JP3075276B2 - Fiber Channel fabric and fabric ports - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ANSI (Ameri)
Fiber Channel, which is a data communication standard standardized as X3T11 by the National Standards for Information Systems (American Standards Association).
Annel) fabric (Fabric), in particular, a fabric port (hereinafter, referred to as a port) of a Fiber Channel fabric (hereinafter, referred to as a fabric).
Related to communication between.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open Nos. 9-238163 and 10-22437 disclose the prior art relating to fabrics.
No. 3 publication. According to the former, Fiber Channel is a type of data communication connection between processors and between processors and peripheral devices, the protocol of which was developed and adopted as ANSI. Briefly, Fiber Channel is an exchange protocol that allows simultaneous communication between workstations, supercomputers, and various peripherals. Internet Protocol (I
P), small computer system interface (SC)
Commands and data can be carried over both fiber optic and copper cables according to existing protocols such as SI).

[0003] A fabric refers to an active intelligent interconnection scheme, ie, a fiber optic switch, and the fiber channel allows the devices to be connected. Specifically, as shown in FIG. 3, it includes a plurality of fabric ports (F ports), which are connected to associated workstations, supercomputers, and peripheral devices by a plurality of node boards (N-boards). ) And interconnect and data frame transfer.

[0004] In the latter case, since the conventional fabric exchanges variable frames as they are, the control becomes complicated, and it is difficult to expand the number of connected nodes and improve the exchange performance. Asynchronous Tra
nsfer Mode) Call setup in frame units not based on standards /
Release processing and congestion control are realized with a simple configuration.

For this purpose, a fiber channel interface control means for connecting to a terminal node or another fabric and performing a fiber channel protocol control, and an input data buffer for temporarily storing a frame received from the terminal node or another fabric. Cell generating means for dividing a received frame into fixed-length cells, cell switching means for exchanging data in units of fixed-length cells, and reconstructing an original frame from fixed-length cells output from the cell switching means. Frame assembling means,
An output data buffer unit for temporarily storing a frame output from the frame assembling unit, and a congestion management unit for monitoring a load on the cell switch unit and controlling suppression of congestion.

[0006]

However, in the above-described conventional fabric, as shown in FIG. 4, each port is not provided with an unnecessary storage means. Prior negotiation is required, but for this negotiation, all ports of the fabric need to communicate with all ports at high speed, as a means of connecting all ports of the fabric with a high-speed bus are doing.

However, according to this bus system, there are problems that the configuration becomes complicated and the high-speed negotiation operation becomes difficult as the number of ports increases. Accordingly, an object of the present invention is to provide a fabric that does not require a special inter-port communication path by using a switch path for exchanging data cells to perform inquiry processing as to whether or not cells can be transmitted between ports. Is to provide.

[0008]

SUMMARY OF THE INVENTION
In a fiber channel fabric that exchanges a fabric port connected to a node port with a fabric switch by a cell switch, a source fabric port performs an inquiry process of a status of a destination fabric port in response to a reception notification from a node. Therefore, an inquiry cell is generated and transmitted to the transmission destination fabric port via the cell switch, and the transmission destination fabric port examines the content of the received inquiry cell to determine whether or not cell transmission can be started, and determines the result. To notify, a response cell is generated and transmitted to a source fabric port via the cell switch, and the source fabric port determines an operation at the source fabric port according to the content of the received response cell. And
The fabric port of the present invention is an input / output port in a fiber channel fabric which is a core of a fabric topology, and is an input frame analyzing means for analyzing and processing a fiber channel frame input from a device outside the fabric, and the input frame analyzing means Based on information held by the input frame buffer means for temporarily holding the data of the frame extracted by the input frame analyzing means, the destination address buffer means for temporarily holding the destination address of the frame extracted by the input frame analyzing means, and the information held by the destination address buffer means. A segmentation control unit that divides data of a frame held by the input frame buffer unit into fixed-length cells, which are units for transferring the data to a cell switch in the fabric, and transmits the divided cells; and a cell received from the cell switch. Input cell type identification means for selecting whether the input cell type includes frame data, output frame buffer means for temporarily holding data cells received from the input cell type identification means in a transmission frame format, and A reassembly control unit that instructs the output frame buffer unit to take out frame data in the cell and buffer the frame in the frame format in response to the data cell reception notification, and an inquiry cell and a response cell received from the input cell type identification unit. The inquiry / response cell buffer means which is temporarily held, and the inquiry processing of the status of the transmission destination fabric port is performed in response to the frame reception notification from the input frame analysis means, and according to the contents of the inquiry / response cell buffer means, Send availability query cell Inquiry / response processing for determining whether or not the response is possible based on the free space information of the buffer via the reassembly control means when receiving the response cell and performing an operation at the source fabric port when receiving a response cell Control means; inquiry / response cell generation means for generating and transmitting an inquiry cell or response cell in accordance with a command from the inquiry / response processing control means; and data cells and inquiry / response cell generation means from the segmentation control means. And an output cell selecting means for sequentially transmitting the inquiry cell to the cell switch.

