JP5737758B2 - Communication apparatus and communication method - Google Patents

Description

  The present invention relates to a communication apparatus and a communication method that contribute to improving the quality of communication traffic in the communication field.

  In the current communication network, when the traffic is transferred, there is a case where the statistical multiplexing effect is used to improve the bandwidth utilization efficiency and improve the economy. When traffic is transferred using the statistical multiplexing effect, when congestion occurs in a communication device that switches communication traffic, there is a problem that frames are discarded at a certain rate and the communication quality deteriorates (Patent Document). 1). As an attempt to improve the communication quality of a network, in an Ethernet (registered trademark) network, a mechanism for indicating a frame priority by providing a tag of Class of Service (CoS) to an Ethernet frame is defined (Non-Patent Document 1). . Further, in the Internet Protocol (IP) network, a mechanism for indicating a packet priority by providing a Type of Service (ToS) / DiffServ Code Point (DSCP) field in a packet is defined (Non-patent Document 2).

JP 2004-193975 A

Glen Kramer and Biswanath Mukherjee, “Supporting differentiated classes of service in Ethernet passive optical networks,” Journal of optical networking August & September 2002, Vol.1, No. 8 & 9, pp.280-298. The Internet Engineering Task Force (IETF) Request for comments (RFC) 2472, “Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers” IEEE802.3 CSMD / CD (Ethernet) ACCESS METHOD, http://standards.ieee.org/about/get/802/802.3.html

  However, even when the traffic quality is controlled by using the above-described method, it is not only possible to reliably guarantee the priority traffic when traffic congestion occurs, but it is difficult to detect which frame is discarded. There is a problem.

  Accordingly, an object of the present invention is to provide a communication apparatus and a communication method for detecting a frame when discarded in a communication apparatus capable of switching frames of communication traffic while improving the quality of priority traffic.

In order to achieve the above object, a communication apparatus according to the present invention is a communication apparatus for switching frames of communication traffic, receiving multicarrier signal light, demodulating a received frame, and a transfer destination port of the received frame And a reception frame confirmation means for confirming the priority, a buffer means for buffering the received frame in a buffer queue corresponding to the priority, and a buffer overflow occurs in the buffer queue, and the buffer queue has a predetermined priority or higher. If the received frame is accommodated, a control means for sending a received frame discard command, a discard means for discarding the received frame instructed to be discarded, and a received frame stored in the queue are transferred to the transfer destination port And means for generating and transmitting multicarrier signal light from the transferred frame. Provided with a door.
When the sum of the transfer interface speeds of the received frames transferred to the transfer destination port is larger than the transfer destination interface capacity, the control means determines that a buffer overflow has occurred and discards the received frame. It is configured.

  The multicarrier signal light is signal light in which traffic is assigned to each subcarrier of the signal according to the priority of traffic, and the demodulation means, the received frame confirmation means, the buffer means, and the discard means It is also preferable to be provided for each subcarrier.

  In addition, it is preferable that the information processing apparatus further includes means for sending information on the received frame discarded by the discarding means to the upper system as an alarm.

  The control means preferably discards a received frame that arrives later when it is determined that a buffer overflow has occurred.

In order to achieve the above object, a communication method according to the present invention is a communication method for switching frames of communication traffic, which receives a multicarrier signal light and demodulates a received frame, and a transfer destination port of the received frame A reception frame confirmation step for confirming the priority, a buffer step for buffering the reception frame in a buffer queue according to the priority, and a sum of transfer interface speeds of the reception frames transferred to the transfer destination port. A control step of determining that a buffer overflow has occurred in the buffer queue if the buffer capacity is greater than the previous interface capacity , and sending a received frame discard command if the buffer queue contains a received frame having a certain priority or higher; , Discarding received frames ordered to be discarded Comprising a step, and transferring the received frame stored in the queue to the destination port, and sending to generate a multi-carrier signal light from the transmitted frames.

  According to the present invention, in an apparatus for switching multicarrier signals, traffic is allocated to each subcarrier of a signal according to the priority of traffic, and priority traffic is protected by separating priority traffic and non-priority traffic. At the same time, the discard frame can be detected.

1 shows a functional block diagram of a communication device according to the present invention. The structure of the switch part of the communication apparatus by this invention is shown. The operation | movement flowchart of the communication apparatus by this invention is shown.

