JPH0677970A - Hub for 10 base-t - Google Patents

Abstract

PURPOSE:To obtain a stable communication path for the port having high priority by disconnecting the port corresponding to the quantity of traffic. CONSTITUTION:The traffic quantity of a packet to be repeated by a centralizing function means 1 is detected by a traffic quantity detecting means 2, and the detected value is compared with a reference value by a level judging means 3. When the traffic quantity is large, the port of low priority is connected to a dummy packet generating means 4 by a port switching means 5 so as to disable the communication of that port. Thus, when the traffic quantity is large, the port having low priority is disconnected, and the stable communication path can be provided for the port having high priority.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a 10BASE-T HUB used in a LAN using twisted pair wires.

[0002]

2. Description of the Related Art Conventionally, a CSMA / CD system LAN using a twisted pair line called 10BASE-T which conforms to the IEEE802.3 standard has been widely used. In the HUB (concentrator) used for this 10BASE-T, all ports are on equal footing, and if prioritized, it is necessary for a person to partition terminals other than the terminal to be prioritized using the management terminal. there were.

[0003]

In the conventional HUB, when the traffic amount becomes large, the transmission waiting and the collision amount become large, and stable communication cannot be performed. In particular,
If the port is connected to a security device,
If stable communication is not possible, a fatal problem may occur.

The present invention has been made in view of the above points, and an object of the present invention is to disconnect a port according to the traffic amount and to provide a stable communication path to a port having a high priority. To provide.

[0005]

10BAS according to the present invention
In the HUB of ET, as shown in FIG. 1, in the hub of 10BASE-T having the concentrating function means 1 for relaying between a plurality of twisted pair ports P1, P2, ..., Pn, the concentrating function means 1 Traffic amount detecting means 2 for detecting the traffic amount of the packet relayed by and the level judging means 3 for comparing the detected value of the traffic amount with a reference value.
A dummy packet generating means 4 for generating a dummy packet to be transmitted when there is a large amount of traffic, and a port P
, Pn are connected to the line concentrating function means 1 or to the dummy packet generating means 4 and a port switching means 5 is provided.

Here, the dummy packet generating means 4
Is a means for generating a dummy packet for making communication of a port connected via the port switching means 5 impossible. The level determination unit 3 has a plurality of determination levels, and is configured to control the port switching unit 5 so that a port with a lower priority is connected to the dummy packet generation unit 4 as the traffic amount increases. ing.

[0007]

According to the present invention, the traffic amount of the packet relayed by the concentrating function means 1 is detected by the traffic amount detecting means 2, and the detected value is compared with the reference value by the level judging means 3, so that the traffic amount is large. Sometimes, the port switching means 5 connects a port having a low priority to the dummy packet generating means 4 to disable communication of the port, thereby providing a stable communication path to a port having a high priority. Is something that can be done.

[0008]

1 is a block diagram of a HUB used in the present invention. The concentrating function means 1 is a part having a HUB function of 10BASE-T, and is a basic function of the HUB.
The traffic amount detecting means 2 is a 10BASE-T HU.
Detect traffic volume of B. The level determination means 3 is
The level is judged from the current traffic volume. The dummy packet generating means 4 is a means for sending out a dummy packet to a terminal so that the terminal cannot transmit using the characteristic of the CSMA / CD system. The port switching means 5 receives the control signal from the level determination means 3,
The signal lines of the ports P1, P2, ...
And the dummy packet generating means 4 are switched. TD +, TD- are transmission signal lines, RD +,
RD- is a reception signal line. In normal state, each port P
1, P2, ..., Pn are connected to the concentrating function means 1, but when a control signal from the level determining means 3 is given,
It is connected to the dummy packet generating means 4.

A block diagram of the traffic amount detecting means 2 is shown in FIG. First, the carrier detection means 21 detects a carrier signal from the packet data a input from the line concentrating function means 1. Then, the carrier signal b is integrated by the integrating means 22. The integrating means 22 is cleared at regular time intervals by the timing pulse c output from the reference time generating means 25. The integrated signal d is sampled and held by the sample and hold means 23 at regular time intervals by the timing pulse c. The sampled and held detected value e is buffered and amplified by the buffer means 24. The reference time generation means 25 generates a reference time timing pulse c for detecting the traffic volume. FIG. 3 shows the waveforms of the packet data a, the carrier signal b, the timing pulse c, the integrated signal d, and the sampled and held detection value e in the block diagram of FIG. When the traffic volume increases, the traffic volume detection means 2
The detected value e of is high.

