loss information reply (LMR) frame, and the first MEP and the second MEP use the same preset sending time;
after receiving the LMM frame from the first MEP, the second MEP replies an LMR frame carrying Tx, Tx 'and Rx' to the first MEP at the next scheduled sending moment;
the first MEP schedules the second MEP at the latest scheduled transmission time t according to the second MEP received from the second MEPlast，tlast-1Tx in transmitted LMR frame, and (t)last+ Δ t) and (t)last-1+ Δ t) time, the value Rx of the local reception counter, and performs frame loss detection at the near end.
Preferably, the first and second liquid crystal films are made of a polymer,
the first MEP informs a second MEP of information of a scheduled transmission time at which an ETH-LM frame is periodically transmitted, including:
the first MEP sends one or more notification frames to the second MEP, and the notification frames carry the information of the preset sending time of the ETH-LM frame; wherein:
when the two MEP clocks are synchronized, the information of the scheduled transmission time of the ETH-LM frame includes: the preset sending time of the first ETH-LM frame, or the preset sending time and the link time delay of the first ETH-LM frame; or
When the two MEP clocks are not synchronized, the information of the scheduled transmission time of the ETH-LM frame includes: time delay delta t from current time to scheduled transmission time of first ETH-LM framefOr the time delay deltat from the current moment to the scheduled transmission moment of the first ETH-LM framefAnd link delay Δ t, the second MEP will be (t)k+Δtf- Δ t) is determined as the scheduled transmission instant for transmitting the first ETH-LM frame.
Preferably, the first and second liquid crystal films are made of a polymer,
the two MEPs determine the scheduled transmission time of the ETH-LM frame received between the two scheduled transmission times as the earlier scheduled transmission time of the two scheduled transmission times; or
The two MEPs use the preset sending time as a time stamp in the ETH-LM frame sent by each preset sending time, and the two MEPs determine the preset sending time of the ETH-LM frame according to the time stamp in the ETH-LM frame received from the peer MEP.
Preferably, the first and second liquid crystal films are made of a polymer,
the first MEP retransmits the ETH-LM frame one or more times after transmitting the ETH-LM frame at each predetermined transmission timing.
Preferably, the first and second liquid crystal films are made of a polymer,
one or more notification frames sent by the first MEP to the second MEP also carry ETH-LM frame markers.
Correspondingly, the invention also provides a frame loss detection device, which comprises:
a convention unit, configured to notify a peer maintenance entity group endpoint (MEP) of information of a scheduled transmission time at which an ethernet loss detection function (ETH-LM) frame is periodically transmitted, or determine the scheduled transmission time of the ETH-LM frame according to the notification of the peer MEP;
a transceiving unit, configured to send an ETH-LM frame carrying Tx to the peer MEP at each scheduled sending time, receive an ETH-LM frame carrying Tx ' and Rx ' sent by the peer MEP, where Tx in the ETH-LM frame is a value of a local sending counter of the MEP sending the ETH-LM frame at the scheduled sending time of the ETH-LM frame, and Tx ' in the ETH-LM frame is a value of a peer MEP, which the MEP sending the ETH-LM frame receives from the peer MEP, at the latest scheduled sending time tlastTx in transmitted ETH-LM frame, Rx' in ETH-LM frame is MEP at (t) where the ETH-LM frame is transmittedlast+ Δ t) the value of the local receive counter, Δ t being the link delay between the two MEPs;
and the detection unit is used for carrying out far-end frame loss detection according to Tx 'and Rx' in the ETH-LM frame sent by the peer MEP at the latest secondary scheduled sending moment.
Preferably, the first and second liquid crystal films are made of a polymer,
the detection unit is further configured to schedule a transmission time t at the last second time according to the peer MEP received from the peer MEPlastAnd tlast-1Tx in transmitted ETH-LM frame, and (t)last+ Δ t) and (t)last-1+ Δ t) time, the value Rx of the local reception counter, and performs frame loss detection at the near end.
Preferably, the first and second liquid crystal films are made of a polymer,
the said appointed unit will periodically send the message of the scheduled sending time of ETH-LM frame to notify the peer MEP, including:
the appointed unit sends one or more notification frames to the peer MEP, and the notification frames carry the information of the preset sending time of the ETH-LM frame; wherein:
when the two MEP clocks are synchronized, the information of the scheduled transmission time of the ETH-LM frame includes: the preset sending time of the first ETH-LM frame, or the preset sending time and the link time delay of the first ETH-LM frame; or
When the two MEP clocks are not synchronized, the information of the scheduled transmission time of the ETH-LM frame includes: time delay delta t from current time to scheduled transmission time of first ETH-LM framefOr the time delay deltat from the current moment to the scheduled transmission moment of the first ETH-LM framefAnd link delay at.