  The best mode for carrying out the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a functional block diagram of a communication apparatus according to the present invention. This device is a communication device that switches frames of communication traffic, assigns traffic to each subcarrier of the multicarrier signal, and improves priority traffic quality by separating and transferring priority traffic and non-priority traffic. And has a function of detecting the frame when discarded.

  This apparatus includes 1 to M transmission side ports 1, 1 to M reception side ports 2, a switch unit 3, and a control unit 4 for controlling them. The transmission side port 1 includes a multicarrier signal transmission interface 11, a transmission frame confirmation unit 12, a buffer unit 13, and a frame discard management unit 14. The reception side port 2 includes a multicarrier signal reception interface 21, a reception frame confirmation unit 22, a buffer unit 23, and a frame discard management unit 24.

  The multicarrier signal transmission interface 11 has a function of generating and transmitting a multicarrier signal. Each signal transferred from the buffer unit 13 is mapped to each subcarrier by the subcarrier signal transmitter 111. The subcarrier signal transmitter 111 includes a transmission signal processing unit 113 and a photoelectric conversion unit 112. The transmission signal processing unit 113 has a function of modulating a transmission signal. Further, the photoelectric conversion unit 112 converts the electrical signal into an optical signal and transmits it to the multiplexer.

  The multicarrier signal reception interface 21 has a function of receiving and demodulating a multicarrier signal. The demodulated multicarrier signal is transferred from the subcarrier signal receiver 211 to the reception frame confirmation unit 22 for each subcarrier. The subcarrier signal receiver 211 includes a reception signal processing unit 213 and a photoelectric conversion unit 212. The photoelectric conversion unit 212 has a function of converting the received optical signal into an electrical signal. The reception signal processing unit 213 demodulates the received signal and transmits it to the reception frame confirmation unit 22.

  The transmission frame confirmation unit 12 confirms the quality of service (QoS) of the frame. The QoS priority is determined by the operation policy.

  The reception frame confirmation unit 22 confirms the transfer destination of the frame accommodated in the demodulated signal and confirms the quality of service (QoS) of the frame. The QoS priority is determined by the operation policy.

  The transmission side buffer unit 13 and the reception side buffer unit 23 have a function of temporarily buffering transmission frames and reception frames, respectively. The buffered frames are managed in a queue corresponding to the priority.

  The transmission side frame discard management unit 14 and the reception side frame discard management unit 24 discard the received frame or the transmission frame based on a command from the control unit 4.

  The switch unit 3 has a function of transferring a signal received from the interface to a port designated by the control unit 4.

  The control unit 4 has a function of controlling each transmission side port 1, each reception side port 2, and the switch unit 3. The switch unit 3 is controlled based on the transfer destination of the frame confirmed by the reception frame confirmation unit 22. Also, based on the priority confirmed by the frame confirmation units 12 and 22, the discard of the frames managed in the queues of the buffer units 13 and 23 is managed. When frame discard is necessary, a frame discard command is sent to the frame discard management units 14 and 24 of each transmission side port 1 and each reception side port 2. Also, the discarded frame information is sent as an alarm to a host system such as a network management device.

  FIG. 2 shows the configuration of the switch unit of the communication apparatus according to the present invention. The switch unit 3 has a function of transferring the received frame to a port designated by the control unit 4. When high-priority QoS frames are concentrated on the same switch (Rk) (k is 1 to x), frames that cannot be accommodated in the reception-side buffer 23 are discarded. In the case of a non-priority QoS frame, there is no restriction on the bandwidth capacity. Even if the interface capacity is exceeded, the frame is transferred, but the frame overflowing from the transmission side buffer 13 is discarded.

