JP6958910B2 - Communication equipment, link control methods, and programs - Google Patents

Description

The present invention relates to communication devices, link control methods, and programs for Fiber Channel communication.

Fiber Channel communication is known as one of the communication methods between devices (see, for example, Patent Document 1). Patent Document 2 discloses a technique for establishing a link at a maximum transfer rate between communication devices by auto-negotiation in Fiber Channel communication.

JP-A-2002-359661 Japanese Unexamined Patent Publication No. 2000-124913

By the way, when the transfer rate is determined by auto-negotiation, it may not be possible to establish a link at the maximum transfer rate depending on the timing of changing the transfer rate settings of both communication devices.

For example, a case where the communication device A and the communication device B can set 8GByte, 4GByte, and 2Gbyte as transfer rates for Fiber Channel communication will be described. If the communication device A is negotiating with the 8GByte setting and the communication device B is setting the transfer rate, synchronization cannot be achieved and the link is down. In response to this, the communication device A changes the transfer rate to 4 Gbyte. After that, when the communication device B finishes setting the transfer rate and the transfer rate is set to 8 Gbyte, the link is down due to the mismatch of the transfer rates. In response to this, the communication device B changes the transfer rate to 4 Gbyte, and the transfer rates of both are linked up at 4 Gbyte. In this case, although the communication device A and the communication device B can be connected at a transfer rate of 8GByte, they are connected at a transfer rate of 4GByte. That is, in the above case, the communication device A and the communication device B cannot establish a link at the maximum transfer rate.

The method described in Patent Document 2 attempts to establish a link at the maximum transfer rate by gradually increasing the transfer rate from a low transfer rate. However, even in the method described in Patent Document 2, if the reception of the negotiation signal fails, the link at the maximum transfer rate may not be established.

An object of the present invention is to provide a communication device, a link control method, and a program that solve the above-mentioned problems.

According to the first aspect of the present invention, the communication device can be set in the partner device by the link service of the FC-2 layer after the link-up of the fiber channel communication with the partner device by the ordered set of the FC-1 layer. a notification receiving unit for receiving a plurality of rate notification indicating the transfer rate from the partner apparatus, a plurality of transfer rates which the rate notification indicating the maximum transfer common in a plurality of transfer rates that can be set in the communication device A rate specifying unit for specifying a rate is provided.

According to the second aspect of the present invention, the link control method is a link control method of a communication device, and after linking up of Fiber Channel communication by an ordered set of FC-1 layer between the communication device and the partner device. , receiving a rate notification indicating a plurality of transfer rates that can be set in the counterpart device by a link service FC-2 layers from the partner apparatus, and a plurality of transfer rates which the rate notification indicates, set in the communication device It includes a step of identifying the maximum transfer rate that is common to a plurality of possible transfer rates.

According to a third aspect of the present invention, the program uses the FC-2 layer link service to link up the computer of the communication device with Fiber Channel communication with the other device by the order set of the FC-1 layer. notice receiving unit that receives from the other party apparatus rate notification indicating a plurality of transfer rates that can be set in the destination device, a plurality of transfer rates which the rate notification indicates, common to a plurality of transfer rates that can be set in the communication device It functions as a rate identification unit that specifies the maximum transfer rate to be performed.

According to at least one of the above aspects, the communication device can specify the maximum transfer rate available.

It is the schematic which shows the structure of the Fiber Channel system which concerns on 1st Embodiment. It is a block diagram which shows the structure of the communication apparatus which concerns on 1st Embodiment. It is a flowchart which shows the connection process of the communication device which concerns on 1st Embodiment. It is a schematic block diagram which shows the basic structure of a communication device.

FIG. 1 is a schematic view showing the configuration of the Fiber Channel system according to the first embodiment.
The Fiber Channel system 1 includes two communication devices 100 connected by an optical fiber cable C. That is, the topology of the Fiber Channel system 1 according to the first embodiment is FC-P2P (Fibre Channel Point-to-Point). The topology of the Fiber Channel system 1 according to another embodiment may be FC-AL (Fibre Channel Arbitrated Loop) or fabric.

FIG. 2 is a block diagram showing a configuration of a communication device according to the first embodiment.
The communication device 100 includes a processor 110, an FC_LSI120 (Fibre Channel Large Scale Integrated Circuit), a main memory 130, a storage 140, an input / output interface 150, and an SFP160 (Small Form Factor Pluggable). FC_LSI120 is a transceiver circuit for realizing Fiber Channel communication. The SFP160 is a communication interface for connecting the optical fiber cable C to the communication device 100.

The storage 140 stores a program for controlling the FC_LSI 120 by the processor 110. The processor 110 reads a program from the storage 140, expands it into the main memory 130, and executes a process for controlling the FC_LSI 120 according to the program.
The program may be for realizing a part of the functions exerted by the communication device 100. For example, the program may exert its function in combination with another program already stored in the storage 140 or in combination with another program mounted on another device. In another embodiment, the communication device 100 may include a custom LSI such as a PLD (Programmable Logic Device) in addition to or in place of the above configuration. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, some or all of the functions realized by the processor 110 may be realized by the integrated circuit.

