Transmission device estimation method and estimating unit

An estimating unit includes: an error detecting unit which detects an error among a plurality of frames received from an interface unit of a transmission device; a request sending unit which produces a first frame including a data collection request for requesting data collection upon the error detecting unit detecting the error, and which sends the first frame to the interface unit; an extracting unit which extracts, from the plurality of frames received from the interface unit, a second frame including the error detected by the error detecting unit and a third frame including a reply of the interface unit to the data collection request; and a saving unit in which the second frame extracted by the extracting unit is saved.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2009-068423, filed on Mar. 19, 2009, the entire contents of which are incorporated herein by reference.

FIELD

The embodiments discussed herein are related to a transmission device estimation method for estimating a transmission device and an estimating unit.

BACKGROUND

In a case, where a transmission device of an IP (Internet Protocol) network is estimated for example, the transmission device is estimated by means of IP packets.

FIG. 1illustrates a configuration diagram of an example of an ordinary transmission device estimation method. InFIG. 1, a packet for estimation produced by a packet producing unit10is provided to an optical transceiver13aprovided in an IF (interface) unit13of a transmission device12through an optical cable11. After being processed in the transmission device12, the packet for estimation is output from an optical transceiver13bof the IF unit13, and is provided to an estimating device15through an optical cable14.

The estimating device15accumulates provided packets for estimation. The estimating device15performs error detection for accumulated packets for estimation.

FIG. 2illustrates a configuration diagram of another example of the ordinary transmission device estimation method. InFIG. 2, packets for estimation produced by the packet producing unit10are provided to the optical transceiver13aprovided in the IF unit13of the transmission device12through the optical cable11. After being processed in the transmission device12, the packets for estimation are output from an optical transceiver13cof the IF unit13, and are provided to an optical transceiver18aprovided in an IF unit18of a transmission device17through an optical cable16. The IF unit18performs a simple error detection process for the provided packets. The IF unit18turns on an LED19provided in the IF unit18for an error indication in case of detecting an error.

As a related art, Japanese Laid-open Patent Publication No. 02-116240 discloses an art such that a packet communication device measures a quantity of flowing from a terminal and abandons a packet of a call of the terminal in a case where the terminal does not obey a declared quantity of flowing.

SUMMARY

According to an aspect of the invention, an estimating unit includes: an error detecting unit which detects an error among a plurality of frames received from an interface unit of a transmission device; a request sending unit which produces a first frame including a data collection request for requesting data collection upon the error detecting unit detecting the error, and which sends the first frame to the interface unit; an extracting unit which extracts, from the plurality of frames received from the interface unit, a second frame including the error detected by the error detecting unit and a third frame including a reply of the interface unit to the data collection request; and a saving unit in which the second frame extracted by the extracting unit is saved.

According to another aspect of the invention, a transmission device estimation method for estimating a transmission device includes: detecting an error among a plurality of frames received from an interface unit of the transmission device; producing a first frame including a data collection request for requesting a data collection upon the error detecting unit detecting the error and sending the first frame to the interface unit; extracting, from the plurality of frames received from the interface unit, a second frame including the error detected by the error detecting unit and a third frame including a reply of the interface unit to the data collection request; and saving the extracted second frame in a saving unit.

DESCRIPTION OF EMBODIMENT(S)

According to the related art illustrated inFIG. 1, when the transmission device12is estimated, the estimating device15takes in, accumulates, and estimates all the transmitted packets for estimation. Thus, the transmission device12is desirably provided with a large quantity of packets for estimation for measuring an error of a very low frequency of occurrence. As a large quantity of packets for estimation is accumulated in the estimating device15in this case, a problem possibly occurs where a memory of the estimating device15for accumulating packets overflows and a target packet may not be obtained. The target packet mentioned here is a packet which produces an error of a very low frequency of occurrence.

There is another problem in that, when an error is detected for a packet for estimation accumulated in the estimating device15, a voltage of the transmission device12or of the IF unit13and environmental data such as temperature at the time of an output of the packet for estimation for which an error is detected may not be collected.

Further, if the optical transceiver13cof the IF unit13is connected to the optical transceiver18aof the IF unit18of the transmission device17through the optical cable16as illustrated inFIG. 2, the estimating device15may not be connected to the optical transceiver18aof the IF unit18. There is a problem in this case in that only an error detection process where an LED19is turned on for an error indication may be performed.

An embodiment will be explained with reference to the drawings hereafter.