ただし、ｋは、ある受信側ポートにおいて、ある宛先ポートへ転送されるサブキャリア数、ｌはある宛先ポートへ転送されるサブキャリアを有する受信側ポート数を示す。
このとき、ＩＦ_ｃａｐ＜＝０の場合：空き容量不足、ＩＦ_ｃａｐ＞０の場合：空き容量ありとなる。空き容量がある場合はステップ６へ進む。空き容量が不足している場合は、ステップ７へ進む。
（Ｓ６）スイッチング：ステップ５において、空き容量があった場合は、受信フレーム確認部において確認された情報に基づき、フレームを宛先ポートへ転送する。
（Ｓ７）優先度？：転送すべきフレームが優先フレームである場合は、ステップ８へ進む。一方、非優先フレームである場合は、ステップ１０へ進む。
（Ｓ８）廃棄処理：受信フレーム確認部において確認された情報に基づき、フレームを宛先ポートへ転送する。ここでは、先着フレームを優先して転送する。そのため、受信バッファ部の優先キューに収容されているフレームを廃棄するにあたり、後から到着したフレームを廃棄する。
（Ｓ９）警報：ステップ８において廃棄された優先フレーム情報を警報として送出する。
（Ｓ１０）廃棄処理：ステップ７において非優先フレームであった場合は、受信フレーム確認部において確認された情報に基づき、フレームを宛先ポートへ転送する。このとき、送信バッファ部のキューに収容しきれないフレームを廃棄する。
（Ｓ１１）終了：一連の動作終了。開始へ戻る。 FIG. 3 shows an operation flowchart of the communication apparatus according to the present invention. Each operation will be described below.
(S1) Start: Starts the operation of the switch function.
(S2) Signal reception: The signal received at the multicarrier signal reception interface is demodulated and transferred to the received frame confirmation unit for each subcarrier.
(S3) Received frame confirmation: In the received frame confirmation unit, the destination port and QoS value of the received frame are confirmed and notified to the control unit and the frame discard management unit, respectively. Here, the definition of the QoS value is based on the operation policy.
(S4) Reception buffer: Frames confirmed by the reception frame confirmation unit are stored in a queue for each combination of priority, input port, and destination port.
(S5) Capacity? : Check the free capacity of the transfer destination port. Here, the sum of the transfer interface speeds of the received frames to a certain destination port confirmed in the received frame confirmation in step 3 is set as the transfer capacity, and whether or not there is a free capacity compared with the interface capacity. Judging.
Here, the parameters are set as follows, and the capacity is determined by the following equation.
_-Remaining capacity of transfer destination port: IF _cap
Transfer interface speed of the received frame transferred to the transfer destination port: IF _sub [i, j] (i indicates the receiving port number. J indicates the subcarrier number)
-Transfer destination interface capacity: IF _dest

Here, k represents the number of subcarriers transferred to a certain destination port in a certain receiving port, and l represents the number of receiving ports having a subcarrier transferred to a certain destination port.
At this time, if IF _cap <= 0: insufficient free space, if IF _cap > 0: free space is present. If there is free space, go to Step 6. If the free space is insufficient, the process proceeds to step 7.
(S6) Switching: If there is free space in step 5, the frame is transferred to the destination port based on the information confirmed by the received frame confirmation unit.
(S7) Priority? : If the frame to be transferred is a priority frame, go to Step 8. On the other hand, if it is a non-priority frame, the process proceeds to step 10.
(S8) Discarding process: The frame is transferred to the destination port based on the information confirmed by the received frame confirmation unit. Here, the first frame is preferentially transferred. For this reason, when discarding a frame stored in the priority queue of the reception buffer unit, a frame that arrives later is discarded.
(S9) Alarm: The priority frame information discarded in step 8 is transmitted as an alarm.
(S10) Discarding process: If it is a non-priority frame in step 7, the frame is transferred to the destination port based on the information confirmed by the received frame confirmation unit. At this time, frames that cannot be accommodated in the queue of the transmission buffer unit are discarded.
(S11) End: A series of operation ends. Return to start.

In the following, embodiments of the present invention will be described.
Embodiment 1 An example in which priority traffic of a multicarrier signal input to port 1 of a communication apparatus is output to port 11 and non-priority traffic is output to port 15 will be described. Assume the following conditions.
-Bit rate of multicarrier signal (bit rate of each interface): 100 Gbps
-Number of subcarriers: 100 (subcarrier numbers 1 to 100)
-Bit rate of subcarrier signal: 1 Gbps
・ Multi-carrier signal input port number: 1
Multicarrier signal output port number: 11 for priority traffic, 15 for non-priority traffic
Priority traffic: Subcarrier numbers 1 to 20 of the input multicarrier signal
(Each is independent Gigabit Ethernet traffic.)
Non-priority traffic: Subcarrier numbers 21 to 100 of the input multicarrier signal
(Each is independent Gigabit Ethernet traffic.)
-Interface initial state: No input signal to other ports-Signal protocol: Ethernet (Non-patent Document 3)

