JP2006203735A - Communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that there is a case that a physical line in link aggregation at line speed specified by a frame identifier of a receiving frame becomes unusable and in that case, a physical line for transmitting a frame can not be specified. <P>SOLUTION: When the physical line in the link aggregation becomes unusable, whether or not a physical line at the same line speed exists is re-checked. When all the physical lines at the same line speed are unusable, a transmitting destination is specified by searching a physical line at the line speed larger than and the closest to specified line speed first and retrieving a physical line at smaller line speed so that a physical line at small line speed is not pressed if possible. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a communication apparatus, and more particularly to a communication apparatus that performs frame distribution according to the line speed of a physical line when different speed lines are virtually collected.

  Link aggregation is a technique for handling a plurality of physical lines (data links) virtually as one line. According to this technique, the bandwidth can be expanded without using a high-speed line. Further, even when a failure occurs in a physical line, another physical line is used, and the entire line can continue to operate without being stopped.

  However, in the link aggregation standard (IEEE802.1ad), there is no description for frame allocation when different speed physical lines are aggregated. Japanese Patent Application Laid-Open No. 2004-228561 describes an invention in which frame distribution is performed by an IP address, a MAC address, a destination port, and the like, but does not describe a method of distributing frames according to the line speed of a physical line. Therefore, in the conventional router device, the frame distribution in the link aggregation function is determined and performed by the transmission / reception IP address and MAC address or logical port number regardless of the line speed of the physical line. When sending and receiving IP addresses and MAC addresses are used, physical addresses are allocated by adding both addresses and dividing by the number of physical lines. In this case, communication between terminals of the same combination always passes through the same physical line.

In link aggregation, received frames are distributed and transmitted to the physical line that is being aggregated. Therefore, when a physical line with a different speed is aggregated, only a physical line with a low line speed can be used even on a physical line with a high line speed. There are cases where it cannot be used, and the bandwidth of the physical line cannot be used efficiently.
On the other hand, even if the QoS bandwidth control function is used, bandwidth control for the link aggregation group is possible, but it is not possible to select a port to be transmitted to each physical line in the link aggregation group.

Special table 2003-526263

  As described above, in the prior art, when physical lines having different speeds are aggregated, there is a problem that the line speeds of a plurality of aggregated lines cannot be used efficiently.

  The present invention has a correspondence table between protocol identifiers and line speeds of physical lines, determines a physical line to be output from the correspondence table, and transmits a frame so that a physical line can be obtained even when different speed physical lines are aggregated. Can be used efficiently.

  According to the present invention, even when physical lines having different speeds are aggregated, the bandwidth of the physical lines in the aggregated group can be used efficiently. In addition, since frames with low priority can be distributed to physical lines with a low line speed, bandwidth control can be performed for each physical line in the aggregated group.

  Hereinafter, embodiments of the present invention will be described using examples with reference to the drawings.

  In the first embodiment, FIG. 1 is a block diagram illustrating a network. FIG. 2 is a block diagram for explaining link aggregation. FIG. 3 is a functional block diagram of the router. FIG. 4 is a correspondence table between frame identifiers and line speeds to be used. FIG. 5 is a table of correspondence between line speed and physical line and availability. FIG. 6 is a block diagram of router hardware. FIG. 7 is a diagram for explaining an IPv4 datagram format. FIG. 8 is a diagram for explaining an Ether frame. FIG. 9 is a diagram for explaining the assignment of the version field of the IP header. FIG. 10 is a diagram for explaining the assignment of the protocol field of the IP header. FIG. 11 is a diagram for explaining the assignment of the type field of the Ether header.

  A network 1000 to which the present invention is applied will be described with reference to FIG. The network 1000 includes four router devices 100, 200, 300, and 400. Five terminals 10 to 14 such as PCs are connected to the router device 100 via a hub 30. Similarly, four terminals 15 to 18 such as PCs are connected to the router device 200 via the hub 31. The terminal 19 is directly connected to the router device 300, and the terminal 20 is directly connected to the router device 400.

  A physical line 90 is extended between the router device 200 and the router device 400. On the other hand, three physical lines (α, β, γ) having different speeds are connected between the router device 100 and the router device 200, and they constitute a link aggregation X40. Similarly, a link aggregation Y50 is stretched between the router device 100 and the router device 300. Further, a link aggregation Z60 is extended between the router device 100 and the router device 400.

  Here, communication between the terminal 10 connected to the router apparatus 100 via the hub 30 and the terminal 15 connected to the router apparatus 200 via the hub 31 will be described with reference to FIG. Hereinafter, the router device is simply referred to as a router. In the following embodiments, description will be made using a router, but the router may be a switch. The communication device is a concept including a router and a switch. In FIG. 2, the description of the hub is omitted.

  In FIG. 2, the terminals 10 and 15 using the link aggregation network are connected via routers 100 and 200 having a link aggregation function. The physical line 70 is connected to the terminal 10 and the router 100, and similarly, the physical line 80 is connected to the terminal 15 and the router 200. The router 100 and the router 200 are connected by a link aggregation group X40 in which physical lines α41, β42, and γ43 having different line speeds are aggregated.

