JPS63131635A - Lan control equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a LAN control device for connecting host computers and various terminals to a local area network (hereinafter referred to as LAN).

[Conventional technology]

FIG. 6 is a block diagram showing a configuration example of a conventional LAN control device. In the figure, 100 is a host computer, 801 operates on the host computer 100, and 051
This is a processing program that supports the network layer and above of the basic reference model.

200 is a LAN control device, and 204 is an IEEE80 LAN controller that executes the logical link control procedure standardized by the IEEE (Institute of Electrical and Electronics Engineers) 802 Committee Subcommittee 2.
2.2 Control function (first control means), 205 is C3MA/CD (C
a r r i e r S sense Mult
iple Access with Co11isi
This is an IEEE802.3 control function (second control means) that executes medium access control procedures such as on Detection). 300 is a LAN transmission line compliant with the above IEEE802.3, and a LAN II control device 200 is connected to this LAN transmission line 300 via a transceiver 301.
is connected, and a host computer 100 is connected to this LAN control device 200.

FIG. 7 is a sequence diagram illustrating the operation. In the figure, 901 is a transmission request from the host computer 100, 902 is a reception process, 1001 is a transmission process by the LAN control device 200, and 1002 is a reception process.

Next, the operation will be explained.

In the conventional technology, the LAN*J control device 200 usually has a capacity of 20
5 is held. These functions are realized by hardware and firmware such as a microprocessor and LANJflLSI.

In this case, the operation of the LAN* control device 200 is as shown in FIG.
), the given data is transmitted onto the LAN (step 1001), the reception from the LAN side is displayed on the host (step 1002), and the host processes the reception (step 902).

LAN! Since the 4'a device 200 realizes the data link layer function, the data link frame length (IEEE802
．． According to 3, it controls and monitors packet length (1518 octets), but it is not concerned with the packet length of higher layers, that is, the network layer and above.

[Problem that the invention seeks to solve]

Since conventional LAN control devices are configured as described above, they are not aware of the network configuration (for example, the connection of LANj packet l) or the characteristics of the other terminal, and the packet length negotiation function that determines the packet length is not performed on the host side. This requires the processing program to take on the burden, leading to problems such as an increase in the load on the host side.

This invention was made to solve the above-mentioned problems.
internal or external network), and
LA that can reduce host load by having a negotiation function to determine packet length
The object of the present invention is to provide an N control device.

[Means for solving problems]

The LAN Mil device according to the present invention includes a third control means that executes a packet control procedure, and also has a packet length that determines a transfer packet length by transmitting and receiving a packet length that can be accepted by the calling side and a called side. The apparatus includes a fourth control means for performing negotiation and a parameter table in which the determined packet length is registered and referred to by the third control means.

[Effect]

The packet length negotiation function in this invention is
This is achieved through cooperation between the calling and called parties.

The calling side LAN control device determines the acceptable packet length of its own station in response to the call request from the processing program on the host.
A negotiation request is issued by embedding it in an INQ packet (negotiation request packet) as an internal management packet. Called side LAN system? The I device writes the smaller of the packet length in the received INQ packet (calling side acceptable packet length) and the own station's acceptable packet length as the negotiated packet length, and at the same time writes the ANS packet ( negotiation response packet)
, and issue a negotiation response. Calling LA
The N controller retrieves the negotiated packet length in the ANS packet and writes it into the parameter table. Thereafter, both the calling and called parties refer to the packet length registered in the parameter table held within their own stations, and perform segmenting/reassembly at the network layer level in accordance with this.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a block diagram showing the configuration of the embodiment, and the same reference numerals as in the conventional example in FIG. 6 indicate the same or corresponding parts, and the explanation thereof will be omitted.

In the figure, 101 operates on the host computer 100:
This is a process and program that supports the transport layer of the O81 basic reference model.

201, 202, and 203 are newly installed in the LAN control device 200, 201 is a parameter table in which various parameters described later are registered, and 202 is a CCIT.
This is the X,25 packet control function (third control means) that executes the packet control procedure at the network layer level within the X,25 convention specified by the International Telegraph and Telephone Advisory Committee (International Telegraph and Telephone Advisory Committee), and the parameter table 201 is Referenced. 203 is a DCE (Data C1rcuit Terre) that transmits and receives intra-LAN management packets between the calling side and the called side to realize the packet length negotiation function of this application.
Minating Equipment) control function (
The negotiated packet length is registered in the parameter table 201.

