JP5077006B2 - Communication apparatus, communication system, and mapping method - Google Patents

Description

  The present invention relates to a communication device, a communication system, and a mapping at that time, for mapping a SONET / SDH (Synchronous Optical Network / Synchronous Digital Hierarchy) frame to a packet received from an Ethernet (registered trademark, hereinafter omitted) network. Regarding the method.

  Conventionally, there is a communication device that connects an Ethernet network and a SONET / SDH network.

  The communication apparatus maps a packet received from the Ethernet network to a SONET / SDH frame and transmits the frame to the SONET / SDH network. Alternatively, the packet is extracted from the frame received from the SONET / SDH network, and the packet is transmitted to the Ethernet network.

  In recent years, it has been required for such a communication apparatus to have a redundant configuration on the SONET / SDH network side interface.

  Conventionally, in a transmission apparatus in a SONET / SDH network, when a failure occurs in an active transmission line, there is a technique for switching to a backup transmission line using the failure detection as a trigger (see, for example, Patent Document 1). This is because the reliability of the packet mapped to the frame can be ensured by the redundant configuration of the communication apparatus and the switching technique.

  One approach to meet the above requirements is to independently map packets to SONET / SDH frames on the working I / F card and the standby I / F card on the SONET / SDH network side. It is done. As the SONET / SDH frame, for example, STS (Synchronous Transport Signal) / VC (Virtual Container) can be used.

  Also, as one method, the Ethernet network side I / F card maps the packet to the SONET / SDH frame, duplicates the frame, and the SONET / SDH network side active I / F card and the standby system It is conceivable to output the exact same frame to each I / F card.

JP 2007-174322 A

  When mapping is performed by the SONET / SDH network side I / F card, the same packet is sent to each I / F card by duplicating the packet before the packet is input to each I / F card in the device. Output.

  However, since the wiring length from the packet duplication unit to each I / F card is different, a packet transmission delay occurs due to the difference in the wiring length.

  Due to this transmission delay, frames with different mapping contents are generated in each of the active I / F card and the standby I / F card.

  As a result, when switching from the working transmission line to the backup transmission line, processing to deal with duplication and omission of packets in the frame is necessary, and there is a problem that the switching cannot be performed without interruption. there were.

  On the other hand, when mapping is performed using the I / F card on the Ethernet network side, the same frame is input to the active I / F card and the standby I / F card.

  Therefore, there is an advantage that switching from the working transmission line to the backup transmission line can be performed without interruption.

  However, when the I / F card on the SONET / SDH network side is changed according to the output band on the SONET / SDH network side, it is necessary to also change the interface between the cards in the device. There was a problem that versatility with respect to the output band on the SONET / SDH network side was lost.

  Accordingly, the present invention has been made to solve the above-described problems of the prior art, and has a versatility with respect to the output band on the SONET / SDH network side, and is a SONET in which packets having the same contents are mapped. An object of the present invention is to provide a communication apparatus, a communication system, and a mapping method capable of transmitting a / SDH frame from each of an active system and a standby system.

  In order to solve the above-described problems and achieve the object, this apparatus connects an Ethernet network and a SONET / SDH network, and each of the active and standby I / O systems for each transmission apparatus facing each other on the SONET / SDH network side. / F card, a communication device for mapping SONET / SDH frames to packets received from the Ethernet network by the I / F card, and integrating means for integrating the number of passing bytes of the packets , A packet is selected based on a result of integration by the integration unit, a marker insertion unit for inserting a marker into the packet, a packet is received via the marker insertion unit, the packet is duplicated, and an active I / F card And a packet duplicating means for outputting the same packet to each of the standby I / F cards, and the working I / F card When the packet received from the packet duplicating means is a packet with a marker, each of the standby I / F cards controls the mapping position of the packet based on the marker and maps the packet with the marker In this case, it is necessary to remove the marker and perform mapping.