Configuration of Transmission Device

FIG. 3illustrates a configuration diagram of an embodiment of a transmission device having an estimating unit. InFIG. 3, a frame (or a packet) for estimation produced by a packet producing unit20is provided to an optical transceiver23aprovided in an IF unit23of a transmission device22through an optical cable21. After being processed by the IF unit23in the transmission device22or by another unit in the transmission device22, the packet for estimation is output from an optical transceiver23bof the IF unit23to an optical transceiver25athrough an optical cable24and is provided to an estimating unit25in the transmission device22. An optical transceiver25bof the estimating unit25is connected to a storage device27through an optical cable26. The estimating unit25may not be connected to the storage device27.

Configuration of Estimating Unit

FIG. 4illustrates a configuration diagram of an embodiment of the estimating unit25.FIG. 5illustrates a configuration diagram of an embodiment of a jig unit32in the estimating unit25.

InFIG. 4, an input unit31, which corresponds to the optical transceiver25a, converts an optical signal provided from the optical cable24into an electric signal and provides the jig unit32with the electric signal. An output unit33converts an electric signal of a main signal provided by the jig unit32into an optical signal and outputs the optical signal.

The jig unit32extracts a frame of a packet for estimation for which an error is detected or a frame of a response OAM packet described later. The jig unit32provides a data saving unit34with the extracted frame so that the extracted frame is saved (accumulated) in the data saving unit34. The jig unit32provides an output unit35with the extracted frame. The output unit35corresponds to the optical transceiver25b. The output unit35converts a provided electric signal into an optical signal and provides the storage device27with the optical signal through the optical cable26for data storage (accumulation).

The storage device27illustrated inFIG. 3corresponds to the function of the data saving unit34illustrated inFIG. 4provided outside the estimating unit25. If the data saving unit34is provided, it is unnecessary to connect the storage device27. Further, if the storage device27is connected and used, it is unnecessary to provide the data saving unit34.

The data saving unit34is connected to an external computer which is not illustrated through a PC (personal computer)-IF unit38. The external computer reads and analyzes what is saved in the data saving unit34.

Further, upon detecting an error of a packet for estimation, the jig unit32produces an OAM (Operation, Administration, & Management) packet, and provides an output unit36with a frame of the OAM packet. The output unit36, which corresponds to the optical transceiver25a, converts an electric signal of the frame of the OAM packet into an optical signal, and provides the IF unit23with the optical signal through the optical cable24. Further, upon detecting an error of a frame of a packet for estimation, the jig unit32turns on an LED (light emitting diode)37arranged on a front panel of the transmission device for indication.

Configuration of Jig Unit

InFIG. 5, a frame (electric signal) of a received packet is input from the input unit31illustrated inFIG. 4to a terminal41and provided to a packet indentifying unit42. The packet indentifying unit42identifies whether the provided received packet is a reply OAM packet, e.g., an OAM packet with which the IF unit23replied to a data collection request OAM packet produced by an OAM producing unit51, by detecting a source address and an ether type.

If the OAM packet is a reply OAM packet, the packet indentifying unit42provides a FIFO43and a CRC operation unit44with the reply OAM packet. If it is an ordinary packet other than a reply OAM packet, e.g., a packet for estimation, the packet indentifying unit42provides the FIFO43and the CRC operation unit44with the packet and provides the output unit33with the packet through a terminal45.

The FIFO43buffers the frame of the received packet and provides a comparing unit46and a FIFO47with the frame of the received packet. The CRC operation unit44carries out an error detection code operation. The CRC operation unit44calculates a CRC (Cyclic Redundancy Check) value from a destination address to data of the received packet, and provides the comparing unit46with the CRC value.

FIG. 6illustrates a frame format of a received packet. The frame format includes a preamble at the head followed by fields of a destination address (Destination MAC Address), a source address (Source MAC Address), and an ether type (Ether Type) provided as a header. In the frame format, the header is followed by a data (Data) field, and an FCS (Frame Check Sequence) field. The data field includes an IP packet as data, and the FCS includes a CRC value (code data for error correction) calculated from the values from the destination address to the data.

A standard holding unit48holds an address of the IF unit23as the source address. The standard holding unit48provides the comparing unit46with the source address (address of the IF unit23) as a standard value. The source addresses in the frame of the packet for estimation provided by the IF unit23to the estimating unit25and in the frame of the reply OAM packet are the address of the above IF unit23.

The standard holding unit48is configured to hold the destination address, a plurality of types of ether types that the packet for estimation or the reply OAM packet may take as a standard value in addition to the source address (address of the IF unit23), and to provide the comparing unit46with the standard value.

The comparing unit46compares the CRC value provided by the CRC operation unit44with an FCS field value of a frame of a received packet output by the FIFO43concurrently with the output of the CRC operation unit44, so as to identify an agreement. Further, the comparing unit46compares the source address of the frame of the received packet with the source address provided by the standard holding unit48so as to identify an agreement.