Preferably, the first and second liquid crystal films are made of a polymer,
the receiving and sending unit determines the scheduled sending time of the ETH-LM frame received between the two scheduled sending times as the earlier scheduled sending time of the two scheduled sending times; or
The sending and receiving unit takes the preset sending time as a time stamp in the ETH-LM frame sent at each preset sending time, and determines the preset sending time of the ETH-LM frame according to the time stamp in the ETH-LM frame received from the peer MEP.
Preferably, the first and second liquid crystal films are made of a polymer,
the transceiving unit retransmits the ETH-LM frame once or more after transmitting the ETH-LM frame at each scheduled transmission moment.
Preferably, the first and second liquid crystal films are made of a polymer,
one or more notification frames sent by the provisioning unit to the peer MEPs also carry the ETH-LM frame marker.
Correspondingly, the invention also provides a maintenance entity group end point (MEP) comprising the frame loss detection device.
According to the scheme, the sending time is appointed among the peer MEPs, and the sending time window and the receiving time window have the same size and the relative time delay is more reasonable on the premise of not increasing hardware, so that the frame loss detection is more accurately carried out.
The scheme can utilize unused bytes in the original frame to carry additional information such as required counting time and the like, has no influence on the function of the frame, and provides better compatibility. The user can set according to the requirement, and the method is flexible.
The invention can be used for frame loss statistics of multiple packet switching technologies such as multi-protocol label switching (MPLS), provider backbone transport technology (PBT) and the like.
Drawings
FIG. 1 is a flow chart of a method of an embodiment of the present invention;
FIG. 2 is a schematic diagram of the method of FIG. 1 transmitting a plurality of notification frames;
fig. 3 is a schematic diagram of the method of fig. 1 transmitting a plurality of CCM frames;
FIG. 4 is a flow chart of a second method of an embodiment of the invention;
fig. 5 is a schematic diagram of a three-frame loss detection apparatus according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.
The invention uses communication network to explain, the frame loss rate detection can be used for monitoring the node and link state, and can find the change of link state in time, thereby adopting corresponding measures to control.
Herein, a CCM frame (carrying ETH-LM information) sent by a MEP in a double-ended ETH-LM, an LMM frame and an LMR frame sent by a MEP in a single-ended ETH-LM are collectively referred to as ETH-LM frames.
Example one
The present embodiment relates to a dual-ended ETH-LM, where two MEPs maintain clock synchronization and periodically transmit CCM frames in the same manner at the same predetermined transmission timing. Of the two MEPs that are peer MEPs to each other, the MEP that actively initiates frame loss detection is hereinafter referred to as the first MEP, and the other MEP is referred to as the second MEP.
Fig. 1 is a flow chart illustrating a frame loss detection method performed by a first MEP, including:
step 110, the first MEP notifies the second MEP of the information of the scheduled sending time of the periodic sending of the CCM frame;
the information of the scheduled transmission time may be transmitted through a notification frame (also referred to as a notification message), which may carry a flag of the CCM frame, such as a sequence number "101", in addition to the information of the scheduled transmission time. The information of the scheduled transmission time instant may be carried in an additional information element of the CCM frame. The first MEP may also send a plurality of notification frames to ensure that the second MEP can receive the notification frames, as shown in fig. 2, where the sending end is the first MEP and the receiving end is the second MEP.
The information of the scheduled transmission time may be the scheduled transmission time (which may also include a transmission period) of the first CCM frame, and the second MEP may determine each scheduled transmission time at which the first MEP transmits a CCM frame according to the information and the transmission period. The two MEPs may also be scheduled for transmission periods in other manners, such as in advance.
Step 120, the first MEP sends CCM frames carrying Tx1, Tx '1 and Rx' 1 to the second MEP at each scheduled sending time, and receives CCM frames carrying Tx2, Tx '2 and Rx' 2 sent by the second MEP;
in this step, the two MEPs may determine the scheduled transmission time of the received CCM frame in one of the following two manners:
the two MEPs determine a scheduled transmission time of a CCM frame received between two scheduled transmission times as the earlier scheduled transmission time of the two scheduled transmission times; or
The two MEPs use the scheduled transmission time as a timestamp in the CCM frame transmitted by each scheduled transmission time, and the two MEPs determine the scheduled transmission time of the CCM frame according to the timestamp in the CCM frame received from the peer MEP.