  In addition, this system includes either an active / protection I / F card installed for each transmission apparatus facing each other on the SONET / SDH network side, and the I / F card as an output destination of a packet received from the Ethernet network. A switching processing unit that determines whether or not to output the packet, and performs a SONET / SDH frame mapping to the packet in the I / F card, the switching processing unit Is a means for accumulating the number of bytes passing through the packet, a marker selecting means for selecting a packet based on the result of integration by the accumulating means, and inserting a marker into the packet, and a packet via the marker inserting means. Receives and duplicates the packet and sends the same packet to both the working I / F card and the standby I / F card A packet duplicating means for outputting, wherein each of the working I / F card and the spare I / F card has a marker when the packet received from the packet duplicating means is the packet with the marker. On the basis of this, the mapping position of the packet is controlled, and when mapping the packet with the marker, it is necessary to include mapping control means for removing the marker and performing mapping.

  Further, in this communication apparatus, the Ethernet network and the SONET / SDH network are connected, and each of the transmission devices facing each other on the SONET / SDH network side includes a working system and a standby system I / F card. A mapping method for mapping a packet received from an Ethernet network to a SONET / SDH frame, an integration step of integrating the number of passing bytes of the packet, and selecting a packet based on an integration result of the integration step, A marker insertion step of inserting a marker into the packet; a packet replication step of receiving the packet, replicating the packet and outputting the same packet to each of the active I / F card and the standby I / F card; When mapping a packet, if it is a packet with the marker, it is based on the marker. Controls the mapping position of the packet Te, for the marker attached packet is a requirement that it contained a mapping control step of performing mapping remove the marker, the.

  A marker is inserted in advance in the packet, and the mapping position of the packet is controlled based on the marker in the active and standby I / F cards. As a result, the packet is mapped to the frame with the same content, and the communication apparatus can transmit the frame to the working transmission line and the backup transmission line.

  Exemplary embodiments of a communication apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.

  First, an outline of the communication apparatus according to the first embodiment will be described. The outline of the communication apparatus will be described. The communication apparatus has an EoS (Ether over SONET / SDH) function, an Ethernet (registered trademark, hereinafter omitted) network, a SONET / SDH (Synchronous Optical NETwork / Synchronous Digital Hierarchy) network, and Connect.

  From the Ethernet network, the communication device receives the packet. The communication apparatus maps the packet to a SONET / SDH frame.

  Specifically, the communication apparatus has a redundant configuration in which an interface on the SONET / SDH network side includes an active EoS card and a standby EoS card, and each EoS card independently uses an Ethernet. A packet received from the network is mapped to a SONET / SDH frame. The above is the outline of the communication apparatus.

  FIG. 1 shows the characteristics of processing performed by the communication apparatus on a packet. As shown in the figure, the communication apparatus determines in advance a packet to be mapped to the head of the frame, and assigns a marker storing information indicating the mapping start position to the packet.

  That is, the communication apparatus determines in advance the packet “A” and the packet “G” as packets to be mapped from the head of the frame among the packets “A” to “O”, and adds a marker.

  Furthermore, the communication apparatus stores “0” in the markers assigned to the packet “A” and the packet “O”, and stores “20” in the markers assigned to the packet “G”.

  When the communication device maps a packet to a SONET / SDH frame, the packet with a marker is mapped from the beginning of the frame. At that time, the mapping start position is based on the information stored in the marker. To decide.

  That is, since the marker is assigned to the packet “A” and “0” is stored in the marker, the communication apparatus performs mapping from the head of the SONET / SDH frame.

  The packets “B” to “F” are sequentially mapped, and a marker is assigned to the packet “G”, and “20” is stored in the marker.

  Therefore, the communication device maps the packet “G” by leaving 20 bytes from the head of the frame (the excess bytes of the packet “F” that could not be mapped to the previous frame are mapped to the 20 bytes). )

  The communication device performs the above-described mapping in the same way with the active and standby EoS cards. Therefore, the communication apparatus can transmit SONET / SDH frames in which packets are mapped with the same content from each of the active system and the standby system.

  FIG. 2 is a block diagram illustrating the configuration of the communication apparatus according to the first embodiment. As illustrated in FIG. 1, the communication device 10 includes a clock signal generation unit 20, an Ether card 30, a switching processing unit 40, and an EoS card 50.

  In the following description, the communication apparatus 10 is assumed to map a packet to an SDH STM-1 (Synchronous Transmission Module-level 1) frame. The object to which the packet is mapped is not limited to STM-1, but may be a SONET frame, for example.