If the standard holding unit48holds for example the destination address, the comparing unit46also identifies an agreement between the destination address of the frame of the received packet and the source address of the standard holding unit48. The comparing unit46notifies the OAM producing unit51, a packet insertion/abandonment unit52, and an LED drive unit53individually of the results of identifying the agreements.

Upon being notified of a disagreement by the comparing unit46, the OAM producing unit51produces a data collection request OAM packet for requesting the IF unit23to collect temperature data or voltage data. At this time, the OAM producing unit51includes time data provided by a timer unit54in the OAM packet. A frame of the data collection request OAM packet produced here is provided to the output unit36through a terminal55. The OAM producing unit51notifies the packet insertion/abandonment unit52of an output of the data collection request OAM packet.

FIG. 7illustrates a frame format of the data collection request OAM packet. The frame format includes a preamble at the head followed by fields of a destination address (Destination MAC Address), a source address (Source MAC Address), and an ether type (Ether Type).

In the frame format, the above fields are followed by various OAM data fields. Fields of “ME level,” “ver,” and “OpCode” indicate OAM level data, a version, and an operation code that indicate the type of OAM messages, respectively. Further, fields of “Flags,” and “TVL offset” are provided. Further, fields of “What is requested” and “Request/Reply Flag” are provided. Requested data such as temperature and voltage and time data are set to “What is requested.” A request is set to the “Request/Reply Flag.”

A data (Data) field is empty (ALL1or0). A field of “End TVL” is provided next to the data field, and then an FCS field is provided. A CRC value calculated from values from the destination address to “End TVL” is saved in the “FCS” field.

FIG. 8illustrates a frame format of the reply OAM packet. The frame format includes a preamble at the head followed by fields of a destination address (Destination MAC Address), a source address (Source MAC Address), and an ether type (Ether Type).

In the frame format, the above fields are followed by various OAM data fields. Fields of “ME level,” “ver,” and “OpCode” indicate OAM level data, a version, and an operation code that indicates the kinds of OAM messages, respectively. Further, fields of “Flags,” and “TVL offset” are provided. Further, fields of “What is requested” and “Request/Reply Flag” are provided. Requested data such as temperature and voltage and time data which are copied from the data collection request OAM packet are set to “What is requested.” A reply is set to the “Request/Reply Flag.”

In a data (Data) field, data such as temperature data and voltage data collected in accordance with what is requested are saved. A field of “End TVL” is provided next to the data field, and then an “FCS” field is provided. A CRC value calculated from values of the destination address to End TVL is saved in the “FCS” field.

If the packet insertion/abandonment unit52illustrated inFIG. 5is notified of an agreement from the comparing unit46and the received packet input to the FIFO47concurrently with the output of the comparing unit46is a reply OAM packet, the packet insertion/abandonment unit52reads the packet for estimation held in the FIFO47and the reply OAM packet, and sends the read packets from a terminal56to the data saving unit34and the output unit35illustrated inFIG. 4. If the received packet input to the FIFO47concurrently with the output of the comparing unit46is a packet for estimation, the packet insertion/abandonment unit52abandons the packet for estimation.

If the packet insertion/abandonment unit52is notified of a disagreement from the comparing unit46and the received packet input to the FIFO47concurrently with the output of the comparing unit46is a reply OAM packet, the packet insertion/abandonment unit52abandons the reply OAM packet. If the received packet input to the FIFO47concurrently with the output of the comparing unit46is a packet for estimation, the packet insertion/abandonment unit52holds the packet for estimation in the FIFO47.

Upon being notified of a disagreement from the comparing unit46, the LED drive unit53produces a driving signal for turning the LED on, and provides the LED37with the driving signal so as to turn the LED37on for indication.

Flowchart of Jig Unit

FIG. 9illustrates a flowchart of an embodiment of a process performed by the jig unit32. InFIG. 9, a frame of a received packet is input at step S1, and the packet indentifying unit42identifies whether the received packet is a reply OAM packet at step S2.

If the received packet is not a reply OAM packet, e.g., the received packet is a packet for estimation, the comparing unit46identifies whether a CRC value of an FCS of the packet for estimation agrees with a CRC value output by the CRC operation unit44at step S3. In case of an agreement at the step S3, the comparing unit46identifies whether a source address and so on of the packet for estimation agree with a source address and so on output by the standard holding unit48at step S4. In case of an agreement at the step S4, the packet insertion/abandonment unit52abandons the packet for estimation at step S5.