となる。転送先ポート１５については、ｌ＝１、ｋ＝８０であることから、

となる。以上のように本例では、転送先ポート１１へのトラフィックは２０Ｇｂｐｓであり、転送先ポート１５へのトラフィックは８０Ｇｂｐｓであることから、サブキャリア番号１〜１００までの各フレーム転送先ポートの容量は空いている。そのため、次のステップであるスイッチングへ進む。
（Ｓ６）スイッチング：受信フレームを、宛先ポートへ転送する。宛先ポートへ転送されたフレームは、マルチキャリア信号送信インタフェースにおいて各サブキャリア信号にマッピングされ送信される。
（Ｓ１１）終了：一連の動作終了。開始へ戻る。 Hereinafter, description will be given according to the operation flow.
(S1) Start: Starts the operation of the switch function.
(S2) Signal reception: The signal received at the multicarrier signal reception interface is demodulated and transferred to the received frame confirmation unit for each subcarrier.
(S3) Received frame confirmation: The destination port of the received Ethernet frame is confirmed, and QoS is confirmed based on the CoS value (Non-patent Document 3). As a result of the QoS confirmation, frames with subcarrier numbers 1 to 20 are priority frames of independent Gigabit Ethernet, and the destination port is 11. The frames with subcarrier numbers 21 to 100 are independent non-priority frames of Gigabit Ethernet, and the destination port is 15.
(S4) Receive buffer: A frame whose received frame is confirmed is accommodated in a queue for each combination of priority, input port, and destination port. Here, the frame is accommodated in the next queue.
Queue (1): priority frame accommodated in subcarrier numbers 1-20 Queue (2): non-priority frame accommodated in subcarrier numbers 21-100 (S5) capacity? : Check the free capacity of the transfer destination port. For the transfer destination port 11, since l = 1 and k = 20,

It becomes. For transfer destination port 15, since l = 1 and k = 80,

It becomes. As described above, in this example, the traffic to the transfer destination port 11 is 20 Gbps, and the traffic to the transfer destination port 15 is 80 Gbps. Therefore, the capacity of each frame transfer destination port from subcarrier numbers 1 to 100 is Vacant. Therefore, the process proceeds to the next step, switching.
(S6) Switching: The received frame is transferred to the destination port. The frame transferred to the destination port is mapped to each subcarrier signal and transmitted in the multicarrier signal transmission interface.
(S11) End: A series of operation ends. Return to start.

Example 2: In this example, priority traffic of signals input to port 1 and port 2 is output to port 11, and non-priority traffic is output to port 15. Assume the following conditions.
-Bit rate of multicarrier signal (bit rate of each interface): 100 Gbps
-Number of subcarriers: 100 (subcarrier numbers 1 to 100)
-Bit rate of subcarrier signal: 1 Gbps
・ Multi-carrier signal input port number: 1, 2
Multicarrier signal output port number: 11 for priority traffic, 15 for non-priority traffic
・ Priority traffic:
-Subcarrier numbers 1 to 20 of the multicarrier signal input to port 1
-Subcarrier numbers 1 to 40 of the multicarrier signal input to port 2
(Each is independent Gigabit Ethernet traffic.)
・ Non-priority traffic:
-Subcarrier numbers 21 to 100 of the multicarrier signal input to port 1
-Subcarrier numbers 41 to 100 of the multicarrier signal input to port 2
(Each is independent Gigabit Ethernet traffic.)
-Interface initial state: No input signal to other ports-Signal protocol: Ethernet (Non-patent Document 3)