  Further, the communication device 10 maps the packet to one VC-4 (Virtual Container-4) accommodated in the payload portion of the STM-1 frame. In addition, you may make it accommodate three VC-3.

  Further, the communication device 10 transmits the packet to the ITU-T. Capsule is performed by GFP (Generic Framing Procedure) defined in G7041. Then, mapping is performed by storing the encapsulated packet in VC-4, and the VC-4 is accommodated in the payload portion of the STM-1 frame.

  The clock signal generation unit 20 generates a timing signal that is an STM-1 frame transmission cycle accommodating VC-4. Specifically, a timing signal with an interval of 125 μs is output to the switching processing unit 40 and the EoS card 50.

  The Ether card 30 performs a reception process on a packet received from the Ethernet network.

  Specifically, when a packet transmitted from a terminal device of the Ethernet network is received, it is determined from which EoS card 50 to transmit to the SDH network based on the destination information. Then, the determination result and the packet are output to the switching processing unit 40.

  The switching processing unit 40 is a processing unit that outputs a packet to a specified EoS card 50, and includes a crossbar switching processing unit 41, a capsule processing unit 42, a shaping processing unit 43, a marker insertion unit 44, and the number of bytes. A count unit 45 and a data replication unit 46 are provided.

  The crossbar switching processing unit 41 switches the route based on the above determination result, and outputs the packet to the capsuling processing unit 42 following the EoS card 50 that is the output destination.

  The encapsulation processing unit 42 is a processing unit that encapsulates a packet by GFP. Hereinafter, the encapsulated packet is referred to as a GFP frame.

  The shaping processing unit 43 shapes data according to the output capacity of the EoS card 50. Note that when the GFP frame is mapped to the STS-1 frame later, shaping is performed in consideration of insertion of a 4-byte idle frame between the GFP frames.

  The byte number counting unit 45 includes an excess byte storage unit 45 a, counts the number of bytes of the GFP frame input to the marker insertion unit 44, and outputs excess byte information indicating the number of excess bytes to the marker insertion unit 44.

  Specifically, as shown in FIG. 3, the byte count unit 45 receives a timing signal at intervals of 125 μs from the clock signal generator 20.

  Then, the byte number counting unit 45 counts and accumulates the number of bytes of the GFP frame based on the GFP frame input to the marker insertion unit 44 after receiving the timing signal.

  However, when the integrated value exceeds a certain threshold value, the number of bytes in the reference GFP frame is counted as the initial value when counting the number of bytes in the next GFP frame.

  The following description is based on the premise that the integrated value of the number of bytes integrated based on the GFP frame input to the marker insertion unit 44 after receiving the timing signal immediately before the timing signal 1 is within 2340 bytes. Note that 2340 bytes is the above-described threshold value, and the threshold value is uniquely determined by the output bandwidth on the SDH network side. For example, the administrator may directly set the threshold value.

  Since the integrated value is within 2340 bytes, the byte count unit 45 sets the excess byte count to “0” and stores “0” in the excess byte storage unit 45a.

  When the GFP frame “A” is input to the marker insertion unit 44 after receiving the timing signal 1, the byte number counting unit 45 reads “0” from the excess byte storage unit 45 a, and stores the GFP frame “A”. Start counting bytes from “0”.

  Further, the byte count unit 45 outputs the read excess byte information “0” to the marker insertion unit 44.

  Here, when the marker insertion unit 44 receives the excess byte information from the byte count unit 45, the marker insertion unit 44 adds the excess byte information to the GFP frame “A”.

  Specifically, as shown in FIG. 4, 4 bytes are added to the head of the GFP frame as a marker, and the excess byte information is indicated using the 4 bytes.

  The byte count unit 45 accumulates the number of bytes of the GFP frames “A” to “F”. When the accumulated value becomes 2340 bytes or more in the GFP frame “F” and becomes 2360 bytes as a result, the number of excess bytes is increased. Is set to “20”, and “20” is stored in the excess byte storage unit 45a.

  Then, when the GFP frame “G” is input to the marker insertion unit 44 after receiving the timing signal 2, the byte number counting unit 45 reads “20” from the excess byte storage unit 45 a, and stores the GFP frame “G”. Start counting bytes from "20".