In case of a disagreement at the step S3or S4, the FIFO47holds the packet for estimation including an error at step S6. The OAM producing unit51produces the data collection request OAM packet and outputs the data collection request OAM packet from the terminal55at step S7.

Meanwhile, if the received packet is a reply OAM packet at the step S2, the comparing unit46identifies whether the CRC value of the FCS of the reply OAM packet agrees with the CRC value output by the CRC operation unit44at a step S8. In case of an agreement at the step S8, the comparing unit46identifies whether the source address and so on of the reply OAM packet agrees with the source address and so on output by the standard holding unit48at step S9. In case of an agreement at the step S9, the packet insertion/abandonment unit52outputs the packet for estimation held in the FIFO47from the terminal56at step S10, and the packet insertion/abandonment unit52outputs the reply OAM packet from the terminal56at step S11.

In case of a disagreement at the step S8or S9, the packet insertion/abandonment unit52abandons the erroneous reply OAM packet at step S12.

Configuration of Data Collecting Unit

FIG. 10illustrates a configuration diagram of an embodiment of a data collecting unit included in the IF unit23. InFIG. 10, a local CPU61includes an AD-converter, and input signals provided to analog input terminals62and63are AD-converted and are taken into the local CPU61.

An end and another end of a thermistor65provided at a measurement position are connected to a power supply VCC and an end of a resistor66, respectively. Another end of the resistor66is grounded. An interface between the thermistor65and the resistor66is connected to the analog input terminal62. As temperature rises, a resistance value of the thermistor65increases and a voltage of the analog input terminal62decreases. The local CPU61takes in the voltage as temperature data of the measurement position.

Further, resistors67and68are connected in series between the power supply VCC and a ground GND. An interface between the resistors67and68is connected to the analog input terminal63. The voltage of the power supply VCC is divided by the resistors67and68, and the divided value of the voltage is taken into the local CPU61as voltage data of the measurement position. A dividing ratio of the resistors67and68is determined in such a way that the voltage provided to the analog input terminal63of the local CPU61is in a voltage range that may be input to the analog input terminal63.

Configuration of if Unit

FIG. 11illustrates a configuration diagram of an embodiment of a packet reply function in the IF unit23. InFIG. 11, an input unit71, which corresponds to the optical transceiver23b, converts an optical signal provided from the optical cable24into an electric signal and provides an OAM extracting unit72with the electric signal.

The OAM extracting unit72, which is made up by, e.g., a network processor, extracts a frame of the data collection request OAM packet provided from the estimating unit25(refer toFIG. 7) and provides an OAM processing unit73with the extracted frame. Further, the OAM extracting unit72provides a following circuit with a packet of a main signal except the data collection request OAM packet.

The OAM processing unit73provides the local CPU61with the extracted data collection request OAM packet. The local CPU61is illustrated inFIG. 10. The local CPU61analyzes the data collection request OAM packet, and reads internal data such as temperature and voltage data of the measurement position and so on in accordance with what is requested of the data collection request OAM packet. The local CPU61produces a frame of a reply OAM packet including the collected temperature and voltage data (refer toFIG. 8), and provides the OAM processing unit73with the produced frame. The reply OAM packet may copy and include time data included in the data collection request OAM packet.

The OAM processing unit73provides an OAM inserting unit74with the reply OAM packet. The OAM inserting unit74is made up by, e.g., a network processor. The OAM inserting unit74inserts the reply OAM packet into a main signal packet and provides an output unit75with the reply OAM packet. The output unit75, which corresponds to the optical transceiver23b, converts an electric signal provided from the OAM inserting unit74to an optical signal, and transmits the optical signal to the optical cable24bound for the estimating unit25.

According to the above embodiment, only a packet for estimation in which an error occurs and a reply OAM packet including temperature and voltage data collected from the IF unit23upon the error occurring are saved in the data saving unit34or the storage device27, and a packet for estimation without an error is abandoned. Thus, a memory size of the data saving unit34or the storage device27may be significantly reduced in comparison with the ordinary estimating device15. Further, as the time data is copied in the reply OAM packet from the data collection request OAM packet, the packets for estimation in which errors occurred corresponding to the reply OAM packet may be identified.

Thus, the packet may be held in the data saving unit34or the storage device27at the time of detecting an error even if the error occurs infrequently. Further, as data collection is requested upon the error being detected, a state of the error and the surrounding data may be held in the data saving unit34or the storage device27and monitored even while being estimated for a long time.