となる。転送先ポート１５については、ｌ＝１のときｋ＝８０、ｌ＝２のときｋ＝６０であることから、

となる。以上のように本例では、転送先ポート１１へのトラフィックは、ポート１からのトラフィックは２０Ｇｂｐｓであり、ポート２からのトラフィックは４０Ｇｂｐｓであることから、転送先ポート１１については、空き容量がある。そのため、転送先ポート１１へのトラフィックに関しては、ステップ６の「スイッチング」処理に進む。一方、宛先ポート１５へのトラフィックは、ポート１からのトラフィックは８０Ｇｂｐｓであり、ポート２からのトラフィックは６０Ｇｂｐｓであることから、転送先ポート１５については、容量が不足している。そのため、転送先ポート１５へのトラフィックに関しては、ステップ７の「優先度？」処理を行う。
（Ｓ６）スイッチング：受信フレームを、宛先ポートへ転送する。宛先ポートへ転送されたフレームは、マルチキャリア信号送信インタフェースにおいて各サブキャリア信号にマッピングされ送信される。
（Ｓ７）優先度？：容量が不足になっている転送先ポートの収容フレームは、非優先フレームである。
（Ｓ１０）廃棄処理：送信側バッファにおいて、あふれた分のフレームが廃棄される。廃棄されずに送信されるフレームは、マルチキャリア信号送信インタフェースにおいて各サブキャリア信号にマッピングされ送信される。
（Ｓ１１）終了：一連の動作終了。開始へ戻る。 Hereinafter, description will be given according to the operation flow.
(S1) Start: Starts the operation of the switch function.
(S2) Signal reception: The signal received at the multicarrier signal reception interface is demodulated and transferred to the received frame confirmation unit for each subcarrier.
(S3) Received frame confirmation: The destination port of the received Ethernet frame is confirmed, and the QoS is confirmed based on the CoS value. Here, the frames of subcarrier numbers 1 to 20 of the multicarrier signal input to port 1 are priority frames, and the destination port is 11. Also, the frames of subcarrier numbers 1 to 40 of the multicarrier signal input to port 2 are priority frames, and the destination port is 11.
On the other hand, the frames of subcarrier numbers 21 to 100 of the multicarrier signal input to port 1 and the frames of subcarrier numbers 41 to 100 of the multicarrier signal input to port 2 are non-priority frames, and the destination port is 15.
(S4) Receive buffer: A frame whose received frame is confirmed is accommodated in a queue for each combination of priority, input port, and destination port. Here, the frame is accommodated in the next queue.
Port 1 receive buffer queue (1): priority frame accommodated in subcarrier numbers 1 to 20 Port 1 receive buffer queue (2): non-priority frame accommodated in subcarrier numbers 21 to 100 Port 2 Reception buffer queue (1): priority frame accommodated in subcarrier numbers 1 to 40 • port 2 reception buffer queue (2): non-priority frame (S5) capacity accommodated in subcarrier numbers 41 to 100? : Check the free capacity of the transfer destination port. For the transfer destination port 11, k = 20 when l = 1 and k = 40 when l = 2.

It becomes. For the forwarding port 15, k = 80 when l = 1 and k = 60 when l = 2.

It becomes. As described above, in this example, the traffic to the transfer destination port 11 is 20 Gbps for the traffic from the port 1 and 40 Gbps for the traffic from the port 2. . Therefore, for the traffic to the transfer destination port 11, the process proceeds to the “switching” process in step 6. On the other hand, as for the traffic to the destination port 15, the traffic from the port 1 is 80 Gbps, and the traffic from the port 2 is 60 Gbps, so that the capacity of the transfer destination port 15 is insufficient. Therefore, the “priority?” Process in step 7 is performed for the traffic to the transfer destination port 15.
(S6) Switching: The received frame is transferred to the destination port. The frame transferred to the destination port is mapped to each subcarrier signal and transmitted in the multicarrier signal transmission interface.
(S7) Priority? : The accommodated frame of the transfer destination port whose capacity is insufficient is a non-priority frame.
(S10) Discarding process: Overflowing frames are discarded in the transmission side buffer. A frame transmitted without being discarded is mapped to each subcarrier signal and transmitted in the multicarrier signal transmission interface.
(S11) End: A series of operation ends. Return to start.