The meaning of each parameter in the CCM frame involved in this step is as follows:
tx1 is the value of the local transmission counter of the first MEP at the scheduled transmission time of the CCM frame;
tx' 1 is the second MEP that the first MEP received from the second MEP at the last scheduled transmission time tlastTx1 in the transmitted CCM frame;
rx' 1 is where the first MEP is at (t)last+ Δ t) the value of the local receive counter, Δ t being the link delay between the two MEPs;
tx2 is the value of the local transmission counter of the second MEP at the scheduled transmission time of the CCM frame;
tx' 2 is the first MEP that the second MEP received from the first MEP at the last scheduled transmission time tlastTx1 in the transmitted CCM frame;
rx' 2 is where the second MEP is at (t)last+ at) the value of the local receive counter, at being the link delay between the two MEPs.
In the case of dual-end ETH-LM, the processing of two MEPs in sending, receiving CCMs and performing frame loss detection is the same, and the parameters in each CCM frame can be uniformly defined as follows:
tx in the CCM frame is the value of a local transmission counter of an MEP which transmits the CCM frame at the scheduled transmission moment of the CCM frame;
tx' in CCM frame is the scheduled transmission time t of the peer MEP (the latest time before the CCM frame is transmitted) from the peer MEP received by the MEP transmitting the CCM framelastTx in a transmitted CCM frame;
rx' in CCM frames isThe MEP sending the CCM frame is at (t)last+ at) the value of the local receive counter, at being the link delay between the two MEPs.
The Δ t may be self-tested by the two MEPs, or may be notified by one MEP to the other MEP, for example, the notification frame sent by the first MEP to the second MEP is carried by the first MEP to notify the second MEP, or may be learned by other manners, which is not limited in the present invention.
The first MEP may also retransmit the CCM frame one or more times after transmitting the CCM frame at each scheduled transmission time, ensuring that the receiving end can receive the CCM frame, as does the second MEP. As shown in fig. 3, the sending end may be a first MEP or a second MEP, the receiving end is a peer MEP of the sending end, and the data packet in the figure
Step 130, the first MEP performs far-end frame loss detection according to Tx '2 and Rx' 2 in the CCM frame sent by the second MEP at the latest secondary scheduled sending time, where the second MEP is received from the second MEP; tx2 in a CCM frame transmitted at the last two scheduled transmission times based on a second MEP received from the second MEP, and (t)last+ Δ t) and (t)last-1+ Δ t) the value Rx1 of the local reception counter, and frame loss detection at the near end is performed.
If the second MEP is scheduled to transmit at the latest scheduled transmission time tlastTx ' 2 and Rx ' 2 in a transmitted CCM frame are denoted as Tx ' 2[ tlast]And Rx' 2[ tlast]The last previous scheduled transmission time t (called the next-to-last time)last-1Tx ' 2 and Rx ' 2 in a transmitted CCM frame are denoted as Tx ' 2[ tlast-1]And Rx' 2[ tlast-1]According to the definition of far-end frame loss, the number of far-end frame loss is calculated according to the following formula:
FrameLostfar-end＝|Tx′2[tlast]-Tx′2[tlast-1]|-|Rx′2[tlast]-Rx′2[tlast-1]|
as can be seen from the above definition of the parameters, Tx' 2[ t [, wherelast]Equal to Tx1[ t ] in CCM frame transmitted by first MEP at the next last scheduled transmission timelast-1]The duplicate is that the first MEP locally transmits the counter value at the next scheduled transmission time, again Tx' 2[ t ]last-1]Duplicated is the first MEP at the next most previous scheduled transmission time tlast-2The value of the counter is sent locally. The difference between the two is that the first MEP is at tlast-2To tlast-1The number of data frames transmitted within this transmission time window. Corresponding, Rx' 2[ tlast]Is the second MEP at (t)last-1+ Δ t) value of the local reception counter, Rx' 2[ t ]last-1]Is the second MEP at (t)last-2The value of the counter is received locally at time + Δ t), so that the difference is that the second MEP is at (t)last-2+ Δ t to (t)last-1+ Δ t) the number of data frames received in this reception time window.
It can be seen that the above formula conforms to the meaning of far-end frame loss detection specified by the protocol, the size of the receiving time window is the same as that of the sending time window, and the relative time delay is equal to the link time delay and is closer to the average transmission time of the data frame. Far-end frame loss detection can thus be performed more accurately.