  Further, the byte count unit 45 outputs the read excess byte information “20” to the marker insertion unit 44.

  Here, the marker insertion unit 44 similarly gives the excess byte information received from the byte count unit 45 to the GFP frame “G”.

  Further, the byte count unit 45 similarly accumulates the number of bytes of the GFP frames “G” to “N”, but this time, even if the number of bytes of the GFP frame “N” is counted, Is 2000 bytes, the number of excess bytes is set to “0”, and “0” is stored in the excess byte storage unit 45a.

  Therefore, when the GFP frame is input to the marker insertion unit 44 after receiving the timing signal 3, the byte number counting unit 45 reads “0” from the excess byte storage unit 45 a and sets the byte number of the GFP frame to “0”. Start counting from.

  The marker insertion unit 44 adds a marker to the GFP frame stored at the head of VC-4 accommodated in the payload portion of the STM-1 frame.

  Specifically, when receiving the excess byte information from the byte number counting unit 45, the marker insertion unit 44 stores the excess byte information in the marker and assigns the marker to the GFP frame that is currently input.

  In addition, the marker insertion unit 44 includes a marker head pulse generation unit 44 a, generates a marker head pulse indicating that a marker is given, and outputs the marker head pulse to the data duplication unit 46.

  The data duplicating unit 46 duplicates the GFP frame received from the marker inserting unit 44, and outputs exactly the same GFP frame to each of the active and standby EoS cards 50. The marker leading pulse received from the marker insertion unit 44 is also output to the active and standby EoS cards 50 in the same manner.

  The configuration of the active and standby EoS cards 50 will be described with reference to FIG. As shown in the figure, the EoS card 50 is a processing unit that maps a packet to a payload of an STS-1 frame, and includes a buffer management unit 51, a buffer unit 52, a mapping processing unit 53, and a frame generation unit 54. .

  Note that the EoS card 50 is a processing unit that also performs reception processing of the STS-1 frame, and constituent elements for performing the processing are originally necessary, but are omitted in the figure.

  The buffer management unit 51 stores the GFP frame received from the switching processing unit 40 in the buffer unit 52.

  Specifically, as shown in FIG. 6, the buffer management unit 51 receives a marker head pulse in addition to the GFP frame.

  When the buffer manager 51 receives the marker head pulse, the buffer manager 51 cuts off the marker of the head 4 bytes of the GFP frame received in parallel.

  Then, the GFP frame is stored in the standby buffer 52a, and the marker is stored in the marker buffer 52b. When the marker is stored, a buffer address indicating the storage location in the standby buffer 52a of the GFP frame from which the marker is separated is stored in association with each other.

  When storing the GFP frame in VC-4, the mapping processing unit 53 stores the GFP frame based on the excess byte information stored in the marker.

  Specifically, when the GFP frame is stored in the standby buffer 52a, the mapping processing unit 53 acquires the GFP frame. If the same buffer address as the buffer address in which the GFP frame is stored is stored in the marker buffer 52b, the marker associated with the buffer address is acquired. The acquisition of the GFP frame and marker is notified to the buffer management unit 51.

  Then, the mapping processing unit 53 stores the GFP frame in VC-4 based on the excess byte information stored in the marker.

  Specifically, as shown in FIG. 7, if the excess byte information stored in the marker of the GFP frame “A” is “0”, mapping is performed immediately after the J1 byte of VC-4. Do.

  Also, as shown in the figure, if the excess byte information stored in the marker of the GFP frame “G” is “20”, mapping is performed with 20 bytes from the J1 byte of VC-4.

  If there is no buffer address identical to the buffer address where the acquired GFP frame is stored, the GFP frame is sequentially stored in VC-4. If the data cannot be stored in the same VC-4, the data is stored across two VC-4s.

  As shown in FIG. 8, the following description will be made assuming that the GFP frames “A” to “N” are stored in the standby buffer 52a.

  The mapping processing unit 53 acquires the GFP frame “A” from the standby buffer 52a, and also acquires the marker from the marker buffer 52b based on the buffer address indicating the storage location of the GFP frame “A”.

  Then, based on the excess byte information “0” and the timing signal 2 stored in the marker, the GFP frame “A” is stored from the head of VC-4.