Example 3 In this example, priority traffic of multicarrier signals input to port 1 and port 2 is output to port 11, and non-priority traffic is output to port 15. Here, it is assumed that the capacity of the destination port of the priority traffic exceeds. The state is as follows.
-Bit rate of multicarrier signal (bit rate of each interface): 100 Gbps
-Number of subcarriers: 100 (subcarrier numbers 1 to 100)
-Bit rate of subcarrier signal: 1 Gbps
・ Multi-carrier signal input port number: 1, 2
Multicarrier signal output port number: 11 for priority traffic, 15 for non-priority traffic
・ Priority traffic:
-Subcarrier numbers 1 to 50 of the multicarrier signal input to port 1
-Subcarrier numbers 1 to 60 of the multicarrier signal input to port 2
(Each is independent Gigabit Ethernet traffic.)
・ Non-priority traffic:
-Subcarrier numbers 51 to 100 of the multicarrier signal input to port 1
-Subcarrier numbers 61 to 100 of the multicarrier signal input to port 2
(Each is independent Gigabit Ethernet traffic.)
-Interface initial state: No input signal to other ports-Signal protocol: Ethernet (Non-patent Document 3)

となる。転送先ポート１５については、ｌ＝１のときｋ＝５０、ｌ＝２のときｋ＝４０であることから、

となる。以上のように本例では、転送先ポート１１へのトラフィックは、ポート１からのトラフィックは５０Ｇｂｐｓであり、ポート２からのトラフィックは６０Ｇｂｐｓであることから、転送先ポート１１については、容量が不足している。そのため、転送先ポート１１へのトラフィックに関しては、ステップ７の「優先度？」処理に進む。一方、宛先ポート１５へのトラフィックは、ポート１からのトラフィックは５０Ｇｂｐｓであり、ポート２からのトラフィックは４０Ｇｂｐｓであることから、転送先ポート１５については、空き容量がある。そのため、転送先ポート１５へのトラフィックに関しては、ステップ６の「スイッチング」処理を行う。
（Ｓ６）スイッチング：受信フレームを、宛先ポートへ転送する。宛先ポートへ転送されたフレームは、マルチキャリア信号送信インタフェースにおいて各サブキャリア信号にマッピングされ送信される。
（Ｓ７）優先度？：容量が不足になっている転送先ポートの収容フレームは、優先フレームである。
（Ｓ８）廃棄処理：受信側バッファにおいて、転送先ポートにおいてあふれる分のフレームが廃棄される。ここでは、サブキャリア番号５１から６０のフレームが廃棄される。廃棄されずに送信されるフレームは、マルチキャリア信号送信インタフェースにおいて各サブキャリア信号にマッピングされ送信される。
（Ｓ９）警報：ステップ８において優先フレームを廃棄された。そのため、警報としてサブキャリア番号５１から６０のフレームが廃棄されたことを送出する。
（Ｓ１１）終了：一連の動作終了。開始へ戻る。 Hereinafter, description will be given according to the operation flow.
(S1) Start: Starts the operation of the switch function.
(S2) Signal reception: The signal received at the multicarrier signal reception interface is demodulated and transferred to the received frame confirmation unit for each subcarrier.
(S3) Received frame confirmation: The destination port of the received Ethernet frame is confirmed, and the QoS is confirmed based on the CoS value. Here, the frames of subcarrier numbers 1 to 50 of the multicarrier signal input to port 1 are priority frames, and the destination port is 11. Also, the frames of subcarrier numbers 1 to 60 of the multicarrier signal input to port 2 are priority frames, and the destination port is 11.
On the other hand, the frames of subcarrier numbers 51 to 100 of the multicarrier signal input to port 1 and the frames of subcarrier numbers 61 to 100 of the multicarrier signal input to port 2 are non-priority frames, and the destination port is 15.
(S4) Receive buffer: A frame whose received frame is confirmed is accommodated in a queue for each combination of priority, input port, and destination port. Here, the frame is accommodated in the next queue.
Port 1 receive buffer queue (1): priority frame accommodated in subcarrier numbers 1 to 50 Port 1 receive buffer queue (2): non-priority frame accommodated in subcarrier numbers 51 to 100 Port 2 Reception buffer queue (1): priority frame accommodated in subcarrier numbers 1 to 60 • Port 2 reception buffer queue (2): non-priority frame (S5) capacity accommodated in subcarrier numbers 61 to 100? : Check the free capacity of the transfer destination port. For the transfer destination port 11, k = 50 when l = 1 and k = 60 when l = 2.

It becomes. For the forwarding port 15, k = 50 when l = 1, and k = 40 when l = 2.

It becomes. As described above, in this example, the traffic to the transfer destination port 11 is 50 Gbps for the traffic from the port 1 and 60 Gbps for the traffic from the port 2. ing. Therefore, regarding the traffic to the transfer destination port 11, the process proceeds to the “priority?” Process in step 7. On the other hand, as for the traffic to the destination port 15, the traffic from the port 1 is 50 Gbps and the traffic from the port 2 is 40 Gbps, so the transfer destination port 15 has a free capacity. Therefore, the “switching” process of step 6 is performed for the traffic to the transfer destination port 15.
(S6) Switching: The received frame is transferred to the destination port. The frame transferred to the destination port is mapped to each subcarrier signal and transmitted in the multicarrier signal transmission interface.
(S7) Priority? : The accommodation frame of the transfer destination port whose capacity is insufficient is a priority frame.
(S8) Discarding process: Overflowing frames at the transfer destination port are discarded in the receiving side buffer. Here, frames with subcarrier numbers 51 to 60 are discarded. A frame transmitted without being discarded is mapped to each subcarrier signal and transmitted in the multicarrier signal transmission interface.
(S9) Warning: The priority frame was discarded in step 8. Therefore, the fact that the frames of subcarrier numbers 51 to 60 have been discarded is sent as an alarm.
(S11) End: A series of operation ends. Return to start.

  Moreover, all the embodiments described above are illustrative of the present invention and are not intended to limit the present invention, and the present invention can be implemented in other various modifications and changes. Therefore, the scope of the present invention is defined only by the claims and their equivalents.

DESCRIPTION OF SYMBOLS 1 Transmission side port 2 Reception side port 3 Switch part 4 Control part 11 Multicarrier signal transmission interface 12 Transmission frame confirmation part 13 Buffer part 14 Frame discard management part 21 Multicarrier signal reception interface 22 Reception frame confirmation part 23 Buffer part 24 Frame discard Management unit 111 Subcarrier signal transmitter 112 Photoelectric conversion unit 113 Transmission signal processing unit 211 Subcarrier signal receiver 212 Photoelectric conversion unit 213 Reception signal processing unit

Claims (5)

A communication device for switching frames of communication traffic,
Demodulating means for receiving the multicarrier signal light and demodulating the received frame;
A reception frame confirmation means for confirming a transfer destination port and priority of the reception frame;
Buffer means for buffering the received frame in a buffer queue according to priority;
Control means for sending a received frame discard command when a buffer overflow occurs in the buffer queue and the buffer queue contains a received frame having a certain priority or higher;
A discarding means for discarding the received frame instructed to be discarded;
Means for forwarding the received frame stored in the queue to the forwarding port;
Means for generating and transmitting multi-carrier signal light from the transferred frame;
Bei to give a,
The control means is means for determining that a buffer overflow has occurred and discarding the received frame when the sum of the transfer interface speeds of the received frames transferred to the transfer destination port is larger than the interface capacity of the transfer destination. communication and wherein the. The multicarrier signal light is signal light in which traffic is allocated to each subcarrier of the signal according to the priority of traffic,
The communication apparatus according to claim 1, wherein the demodulation unit, the reception frame confirmation unit, the buffer unit, and the discard unit are provided for each subcarrier.   The communication apparatus according to claim 1, further comprising means for sending information on the received frame discarded by the discarding means to the upper system as an alarm. Wherein, the communication apparatus according to any one of claims 1 to 3, characterized in that discards the received frame when, arriving after the buffer overflow is determined to have occurred. A communication method for switching frames of communication traffic,
A demodulation step for receiving the multicarrier signal light and demodulating the received frame;
A reception frame confirmation step for confirming a transfer destination port and priority of the reception frame;
A buffer step of buffering the received frame in a buffer queue according to priority;
If the sum of the transfer interface speeds of the received frames transferred to the transfer destination port is larger than the interface capacity of the transfer destination, it is determined that a buffer overflow has occurred in the buffer queue , and the buffer queue has a certain priority or higher. A control step of sending a received frame discard command,
A discard step for discarding a received frame instructed to be discarded;
Forwarding the received frame stored in the queue to the forwarding port;
Generating and transmitting multicarrier signal light from the transferred frame; and
A communication method comprising:

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