E.g. by setting the second MEP at tlastTx2 in the transmitted CCM frame is denoted as Tx2[ t [ ]last]At tlast-1Tx2 in the transmitted CCM frame is denoted as Tx2[ t [ ]last-1]The first MEP is at (t)last+ Δ t) the value of the local receive counter Rx1 is denoted as Rx1[ t [last]At (t)last-1+ Δ t) the value of the local receive counter Rx1 is denoted as Rx1[ t [last-1]According to the definition of near-end frame loss, the number of near-end frame loss is calculated according to the following formula:
FrameLostnear-end＝|Tx2[tlast]-Tx2[tlast-1]|-|Rx1[tlast]-Rx1[tlast-1]|
according to the definition of the above parameters, Tx2[ t [ t ] ]last]Is the value of the local transmit counter, Tx2[ t ], of the second MEP at the last scheduled transmit timelast-1]Is that the second MEP is at the next most recent scheduled transmission time tlast-1The value of the counter is sent locally. The difference between the two is the second MEP at tlast-1To tlastThe number of data frames transmitted within this transmission time window. Correspondingly, Rx1[ t ]last]Is the first MEP at (t)last+ Δ t) value of the local reception counter, Rx1[ tlast-1]Is the first MEP at (t)last-1The value of the counter is received locally at time + Δ t), so that the difference between the two is that the first MEP is at (t)last-1+ Δ t to (t)last+ Δ t) the number of data frames received in this reception time window.
It can be seen that the formula conforms to the specification of near-end frame loss detection, the size of the receiving time window is the same as that of the sending time window, and the relative time delay of the two time windows is equal to the link time delay and is closer to the average transmission time of the data frame. Near-end frame loss detection can thus be performed more accurately.
Compared with the prior art, the scheduled sending time of the CCM frame is defined between two peer MEPs, the receiving time window corresponding to the sending time window formed by two adjacent scheduled sending times is designed to be the position where the sending time window is delayed by one link delay, the sending time window and the receiving window can be ensured to be the same in size, and the relative delay is equal to the average transmission time of the data frame, so that the effect of more accurately detecting the frame loss is achieved. In addition, the unused bytes in the original frame can be used for carrying additional information such as required scheduled transmission time, the function of the frame is not affected, and better compatibility is provided. The user can set according to the requirement, and the method is flexible.
In a variation of this embodiment, the two MEPs do not require strict clock synchronization. At this time, in order to enable two MEPs to transmit CCM frames at the same scheduled transmission time, in this modification, the time delay Δ t from the current time to the scheduled transmission time at which the first CCM frame is transmitted is setfAs the information that the first MEP notifies the scheduled transmission time of the CCM frame of the second MEP, the information may further include information of the link delay Δ t. Second MEP at time tkAfter receiving the notification, (t)k+Δtf- Δ t) determining a scheduled transmission instant for the first MEP to transmit the first CCM frame. Other processes andthe same applies to the first embodiment.
Example two
The embodiment relates to a single-ended ETH-LM, two MEPs keep clock synchronization, and an MEP actively initiating frame loss detection in the two MEPs which are mutually peer MEPs is called a first MEP, and the other MEP is called a second MEP. The first MEP sends LMM frames, the second MEP sends LMR frames, and the LMM frames and the LMR frames are scheduled to be sent at the same time.
Fig. 4 is a flowchart illustrating a frame loss detection method performed by the first MEP, including:
step 210, the first MEP notifies the second MEP of the information of the scheduled sending time of the periodically sent LMM frame;
this step can implement notification in the same manner as in the first embodiment.
Step 220, the first MEP sends an LMM frame carrying Tx1 to the second MEP at each scheduled sending time, and receives an LMR frame carrying Tx2, Tx '2 and Rx' 2 sent by the second MEP;
in this step, the two MEPs may determine the LMM frame received from the peer MEP or the scheduled transmission time of the LMR in two ways as in the first embodiment.
The meaning of each parameter in the frame involved in this step is as follows:
tx1 is the value of the local transmission counter of the first MEP at the time of the scheduled transmission of the LMM frame;
tx2 is the value of the local transmission counter of the second MEP at the time of the scheduled transmission of the LMR frame;
tx' 2 is the first MEP that the second MEP received from the first MEP at the last scheduled transmission time tlastTx1 in the transmitted LMM frame;
rx' 2 is where the second MEP is at (t)last+ Δ t) the value of the local reception counter, Δ t being the link time between the two MEPsAnd (5) delaying.