  Thereafter, the GFP frames “B” to “F” are read from the standby buffer 52a, and since no marker is attached to the GFP frame, they are sequentially stored in the VC-4.

  When VC-4 is generated while leaving the rear 20 bytes of the GFP frame “F”, it is output to the frame generation unit 54.

  Since the rear 20 bytes of the GFP frame “F” are exceeded, they are stored in the next VC-4 based on the timing signal 3.

  Next, the mapping processing unit 53 acquires the GFP frame “G” from the standby buffer 52a, and also acquires the marker from the marker buffer 52b with the buffer address indicating the storage location of the GFP frame “G”.

  Based on the excess byte information “20” stored in the marker, the GFP frame “G” is stored from the 20th byte of VC-4.

  Thereafter, the GFP frames “H” to “N” are read from the standby buffer 52a, and since no marker is attached to the GFP frame, they are sequentially stored in the VC-4. When VC-4 is generated, it is output to the frame generation unit 54.

  The frame generation unit 54 generates an STS-1 frame using VC-4 output from the mapping processing unit 53 and transmits it to the SDH network.

  Next, a processing operation when the mapping processing unit 53 stores a GFP frame in the VC-4 will be described with reference to FIG. The processing flow shown in the figure is repeatedly executed every time a GFP address is stored in the standby buffer 52a.

  As shown in the figure, the mapping processing unit 53 acquires a GFP frame from the standby buffer 52a (step S110).

  If a marker is attached to the GFP frame (Yes at Step S120), the GFP frame is stored in VC-4 based on the excess byte information stored in the marker (Step S130).

  On the other hand, if no marker is attached to the GFP frame (No at Step S120), it is determined whether all bytes can be stored in the VC-4 storing the GFP frame (Step S140). Are stored in sequence (step S150).

  As a result of the determination, if the data cannot be stored (No at Step S140), the data is stored across the next VC-4 (Step S160), and the process is terminated.

  As described above, according to the first embodiment, a marker is assigned in advance to the GFP frame stored at the beginning of VC-4, and information indicating the number of bytes from the beginning is stored in the marker. . Then, when the same GFP frame is output to the active and standby EoS cards and the GFP frame is stored in VC-4 by the EoS card, based on the marker and the information stored in the marker Store. By doing so, it is possible to generate an STS-1 frame in which the GFP frame is mapped with the same contents by the active and standby EoS cards and transmit the STS-1 frame to the SDH network.

  In the first embodiment, when a marker is inserted in advance into the GFP frame stored at the beginning of VC-4 and the GFP frame is stored at the beginning of VC-4, any of the GFP frames is stored based on the excess byte information stored in the marker. Decided whether to store from the position, and stored.

  In the second embodiment, it is assumed that a marker is inserted at the head of the GFP frame or in the frame, and the GFP frame is stored so that the marker insertion position is at the head of VC-4.

  The characteristics of the communication apparatus according to the second embodiment will be described. The communication apparatus determines in advance which position of which packet is to be arranged at the head of the frame, and inserts a marker for indicating the position into the packet. Then, the same packet is output to each of the active and standby EoS cards.

  Each EoS card performs mapping based on a marker inserted in the packet when mapping the packet to a SONET / SDH frame. The above is the feature of the communication device.

  Specifically, as illustrated in FIG. 10, the communication device inserts a marker in the beginning of the packet “A” or in the middle of the packet “F” among the packets “A” to “O”.

  Since the marker is inserted at the head of the packet “A”, the EoS card performs mapping for the SONET / SDH frame with the packet “A” at the head.

  The packets “B” to “F” are sequentially mapped, and a marker is inserted in the packet “F”.

  Therefore, the EoS card performs mapping for the next frame from the position where the marker is inserted, starting with the rear packet “F”.

  Since the above mapping is performed in the same way in the active and standby EoS cards, the communication apparatus according to the second embodiment transmits the SONET / SDH frame mapped with the same contents from each of the active and standby systems. Is possible.

  The configuration of the communication apparatus according to the second embodiment is the same as that of the first embodiment, and only components that perform different processing operations will be described below.

  The byte number counting unit 45 counts the number of bytes of the GFP frame input to the marker insertion unit 44, and outputs a predetermined signal to the marker insertion unit 44 at the timing of inserting the marker.