Examples of the storage 140 include HDD (Hard Disk Drive), SSD (Solid State Drive), magnetic disk, optical magnetic disk, CD-ROM (Compact Disc Read Only Memory), DVD-ROM (Digital Versatile Disc Read Only Memory). , Semiconductor memory and the like. The storage 140 may be an internal medium directly connected to the bus of the communication device 100, or an external medium connected to the communication device 100 via the input / output interface 150 or the communication line. When this program is distributed to the communication device 100 via a communication line, the distributed communication device 100 may expand the program in the main memory 130 and execute the above processing. The storage 140 is an example of a non-temporary tangible storage medium.

Further, the program may be for realizing a part of the functions to be executed by the communication device 100. Further, the program may be a so-called difference file (difference program) that realizes a function to be executed by the communication device 100 in combination with another program already stored in the storage 140.

By executing the program, the processor 110 functions as a link unit 111, a login unit 112, a rate determination unit 113, a notification transmission unit 114, a notification reception unit 115, a rate identification unit 116, an initialization unit 117, and a mapping unit 118. ..

The link unit 111 executes the link establishment control specified in Fiber Channel communication. That is, when the optical fiber cable C is connected to the SFP160, the link unit 111 synchronizes with the communication device 100 (hereinafter referred to as a partner device) of the connection destination, speed negotiation, and the speed negotiation by the ordered set of the FC-1 layer. Initialize the link.

After the link is established by the link unit 111, the login unit 112 executes the login control specified in the Fiber Channel communication. That is, the login unit 112 performs FLOGI (Fabric Login) and PLOGI (Port Login), which are FC-2 layer link services.

The rate determination unit 113 determines one or a plurality of transfer rates that can be set in the communication device 100 based on one or a plurality of transfer rates that can be set in the FC_LSI 120 and one or a plurality of transfer rates that can be set in the SFP 160. For example, the rate determination unit 113 sets a common term of one or more transfer rates that can be set in FC_LSI 120 and one or more transfer rates that can be set in SFP160 as one or more transfer rates that can be set in the communication device 100. judge.

The notification transmission unit 114 transmits a rate notification indicating one or a plurality of transfer rates determined by the rate determination unit 113 to the other device by the FC-2 layer link service (hereinafter, referred to as a notification link service).
The notification receiving unit 115 receives the rate notification from the remote device by the notification link service.

The rate specifying unit 116 is used for communication with the other device based on the one or more transfer rates indicated by the rate notification received by the notification receiving unit 115 and the one or more transfer rates determined by the rate determining unit 113. Identify the maximum possible transfer rate. That is, for example, the rate specifying unit 116 is the largest of the common terms between the one or more transfer rates indicated by the rate notification received by the notification receiving unit 115 and the one or more transfer rates determined by the rate determining unit 113. The transfer rate is specified as the maximum transfer rate that can be used for communication with the remote device.

The initialization unit 117 initializes the link of Fiber Channel communication with the remote device based on the transfer rate specified by the rate specifying unit 116. That is, the initialization unit 117 performs speed negotiation with the partner device at the specified transfer rate and initialization of the link by the ordered set of the FC-1 layer.

The mapping unit 118 notifies the other device of parameter information related to the upper layer protocol by PRLI (Process Login) of the FC-4 layer.

FIG. 3 is a flowchart showing a connection process of the communication device according to the first embodiment.
When the optical fiber cable C is connected to the SFP 160, the rate determination unit 113 determines one or a plurality of transfer rates that can be set in the communication device 100 (step S1). Next, the notification transmission unit 114 generates a notification link service for transmitting a rate notification indicating one or a plurality of transfer rates determined by the rate determination unit 113 (step S2).

The link unit 111 synchronizes the partner device, speed-negotiates, and initializes the link by the ordered set of the FC-1 layer (step S3). At this point, the link unit 111 determines the transfer rate by auto-negotiation because the maximum transfer rate that can be used for communication with the other device is unknown. After establishing the link in step S3, the login unit 112 performs FLOGI and PLOGI (step S4).

After the completion of PLOGI in step S4, the notification transmission unit 114 transmits a rate notification to the other device by the notification link service generated in step S2. Further, the notification receiving unit 115 receives the rate notification from the remote device by the notification link service (step S5). The rate specifying unit 116 can be used for communication with the other device based on the one or more transfer rates indicated by the rate notification received from the other device in step S5 and the one or more transfer rates determined in step S1. The maximum transfer rate is specified (step S6). The rate specifying unit 116 determines whether or not the transfer rate set in the current link matches the specified maximum transfer rate (step S7).

When the current transfer rate and the maximum transfer rate specified in step S6 are different (step S7: NO), the initialization unit 117 determines the maximum transfer rate specified in step S6 according to the ordered set of the FC-1 layer. Speed negotiation is performed based on the above, and the link is initialized (step S8). Then, the communication device 100 returns the process to step S4.

On the other hand, when the current transfer rate and the maximum transfer rate specified in step S6 match (step S7: YES), the mapping unit 118 executes PRLI of the FC-4 layer (step S9). As a result, the communication device 100 ends the connection process.