Similarly, the first MEP may retransmit the LMM frame one or more times after transmitting the LMM frame at each scheduled transmission time, so as to ensure that the LMM frame can be received by the receiving end. And the second MEP transmits a reply LMR frame to the LMM frame transmitted by the first MEP at the last scheduled transmission time at each scheduled transmission time. The LMR frame may also be retransmitted one or more times.
Step 230, the first MEP performs far-end frame loss detection according to Tx '2 and Rx' 2 in the LMR frame sent by the second MEP at the latest scheduled sending time, which is received from the second MEP; tx2 in an LMR frame transmitted at the last second scheduled transmission time based on a second MEP received from the second MEP, and (t)last+ Δ t) and (t)last-1+ Δ t) the value of the local reception counter Rx1 for near-end frame loss detection.
In the single-ended ETH-LM of this embodiment, the frame loss detection calculation of the first MEP is the same as the frame loss detection calculation formula of the first MEP in the double-ended ETH-LM, except that the relevant parameters are obtained from the LMR frame instead of the CCM frame. Therefore, the present embodiment conforms to the provision of frame loss detection, and the receiving time window and the sending time window have the same size, and the relative time delay of the two time windows is equal to the link time delay and is closer to the average transmission time of the data frame. Near-end frame loss detection can thus be performed more accurately.
EXAMPLE III
Based on the solutions provided by the two embodiments, this embodiment provides a maintenance entity group end point (MEP) used in the two embodiments, where the MEP includes a frame loss detection apparatus, as shown in fig. 5, the frame loss detection apparatus includes:
an appointment unit 10, configured to notify the peer MEPs of information of a scheduled transmission time at which an ethernet loss detection function (ETH-LM) frame is periodically transmitted, or determine the scheduled transmission time of the ETH-LM frame according to the notification of the peer MEPs;
transceiver unit20, configured to send an ETH-LM frame carrying Tx to the peer MEP at each scheduled sending time, receive an ETH-LM frame carrying Tx ' and Rx ' sent by the peer MEP, where Tx in the ETH-LM frame is a value of a local sending counter of the MEP sending the ETH-LM frame at the scheduled sending time of the ETH-LM frame, and Tx ' in the ETH-LM frame is a value of a peer MEP, which the MEP sending the ETH-LM frame receives from the peer MEP, at the latest scheduled sending time tlastTx in transmitted ETH-LM frame, Rx' in ETH-LM frame is MEP at (t) where the ETH-LM frame is transmittedlast+ Δ t) the value of the local receive counter, Δ t being the link delay between the two MEPs;
the detecting unit 30 is configured to perform far-end frame loss detection according to Tx 'and Rx' in the ETH-LM frame sent by the peer MEP at the latest secondary scheduled sending time, where the peer MEP is received from the peer MEP.
Further, the air conditioner is provided with a fan,
the detection unit 30 may also be configured to schedule the transmission time t at the last second scheduled transmission time according to the peer MEPs received from the peer MEPslastAnd tlast-1Tx in transmitted ETH-LM frame, and (t)last+ Δ t) and (t)last-1+ Δ t) time, the value Rx of the local reception counter, and performs frame loss detection at the near end.
Further, the air conditioner is provided with a fan,
the said appointment unit 10 notifies the peer MEP of the information of the scheduled transmission time of the periodically transmitted ETH-LM frame, including:
the appointment unit 10 sends one or more notification frames to the peer MEPs, carrying information of the scheduled sending time of the ETH-LM frame; wherein:
when the two MEP clocks are synchronized, the information of the scheduled transmission time of the ETH-LM frame includes: the preset sending time of the first ETH-LM frame, or the preset sending time and the link time delay of the first ETH-LM frame; or
When the two MEP clocks are not synchronized, the information of the scheduled transmission time of the ETH-LM frame includes: from the current time to the first ETH-LM frameTime delay delta t of predetermined transmission timefOr the time delay deltat from the current moment to the scheduled transmission moment of the first ETH-LM framefAnd link delay at.
Further, the air conditioner is provided with a fan,
the transceiving unit 20 may determine the scheduled transmission time of the ETH-LM frame received between the two scheduled transmission times as an earlier scheduled transmission time of the two scheduled transmission times; or
The transceiving unit 20 takes the scheduled transmission time as a timestamp in the ETH-LM frame transmitted at each scheduled transmission time, and determines the scheduled transmission time of the ETH-LM frame according to the timestamp in the ETH-LM frame received from the peer MEP.
Further, the air conditioner is provided with a fan,
the transceiving unit 20 retransmits the ETH-LM frame once or more after transmitting the ETH-LM frame at each predetermined transmission time.