FIG. 2 shows a state in which the parameter table 201 is initialized prior to communication, and 201a shown in FIG.
This is a table showing the correspondence between LCGN/LCN (logical channel), destination physical address, and negotiated packet length in the 25 packet control procedure, and the 2
01b is the DTE (Data
This is a table showing terminal equipment addresses and packet lengths that can be accepted by the own station. FIG. 3 shows the state in which the parameter table 201 is set after negotiation. FIG. 4 is an operation sequence flowchart on the calling side, and FIG. 5 is an operation sequence flowchart on the called side.

Next, the operation will be explained.

In Figures 4 and 5, the L
Parameter table 2 placed in the ANMm device 200
01a and 201b are initialized (step 401). This is the LCGN used by the processing program 101 on the host.
/LCN (logical channel) and parameters related to the own station are set in tables 201a and 201b, and as a result, parameter tables 201a and 201
b has the shape shown in Figures 2(a) and (b).

In this state, a call request from the processing program 101 on the host is sent to the LAN controller W2 with the destination DTE address specified.
When sent to O0 (step 402), the LAN control device 200 embeds "other party's DTE address, own station's DTE address, and own station's acceptable packet length" in an INQ packet as an intra-LAN management packet, and then performs negotiation. Send an INQ packet as a request (step 5)
01). This INQ packet is transmitted to all LAN control devices using the LAN broadcasting function.

In FIG. 5, the LAN control device that received the INQ packet compares the "other party's DTE address" in the INQ packet with the "own station DTE address" in the parameter table 201b (step 701), and if they do not match, discards the INQ packet and ends the process. do. If they match, compare the "packet length that can be accepted by local station" in the INQ packet (that is, that of the calling side) and the "packet length that can be accepted by local station" (that is, that of the called side) in the parameter table 201b, After registering the smaller one in the parameter table 201a as the "negotiated packet length" of the negotiation result (step 702), the "negotiated packet length" is embedded in the ANS packet and sent back to the calling party (step 702). 7o3). In FIG. 4, the calling side LAN control device f200 that has received the ANS packet stores the "negotiated packet length" in the ANS packet in the parameter table 2.
01a (step 5o2). As a result, the parameter table 201a is set as illustrated in FIG. 3(a). Thereafter, a call is made according to the CALL procedure for x, 25 packets (step 503).

Incoming call processing (step 704), incoming call acceptance (step 6)
02), incoming call response (step 705).

Call completion (step 504) is executed, and the connection between the calling side and the called side is completed.

In the subsequent data transmission/reception sequence, by performing segmenting/reassembly according to the contents of the parameter table 201a, data can be efficiently transferred using the optimal packet length negotiated by both parties.

In the above embodiment, the packet length that can be accepted by the local station in the parameter table 201b is set by initialization from the host, but it may be fixed in the LAN control device.

In addition, the parameter table 201 is
Although an example has been shown in which the information is divided into 01a and 202b, they may be integrated.

〔Effect of the invention〕

As described above, according to the present invention, the third control means for executing the packet control procedure is provided, and the calling side and the called side transmit and receive the length of packets that can be accepted by their own stations (7) to determine the transfer packet length. and a parameter table in which the determined packet length is registered and referred to by the third control means, and a parameter table that performs packet length negotiation to determine the packet length.
Since the LiB device performs the processing, there is an effect that the load on the host is reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a LAN control device according to an embodiment of the present invention, FIG.
Figures (a) and (b) are diagrams showing the state of the above parameter table after negotiation, Figure 4 is an operation sequence flowchart on the calling side, Figure 5 is an operation sequence flowchart on the called side, and Figure 6. 7 is a block diagram of a conventional LAN control device, and FIG. 7 is an operation sequence flowchart of the conventional example. 100...Host computer, 101...Processing program, 200...LAN control device, 201...Parameter table, 202...X, 25 Packet control function (third control means), 203...・DCE control function (
4th control means), 204... IEEE802.2 control function (first control means), 205... IEEE80
2.3 Control function (second control means), 300...LA
N transmission line, 301...transceiver. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent: Masuo Oiwa ((talented\2chi) Figure 1 Figure 4

Claims (1)

[Claims] A LAN control device comprising a first control means and a second control means for executing a logical link control procedure and a medium access control procedure of a local area network, further comprising a third control means for executing a packet control procedure; a fourth control means that performs packet length negotiation in which the calling side and the called side transmit and receive acceptable packet lengths of their own stations to determine a transfer packet length; and the third control means in which the determined packet length is registered. A LAN control device comprising: a parameter table referenced by means.