  Specifically, referring to FIG. 3, the byte count unit 45 accumulates the number of bytes accumulated based on the GFP frame input to the marker insertion unit 44 after receiving the timing signal immediately before the timing signal 1. Since the value is within 2340 bytes, the number of excess bytes is set to “0”, and “0” is stored in the excess byte storage unit 45a.

  When the GFP frame “A” is input to the marker insertion unit 44 after receiving the timing signal 1, the byte number counting unit 45 reads “0” from the excess byte storage unit 45 a, and stores the GFP frame “A”. Start counting bytes from “0”.

  Further, unlike the first embodiment, the byte count unit 45 outputs a predetermined signal to the marker insertion unit 44.

  Here, when the marker insertion unit 44 receives a predetermined signal from the byte number counting unit 45, the marker insertion unit 44 inserts a marker at the head of the currently input GFP frame “A”.

  In the first embodiment, excess byte information is stored in the marker. However, in the second embodiment, such information need not be stored.

  The byte count unit 45 accumulates the number of bytes of the GFP frames “A” to “F”, but unlike the first embodiment, when the accumulated value becomes 2340 bytes in the GFP frame “F”, a predetermined number is obtained. Is output to the marker insertion unit 44.

  Here, when the marker insertion unit 44 receives a predetermined signal from the byte number counting unit 45, the marker insertion unit 44 inserts a marker at a position corresponding to the 2341st byte of the currently input GFP frame “F”.

  In addition, when the integrated value becomes 2340 bytes or more and the result is 2360 bytes, the byte count unit 45 sets the excess byte count to “20” and stores “20” in the excess byte storage unit 45a.

  Then, when the GFP frame “G” is input to the marker insertion unit 44 after receiving the timing signal 2, the byte number counting unit 45 reads “20” from the excess byte storage unit 45 a, and stores the GFP frame “G”. Start counting bytes from "20".

  As described above, in the first embodiment, the marker storing the excess byte information “20” is added to the GFP frame “G”. However, in the second embodiment, as described above, the marker itself is included in the GFP frame “F”. Insert.

  Further, the byte count unit 45 similarly accumulates the number of bytes of the GFP frames “G” to “N”, but this time, even if the number of bytes of the GFP frame “N” is counted, Is 2000 bytes, the number of excess bytes is set to “0”, and “0” is stored in the excess byte storage unit 45a.

  Therefore, when the GFP frame is input to the marker insertion unit 44 after receiving the timing signal 3, the byte number counting unit 45 reads “0” from the excess byte storage unit 45 a and sets the byte number of the GFP frame to “0”. Start counting from.

  The marker insertion unit 44 inserts a marker indicating which part of which GFP frame is mapped into VC-4 accommodated in the payload part of the STM-1 frame.

  Specifically, when the marker insertion unit 44 receives a predetermined signal from the byte number counting unit 45, the marker insertion unit 44 inserts a marker into the currently input GFP frame based on the timing at which the predetermined signal is received.

  In the first embodiment, the marker is 4 bytes, and the excess byte information is stored in the 4 bytes. However, in the second embodiment, the marker may be an arbitrary number of bytes, and it is necessary to store the excess byte information. Absent.

  In addition, the marker insertion unit 44 generates a marker head pulse indicating the insertion position of the marker and outputs it to the data replication unit 46.

  The buffer management unit 51 stores the GFP frame received from the switching processing unit 40 in the buffer unit 52.

  Specifically, as in the first embodiment, as shown in FIG. 6, the buffer management unit 51 receives a marker head pulse in addition to the GFP frame.

  When the buffer management unit 51 receives the marker head pulse, the buffer management unit 51 separates a predetermined byte of the GFP frame received in parallel as a marker.

  When the marker is separated from the head of the GFP frame, the buffer management unit 51 stores the GFP frame in the standby buffer 52a and stores a buffer address indicating the storage location of the GFP frame in the marker buffer 52b. .

  On the other hand, when the marker is separated from the middle of the GFP frame, the GFP frame is divided and stored in the standby buffer 52a, and a buffer address indicating the storage location at the rear of the GFP frame is stored in the marker buffer 52b.