  The router 100 and the router 200 implement a link aggregation function, and a functional block configuration related to transmission / reception of the link aggregation function of the router 100 is shown in FIG.

  In FIG. 3, the router 100 includes frame reception units 111 to 114, frame transmission units 121 to 124, a reception frame control unit 110, and a transmission frame control unit 120. Since the frame reception units 111 to 114 include a timing extraction unit and a signal identification unit (not shown), they can receive signals up to 10 Gbit / s regardless of the signal bit rate. Similarly, the frame transmission units 121 to 124 can transmit signals up to 10 Gbit / s. Here, the frame receiver of the physical line 70 is 111, the frame transmitter is 121, the frame receiver of the physical line α41 is 112, the frame transmitter is 122, the frame receiver of the physical line β42 is 113, The frame transmitter is denoted by reference numeral 123; the frame receiver of the physical line γ43 is denoted by reference numeral 114, and the frame transmitter is denoted by reference numeral 124.

  The reception frame control unit 110 includes a frame input unit 115 and a frame identifier acquisition unit 116. The transmission frame control unit 120 includes a line speed determination unit 127, an output line determination unit 126, a frame output unit 125, an identifier-line speed table 130, and a line speed / physical line correspondence table 140. . Here, the identifier-line speed table 130 is shown in FIG. 4, and the line speed-physical line correspondence table 140 is shown in FIG.

  In FIG. 4, a link aggregation column 131 is a link aggregation code (X, Y, Z) connected to the router 100 of FIG. The frame identifier column 132 records frame identifiers (A, B,..., N), and the line speed column 133 records the line speed for each frame identifier. Further, in FIG. 5, a link aggregation column 141 is a link aggregation code (X, Y, Z) connected to the router 100 of FIG. The physical line column 142 records the physical line codes (α, β, γ,...) Accommodated in the link aggregation, the line speed column 143 and the availability column 144, and records the line speed and availability of the physical line.

  4 and 5 are configuration definitions for the configuration in which the router is used. Therefore, the relationship between the frame identifier and the line speed may be different for each link aggregation group. Also, it is updated as appropriate due to the speed improvement of the physical line. Furthermore, the table of FIG. 4 and the table of FIG. 5 may be configured as a single table, and the identifier and the physical line may be directly associated with each other. In this case, the line speed determination unit 127 and the output line determination unit 126 are integrated.

  The hardware configuration of the router 100 will be described with reference to FIG. The router 100 includes a central processing unit (CPU) 180 connected to the bus 160, a memory 190, and four frame transmission / reception IFs 150 to 153. As is clear when compared with the functional blocks described with reference to FIG. 3, the frame reception unit and the frame transmission unit in FIG. 3 are realized by hardware as a frame transmission / reception IF having both functions. Further, the reception frame control unit and the transmission frame control unit in FIG. 3 are realized as programs or tables written in the memory 190. 3, the frame input unit 115 is a frame input program, the identifier acquisition unit 116 is a program that acquires a frame identifier, and the line speed determination unit 127 determines the line speed by referring to the identifier-line speed table 130. The output line determination unit 126 is a program that refers to the line speed / physical line correspondence table 140 and determines a physical line for transmitting a frame.

Next, the operation centering on the router 100 will be described with reference to FIGS.
A case where frame A (identifier “A”) and frame B (identifier “B”) having different frame identifiers such as different protocols are communicated from the terminal 10 to the terminal 15 using a link aggregation network. Think.

  The frame A is transmitted from the terminal 10 and is received by the frame receiving unit 111 of the router 100 via the physical line 70. The frame reception unit 111 that has received the frame A passes the received frame to the identifier acquisition unit 116 via the frame input unit 115 in order to transmit the frame to the line of the link aggregation group X40. The identifier acquisition unit 116 acquires a frame identifier from the field including the received frame identifier, and passes the identifier and the received frame to the line rate determination unit 127. The line speed determination unit 127 is described in the line speed column 133 from the identifier-line speed correspondence table 130 of FIG. 4 using “X” in the link aggregation group column 131 and “A” in the frame identifier column 132 as keys. The line speed to be used (in this case, 10 Mbit / s) is determined. The line speed determination unit 127 passes the determined line speed to be used and the received frame to the output line determination unit 126. From the line speed / physical line correspondence table 140 shown in FIG. 5, the output line determination unit 126 uses the “X” in the link aggregation group column 141 and “10 Mbit / s” in the line speed column 143 as keys. The physical line (in this case α) that is “available” is determined. The identifier is acquired from the version field 701 or protocol field 702 of the IPv4 datagram format shown in FIG. 7, or the frame type field 801 of the Ether frame shown in FIG. The version field 701 is composed of 4 bits, and the version is represented by the decimal (decimal number) value of FIG. The protocol field 702 is composed of 8 bits and represents the protocol with the decimal value of FIG. The frame type field 801 is composed of 2 octets, and represents the protocol by the hexadecimal value of FIG. In this specification, the numerical value described in the field is an identifier.

