JPH01188137A - Burst communication system in slot ring type lan - Google Patents

Abstract

PURPOSE:To improve the using efficiency of a transmission path by inserting a burst communication packet to an idle slot, which is generated when there is a gap between a band to be obtained by a reserved slot and the communication band of real synchronous continuing communication. CONSTITUTION:When transmission data from a communication device 15 are the synchronous continuing communication, a slot reserving table 19 is referred based on an ID number each time the slot is received. When a transmission buffer 21 completes transmission preparation and the slot is reserved slot, a transmission packet is inserted to the slot and when the transmission buffer 21 does not complete the transmission preparation, a dummy packet is inserted. When the transmission data from the communication device 15 are burst communication data, the transmission packet is inserted to the received slot in case of a constant condition. For the transmission slot for which branch, qualification, repetition and insertion are completed, a redundant it for the error detection of data is added in a packet check adding part 17 and the slot is transmitted to a transmission path 12. Thus, the burst communication is efficiently received and the utilizing efficiency of a transmission path band is improved.

Description

[Detailed Description of the Invention] [Summary] Regarding a burst communication method in a throttling type LAN.

The purpose is to efficiently accommodate burst communications and increase the efficiency of using transmission line bandwidth.

A drop/insertion control unit provided in a communication node that performs drop/insertion of packets to slots.

A means is provided for detecting an empty reserved slot and determining whether or not a burst communication packet can be inserted.

When a communication node that performs synchronous continuous communication cannot insert a data packet into a reserved slot, it inserts a dummy packet indicating that the slot is empty.

In a communication node that performs burst communication, when the branch/insertion control unit detects an empty reserved slot, it determines whether or not a burst communication packet can be inserted into the reserved slot, and inserts a burst communication packet if possible. Configure it to do so.

[Industrial application field]

The present invention relates to a burst communication method in a LAN, and in particular, in a SLOTTED RING type LAN that performs synchronous continuous communication using a slot reservation method, communication is performed by using reserved slots that circulate while remaining empty as slots for burst communication. This invention relates to a method for increasing the utilization efficiency of transmission line bandwidth.

Here, burst communication refers to the point-to-point of receiving station erasure, which mainly uses non-reserved slots to transmit packets.
Point (P-P) refers to il belief.

[Conventional technology]

Packet communication is important in promoting the integration of various networks because by transmitting all data as packets, it is possible to combine lines that were previously set up individually depending on the nature of the data to be communicated.

A throttling-type LAN is a LAN (local area network) that transmits all data based on fixed-length mini-packets. slot exists.

Each slot has an ID number assigned to it.

For example, by always using a specific slot for communication, a constant bandwidth can be obtained regardless of the ID number of the slot in use.

In this description, a slot refers to a container for transferring data, and a packet refers to data transferred by a slot.

In order to accommodate synchronous continuous communication in a throttling type LAN, slots of the necessary bandwidth are reserved for use, exclusive control is performed so that they are not used for other communications, and the reserved communication is Communication is carried out by using only

FIG. 7 shows a principle diagram when accommodating synchronous continuous communication in a throttling type LAN.

In FIG. 7, 1 is a transmitting side communication device (A).

2 is a packet assembling device, 3 is a transmitting buffer, 4 is a throttling type LAN, 5 is a receiving buffer, 6 is a packet disassembling device, and 7 is a receiving side communication device (B).

A certain number of slots always exist on the throttling type LANA, and among these, slot 4 shown with diagonal lines
-1, the sending side communication device (A) 1 is the receiving side communication device (
B) This is a slot reserved for use in transferring data (packets) to 7.

The remaining slot 4-2 shown in white is a non-reserved slot for the transmitting communication device (A)l.

In the illustrated example, the transmitting side communication device (A) 1 performs synchronous continuous communication using three reserved slots 4-1 per frame (one round of the throttling LAN).

By the way, for example, the bandwidth of a slot is 2.048Mbp.
In order to accommodate the digital secondary group (6,312 Mbps) at the time of s, 4 slots (resulting in a band of 8,192 Mbps) are reserved for use.

However, in this case, the sending side inserts packet data into the slot only 77% of the time, and the remaining 23% (1,
880Mbps) was wasted as it could not be used for other communications.