Further, the air conditioner is provided with a fan,
one or more notification frames sent by the provisioning unit 10 to the peer MEPs also carry the ETH-LM frame flag.
It will be understood by those skilled in the art that all or part of the steps of the above methods may be implemented by instructing the relevant hardware through a program, and the program may be stored in a computer readable storage medium, such as a read-only memory, a magnetic or optical disk, and the like. Alternatively, all or part of the steps of the foregoing embodiments may also be implemented by using one or more integrated circuits, and accordingly, each module/unit in the foregoing embodiments may be implemented in the form of hardware, and may also be implemented in the form of a software functional module. The present invention is not limited to any specific form of combination of hardware and software.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A frame loss detection method is applied to a system including a first MEP and a second MEP which are mutually peer-to-peer maintenance entity group end point MEPs, and the method comprises the following steps:
the first MEP informs a second MEP of the information of the scheduled sending time of the Ethernet loss detection function ETH-LM frame which is sent periodically;
the first MEP sends an ETH-LM frame carrying Tx to the second MEP at each preset sending time, receives an ETH-LM frame carrying Tx 'and Rx' sent by the second MEP, and Tx in the ETH-LM frame is the local position of the MEP sending the ETH-LM frame at the preset sending time of the ETH-LM frameThe value of the transmission counter, Tx' in ETH-LM frame is the peer MEP received by MEP transmitting the ETH-LM frame from peer MEP at the latest scheduled transmission time tlastTx in transmitted ETH-LM frame, Rx' in ETH-LM frame is MEP at (t) where the ETH-LM frame is transmittedlast+ △ t) the value of the local receive counter, △ t being the link delay between the two MEPs;
the first MEP carries out far-end frame loss detection according to Tx 'and Rx' in ETH-LM frames sent by the second MEP at the latest preset sending moment;
wherein,
the two MEPs determine the scheduled transmission time of the ETH-LM frame received between the two scheduled transmission times as the earlier scheduled transmission time of the two scheduled transmission times; or
The two MEPs use the preset sending time as a timestamp in the ETH-LM frame sent by each preset sending time, and the two MEPs determine the preset sending time of the ETH-LM frame according to the timestamp in the ETH-LM frame received from the peer MEP;
the first MEP informs a second MEP of information of a scheduled transmission time at which an ETH-LM frame is periodically transmitted, including:
the first MEP sends one or more notification frames to the second MEP, and the notification frames carry the information of the preset sending time of the ETH-LM frame; wherein:
when the two MEP clocks are synchronized, the information of the scheduled transmission time of the ETH-LM frame includes: the preset sending time of the first ETH-LM frame, or the preset sending time and the link time delay of the first ETH-LM frame; or
When the two MEP clocks are not synchronized, the information of the scheduled transmission time of the ETH-LM frame comprises a time delay △ t from the current time to the scheduled transmission time of the first ETH-LM framefOr a time delay △ t from the current time to the scheduled transmission time of the first ETH-LM framefAnd link latency △ t, the second MEP will be (t)k+△tf- △ t) is determined as the scheduled transmission instant for transmitting the first ETH-LM frame.
2. The frame loss detection method of claim 1, wherein:
the method comprises the steps that a first MEP and a second MEP carry out double-end ETH-LM, an ETH-LM frame is a CCM frame of communication check information, the two MEPs send CCM frames carrying Tx, Tx 'and Rx' in the same mode at the same preset sending time, and frame loss detection is carried out in the same mode;
the first MEP schedules the second MEP at the latest scheduled transmission time t according to the second MEP received from the second MEPlastAnd tlast-1Tx in a transmitted CCM frame, and (t)last+ △ t) and (t)last-1+ △ t) the value Rx of the local reception counter, and frame loss detection at the near end is performed.
3. The frame loss detection method of claim 1, wherein:
the method comprises the steps that a first MEP and a second MEP carry out single-ended ETH-LM, an ETH-LM frame sent by the first MEP is a loss detection message (LMM) frame, an ETH-LM frame sent by the second MEP is a loss information reply LMR frame, and the first MEP and the second MEP use the same preset sending time;
after receiving the LMM frame from the first MEP, the second MEP replies an LMR frame carrying Tx, Tx 'and Rx' to the first MEP at the next scheduled sending moment;
the first MEP schedules the second MEP at the latest scheduled transmission time t according to the second MEP received from the second MEPlast,tlast-1Tx in transmitted LMR frame, and (t)last+ △ t) and (t)last-1+ △ t) the value Rx of the local reception counter, and frame loss detection at the near end is performed.
