JP3132232B2 - Data link layer type automatic setting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic setting device of a data link layer type of a network, and more particularly to an American Institute of Electrical and Electronics Engineers (hereinafter referred to as "IEEE") 80.
Bus-type LAN (hereinafter referred to as 2.3) adopting the carrier sense multiple access / collision detection (CSMA / CD) standardized by 2.3
(Referred to as "Ethernet") and the like in a local area network.

[0002]

2. Description of the Related Art Conventionally, when performing data communication in a network such as Ethernet, the International Standards Organization (IS)
O) The open system interconnections adopted in (O)
In general, communication functions are hierarchized based on a reference model of “OSI”.

[0003] For example, Ethernet supports the lower two layers of a physical layer and a data link layer.
Network System (XNS) Protocol, TCP
/ IP (Transmission Control Protocol / Internet P
A higher-level protocol such as rotocol and netware is built on the network.

Here, the physical layer is a layer that provides means for activating and deactivating a physical connection.
Since the data link layer is a layer that provides services such as establishment and release of a data link connection to an upper layer, a header such as a destination address and a source address is added to the data in the data link layer.

Further, since there are a plurality of types of header formats added in the data link layer, it is necessary to set the same as the header format of the communication partner.

Conventional techniques for setting the header format of the data link layer include a method in which a user manually sets the data format using a console or a switch (hereinafter, referred to as a "manual setting method").
) And a method of automatically setting using an application higher than the data link layer (hereinafter, referred to as an “automatic setting method”).

In this automatic setting method, transmission is performed to the other party in a certain header format, and if there is no response, transmission is performed by trial and error in various header formats until there is a response.
It is common to use a method that employs the response header format.

[0008] For example, a routing information protocol (Routing Info) of a network layer which is an upper layer protocol.
When a transmission request is received from a rmation Protocol (hereinafter referred to as "RIP") or a service advertisement protocol (Service Advertise Protocol: hereinafter referred to as "SAP"), a packet is transmitted using a default header format. If there is a response from the device on the side, the header format is adopted. On the other hand, if there is no response from the partner device, transmission using the following header format is performed, and the presence or absence of a response is confirmed. Hereinafter, the same procedure is repeated to determine the header format used by the partner device.

[0009]

However, in the manual setting method, it is necessary to manually set the header format. Therefore, when a network device having a plurality of data link layer header formats is connected to a network, the header format must be set manually. Is
There is a problem that changing the header format is complicated.

Although the above-mentioned problem can be solved by the automatic setting method, packets are transmitted in a header format not used by the other party, so that meaningless packets are accumulated on the line and network efficiency is reduced. Problems arise.

In Japanese Patent Application Laid-Open No. 3-89645, addresses corresponding to a plurality of types of upper-layer protocols are prepared in advance, and the destination address of the received frame is compared with the address to automatically transmit the received frame to the upper layer. However, the above problem cannot be solved because it is necessary to use a manual setting method or an automatic setting method when transmitting a data link layer packet.

Therefore, the present invention eliminates such a problem and automatically sets a data link layer format to be used without affecting the network. It is intended to provide a device.

[0013]

To achieve the above object, the present invention provides a data link layer type automatic setting device used for a node device connected to a network. And a setting unit for setting the format of the data link layer header at the time of data transmission in the node device from the result of the judgment by the judgment unit. I do. According to a second aspect of the present invention, in the first aspect of the present invention, the determining means determines a header format of a data link layer based on a statistical processing result of a packet received from the network and a plurality of packets received in the past. It is characterized by making a judgment.
According to a third aspect of the present invention, in the first or second aspect of the invention, when the format of the header to be set is an initial setting, the setting unit permits data transmission by the node device after the setting of the initial setting. It is characterized by doing.

[0014]

According to the present invention, when a node device connected to a network automatically sets a data link layer format, data used by the node device is determined based on the data link layer format of data received from the network. Determine the header format of the link layer using the determination means,
Based on the determination result, the data link layer format of the node device is set using the setting unit. With such a configuration, the format of the data link layer header can be automatically set without affecting the network.

[0015]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the overall configuration of a network and the configuration of a node device incorporating a data link layer type automatic setting device (automatic setting module) according to the present invention.