Here, the correspondence between the traffic volume and the state is shown in FIG. Although the state is divided into three in this embodiment,
This is an example. The traffic volume increases in the order of state, state, state. The state is normal,
The state is a state in which the traffic volume becomes high and a terminal waiting for transmission comes out, and the state is a state in which the traffic volume is large and the transmission efficiency is poor. Here, the levels L0, L1, and L2 are introduced as indicators indicating the priority order of the ports. In this embodiment, the levels are divided into three, but this is just an example. Table 1 shows the correspondence between the three states and the three levels.

[0011]

[Table 1]

Next, a block diagram of the level judging means 3 is shown in FIG. The reference value generating means 31 is a means for generating a reference value f ₁ for separating the state and the state. The reference value generating means 32 has a reference value f for separating the state and the state.
It is a means to generate ₂ . The comparison means 33 uses the reference value f ₁
And traffic amount e are compared, and when e> f ₁ , g
₁ = 1 is output, otherwise g ₁ = 0 is output. The comparing means 34 compares the reference value f ₂ with the traffic amount e, and outputs g ₂ = 1 when e> f ₂ , and otherwise outputs g ₂ = 0. The level determining means 35 determines the levels L0, L1 and L2 based on the comparison results g ₁ and g ₂ of the comparing means 33 and 34. When in the state, all ports of levels L0, L1, and L2 can communicate. In the state, the level L0 and L1 ports can communicate, and the level L2 port cannot communicate.
In the state, only the port of level L0 can communicate, and the ports of levels L1 and L2 cannot communicate.

Table 2 shows the correspondence between the inputs and outputs of the level determining means 3. The port level setting means 36 determines each port P
1, P2, ..., Pn are levels L0, L1, and L2,
It is to set which level it belongs to, for example,
It can be realized by jumpers in a matrix circuit.

[0014]

[Table 2]

Next, a block diagram of the dummy packet generating means 4 is shown in FIG. The clock generating means 41 generates a clock signal of 10 MHz required to create a dummy packet. The dummy packet is a pattern of 1010 ... With a packet length of 1518 octets, and there is an interframe gap of 9.6 μs between the packets. The frequency dividing means 42 is a means for dividing 10 MHz into 5 MHz.
The counter 43 is means for generating a timing of 12240 BT (BT is an abbreviation for bit time, 1 BT is 100 ns). 12240BT is the packet length (1
518 octets = 12144BT) and the inter-packet gap (9.6 μs = 96BT). This 12
The falling edge of 240BT resets the counter 44. The counter 44 displays the packet length (151
8 octets = 12144BT). The gate means 45 gates the 5 MHz clock signal from the frequency dividing means 42 by the output of the counter 44. The differential driver means 46 converts the NRZ signal into a differential signal. FIG. 6 shows waveforms of the output A of the counter 43, the output B of the counter 44, the output C of the gate means 45, and the output D of the differential driver means 46 in the block diagram of FIG.

[0016]

According to the present invention, 10BASE having a concentrating function means for relaying between a plurality of twisted pair ports.
In the -T HUB, the detected value of the traffic amount of the packet relayed by the concentrator function unit is compared with the reference value by the level determination unit, and when the traffic amount is large, the port switching unit generates a dummy packet of a port with a low priority. Since it is connected to the means and communication of the port is disabled, there is an effect that a stable communication path can be provided to a port having a high priority.

[Brief description of drawings]

FIG. 1 is a block diagram of a 10BASE-E HUB according to the present invention.

FIG. 2 is a block diagram of traffic amount detection means used in the present invention.

FIG. 3 is an operation waveform diagram of traffic amount detection means used in the present invention.

FIG. 4 is a block diagram of level determination means used in the present invention.

FIG. 5 is a block diagram of a dummy packet generating means used in the present invention.

FIG. 6 is an operation waveform diagram of the dummy packet generating means used in the present invention.

FIG. 7 is a conceptual diagram showing correspondence between traffic volume and status.

[Explanation of symbols]

 1 Concentration function means 2 Traffic amount detection means 3 Level determination means 4 Dummy packet generation means 5 Port switching means

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Claims (3)

[Claims] 1. In a 10BASE-T HUB having a concentrating function means for relaying between a plurality of twisted pair ports, a traffic amount detecting means for detecting a traffic amount of a packet relayed by the concentrating function means, and a detected value of the traffic amount. Is compared with a reference value, a dummy packet generating means for generating a dummy packet to be transmitted when the amount of traffic is heavy, and a port is connected to the concentrating function means or the dummy packet generating means. A HUB of 10BASE-T, which is provided with a port switching means. 2. The 10BASE according to claim 1, wherein the dummy packet generating means is means for generating a dummy packet for disabling communication of a port connected through the port switching means. -T HUB. 3. The level judgment means has a plurality of judgment levels, and as the traffic volume increases,
10. The 10BASE-T according to claim 2, wherein the port switching means is controlled so that a port having a lower priority is connected to the dummy packet generating means.
HUB.