4. The frame loss detection method of claim 1, wherein:
the first MEP retransmits the ETH-LM frame one or more times after transmitting the ETH-LM frame at each predetermined transmission timing.
5. The frame loss detection method of claim 1, wherein:
one or more notification frames sent by the first MEP to the second MEP also carry ETH-LM frame markers.
6. A frame loss detection apparatus, characterized in that the frame loss detection apparatus comprises:
the system comprises a convention unit, a peer maintenance entity group end point MEP and a peer MEP, wherein the convention unit is used for notifying the information of the scheduled sending time of the Ethernet loss detection function ETH-LM frame to the peer maintenance entity group end point MEP periodically or determining the scheduled sending time of the ETH-LM frame according to the notification of the peer MEP;
a transceiving unit, configured to send an ETH-LM frame carrying Tx to the peer MEP at each scheduled sending time, receive an ETH-LM frame carrying Tx ' and Rx ' sent by the peer MEP, where Tx in the ETH-LM frame is a value of a local sending counter of the MEP sending the ETH-LM frame at the scheduled sending time of the ETH-LM frame, and Tx ' in the ETH-LM frame is a value of a peer MEP, which the MEP sending the ETH-LM frame receives from the peer MEP, at the latest scheduled sending time tlastTx in transmitted ETH-LM frame, Rx' in ETH-LM frame is MEP at (t) where the ETH-LM frame is transmittedlast+ △ t) the value of the local receive counter, △ t being the link delay between the two MEPs;
the detection unit is used for carrying out far-end frame loss detection according to Tx 'and Rx' in ETH-LM frames sent by peer MEPs at the latest secondary scheduled sending time;
wherein,
the receiving and sending unit determines the scheduled sending time of the ETH-LM frame received between the two scheduled sending times as the earlier scheduled sending time of the two scheduled sending times; or
The receiving and sending unit takes the preset sending time as a time stamp in the ETH-LM frame sent at each preset sending time, and determines the preset sending time of the ETH-LM frame according to the time stamp in the ETH-LM frame received from the peer MEP;
the said appointed unit will periodically send the message of the scheduled sending time of ETH-LM frame to notify the peer MEP, including:
the appointed unit sends one or more notification frames to the peer MEP, and the notification frames carry the information of the preset sending time of the ETH-LM frame; wherein:
when the two MEP clocks are synchronized, the information of the scheduled transmission time of the ETH-LM frame includes: the preset sending time of the first ETH-LM frame, or the preset sending time and the link time delay of the first ETH-LM frame; or
When the two MEP clocks are not synchronized, the information of the scheduled transmission time of the ETH-LM frame comprises a time delay △ t from the current time to the scheduled transmission time of the first ETH-LM framefOr a time delay △ t from the current time to the scheduled transmission time of the first ETH-LM framefAnd link latency △ t.
7. The frame loss detection apparatus of claim 6, wherein:
the detection unit is further configured to schedule a transmission time t at the last second time according to the peer MEP received from the peer MEPlastAnd tlast-1Tx in transmitted ETH-LM frame, and (t)last+ △ t) and (t)last-1+ △ t) the value Rx of the local reception counter, and frame loss detection at the near end is performed.
8. The frame loss detection apparatus of claim 6, wherein:
the transceiving unit retransmits the ETH-LM frame once or more after transmitting the ETH-LM frame at each scheduled transmission moment.
9. The frame loss detection apparatus of claim 6, wherein:
one or more notification frames sent by the provisioning unit to the peer MEPs also carry the ETH-LM frame marker.