As shown in FIG. 1, the communication system used in this embodiment has four workstations (WS) 2 to 5.
Is connected to an Ethernet 6 as a local area network (LAN), an Ethernet driver (transceiver) 10 for transmitting and receiving packets, and an automatic setting for setting a data link layer header format (hereinafter referred to as “configuration”). A module 11 is connected to a node device 1 having a network (NetWare) 12 as one upper layer protocol of one or more upper layer protocols.

Here, the Ethernet driver 10 may transmit a received packet addressed to the node device 1 to the automatic setting module 11 in the same manner as a normal driver, and further, may transmit the packet flowing on the Ethernet 6 to the automatic setting module 1.
1 may be sent.

Further, the automatic setting module 11 includes a determining unit 11a, a storage unit 11b, and a setting unit 11c.

The judging unit 11a includes the Ethernet driver 1
The configuration of the received packet received from 0 is determined, and whether the configuration is a configuration usable in the node device 1 is determined.

The storage unit 11b stores a plurality of types of configurations supported by the node device 1. Then, referring to the contents of the storage unit 11b, the judgment unit 11a
Is determined.

At this time, the received packet is not only a packet transmitted to the node device 1 as a destination but also a packet transmitted to the workstations 2 to 5 if it is a packet flowing on the Ethernet 6. It doesn't matter.

The setting unit 11c receives the judgment result of the judgment unit 11a, and sets a configuration corresponding to the judgment result in the data link layer.

Next, a series of operations in which the node device 1 having the above configuration sets the configuration is shown in FIG.
This will be described with reference to FIG.

Now, consider the case where the workstations 2 to 5 are performing data communication with each other when the node device 1 is started up. In this case, the Ethernet driver 10 of the node device 1 receives an Ethernet packet destined for any of the workstations 2 to 5 from the Ethernet 6 (S201). This received packet is
The information is output to the determination unit 11a in the automatic setting module 11 of the node device 1.

The determining unit 11a first determines the configuration of the received packet (S202). The configuration determination processing will be described later in detail.

Thereafter, it is determined whether this configuration is usable in this node device 1 (S20).
3). This determination is made by the determination unit 11a referring to a plurality of configurations stored in the storage unit 11b. That is, the configuration of the received packet is compared with the configuration supported by the node device 1 stored in the storage unit 11b, and the configuration is the one supported by the node device 1 and the higher-order packet. If the types are the same, it is determined that they can be used. On the other hand, if the node device 1 does not support it, it is determined that the node device 1 cannot be used.

Note that, instead of the above-mentioned judgment index, this received packet is, for example, a higher-level protocol (RIP, SAP, etc.)
As in the case of the response packet described above, whether or not the packet is transmitted by a highly reliable node (router, server, or the like) can be used as a judgment index.

After that, the setting unit 11c receives the result of the judgment and sets the configuration corresponding to the result of the judgment (S204).

If the configuration of the received packet is not available in S203, the process is terminated.

Next, the configuration judgment processing performed in S202 will be described in more detail.

FIG. 3 is a diagram showing an example of a plurality of configurations supported by the node device 1 stored in the storage unit 11b.

In FIG. 3, format 1 is a standard Ethernet improved version (version 2 (v.2)) format, in which a first field (6 bytes) describing a destination address (DA), a source address It consists of a second field (6 bytes) that describes (SA) and a third field (2 bytes) that describes the packet type (TYPE) of the third layer.

Format 2 is a format unique to Novell that conforms only to IEEE802.3, and has a first address describing a destination address and a source address.
Field and the second field, and the frame length (LE
N) is composed of a third field (2 bytes) describing N).

Format 3 is a format unique to Novell in compliance with IEEE 802.3 and 802.2. The format 2 includes a destination service access point header (DSAP) and a source service access point header (SSAP). , A fourth field (3 bytes) describing a control header is added.

Format 4 is based on IEEE802.3,
This is an OSI international standard format conforming to 802.2 and 802.1, and has a configuration in which a fifth field (5 bytes) describing a packet type and the like is added to the format 3 format.

Here, the formats 1 to 4 are common in that a first field and a second field are provided.

However, the format 1 has a difference that the packet type is described in the third field, whereas the frame length is described in the formats 2 to 4.

At this time, since the packet type is data for designating a plurality of types of upper layer protocols,
In the format 1 having this packet type, a multi-protocol can be allowed. For example, XNS
IPP (Internet Datagram Protocol), IPX for network, and IP for TCP / IP correspond to packet types.

The format 2 does not use the fourth field, whereas the formats 3 and 4 use the fourth field.