Modification of Transmission Device

FIG. 12illustrates a configuration diagram of a modification of an embodiment of a transmission device having an estimating unit. InFIG. 12, a frame of a packet for estimation produced by the packet producing unit20is provided to the optical transceiver23aprovided in the IF unit23of the transmission device22through the optical cable21. The packet for estimation is processed in the transmission device22, multiplexed with the main signal in operation so as to be output from the optical transceiver23bof the IF unit23, and provided from the optical transceiver25a(which corresponds to the input unit31) to the estimating unit25through the optical cable24.

The optical transceiver25b(which corresponds to the output unit35) of the estimating unit25is connected to the storage device27by the optical cable26. An optical transceiver25cof the estimating unit25corresponds to the output unit33, and converts an electric signal of a main signal packet in operation provided from the jig unit32into an optical signal and outputs the optical signal. The main signal packet output from the optical transceiver25cis provided to an optical transceiver30aprovided in an IF unit30of a transmission device29through an optical cable28.

The transmission device22may be estimated through this configuration even while the transmission devices22and29are connected to each other and in operation.

According to the above embodiment, the CRC operation unit44, the comparing unit46, and a standard holding unit48are used as an example of an error detecting unit, the OAM producing unit51is used as an example of a request sending unit, the packet insertion/abandonment unit52is used as an example of an extracting unit, the storage device27or the data saving unit34is used as an example of a saving unit, the packet identifying unit42and the output unit33are used as an example of an output unit, the CRC operation unit44is used as an example of an operation unit, and the standard holding unit48is used as an example of a standard holding unit.

Another Configuration of Jig Unit

The embodiments illustrated inFIGS. 3 and 12illustrate the configurations in which the transmission devices22and29are a transmission device of an IP (Internet Protocol) network. Whereas,FIG. 13illustrates a configuration in which the transmission devices22and29are a transmission device of a SONET (Synchronous Optical Network) or SDH (Synchronous Digital Hierarchy) network.

FIG. 13illustrates a configuration diagram of another embodiment of the jig unit32in the estimating unit25. InFIG. 13, an SDH frame of an electric signal is input from the input unit31illustrated inFIG. 4to a terminal141, and is provided to an OH (overhead) extracting unit142. The OH extracting unit142extracts an overhead, e.g., SOH (Selection OverHead), POH (Path OverHead), provides a FIFO143with the SDH frame, provides the output unit33with the SDH frame from a terminal145, and provides an OH analyzing unit144with the extracted SOH and POH.

The OH analyzing unit144detects a B1 byte error from a B1 byte of SOH, and detects a B3 byte error from a B3 byte of POH. The OH analyzing unit144produces an error detection signal when detecting the B1 byte error or the B3 byte error, and provides an OH inserting unit151, a frame output unit152, and an LED driving unit153with the error detection signal. Further, upon detecting temperature data or voltage data included on a channel for maintenance of, e.g., F2 byte of POH, the OH analyzing unit144produces a data detection signal and provides the frame output unit152with the data detection signal.

Upon being provided with the error detection signal from the OH analyzing unit144, the OH inserting unit151produces an SDH frame for which a data collection request for requesting the IF unit23to collect temperature or voltage data is inserted into the channel for maintenance of F2 byte of, e.g., POH of an overhead of the main signal. At this time, time data provided from a timer unit154in the data collection request is included. The SDH frame is provided from a terminal155to the output unit36illustrated inFIG. 4.

Upon being provided with the error detection signal from the OH analyzing unit144, the frame output unit152outputs, from a terminal156, an SDH frame provided by the FIFO143concurrently with the output of the OH analyzing unit144. Further, upon being provided with the data detection signal from the OH analyzing unit144, the frame output unit152outputs, from the terminal156, the SDH frame provided by the FIFO143concurrently with the output of the OH analyzing unit144. Moreover, upon being provided with no error detection signal or data detection signal from the OH analyzing unit144, the frame output unit152abandons the SDH frame output from the FIFO143.

Upon being provided with the error detection signal from the OH analyzing unit144, the LED driving unit153produces a driving signal for turning the LED37on and provides the LED37with the driving signal so as to turn the LED37on for indication.

Also for SDH, as described above, only an SDH frame in which an error occurs and an SDH frame including temperature and voltage data collected from the IF unit23upon the error occurring and the time data copied from the data collection request are saved in the data saving unit34or the storage device27. Thus, a memory size of the data saving unit34or the storage device27may be significantly reduced in comparison with the related art estimating device15. Upon an error being detected even if the error occurs least frequently, the packet may be held in the data saving unit34or the storage device27at the time of error detection. This is also true for SONET.

According to the embodiment, the OH analyzing unit is used as an example of an error detecting unit, the OH inserting unit151is used as an example of a request sending unit, the frame output unit152is used as an example of an extracting unit, and the storage device27or the data saving unit34is used as an example of a saving unit.