  When storing the GFP frame in VC-4, the mapping processing unit 53 stores the GFP frame based on the marker insertion position.

  Specifically, when the GFP frame is stored in the standby buffer 52a, the mapping processing unit 53 acquires the GFP frame. If the same buffer address as the buffer address in which the GFP frame was stored is stored in the marker buffer 52b, it is stored in VC-4 with the GFP frame as the head.

  If there is no buffer address identical to the buffer address where the acquired GFP frame is stored, the GFP frame is sequentially stored in VC-4.

  Specifically, as shown in FIG. 11, since the same buffer address as the storage address where the GFP frame “A” is stored is stored in the marker buffer 52b, as shown in FIG. Mapping is performed immediately after the J1 byte.

  Also, as shown in the figure, since the same buffer address as the buffer address of the storage location where the rear part of the GFP frame “F” is stored is stored in the marker buffer 52b, immediately after the J1 byte of VC-4 Perform mapping.

  Next, a processing operation when the mapping processing unit 53 stores a GFP frame in the VC-4 will be described with reference to FIG. The processing flow shown in the figure is repeatedly executed every time a GFP address is stored in the standby buffer 52a.

  As shown in the figure, the mapping processing unit 53 acquires a GFP frame from the standby buffer 52a (step S170).

  When the same buffer address as the buffer address indicating the storage location of the GFP frame is stored in the marker buffer 52b (Yes at Step S180), the GFP frame is stored at the head of VC-4 (Step S190). ).

  On the other hand, if not stored in the marker buffer 52b (No at Step S180), the data are sequentially stored (Step S200), and the process is terminated.

  As described above, according to the second embodiment, a marker indicating from which position of which GFP frame to store at the head of VC-4 is inserted in advance in the head or frame of the GFP frame. When the same GFP frame is output to the active and standby EoS cards and the GFP frame is stored in the VC-4 by the EoS card, it is stored based on the marker. By doing so, it is possible to generate an STS-1 frame in which the GFP frame is mapped with the same contents by the active and standby EoS cards and transmit the STS-1 frame to the SDH network.

  The communication devices according to the first and second embodiments have been described so far, but the present invention may be implemented in various different forms other than the first and second embodiments described above. Therefore, as shown below, different embodiments will be described by dividing into (1) to (3).

(1) Frame to be mapped In the above embodiment, the communication apparatus 10 is premised on “High Order EoS / VCAT” that stores a packet in VC-N (corresponding to STS-N in the case of SONET). However, the present invention is not limited to this, and the packet may be stored in a VT (Virtual Tributary) frame on the premise of “Low Order EoS / VCAT”.

  The configuration of the communication device in that case is the same as the configuration shown in FIG.

  The VC-N is configured in units of 8 kHz (125 μs), whereas the VT frame is configured in units of 2 kHz (500 μs). Therefore, it is necessary to reset the timing signal interval generated by the clock signal generation unit 20 and the threshold value used by the byte count unit 45. Also, it is desirable to map a packet that has been encapsulated by PPP (Point-to-Point Protocol) to the VT frame.

(2) Encapsulation In the above embodiment, the packet is described as being encapsulated by GFP (PPP). However, the present invention is not limited to this, and the packet is directly framed by SONET / SDH. You may make it map to.

(3) System Configuration The components of the illustrated devices are functionally conceptual and need not be physically configured as illustrated. In other words, the specific forms of distribution and integration of the devices are not limited to those shown in the figure. For example, all or a part of the integration of the marker insertion unit 44 and the byte count unit 45 may be combined with various loads. It can be configured to be functionally or physically distributed and integrated in arbitrary units according to the usage situation or the like. Further, all or any part of each processing function performed in each device may be realized by a CPU and a program analyzed and executed by the CPU, or may be realized as hardware by wired logic.