That is, in the format 2, 'FFFF (H)' indicating pseudo data of a checksum used in the upper layer is stored in a 2-byte area corresponding to DSAP and SSAP in the fourth field.

On the other hand, in format 3, DS
Hexadecimal 'E0' (hereinafter referred to as “E0 (H)”) is used as the value of AP and SSAP, and 'AA (H)' is used in format 4.

The fifth format used only by format 4
In the field, a packet type and the like similar to the third field of the format 1 are described.

Since the formats 2 and 3 do not include a description of the packet type, the packet type is treated as netware.

As described above, the formats 1 to 4 are:
Since there is a difference after the third field, formats 1 to 4 can be identified using this difference.

FIG. 4 is a flowchart showing a procedure for identifying the formats 1 to 4.

First, the format 1 is identified using the third field.

That is, in the third field, the packet type is stored in the case of the format 1, whereas in the case of the formats 2 to 4, the frame length is stored. Check (S40
1) If the packet type is described, it is determined to be format 1.

Specifically, since the frame length is limited to 1500 bytes or less, the value of the third field is set to 0600
(H) In the case above, it is determined that the packet type is described.

Next, the formats 2 to 4 are identified by using the fourth field.

That is, in the case of the format 2, 'FF (H)' is stored in the area corresponding to DSAP and SSAP in the fourth field. On the other hand, each of the format 3 DSAP and SSAP has "E0 (H)"
However, in the case of format 4, 'AA (H)' is stored.

Therefore, 2 bytes of the fourth field (DS
(AP and SSAP) is 'FFFF (H)' (S4
02), it is determined that the format is “2”, and 'E0E0
If it is (H) '(S403), it is determined to be format 3, and if it is' AAAAA (H)' (S404), it is determined to be format 4.

If the format does not correspond to any of the formats 1 to 4, it is determined that there is no supported configuration (S405).

As described above, based on the configuration supported by the node device 1 stored in the storage unit 11b,
The determining unit 11a can determine the configuration of the received packet (S202).

For this reason, for example, the workstations 2 to
When 5 uses the format 1 configuration, the configuration of the node device 1 can be set to format 1 by the above-described series of packet reception processing.

However, for example, when a low-reliability device is used for the workstations 2 to 5, the format 2 may be erroneously used even though the format 1 is set in the workstation.

In such a case, if the configuration setting process is performed, since the format 2 is a configuration supported by the node device 1, it is necessary to change the configuration format every time the error occurs. As a result, the transmission operation of the node device 1 is restricted.

Therefore, in the following second embodiment, a processing procedure when a statistical method is applied in order to eliminate unnecessary setting (changing) operations performed every time the above error occurs will be described.

FIG. 5 is a flowchart showing a procedure for setting a configuration using a statistical method.

As shown in FIG. 5, similarly to the previous example (FIG. 2), if an Ethernet packet is received (S501), the configuration of the received packet is determined using S401 to S404 (S502). It is determined whether the configuration is usable (S50).
3). If it is determined that the packet can be used, the format of the configuration of the received packet is stored in the storage unit 1.
1b (S504).

Next, before proceeding to the received packet statistical processing, the format of the previously received packet stored in the storage unit 11b is extracted and compared with the format of the received packet (S505). As a result, if the format of the received packet matches the format of the previously received packet stored in the storage unit 11b, the process proceeds to statistical processing (S506). On the other hand, if they do not match, the process ends.

Here, the condition that the format of the packet received this time matches the format received last time was set as a condition for transition to the statistical processing. Only the received packets having the format received twice consecutively are subjected to the statistical processing. By doing so, a received packet having an error in the format is eliminated.

In the configuration statistical processing (S 506), for example, processing such as calculating the frequency distribution of each format is performed, and based on the processing result, it is determined whether to set or change the configuration. Perform (S507).

Here, when making the above determination (S507), for example, if the packets of a certain format among the packets received during a certain period of time are 80% or more, it is determined that the setting is to be performed.

It should be noted that the criterion of S507 is as follows.
This is determined in cooperation with the statistical processing method used in step 506.

Thereafter, when the result of the determination is that the setting (change) is to be performed, the setting unit 11c sets (changes) this configuration (S508), whereas when the setting or change is not performed, the processing is performed. To end.

When the setting process is completed, it is confirmed whether the setting process corresponds to the initial setting (S5).
09). And if this setting is the initial setting,
At this point, transmission of the packet is permitted for the first time (S51).
0).