As described above, the communication device 100 according to the first embodiment receives the rate notification from the other device after linking up with the other device, and the rate notification and one or a plurality of transfer rates that can be set in the communication device 100. Identify the maximum transfer rate that is common in. Thereby, the communication device 100 can specify the maximum transfer rate that can be used.

Further, the communication device 100 according to the first embodiment initializes the link with the partner device according to the specified transfer rate. This allows the communication device 100 to establish a link at the maximum transfer rate available. In other embodiments, the present invention is not limited to this. For example, the communication device 100 according to another embodiment may notify the user of the maximum available transfer rate without reinitializing at the maximum transfer rate. Further, the communication device 100 according to another embodiment may notify the user whether or not the transfer rate of the link is the maximum available transfer rate.

Further, the communication device 100 according to the first embodiment initializes the link at the maximum transfer rate before carrying out PRLI of Fiber Channel communication. When the link is initialized after the PRLI is executed, there is a possibility that both communication devices 100 recognize the path by issuing a SCSI (Small Computer System Interface) command. In this case, there is a possibility that both communication devices 100 will be temporarily lost in the path due to the link down due to the subsequent reinitialization of the link. Therefore, according to the first embodiment, by initializing the link before the implementation of PRLI, it is possible to prevent the path from being recognized as lost.

Further, the communication device 100 according to the first embodiment transmits / receives rate notification by a link service of Fiber Channel communication. In other embodiments, the present invention is not limited to this. For example, the communication device 100 according to another embodiment may send and receive rate notifications by a new primitive equipped with rate notifications.

Further, the communication device 100 according to the first embodiment transmits / receives rate notifications by using the notification link service after the implementation of PLOGI. In other embodiments, the present invention is not limited to this. For example, the communication device 100 according to another embodiment may send and receive rate notifications by setting rate notifications in a vendor specific area in the payload of FLOGI or PLOGI without generating a notification link service.

Although one embodiment has been described in detail with reference to the drawings, the specific configuration is not limited to the above, and various design changes and the like can be made.

<< Basic configuration >>
FIG. 4 is a schematic block diagram showing a basic configuration of a communication device.
In the above-described embodiment, the configuration shown in FIG. 2 has been described as an embodiment of the communication device, but the basic configuration of the communication device is as shown in FIG.
That is, the communication device 300 has a basic configuration of the notification receiving unit 301 and the rate specifying unit 302.

After linking up the Fiber Channel communication with the remote device, the notification receiving unit 301 receives a rate notification indicating one or a plurality of transfer rates that can be set in the remote device from the remote device.
The rate specifying unit 302 identifies the maximum transfer rate that is common to one or more transfer rates indicated by the rate notification and one or more transfer rates that can be set in the communication device 300.
Thereby, the communication device 300 can specify the maximum transfer rate that can be used.

1 Fiber Channel System 100 Communication Device 110 Processor 120 FC_LSI
130 Main memory 140 Storage 150 I / O interface 160 SFP
111 Link unit 112 Login unit 113 Rate determination unit 114 Notification transmission unit 115 Notification reception unit 116 Rate identification unit 117 Initialization unit 118 Mapping unit C Optical fiber cable

Claims (7)

It ’s a communication device,
After linking up Fiber Channel communication with the other device by the ordered set of the FC-1 layer, a rate notification indicating a plurality of transfer rates that can be set in the other device is received from the other device by the link service of the FC-2 layer. Notification receiver and
A communication device including a plurality of transfer rates indicated by the rate notification and a rate specifying unit that specifies the maximum transfer rate common to the plurality of transfer rates that can be set in the communication device. The communication device according to claim 1, further comprising an initialization unit that initializes a link of Fiber Channel communication with the other device according to the specified transfer rate in the order set of the FC-1 layer. The communication device according to claim 2, wherein the initialization unit initializes the link before carrying out PRLI for Fiber Channel communication. According to any one of claims 1 to 3, further comprising a notification transmission unit that transmits the rate notification indicating a plurality of transfer rates that can be set in the communication device to the destination device by a link service FC-2 layers Communication device. The rate notification is transmitted after the implementation of PLOGI for Fiber Channel communication.
The communication device according to any one of claims 1 to 4. It is a link control method for communication devices.
After linking up the Fiber Channel communication by the ordered set of the FC-1 layer between the communication device and the remote device, the rate notification indicating a plurality of transfer rates that can be set in the remote device by the link service of the FC-2 layer is sent. Steps to receive from the other device and
The rate notification and a plurality of transfer rate indicated, link control method comprising the steps of identifying the maximum transfer rate which is common in a plurality of transfer rates that can be set in the communication device. The computer of the communication device,
After linking up Fiber Channel communication with the other device by the ordered set of the FC-1 layer, a rate notification indicating a plurality of transfer rates that can be set in the other device is received from the other device by the link service of the FC-2 layer. Notification receiver,
The rate notification and a plurality of transfer rate indicated by the program to function as the rate identifying unit for identifying the maximum transfer rate which is common in a plurality of transfer rates that can be set in the communication device.

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