  When there is no physical line with the same line speed of “available”, the output line determination unit 126 sets a physical line having a line speed larger than the designated line speed and closest to the next best candidate. If there is none, the next candidate is the physical line with the slowest line speed closest to the specified line speed.

  The output line determination unit 126 transmits the determined physical line and the received frame to the frame output unit 125. The frame output unit 125 transmits the frame to the router 200 using the physical line α41 in the link aggregation group X40 via the frame transmission unit 122.

  The router 200 receives a frame from the physical line α41 in the link aggregation group X40 and transmits the frame to the terminal 15 via the physical line 80. Thereby, the communication of the frame A is completed between the terminal 10 and the terminal 15. Although the functional blocks and hardware blocks of the router 200 are the same as those of the router 100, the identifier-line speed correspondence table and the line speed-physical line correspondence table are different from those in the link aggregation to be connected. (The part of the link aggregation group X is the same).

  Similarly, the frame B is similarly communicated via the router 100 and the router 200. However, in the identifier-speed determination table 130 of the router 100, the line speed of 100 Mbit / s is determined for the frame “B”. Also, the physical line γ is determined for the line speed of 100 Mbit / s in the line speed-physical line correspondence table 140. Therefore, the router 100 transmits from the physical line γ43 in the link aggregation group X40. As a result, as shown in FIG. 2, communication between terminals in the same combination can be performed via different physical lines that are optimal for the frame among a plurality of link-aggregated physical lines if the frame identifiers are different. .

  According to this embodiment, even when physical lines having different speeds are aggregated, the bandwidth of the physical lines in the aggregated group can be used efficiently.

Using the identifier-line speed correspondence table described in the first embodiment, it is possible to perform bandwidth control in units of link-aggregated physical lines.
As a type of transport layer packet in TCP / IP, TCP in FIG. 10 is connection type, reliable, and high-priority data. On the other hand, UDP is connectionless, unreliable, and low-priority data. In such a case, in the identifier-line speed correspondence table, the identifier tcp is assigned to a line with a high line speed, and the identifier udp is assigned to a physical line with a low line speed.
Further, as in the modification of the first embodiment, the identifier and the physical line may be directly associated with each other.

  According to the present embodiment, a frame having a low priority can be distributed to a physical line with a low line speed, and thus band control can be performed for each physical line in the aggregated group.

It is a block diagram explaining the structure of a network. It is a block diagram explaining the structure of a link aggregation. It is a functional block diagram of a router. It is a correspondence table of a frame identifier and a line speed to be used. It is a table of correspondence between physical line and line speed and availability. It is a block diagram of the hardware of a router. It is a figure explaining the datagram format of IPv4. It is a figure explaining an Ether frame. It is a figure explaining allocation of the version field of an IP header. It is a figure explaining allocation of the protocol field of an IP header. It is a figure explaining allocation of the type field of an Ether header.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10-20 ... Terminal device, 30 ... Hub, 31 ... Hub, 40 ... Link aggregation group, 41-43 ... Physical line, 50 ... Link aggregation group, 60 ... Link aggregation group, 70 ... Physical line, 80 ... Physical line, DESCRIPTION OF SYMBOLS 90 ... Physical line, 100 ... Router, 110 ... Reception frame control part, 111-114 ... Frame reception part, 115 ... Frame input part, 116 ... Identifier acquisition part, 120 ... Transmission frame control part, 121-124 ... Frame transmission part , 125 ... Frame output unit, 126 ... Output line determination unit, 127 ... Line speed determination unit, 130 ... Identifier-line speed correspondence table, 140 ... Line speed-physical line correspondence table, 150 to 170 ... Frame transmission / reception IF, 180 ... CPU, 190 ... memory, 200 ... router, 300 ... router, 40 ... router, 701 ... version field, 702 ... protocol field, 801 ... frame type field, 1000 ... network.

Claims (6)

A communication device that aggregates a plurality of lines as a virtual line and transfers a frame using the virtual line,
Identify the identifier containing protocol information from the received frame,
Determine the line by referring to the correspondence table between the identifier and the line,
A communication apparatus that transfers the frame to the determined line. The communication device according to claim 1,
The communication device, wherein the plurality of lines include two lines having different line speeds. The communication device according to claim 1 or 2,
The correspondence table is composed of a first table in which correspondence between identifiers and line speed is recorded, and a second table in which correspondence between line speed and line is recorded. The communication device according to claim 1,
The communication apparatus is characterized in that the correspondence table is described so that data with high priority is allocated to a line with a high line speed. A communication device connected to a plurality of lines and transferring a frame to any one of the plurality of lines,
A first table describing an identifier and a line speed corresponding to the identifier; and a second table describing a line and a line speed corresponding to the line;
A protocol identifier is detected from the received frame, a line speed corresponding to the identifier is obtained by referring to the first table, and a line corresponding to the line speed is obtained from the line speed by referring to the second table. A communication device characterized by: The communication device according to claim 5,
A communication apparatus, wherein at least two of the plurality of lines are link aggregated.

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