In addition, in recent years, as the speed of terminal devices has increased, some communication devices have appeared that require an instantaneous transmission bandwidth of 100 Mbps for burst communication, which limits burst communication to communication using only non-reserved slots. Under this, in a system that accommodates a large number of synchronous continuous communications, when communication devices that perform a large number of burst communications attempt to transmit simultaneously.

Sufficient bandwidth cannot be obtained, and the throughput of burst communication decreases.

[Problems to be Solved by the Invention] In the conventional throttling type LAN, the bandwidth of slots reserved for synchronous continuous communication is wasted, and the usage efficiency of the transmission path is kept low.

On the other hand, in burst communication where reserved slots cannot be used,
Even though there are empty slots circulating on the transmission path,
Due to exclusive control, only the bandwidth for non-reserved slots can be used, resulting in a problem that the bandwidth is limited.

An object of the present invention is to efficiently accommodate burst communications in a throttled LAN that performs synchronous continuous communications using a slot reservation method, and to improve the efficiency of use of transmission line bandwidth.

[Means for solving problems]

In a throttling type LAN that uses a slot reservation method to accommodate synchronous continuous communication, the present invention deals with empty slots that occur when there is a gap between the bandwidth of reserved slots and the actual communication band of synchronous continuous communication. To,
By inserting burst communication packets under certain conditions, the usage efficiency of the transmission path is increased and the communication band for burst communication is increased.

FIG. 1 is a diagram showing the basic configuration of the present invention, and exemplarily shows the configuration of one communication node of a slow ring type LAN.

In FIG.

11 is a communication node.

12 is a LAN transmission line.

13 is a packet add/drop control unit.

14 is a packet assembly and disassembly device.

15 is one letter and three devices.

16 is a packet check inspection section.

17 is a packet check addition section.

18 is a packet analysis section.

19 is a slot reservation table.

20 is a receiving buffer.

21 is a transmission buffer.

Next, the operational functions of the communication node shown in FIG. 1 will be explained.

In the communication node 11, the packet in the slot received from the transmission path 12 is checked for transmission path errors by the packet check inspection section 16, and then taken into the packet analysis section 18.

The packet analysis unit 18 first determines whether to perform branching, modification, or relaying by analyzing the packet header section.

In the case of branching, bit operations such as branching the packet from the receiving slot, taking it into the receiving buffer 20, and making the slot 7) empty are performed.

In the case of modification, only bit manipulation is performed without branching the packet from the receive slot.

Furthermore, in the case of relay, no bit manipulation is performed.

Next, if the transmission data from one communication device 15 is synchronous continuous communication, each time a slot is received, the slot reservation table 19 is referred to based on the ID number, and the transmission buffer 2 is
If 1 is ready to send and the slot is a reserved slot, then
A transmission packet is inserted into the slot, and if the transmission buffer 21 is not ready for transmission, a dummy packet is inserted. Furthermore, if the transmission data from the second communication device 15 is burst communication data, the transmission packet is inserted into the reception slot under certain conditions.

The transmission slot for which branching/modification/relay/insertion has been completed is added with redundant bits for data error detection by the packet check addition section 17, and is transmitted to the transmission line 12.

Data format conversion between the receiving buffer 4203 and the transmitting buffer 21 and the communication device 15 is performed by the packet assembling and disassembling device 14.

[Effect]

In the present invention, conditions under which a communication node performing burst communication inserts a packet into a reception slot will be described.

a: If the vacant slot is a non-reserved slot, it is possible to transmit a packet using it.

In the conventional method, only this case was possible.

b: When the vacant slot is a reserved slot.

If the communication type is such that the own station is the erasing station.

Packet transmission becomes possible in the following cases ■, ■, and ■.

■: Point-to-point (P-P) communication (transmitting station erased)...Transmission is possible only when the destination address set in the reserved slot is larger than the address value of the destination of burst communication (receiving station erased) )...Transmission is possible only when the source address set in the reserved slot is larger than the address value of the destination of burst communication.
・Transmission is possible only when the source address set in the reserved slot is larger than the address value for burst communication ■: Broad-Cast (-simultaneous broadcast communication)...
Transmission is possible only when the source address preset in the reserved slot is greater than the burst communication address value.The destination address and source address preset in the reserved slot are used when the node using the reserved slot prepares to send the packet. Since it has not yet been completed, this value is the result of only setting the slot header.