The reason that the processing of S509 to S510 is adopted is that, when the configuration is not determined, such as when the power is turned on, when a transmission request is issued from a higher-level protocol, a packet is assembled in an incorrect format and transmitted. This is to prevent that.

In this embodiment, packets having the same format are continuously received twice (S504 to S50).
5) is a condition for determining that a received packet is valid. However, it is also possible to use three or more consecutive receptions.

In the statistical processing (S506),
Although the frequency distribution is used, a process using a standard deviation or the like can be performed.

By performing the processing using the above-described statistical method, for example, the workstation 2 transmitting a packet using the format 1 erroneously receives the format 2
Even when a packet is transmitted by using, the setting of the format 1 that should be used can be continued without changing the configuration of the node device 1 to the format 2.

In the above embodiment, the case where packets addressed to the workstations 2 to 5 flowing on the Ethernet 6 are received has been described. However, the same processing is performed when a packet addressed to the node device 1 is received. Is possible.

As described above, in this embodiment, the judgment unit 1
1a determines the configuration to be set from the packet received from the Ethernet 6, and the setting unit 11c sets the configuration based on the determination result of the determination unit 11a, so that unnecessary packets are not transmitted to the Ethernet 6. , Configuration can be set automatically.

Further, even when a packet having an erroneous format is transmitted on the Ethernet 6, a configuration that is frequently used can be set by using a statistical method.

Further, by performing this automatic setting, it is not necessary to perform trial and error transmission using an application in a layer higher than the data link layer, so that the configuration can be performed at the data link layer level independently of the application in the upper layer. Since the configuration is determined and set, even when the header format is changed, the configuration can be automatically and dynamically set without performing a reset process or the like.

In the present embodiment, the configuration supported by the node device 1 is stored in the storage unit 11b, but it is also possible to store the configuration in the determination unit 11a.

In this embodiment, the configuration is determined for the four header formats of the Ethernet data link layer. However, the present invention can be applied to any packet that can be mixed on the same network. it can.

Furthermore, by using the present invention together with the manual setting method, the configuration setting method can be selectively used depending on the situation.

In this embodiment, the Ethernet 6 is used as the network and the network 12 (IPX / SPX) is used as the upper protocol group. However, the present invention is applicable to various networks and various upper protocols such as TCP / IP. Applicable to one or more protocols.

[0080]

As described above in detail, according to the present invention, when the data link layer format is automatically set in the node device connected to the network, the format of the data link layer header is converted from the data received from the network. Judgment is made, and the format of the data link layer header is set according to the judgment result. Therefore, the data link layer header format to be used is automatically set without adversely affecting the network. There are advantages that can be.

Further, unlike the related art, without using a special application for automatic setting of the upper layer, independently of the application of the upper layer, at the data link layer level,
Since the header format of the data link layer is determined and set, there is an advantage that even when the header format is changed, the header format of the data link layer can be automatically automatically set without performing a reset process or the like.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the overall configuration of a network and the configuration of a node device according to the present invention.

FIG. 2 is a flowchart illustrating an example of a processing procedure at the time of receiving a packet in the node device illustrated in FIG. 1;

FIG. 3 is a diagram showing four header formats supported by the node device shown in FIG. 1;

FIG. 4 is a flowchart showing a procedure for identifying the header format shown in FIG. 2;

5 is a flowchart showing another processing procedure when the node device shown in FIG. 1 receives a packet.

[Explanation of symbols]

1 node device, 2 to 5 workstations (W
S), 6 Ethernet, 10 Ethernet driver, 11 automatic setting module, 11a judgment unit,
11b storage unit, 11c setting unit, 12 netware

Claims (3)

(57) [Claims] 1. An automatic setting apparatus of a data link layer format used for a node device connected to a network, comprising: a determination unit for determining a data link layer header format from data received from the network; Setting means for setting a format of a data link layer header at the time of data transmission in the node device based on a result of the determination. 2. The data link layer header format according to claim 1, wherein the determination unit determines a header format of a data link layer based on a statistical processing result of a packet received from the network and a plurality of packets received in the past. Data link layer type automatic setting device. 3. The apparatus according to claim 1, wherein, when the format of the header to be set is an initial setting, the setting means permits data transmission by the node device after the setting of the initial setting. Data link layer type automatic setting device.