[0009]

Next, embodiments of the present invention will be described with reference to the drawings. First, FIG. 2 is a block diagram showing one embodiment of the fabric of the present invention. One cell switch 100 and four ports 101, 102, 103, 104
Consists of Although FIG. 2 shows an example of a 4-port fabric, the present invention is not limited by the number of ports in the fabric.

FIG. 1 shows the configuration of a representative embodiment of the port of the present invention. Ports 101 and 10 shown in the block diagram of FIG.
2, 103 and 104 all have a configuration as shown in FIG. In FIG. 1, an input frame analysis unit 1 analyzes a fiber channel frame input from a device outside the fabric. The input frame buffer means 2 temporarily holds the data of the frame extracted by the input frame analysis means 1, and the destination address buffer means 5 temporarily holds the destination address of the frame extracted by the input frame analysis means 1.

The segmentation control means 3 is a fixed-length cell which is a unit for transferring frame data held by the input frame buffer means 2 to the cell switch 100 in the fabric based on information held by the destination address buffer means 5. Divide and send.

The input cell type identifying means 8 determines whether the cell received from the cell switch 100 contains frame data. The inquiry / response cell buffer means 9 temporarily holds the inquiry cell and the response cell received from the input cell type identification means 8, and the output frame buffer means 11 converts the data cell received from the input cell type identification means 8 into a transmission frame format. Temporarily hold.

The reassembly control means 10 receives the data cell reception notification from the input cell type identification means 8 and instructs the output frame buffer means 11 to take out frame data in the cell and buffer the data in a frame format.

The inquiry / response processing control means 7 performs an inquiry processing of the status of the transmission destination port in response to a frame reception notification from the input frame analysis means 1, and reassembly control means when a transmission permission / inhibition inquiry cell is received. Based on the information on the free space of the buffer via the server 10, the availability is determined, and the response process is performed.

The inquiry / response cell generating means 6 generates and transmits an inquiry cell and a response cell according to a command from the inquiry / response processing control means 7.

The output cell selection means 4 sequentially transmits the data cells from the segmentation control means 3 and the inquiry cells from the inquiry / response cell generation means 6 to the cell switch.

Next, the operation of this embodiment will be described with reference to an example in which a frame is transferred from the port 101 to the port 104 in FIG. The input frame analyzing means 1 of the port 101 which is a cell transmission source port extracts and analyzes a fiber channel frame from a data stream input from a device outside the fabric, and converts necessary information into an input frame which is a next-stage processing unit. Transfer to buffer means 2.

Input frame buffer means 2 of port 101
Temporarily stores the frame extracted by the input frame analysis means 1 as data. Further, the destination address buffer means 5 of the port 101 temporarily holds the destination address of the frame extracted by the input frame analyzing means 1.

The segmentation control means 3 of the port 101 extracts the data of the frame held by the input frame buffer means 2 for each unit length to be transferred to the cell switch, and based on the destination information held by the destination address buffer means 5 , And generates a fixed-length cell to which an internal address that can be interpreted by the cell switch 100 is added, and sends it to the next stage.

The inquiry / response processing control means 7 for the port 101 receives the frame reception notification from the input frame analysis means 1 and inquires about the status of the port 104 which is the destination port. It instructs the response cell generation means 6 to generate and transmit an inquiry cell.

The inquiry / response cell generating means 6 receiving this generates an inquiry cell based on the information held by the destination address buffer means 5 and transfers it to the next stage. At this time, the output cell selection means 4 of the port 101, which is the next stage, switches the cell passed from the
Transfer to 100. As a result, the interrogation cell arrives at the destination port, ie, port 104, via the cell switch 100.

If the received cell is an inquiry cell, the input cell type identification means 8 of the port 104, which is the destination port, passes this to the inquiry / response cell buffer means 9 of the port 104. The inquiry / response processing control means 7 of the port 104 checks the contents of the inquiry cell stored in the inquiry / response cell buffer means 9 and determines whether or not to start cell transmission. Then, in order to notify the result, the inquiry / response cell generation means 6 of the port 104 is instructed to generate a response cell.