In the above description, node addresses are compared as a condition for determining whether or not burst communication uses the synchronous continuous communication reserved slot. The reason for this will be explained below.

(A), CB), and (C) of FIG. 2 are explanatory diagrams showing specific examples of reservation packet use availability determination conditions.

(A) in Figure 2 shows p-p between node addresses 2-6.
<Delete receiving station) This is an example of communication.

The reserved slots for communication between 2 and 6 carry packets from 2 to 6, are cleared at 6, and then carry packets from 6 to 2.

Therefore, when 3, for example 4, performs burst communication using the reserved slot between 2 and 6, this is possible only when the destination is 5 or 6.

The shaded node is a packet in which 4 can transmit a burst communication packet using slots reserved for 2 to 6. because.

For example, if 4 sends a message using reserved slot 7,
6 is because packets cannot be transmitted from 6 to 2.

(B) in Figure 2 shows r'-P between node addresses 2-6.
(Transmitting station erased) This is an example of communication.

The reserved slots for communication between 2 and 6 carry packets from 2 to 6, are erased at 2, and carry packets from 2 to 6. Therefore, when 1, for example 4, performs burst communication using the reserved slot for 2-6, the destination is either 5°6.7, 0, or 1.2 shown with diagonal lines. This is possible only when the node is .

(C) in FIG. 2 is an example in which Multi-Cast communication is performed between node addresses 2 and 5.6°0.

The reserved slots for communication between 2 and 5.6.0 are between 2 and 5.6.0.
It carries the packet to 6.0 and is erased by 2.

Also from 2 to 5.6. Therefore, transport the packet to O.

For example, when 4 performs burst communication using reserved slots between 2-5.6,0, the destination is 5 with diagonal lines.
, 6.7, 0, 1.2.

As described above, in the past, when synchronous continuous communication was accommodated by the slot reservation method, reserved slots were used exclusively for the communication that was the subject of the reservation, but in the present invention,
When synchronous continuous communication has no transmission packet to insert into a reserved slot and an empty slot occurs, burst communication can use the reserved slot for transmission.

〔Example〕

Embodiments of the present invention will be described using FIGS. 3 to 6.

FIG. 3 shows a throttling type LA according to an embodiment of the present invention.
The packet format of N is shown. As shown at ta+ in Figure 3, the entire packet consists of the header section (8 BYTE)
, data (64BYTE), l-railer part (2B
YTE) Consists of a total of 74 BYTE.

The packet header section further includes a control (CTL) section, a destination address (DA) section, a source address (SA) section,
(DM) Department. Among these, control (CTL
) details are shown in the mountain in Figure 3).

Also, the details of the source address (DA) part are shown in (C) in Figure 3.
Shown below.

FIG. 4 shows a detailed block diagram of a packet add/drop control section of a communication node according to an embodiment of the present invention.

In Fig. 4.

A delay circuit section 41 performs delay adjustment for analyzing and processing packets while the slot passes from the packet check inspection section to the packet check addition section.

42 is a timing generation unit that generates various timings necessary for the entire packet analysis group to operate.

A packet latch section 43 latches a packet header section, which will be described later, in order to analyze conditions for branching/modifying/relaying/inserting a packet in a reception slot.

44 to 46 are CTL unit determination units, respectively.

These are a DA section determining section and an SA section determining section, which determine the contents of each field of the control i (CTL) section, destination address (DA) section, and source address (SA) section in the packet header section.

A packet header section 47 performs bit operations on the packet header section.

Reference numeral 48 denotes a delay circuit section, which performs appropriate delay adjustment in order to branch the packet from the reception slot and take it into the reception buffer.

Reference numeral 49 denotes 8 branch/modification/relay determination units, and each condition indicated by 44 to 46 (CTL, DA, and SA determination units) determines which branch, modification, or relay should be performed for the received slot. 250 is an insertion determination unit that makes a determination based on
It is determined whether or not to insert a packet into the reception slot based on the conditions indicated by the two-branch/modification/relay determination unit 49 and the transmission buffer 21 in FIG.

Reference numeral 51 denotes a dummy packet unit in a communication node accommodating a terminal that performs synchronous continuous communication.