10. A maintenance entity group end point, MEP, comprising frame loss detection means as claimed in claim 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210162728.5A CN102684838B (en) | 2012-05-23 | 2012-05-23 | A kind of LOF detection method, device and Maintenance Entity end points |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210162728.5A CN102684838B (en) | 2012-05-23 | 2012-05-23 | A kind of LOF detection method, device and Maintenance Entity end points |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102684838A CN102684838A (en) | 2012-09-19 |
| CN102684838B true CN102684838B (en) | 2016-01-20 |
Family
ID=46816251
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210162728.5A Active CN102684838B (en) | 2012-05-23 | 2012-05-23 | A kind of LOF detection method, device and Maintenance Entity end points |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102684838B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105530141A (en) * | 2014-10-27 | 2016-04-27 | 中兴通讯股份有限公司 | Link state detection method and device |
| CN105812155A (en) * | 2014-12-25 | 2016-07-27 | 中兴通讯股份有限公司 | Method and device for optimizing loss monitoring |
| CN112688833A (en) * | 2020-12-31 | 2021-04-20 | 昆高新芯微电子(江苏)有限公司 | Method and device for measuring network time delay and time delay jitter and computer storage medium |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101056223A (en) * | 2007-05-30 | 2007-10-17 | 杭州华三通信技术有限公司 | Link failure detection method and device |
| JP2008244870A (en) * | 2007-03-27 | 2008-10-09 | Sumitomo Electric Ind Ltd | COMMUNICATION SYSTEM, RELAY DEVICE USED FOR THE SAME, AND METHOD OF MEASURING FRAME LOSS |
| CN101800679A (en) * | 2010-03-10 | 2010-08-11 | 华为技术有限公司 | Message packet loss detection method and system |
| CN102045230A (en) * | 2010-12-07 | 2011-05-04 | 中兴通讯股份有限公司 | Ethernet link protection switching method and device |
| CN102546117A (en) * | 2012-02-20 | 2012-07-04 | 瑞斯康达科技发展股份有限公司 | Frame loss measuring method, frame loss measuring device and frame loss measuring system |
-
2012
- 2012-05-23 CN CN201210162728.5A patent/CN102684838B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008244870A (en) * | 2007-03-27 | 2008-10-09 | Sumitomo Electric Ind Ltd | COMMUNICATION SYSTEM, RELAY DEVICE USED FOR THE SAME, AND METHOD OF MEASURING FRAME LOSS |
| CN101056223A (en) * | 2007-05-30 | 2007-10-17 | 杭州华三通信技术有限公司 | Link failure detection method and device |
| CN101800679A (en) * | 2010-03-10 | 2010-08-11 | 华为技术有限公司 | Message packet loss detection method and system |
| CN102045230A (en) * | 2010-12-07 | 2011-05-04 | 中兴通讯股份有限公司 | Ethernet link protection switching method and device |
| CN102546117A (en) * | 2012-02-20 | 2012-07-04 | 瑞斯康达科技发展股份有限公司 | Frame loss measuring method, frame loss measuring device and frame loss measuring system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102684838A (en) | 2012-09-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11943644B2 (en) | Method and system for performance estimation of a communication link | |
| EP2242236B1 (en) | Method for measuring frame loss, system for measuring frame loss, and device for measuring frame loss | |
| EP1931084B1 (en) | A method for getting the link estimating parameters | |
| JP4685672B2 (en) | Available bandwidth estimation | |
| US20100020698A1 (en) | Communication apparatus and OAM frame transmission method | |
| JP2015528241A (en) | Method and system for measuring communication line performance | |
| Haxhibeqiri et al. | Enabling TSN over IEEE 802.11: Low-overhead time synchronization for Wi-Fi clients | |
| JP2017526296A (en) | Data transmission method and base station | |
| CN103107870A (en) | Wireless network device and automatic parameter setting method thereof | |
| WO2022063078A1 (en) | Data processing method and apparatus | |
| CN102684838B (en) | A kind of LOF detection method, device and Maintenance Entity end points | |
| US9077629B2 (en) | Communication device, and signal degradation monitoring system and method | |
| CN102487338B (en) | Method and device for adjusting bidirectional forwarding detection (BFD) sending interval according to network jitter | |
| KR20150041952A (en) | IP based sleep mode control method using synchonization information | |
| US10050856B2 (en) | Communication device, network available bandwidth estimation method in communication device, and storage medium on which network available bandwidth estimation program has been recorded | |
| EP2628274B1 (en) | Reducing continuity check message (ccm) bursts in connectivity fault management (cfm) maintenance association (ma) | |
| JP3614835B2 (en) | Packet communication quality measuring method and system | |
| EP2854339B1 (en) | Transmission monitoring method and device | |
| WO2023231426A1 (en) | Delay measurement method and apparatus, storage medium and program product | |
| US9203718B2 (en) | Frame loss measurement device, communication device, communication system and performance measurement method | |
| US20150071096A1 (en) | Loss measurement in a link aggregation group | |
| CN102624746B (en) | Detect the method for two ends, tunnel GRE head configuration, source, destination and system | |
| US9473597B2 (en) | Implementing multiple MAC protocols using a single wireless communication unit | |
| TW202418788A (en) | Methods of ue-assisted report and ue | |
| Cotroneo et al. | Reliable monitoring of network-related performance parameters in wireless environments |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |