JP2017011582A - Communication device and communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ring connection device that achieves suitable band control of traffic passing through a plurality of rings.SOLUTION: A line card 34 and a line card 36 of a ring connection device 10 transfers a straddle frame, i.e. a frame received from a ring network 22 and to be transmitted to a ring network 20, to a return port 45 of a line card 38. The line card 38 applies a band control process to a plurality of straddle frames on the basis of a common criterion, and transfers the straddle frames having gone through the band control process to a line card 30 or line card 32 to have it transmit the straddle frames to the ring network 20.SELECTED DRAWING: Figure 4

Description

  The present invention relates to data communication technology, and more particularly to a communication apparatus and a communication method.

  Band control in a communication device such as a conventional layer 2 switch is performed in units of data frame input ports or output ports. For example, the priority class of the data frame may be identified based on the VLAN tag attached to the input data frame, the ToS information of the IP header, or the like, and the bandwidth control may be executed according to the priority class.

JP 2006-157592 A

  In a communication apparatus that interconnects a plurality of ring networks, bandwidth control for traffic across a plurality of rings may be required. However, the present inventor considered that the bandwidth control for each input port or output port may not be able to perform sufficient bandwidth control for traffic across a plurality of rings.

  The present invention has been made on the basis of the above-mentioned problem recognition of the present inventor, and a main object thereof is to provide a technique for realizing suitable bandwidth control for traffic across a plurality of rings.

  In order to solve the above problems, a communication device according to an aspect of the present invention includes a first port and a second port connected to a first ring network, and a third port and a fourth port connected to a second ring network. And a first transfer unit that transfers a frame received from the first port or the second port and to be transmitted from at least one of the third port and the fourth port to a predetermined fifth port; A bandwidth control unit that executes bandwidth control processing based on a common reference for a plurality of frames transferred to the fifth port, and a frame that has undergone bandwidth control processing by the bandwidth control unit is at least a third port and a fourth port A second transfer unit for transferring to one side.

  Another aspect of the present invention is a communication method. In this method, a communication device including a first port and a second port connected to a first ring network, and a third port and a fourth port connected to a second ring network is connected to the first port or the second port. A step of transferring a frame to be transmitted from at least one of the third port and the fourth port to a predetermined fifth port that is a received frame, and a plurality of frames transferred to the fifth port Performing a bandwidth control process based on a common standard and transferring a frame that has undergone the bandwidth control process to at least one of the third port and the fourth port.

  It should be noted that any combination of the above components and the expression of the present invention converted between a method, a program, a recording medium storing the program, and the like are also effective as an aspect of the present invention.

  According to the present invention, it is possible to realize suitable bandwidth control for traffic across a plurality of rings.

It is a figure which shows the structure of the communication system of embodiment. It is a block diagram which shows the structure of the ring connection apparatus of FIG. It is a figure which shows an example of the header in an apparatus. It is a figure which shows typically operation | movement of a ring connection apparatus.

  FIG. 1 shows a configuration of a communication system 100 according to the embodiment. The communication system 100 is a system for a carrier to provide a communication service to a user, and includes a ring connection device 10, an L2 switch 12, an L2 switch 14, an L2 switch 16, and an L2 switch 18. The L2 switch 12 and the L2 switch 14 are layer 2 switches that form a ring network 20 for MAC frame transmission together with the ring connection device 10. The L2 switch 16 and the L2 switch 18 are layer 2 switches that constitute a ring network 22 for MAC frame transmission together with the ring connection device 10. The ring network 20 and the ring network 22 are, for example, ring networks in geographically different areas.

  The ring connection device 10 is a communication device that interconnects the ring network 20 and the ring network 22. The ring connection device 10 relays the traffic remaining in the ring network 20 (frame transmitted within the ring network 20) and the traffic remaining in the ring network 22 (frame transmitted within the ring network 22). A frame of traffic that remains in these single rings, and a frame to be transferred to the same ring network is called a “pass frame”. Further, the ring connection device 10 relays traffic across the ring network 20 and the ring network 22, that is, a frame to be transmitted across a plurality of rings (hereinafter referred to as “strand frame”).

  The ring connection device 10 according to the embodiment is a shelf-type layer 2 switch including a plurality of line cards (also called interface cards). Each line card includes a plurality of ports 40 (also called input / output ports). One port 40 of the line card 30 is connected to one end of the ring network 20, and one port 40 of the line card 32 is connected to the other end of the ring network 20. One port 40 of the line card 34 is connected to one end of the ring network 22, and one port 40 of the line card 36 is connected to the other end of the ring network 22.

  Here, the problems of the prior art will be described. The ring connection device 10 may be required to perform bandwidth control on a straddling frame to be transmitted across the rings. For example, there is a case where the bandwidth of the straddle frame corresponding to the contract content with the user should be provided. In this case, the ring connection device 10 is a plurality of straddling frames input from ports of different line cards, and a common band for a plurality of straddling frames to be output from the ports of different line cards It is necessary to execute control. For example, it is common to both the straddle frame received at the port of the line card 34 and transmitted from the port of the line card 32 and the straddle frame received at the port of the line card 36 and transmitted from the port of the line card 30. Therefore, it is necessary to execute bandwidth control based on the criteria.

  In addition, a frame received at a port connected to the ring network (hereinafter referred to as “ring port”) among the ports of the ring connection device 10 includes a straddling frame and a passing frame. Depending on the content of the contract with the user, the ring connection apparatus 10 may be required to perform individual (typically different) bandwidth control for each of the straddling frame and the passing frame.

  In conventional bandwidth control in units of frame input ports or output ports, it is sometimes difficult to perform suitable bandwidth control for straddling frames. For example, in bandwidth control in units of input ports, common bandwidth control can be executed for input traffic to the same line card. However, bandwidth control common to both the straddling frame and the passing frame is executed. That is, it is not possible to execute individual band control for each of the straddling frame and the passing frame.

  In addition, in bandwidth control in units of output ports, common bandwidth control can be performed for output traffic of the same port, but common bandwidth control is performed for both straddle frames and passing frames. Become. In other words, even with bandwidth control in units of output ports, individual bandwidth control cannot be executed for each of the straddle frame and the passing frame.

  Furthermore, in both conventional bandwidth control in units of input ports and bandwidth control in units of output ports, a plurality of straddling frames received by different line card ports and output from different line card ports are used. However, common bandwidth control could not be executed.

  In order to solve such a problem of the prior art, the ring connection device 10 according to the embodiment temporarily transfers a straddle frame to be transferred from the first ring network to the second ring network to a specific port, The bandwidth control is executed collectively for a plurality of straddling frames. Then, after the bandwidth control is executed, the straddling frame is transferred to the second ring network. Specifically, the ring connection device 10 once aggregates all the straddle frames received at the ports of different line cards into a specific line card (in the embodiment, the line card 38). Then, band control based on a common criterion is executed for the straddling frames aggregated in the specific line card, the straddling frame is returned from the specific line card, and the straddling frame is transmitted to the transfer destination ring network. As a result, common bandwidth control is realized for a straddling frame in which a plurality of input ports from the ring network and a plurality of output ports to the ring network exist.

  FIG. 2 is a block diagram showing a configuration of the ring connection device 10 of FIG. Each block shown in the block diagram of the present specification can be realized by hardware such as a computer CPU, memory, FPGA (Field-Programmable Gate Array), and the like, and can be realized by software. Although realized by a computer program or the like, here, functional blocks realized by their cooperation are depicted. Therefore, those skilled in the art will understand that these functional blocks can be realized in various forms by a combination of hardware and software.

  The ring connection device 10 includes a line card 30, a line card 32, a line card 34, a line card 36, a line card 38, and an interconnection unit 50. The interconnection unit 50 is a switch fabric card, and relays frames between different line cards.

  The line card 30, line card 32, line card 34, and line card 36 connected to the ring network will be described. Each of these line cards includes a ring port 41, a route determination unit 42, a transfer unit 43, and a transmission control unit 44. The ring port 41 is a port connected to the transmission path of the ring network among the plurality of ports 40 provided in each line card.

  The route determination unit 42 holds a MAC address table and determines a route of a frame received by the ring port 41 on a learning basis. For example, the path control for the received frame is executed by searching the MAC address table using the destination MAC address of the received frame as a key and determining the transmission port (in other words, the transfer destination in the apparatus). The route determination unit 42 adds a predetermined in-device header to the received frame and sets information for controlling the frame transmission path in the ring connection device 10 in the in-device header.

  FIG. 3 shows an example of the in-device header. When the transmission port is determined by searching the MAC address table, the route determination unit 42 determines the reception port information (for example, line card ID + port ID), the VLAN information (for example, VLAN-ID), and the information specified by the information. 1 in-device identifier is set in the in-device header. In addition, the route determination unit 42 sets the transmission port information (for example, line card ID + port ID) of the MAC frame and the second in-device identifier specified by the information in the in-device header.

  The route determination unit 42 associates specific reception port information and VLAN information with a specific in-device identifier, and also associates specific transmission port information with a specific in-device identifier (for example, a table) ) May be held. The route determination unit 42 may specify in-device identifiers corresponding to the reception port information and the transmission port information according to this rule. In the in-device identifier determination rule, the first in-device identifier and the second in-device identifier match in the case of a passing frame, and the first in-device identifier and the second in-device identifier do not match in the case of a straddle frame. Is set in advance.

  For example, in the in-device identifier determination rule, the in-device identifier “1” is associated with the reception port information and transmission port information (for example, the ring port 41 of the line card 30 and the line card 32) corresponding to the input / output frame of the ring network 20. May be attached. On the other hand, the in-device identifier “2” may be associated with the reception port information and the transmission port information (for example, the ring port 41 of the line card 34 and the line card 36) corresponding to the input / output frame of the ring network 22.

  Returning to FIG. 2, the transfer unit 43 refers to the in-device header of the frame output from the route determination unit 42, and transmits the frame in the device according to the in-device identifier and transmission port information set in the in-device header. Forward. When the frame output from the route determination unit 42 is a straddling frame, the transfer unit 43 transfers the straddling frame to a predetermined return port (a line card including the return port).

  Specifically, the transfer unit 43 has a frame type identification function for identifying whether the frame output from the route determination unit 42 is a passing frame or a straddling frame. For example, the transfer unit 43 identifies a passing frame when the first intra-device identifier and the second intra-device identifier in the intra-device header match, and identifies both as a straddle frame when they do not match.

  If the frame output from the route determination unit 42 is a passing frame, the transfer unit 43 transfers the frame to the line card indicated by the transmission port information in the in-device header. On the other hand, if the frame output from the route determination unit 42 is a straddling frame, the frame is transferred to the line card 38 regardless of the transmission port information in the in-device header. For example, special transfer information instructing transfer to the return port 45 of the line card 38 may be set in the in-device header of the straddle frame, and the straddle frame may be output to the interconnection unit 50. The interconnection unit 50 may relay the frame in which the special transfer information is set in the in-device header to the uniform line card 38.

  In the embodiment, the frame type is identified by the difference between the in-device identifiers, but may be identified by other methods. For example, the frame type may be identified based on a combination of reception port information and transmission port information. In this case, the transfer unit 43 may hold a frame type determination rule (for example, a table) in which a combination of a plurality of types of reception port information and transmission port information is associated with either a passing frame or a straddling frame. Then, according to the combination of the reception port information and the transmission port information set in the in-device header of the frame, it may be identified whether it is a passing frame or a straddling frame.

  The transmission control unit 44 outputs the frame from the port indicated by the transmission port information in the in-device header of the frame transferred from the transfer unit 43 in the card or the frame input from the interconnection unit 50. When a passing frame or a crossing frame is input from the interconnection unit 50, the transmission control unit 44 outputs the frame from the ring port 41 among a plurality of ports in the card.

  Next, the line card 38 will be described. The line card 38 includes a return port 45, a transmission control unit 46, and a transfer unit 48. The transmission control unit 46 and the transfer unit 48 correspond to the transmission control unit 44 and the transfer unit 43 described above.

  The loopback port 45 is a port in which the frame loopback function is enabled among a plurality of ports included in the line card 38. The return port 45 executes a known return process for the frame input from the transmission control unit 46, that is, outputs the input frame to the transfer unit 48 as it is as a received frame without outputting it to the outside of the apparatus (outside the card). To do. The loopback port 45 of the embodiment is a port that is a common transfer destination of a plurality of straddling frames in the ring connection device 10, and can be said to be a port that aggregates a plurality of straddling frames.

  The transmission control unit 46 outputs the frame (the straddling frame in the embodiment) input from the interconnection unit 50 to the return port 45. The transmission control unit 46 includes a band control unit 47. The bandwidth control unit 47 performs bandwidth control processing based on a predetermined common criterion for a plurality of straddling frames transferred to the return port 45.

  The bandwidth control unit 47 executes a known bandwidth control process. For example, as traffic policing, frames that exceed a predetermined bandwidth may be discarded so that the frame output rate (in other words, the output flow rate per unit time) may be controlled to fall within the bandwidth. As traffic shaping, a frame output rate may be controlled by temporarily storing a frame exceeding a predetermined bandwidth in a frame buffer.

  Further, the bandwidth control unit 47 may execute bandwidth control processing with the same limit value (bandwidth) for all straddling frames. Further, a common bandwidth control process may be executed in units of predetermined identification information set in a frame, such as a VLAN-ID unit set in a straddling frame or an in-device identifier unit. For example, the bandwidth control process may be executed by setting 1 Gbps as the upper limit value for a plurality of straddling frames belonging to VLAN 1 while using 5 Gbps as the upper limit value for a plurality of straddling frames belonging to VLAN 2.

  The transfer unit 48 is input to the return port 45 through the bandwidth control processing by the bandwidth control unit 47, and the straddle frame output from the return port 45 is transferred to at least one of a plurality of ring ports connected to the transfer destination ring network. Forward. Specifically, the straddling frame is transferred to the port of the line card indicated by the transmission port information set in the in-device header of the straddling frame, that is, the transmission port determined by the line card that has received the straddling frame. When the address of the straddling frame is a multicast address indicating that the address should be output from a plurality of ring ports connected to the transfer destination ring network, the transfer unit 48 transmits the straddle frame to the number of transfer destination ring ports. You may copy. Then, the data may be transferred to each of a plurality of ring ports connected to the transfer destination ring network and output from each ring port.

The operation of the ring connecting device 10 having the above configuration will be described.
FIG. 4 schematically shows the operation of the ring connecting device 10. The figure shows the operation when a frame (stradded frame) received from the ring network 22 is transferred / relayed to the ring network 20. An arrow indicated by a solid line indicates a transfer path of a straddling frame received by the line card 34, and an arrow indicated by a broken line indicates a transfer path of a straddling frame received by the line card 36.

  The ring port 41 of the line card 34 receives the frame transmitted in the first direction on the ring network 22 (S10). The route determination unit 42 of the line card 34 determines the ring port 41 of the line card 30 as a transmission port according to the destination MAC address of the received frame. The route determination unit 42 adds an intra-device header in which transmission port information, a first intra-device identifier corresponding to the reception port, and a second intra-device identifier corresponding to the transmission port are set to the reception frame. Since the first in-device identifier and the second in-device identifier do not match, the transfer unit 43 of the line card 34 identifies the received frame as a straddling frame and transfers the straddling frame to the return port 45 of the line card 38. (S12).

  Similarly, the ring port 41 of the line card 36 receives a frame transmitted in the second direction on the ring network 22 (S14). The route determination unit 42 of the line card 36 determines the ring port 41 of the line card 32 as the transmission destination port according to the destination MAC address of the received frame. The route determination unit 42 adds an intra-device header in which transmission destination port information, a first intra-device identifier corresponding to the reception port, and a second intra-device identifier corresponding to the transmission port are set to the received frame. Since the first in-device identifier and the second in-device identifier do not match, the transfer unit 43 of the line card 36 identifies the received frame as a straddling frame and transfers the straddling frame to the return port 45 of the line card 38. (S16).

  The bandwidth control unit 47 of the line card 38 executes bandwidth control processing based on a common standard for the plurality of straddling frames transferred from the line card 34 and the line card 36 (S18). The straddling frame that has undergone the band control processing by the band controller 47 is input to the return port 45, and the return port 45 returns the input straddling frame within the apparatus (S20). The transfer unit 48 of the line card 38 transfers the straddling frame returned by the return port 45 to the transmission port indicated by the in-device header (S22). The ring port 41 of the line card 30 sends the straddling frame transferred from the line card 38 in the first direction of the ring network 20 (S24). The ring port 41 of the line card 32 sends the straddling frame transferred from the line card 38 in the second direction of the ring network 20 (S26).

  Although not shown in FIG. 4, the same operation is performed when the line card 30 and the line card 32 receive a straddle frame from the ring network 20. That is, the straddle frame received at the ring port 41 of the line card 30 and the line card 32 is once transferred to the line card 38. The bandwidth control unit 47 executes bandwidth control processing based on a common criterion for a plurality of straddling frames transferred from the line card 30 and the line card 32. These straddling frames are turned back at the turn-back port 45, transferred to at least one ring port 41 of the line card 34 and the line card 36, and output to the ring network 22.

  The reference for bandwidth control for the straddle frame transferred from the line card 30 and the line card 32 may be the same as or different from the reference for the straddle frame transferred from the line card 34 and the line card 36. . In the latter case, separate criteria may be defined for each of traffic transmitted from the ring network 20 to the ring network 22 and traffic transmitted from the ring network 22 to the ring network 20. The bandwidth controller 47 controls the bandwidth so that the total amount of the straddling frames transferred from the line card 30 and the line card 32 and the straddling frames transferred from the line card 34 and the line card 36 is within a predetermined range. May be executed.

  Further, although not shown in FIG. 4, if the frame received by the ring port 41 of the line card 34 is a passing frame, the passing frame is transferred from the line card 34 to the line card 36, and is transmitted from the ring port 41 of the line card 36 to the ring. It is sent to the network 22. Similarly, if the frame received by the ring port 41 of the line card 36 is a passing frame, the passing frame is transferred from the line card 36 to the line card 34 and sent from the ring port 41 of the line card 34 to the ring network 22. The

  At this time, a band control unit may be provided on either the reception card or the transmission card of the passing frame. This band control unit may execute the band control process for the pass frame in accordance with the band control standard determined independently of the band control standard of the band control unit 47, in other words, for each pass frame. The same applies when the frame received by the line card 30 and the line card 32 is a passing frame, and at least one of the line card 30 and the line card 32 executes a band control process for the passing frame in accordance with the band control standard for each passing frame. May be.

  According to the ring connection device 10 of the embodiment, it is possible to perform suitable bandwidth control for traffic straddling a plurality of rings. For example, a common bandwidth control is performed for a plurality of straddling frames received by each port of a plurality of line cards connected to the ring network 22 and transmitted from each port of the plurality of line cards connected to the ring network 20. It becomes possible. In addition, it is possible to individually control the bandwidth of the straddling frame and the passing frame received at the same port or output from the same port. As described above, according to the ring connection device 10, bandwidth management in units of frame types can be performed, and effective securing of network resources and optimization of service levels can be supported.

  Further, the ring connection device 10 once aggregates straddle frames received at a plurality of ports across different line cards into a specific line card (turnback port), and collectively executes bandwidth control. As a result, there is also an advantage that adjustment processing (for example, in-device communication for adjustment) which is necessary when performing bandwidth control distributed over a plurality of ports becomes unnecessary.

  Furthermore, in the ring connection device 10, since the line card that collectively executes the bandwidth control for the plurality of straddling frames is provided separately from the line card connected to the ring network, the processing load of each line card can be reduced and distributed. Furthermore, the ring connection device 10 has a plurality of interfaces (for example, four) with a plurality of ring networks (for example, two), but any interface function is distributed and executed on different line cards. Thereby, in addition to reducing the processing load of each line card, the redundancy of the ring network connection can be secured, in other words, the availability of the ring network can be increased.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. is there.

  In the above embodiment, a plurality of ring ports (four in the embodiment) connected to the ring network in the ring connection device 10 are provided in different line cards, and a return port for common bandwidth control is provided. In addition, they were provided on different line cards. As a modified example, at least a part of the plurality of ring ports and the return port may be collected on the same line card. For example, all the ring ports 41 and the return ports 45 may be provided in one line card. However, from the viewpoint of redundancy of the ring network, it is preferable to provide two ring ports connected to the ring network 20 in different line cards, and the two ring ports connected to the ring network 22 are also different lines. It is preferable to disperse the card.

  In the above embodiment, the band control process for the straddling frame by the band control unit 47 is executed before the straddling frame is folded by the folding port 45. As a modification, the bandwidth control unit 47 may perform bandwidth control processing on the straddling frame that is looped back at the loopback port 45.

  In the embodiment described above, the folding of the straddling frame is realized by the frame folding process in the line card 38 by the folding port 45. As a modified example, after the band control, the bridge frame is temporarily output from the port of the line card 38 to the outside of the card (outside the apparatus), and the bridge frame is received by another port of the line card 38 and transferred to the transmission port. It is also possible to realize folding of the straddling frame.

  Although not mentioned in the above embodiment, a route determination unit may be provided in the line card 38, and the route determination unit searches the crossing frame in the line card 38 by searching the MAC address table. A transmission port may be determined. Further, an in-device header including the determined transmission port information and in-device identifier may be added to the straddling frame after the return. For example, as in the above-described modification, when the straddle frame is temporarily output to the outside of the card (outside the device) and turned back, and the in-device header of the straddle frame before output is deleted at the time of output, the transmission port is determined after the turn back. The configuration is useful.

  It should also be understood by those skilled in the art that the functions to be fulfilled by the constituent elements described in the claims are realized by the individual constituent elements shown in the embodiments and the modification examples or by their cooperation.

  10 ring connection device, 20 ring network, 22 ring network, 41 ring port, 42 route determination unit, 43 transfer unit, 44 transmission control unit, 45 return port, 46 transmission control unit, 47 band control unit, 48 transfer unit.

Claims (4)

A first port and a second port connected to the first ring network;
A third port and a fourth port connected to the second ring network;
A first transfer for transferring a frame received from the first port or the second port and to be transmitted from at least one of the third port and the fourth port to a predetermined fifth port; And
A bandwidth control unit that performs bandwidth control processing based on a common criterion for a plurality of frames transferred to the fifth port;
A second transfer unit that transfers a frame that has undergone band control processing by the band control unit to at least one of the third port and the fourth port;
A communication apparatus comprising:   2. The fifth port is provided in a line card different from a line card in which at least one of the first port, the second port, the third port, and the fourth port is provided. The communication device described.   The communication apparatus according to claim 1 or 2, wherein each of the first port, the second port, the third port, and the fourth port is provided on a different line card. A communication device comprising a first port and a second port connected to the first ring network, and a third port and a fourth port connected to the second ring network,
Transferring a frame received at the first port or the second port to be transmitted from at least one of the third port and the fourth port to a predetermined fifth port;
Performing bandwidth control processing based on a common criterion for a plurality of frames transferred to the fifth port;
And a step of transferring the frame that has undergone the bandwidth control processing to at least one of the third port and the fourth port.

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