If transmission data cannot be inserted into the reserved slot because the transmission buffer is not ready for transmission, the slot usage status (USD = 0) in the control 411 (CTL) part of the packet header is
), a dummy packet in which only the slot reservation letter B (R3V=1), each bit of the packet erasure station (TN), and the transmission address (DA) part are set is inserted.

Reference numeral 52 denotes a data selector section, which selects which of the data transferred from each section is to be transmitted to the packet check addition section 17 in FIG.

53 is a selector control section, and the data selector section 52
control.

Note that the addresses NDA of each communication node connected on the ring are assigned in ascending order from small to large from O to N-1, with the total number of communication nodes being N, as shown in FIG. shall be taken as a thing.

According to this embodiment, by making a condition determination in the packet branching/modification/relay determination unit of the communication node accommodating burst communication, burst communication can transmit packets using reserved slots. .

The process will be explained below using the flowchart shown in FIG. When the packet branch/modification/relay determination unit receives a reserved slot, it executes each of the first steps.

Determines whether burst communication packets can be inserted.

Reservation slot for flJP-P synchronous continuous communication (R
3V=1) is received with an empty state (USD=O), step 3 is executed.

(21Multi-Cast or Broad-Ca
Reserved slot for synchronous continuous communication of s L (R3V=
1) is received as empty (USD=0), step (
Execute 3).

(3) Check the packet erasing station (TN) of the packet header control (CTL) section, and if TN=0 (receiving station erasing), execute step (4).

When TN=1 (transmitting station erased), step (5) is executed.

+417N=O, the preset destination address (DA
) part, and if it is larger than the address (NDA) of the destination node to which burst transmission is to be performed from the own node, a transmission packet is inserted.

(If 517N=1, the preset source address (SA
) part, and if it is larger than the address (NDA) of the destination node to which burst transmission is to be performed from the own node, a transmission packet is inserted.

Thus, the tree embodiment uses reserved slots to accommodate i-synchronous continuous communications.

When the reserved slot becomes vacant due to a gap between the bandwidth of the reserved slot and the communication bandwidth of synchronous continuous communication, the bandwidth can be used for transmitting burst communication data packets without wasting the bandwidth.

Furthermore, in this embodiment, one communication node is configured to accommodate only one communication device.

Even when a plurality of communication devices are accommodated in one communication node, the configuration and control for realizing the present invention can be easily analogized.

〔Effect of the invention〕

According to the present invention, in a throttling LAN that uses a slot reservation method to accommodate synchronous continuous communication,
It is possible to insert burst communication packets into empty slots that occur when there is a gap between the bandwidth of the reserved slot and the actual communication bandwidth of synchronous continuous communication, thereby increasing the communication bandwidth of burst communication. is possible,
Burst communications can be accommodated efficiently and the efficiency of using the transmission path is improved.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the basic configuration of the present invention, Fig. 2 is an explanatory diagram of conditions for determining whether reservation packets can be used, Fig. 3 is an explanatory diagram of the packet format according to an embodiment of the present invention, and Fig. 4 is an illustration of the implementation of the present invention. A detailed block diagram of the packet drop/insertion control unit according to an example, FIG. 5 is an explanatory diagram of the address NDA of the communication node, and FIG.
The figure is a flowchart for determining whether or not a burst communication packet can be inserted into a slot reserved for synchronous continuous communication, and FIG. 7 is a principle diagram of a system for accommodating synchronous continuous communication in a throttling type LAN. In Figure 1. 11: Communication node 12: LAN transmission line 13: Packet drop/insertion control section 16: Packet check section 17: Packet check addition section 18: Packet analysis section 19 Nislot reservation table

Claims (1)

[Claims] In a throttled LAN that uses a slot reservation method to accommodate synchronous continuous communication, communication nodes (11
) is provided in the drop-and-insert control unit (13) that performs drop-insertion of packets to slots, and is provided with means for detecting vacant reserved slots and determining conditions for whether packets can be inserted for burst communication, thereby achieving synchronous continuous communication. A communication node that performs burst communication inserts a dummy packet indicating an empty slot when a data packet cannot be inserted into a reserved slot, and a communication node that performs burst communication inserts a dummy packet indicating an empty reserved slot when the drop-and-insert control unit (13) detects an empty reserved slot. A throttling type LAN characterized by conditionally determining whether or not a burst communication packet can be inserted into the reserved slot, and inserting a burst communication packet when possible.
burst communication method.