FIG. 6 is a diagram for explaining the characteristics of processing performed on a packet by the communication apparatus according to the first embodiment. It is a block diagram which shows schematic structure of a communication apparatus. It is a figure for demonstrating the integration process of the byte number by a byte number count part. It is a figure which shows the GFP frame to which the marker was provided. It is a block diagram which shows the outline | summary structure of an EoS card | curd. It is a figure which shows the marker head pulse which a buffer management part receives. It is a figure which shows VC-4 in which the GFP frame was stored. It is a figure for demonstrating a specific mapping process. 6 is a flowchart illustrating a processing operation when the mapping processing unit according to the first embodiment stores a GFP frame in VC-4. FIG. 10 is a diagram for explaining the characteristics of processing performed on a packet by the communication apparatus according to the second embodiment. It is a figure which shows VC-4 in which the GFP frame was stored. 12 is a flowchart illustrating a processing operation when the mapping processing unit according to the second embodiment stores a GFP frame in VC-4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Communication apparatus 20 Clock signal generation part 30 Ether card 40 Switching processing part 41 Crossbar switching processing part 42 Capselling processing part 43 Shaping processing part 44 Marker insertion part 44a Marker head pulse generation part 45 Byte number count part 45a Excess byte storage part 46 Data replication unit 50 EoS card 51 Buffer management unit 52 Buffer unit 52a Standby buffer 52b Marker buffer 53 Mapping processing unit 54 Frame generation unit

Claims (6)

An Ethernet network and a SONET / SDH network are connected to each other, and a working system and a standby system I / F card are provided for each of the opposing transmission devices on the SONET / SDH network side. A communication device that performs SONET / SDH frame mapping for received packets,
Integrating means for integrating the number of bytes passing through the packet;
Marker insertion means for selecting a packet based on the integration result by the integration means and inserting a marker into the packet;
A packet duplicating unit that receives a packet through the marker inserting unit, duplicates the packet, and outputs the same packet to each of the active I / F card and the standby I / F card;
With
Each of the working I / F card and the standby I / F card controls the mapping position of the packet based on the marker when the packet received from the packet duplicating unit is the packet with the marker, When mapping the said packet with a marker, the communication apparatus characterized by removing a marker and mapping. The accumulating means accumulates the number of passing bytes of the packet every predetermined period,
The marker insertion unit selects a packet according to the timing of integration by the integration unit, and inserts a marker that stores byte number information corresponding to the cumulative value exceeding the predetermined number of bytes by the marker insertion unit. ,
2. The active I / F card and the backup I / F card respectively map the marker-added packet with the number of bytes indicated by the byte number information from the head of the frame. The communication apparatus as described in. The accumulating means accumulates the number of passing bytes of the packet every predetermined period,
The marker insertion means selects a packet according to the timing of integration by the integration means,
Each of the working I / F card and the backup I / F card maps the packet received after the marker from the packet duplicating means or the rear part of the packet to the head position of the frame. The communication apparatus according to claim 1 .   The object to which the packet is mapped by each of the working I / F card and the standby I / F card is any one of a VC, an STS, and a VT1.5 frame. The communication device according to any one of the above. The active / standby I / F card installed for each opposing transmission apparatus on the SONET / SDH network side and the I / F card as the output destination of the packet received from the Ethernet network A switching processing unit that outputs a packet, and a communication system that performs SONET / SDH frame mapping on the packet in the I / F card,
The switching processing unit
Integrating means for integrating the number of bytes passing through the packet;
Marker insertion means for selecting a packet based on the integration result by the integration means and inserting a marker into the packet;
A packet duplicating unit that receives a packet through the marker inserting unit, duplicates the packet, and outputs the same packet to each of the active I / F card and the standby I / F card;
With
Each of the working I / F card and the standby I / F card is
When the packet received from the packet duplicating means is the packet with the marker, the mapping position of the packet is controlled based on the marker, and when mapping the packet with the marker, mapping is performed by removing the marker A communication system comprising control means. Packets received from the Ethernet network in a communication device that connects the Ethernet network and the SONET / SDH network and includes a working I / F card for each transmission device facing the SONET / SDH network. Is a mapping method when mapping a frame to a SONET / SDH frame,
An integration step of integrating the number of bytes passing through the packet;
Select a packet based on the integration result of the integration step, a marker insertion step of inserting a marker into the packet,
A packet duplicating step of receiving the packet, duplicating the packet and outputting the same packet to each of the active I / F card and the standby I / F card;
When mapping the packet, if it is a packet with a marker, the mapping position of the packet is controlled based on the marker, and for the marker-added packet, a mapping control step of mapping by removing the marker;
A mapping method characterized by including

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