The inquiry / response cell generating means 6 for the port 104 generates a response cell in accordance with the command and outputs the response cell via the output cell selecting means 4 for the port 104.
And sends the response cell to port 101 which is the source port. Port 10, the source port
When the input cell type identification means 8 receives the response cell, it receives the response cell in the same manner as the operation at the port 104.
In the inquiry / response cell buffer means 9, the inquiry / response processing control means 7 determines the operation at the source port according to the contents of the response cell.

If the content of the response cell at this time is transmission permission of the cell, the inquiry / response processing control means 7 of the port 101 sets the segmentation control means 3 of the port 101
To start frame transfer. Upon receiving this, the segmentation control means 3 sequentially takes out frame data from the input buffer means 2 and sends the frame data to the cell switch 100 via the output cell selection means 4.

On the other hand, when the input cell type identification means 8 of the port 104 which is the destination port receives the data cell from the cell switch 100, it sequentially transfers the data cell to the output frame buffer means 11 of the port 4. At this time, the reassembly control means 10 of the port 104 controls the output frame buffer means 11 so as to buffer only the data of the frame from which unnecessary control data and the like have been removed from the received cells.

[0026]

According to the present invention, there is no need for a dedicated inter-port communication means for negotiation prior to the start of data transfer between a source port and a destination port of a fabric as in the prior art. It is possible to obtain an effect that necessary information can be exchanged only by the path via the cell switch.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a fabric port of the present invention.

FIG. 2 is a block diagram showing one embodiment of the fabric of the present invention.

FIG. 3 is a general block diagram of a fabric.

FIG. 4 is a block diagram showing an example of a conventional fabric.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input frame analysis means 2 Input frame buffer means 3 Segmentation control means 4 Output cell selection means 5 Destination address buffer means 6 Inquiry / response cell generation means 7 Inquiry / response processing control means 8 Input cell type identification means 9 Inquiry / response Cell buffer means 10 Reassembly control means 11 Output frame buffer means 100,200 Cell switch 101,201 port 102,202 port 103,203 port 104,204 port

Continuation of the front page (56) References JP-A-10-224373 (JP, A) JP-A 8-251168 (JP, A) JP-A 10-285171 (JP, A) JP-A 8-251195 (JP) JP-A-9-121212 (JP, A) JP-A-9-238163 (JP, A) NEC Technical Report, VOL. 50, NO. 8, p. 31-34 (58) Field surveyed (Int.Cl. ⁷ , DB name) H04L 12/66 H04L 12/28 H04L 12/56

Claims (3)

(57) [Claims] In a fiber channel fabric for exchanging a fabric port connected to a node port with a cell switch, a source fabric port performs a process of inquiring about a status of a destination fabric port in response to a reception notification from a node. In order to do so, an inquiry cell is generated and transmitted to a destination fabric port via the cell switch, and the destination fabric port examines the content of the received inquiry cell to determine whether or not to start cell transmission, and as a result, In order to notify the source fabric port, a response cell is generated and transmitted to the source fabric port via the cell switch.The source fabric port determines the operation in the source fabric port according to the content of the received response cell. Featured Fiber Channel Fabric Click. 2. A fabric port in a fiber channel fabric which is a core of a fabric topology, wherein the input frame analyzing means analyzes and processes a fiber channel frame input from a device outside the fabric. Input frame buffer means for temporarily holding frame data, destination address buffer means for temporarily holding the destination address of the frame extracted by the input frame analysis means, and information held by the destination address buffer means,
A segmentation control unit that divides the data of the frame held by the input frame buffer unit into fixed-length cells, which are units to be transferred to a cell switch in the fabric, and transmits the divided data. Input cell type identification means for selecting whether to include the data, output frame buffer means for temporarily holding data cells received from the input cell type identification means in a transmission frame format, and data cell reception from the input cell type identification means Reassembly control means for instructing the output frame buffer means to take out frame data inside the cell and buffer in a frame format in response to the notification, and temporarily hold inquiry cells and response cells received from the input cell type identification means. Inquiry / response cell buffer Means for performing an inquiry process of the status of the destination fabric port triggered by a frame reception notification from the input frame analyzing means, and receiving the transmission enable / disable inquiry cell according to the contents of the inquiry / response cell buffer means. Inquiry / response processing control means for determining whether or not the response is possible based on the free space information of the buffer via the reassembly control means and performing response processing, and determining operation at the source fabric port when a response cell is received; An inquiry / response cell generating means for generating and transmitting an inquiry cell or a response cell in accordance with a command from the inquiry / response processing control means; a data cell from the segmentation control means and an inquiry cell from the inquiry / response cell generating means To the cell switch in sequence. Fabric port, characterized in that it comprises a selection means. 3. A fiber channel fabric using the fabric port according to claim 2 .