KR970002719B1 - Variable bandwidth allocation device and method of time slot method to connect lans - Google Patents

Abstract

A variable band allocation device and method of the time slot type where allocates and extracts the band about the LAN packet that passes for proscribed time having the protocol transfer layer queue in order to interconnect the LANs between the remote distance.

Description

Time slot type provisional band allocation device for LAN-to-LAN access and variable band allocation method accordingly

1a or a system block diagram to which the present invention is applied;

1b is a schematic conceptual diagram of the present invention,

2 is a configuration block diagram of a variable band allocation apparatus according to the present invention;

3 is a diagram showing the buffer configuration of FIG.

4 is a flowchart of a variable band allocation using timeslots according to the present invention;

5 is a flowchart illustrating an update process of the band management and virtual channel connection table of FIG. 2;

6 is a process flow diagram of the band allocation signal protocol of FIG.

* Explanation of symbols for main parts of the drawings

11: LAN 12: Router / Interlock

13: ATM exchange 501: timer

502: variable band detection and allocation unit 503: band management and virtual channel connection table

504: disk 505: band allocation signal protocol processing unit

506: ATM cell generation and processing unit

The present invention provides a connection between local area networks (LANs) in an ATM (Asynchronous Transfer Mode) network. Each packet, which is LAN data, is connected to a call through a switched virtual channel (SVC). The present invention relates to a time slot type variable band allocation device and a variable band allocation method for inter-LAN access in which a bandwidth of LAN packet data is counted and a bandwidth allocated according to each call connection is variably allocated.

A conventional band allocation method for a long distance LAN connection will be described below.

First, a LAN packet sent by a sender is received by a router or an interworking unit, and a band change request signal is transmitted according to the buffer and network state of the receiver. Since the cells are connected at a transmission rate of 622 Mbps, many cells are stacked in an actual ATM network, or a smooth band cannot be actively adjusted according to the state of an ATM network during transmission. In addition, the method of pre-advertising the available band to the ATM network includes information on the bandwidth used by the router / interlocker connecting the LAN and the ATM network or the bandwidth currently available to the ATM switch and the digital cross connector (DCS). Pre-reserved bandwidth is delivered to ATM network components such as connectors). Overheader is used to transmit information such as bandwidth and available bandwidth to each device in ATM network. There was a problem that it is difficult to use because the basic information exchange protocol for information exchange between devices is not standardized.

In addition, the method of varying the band when the LAN connection device at the transmitting side is above a certain level according to the length and frequency of the LAN packet has the advantage of controlling the band at the transmitting side, so that the band can be allocated without substantially affecting the network. However, since the bandwidth allocation level according to the length and number of LAN packets is different depending on the state of each network, there is a problem in that the regulation level must be empirically set according to a separate bandwidth allocation level tuning operation for the actual operation of the network.

Accordingly, the present invention has been made to solve the above problems of the prior art, by extracting the band for the LAN packet passed for a predetermined time by placing a protocol conversion layer queue to interconnect the LAN between the long distance It allocates and manages the information required by the band management and ATM connection table CAM (Contention Adderss Memory) memory and maintains the call for a certain time in order to make a call connection by signal processing for every packet. It is an object of the present invention to provide a time slot type variable band allocation apparatus for LAN-to-LAN connection and a variable band allocation method for eliminating a waste of time.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a time slot type variable band allocation device for LANs, a LAN that is a relatively small area premises communication network, an ATM switch for asynchronous transmission, and the LAN of different protocols. A variable band allocation apparatus applied to a system having a router / interlocking device for connecting an ATM switch, comprising: a timer for notifying a timeslot and a LAN band counting from a LAN for each timeslot allocated by the timer. A variable band detecting and allocating unit for allocating the quantized data, and a variable band detecting and allocating unit for storing the information on the number of packets, the average packet length, and the used band according to each connected virtual channel using the disk as an auxiliary means. A band management and virtual channel connection table and the variable band detection and allocation unit, A bandwidth allocation signal protocol processor for providing band information for bandwidth allocation to an external wideband signal protocol (Q.2931) processor, and a LAN connected to the external wideband signal protocol processor and input from the variable band detection and allocation unit; It is characterized in that it comprises an ATM cell generation and processing unit for processing the packet to an ATM cell and outputs the packet to an ATM switch via an external ATM link.

In addition, the variable slot allocation method of the timeslot method for the LAN connection in the ATM network, the variable band allocation method applied to the variable slot allocation apparatus of the time slot method, the method for initializing the band management and virtual channel connection table contents; Step 1, a second step of checking whether there is a LAN packet arriving when a timer is operated and a timeslot is allocated, and a third step of updating the band management and virtual channel connection table if there is a LAN packet arriving as a result of the checking; After performing the third step, after processing the band allocation signal protocol according to the number of packets received, a new band is allocated from the ATM switch, and then transition to the second step, and after performing the second step, And a fifth step of releasing the ATM connection if the LAN packet does not arrive in the allocated timeslot.

The present invention relates to a method of allocating bands for packet transmission between LANs when remote LANs are connected to each other in an ATM network. Unlike a method of varying a transmission band by feeding back a band by a network or a router of a receiver for data transmitted from a transmitting end through a network, the variable bandwidth is measured by measuring the length and number of LAN packets passed for a predetermined time. How to assign In addition, since the time required for signal processing is saved by the number of LAN packets that arrive and transmit each time by maintaining an ATM connection for a predetermined time, packet data delay and performance in actual communication are advantageous over the conventional method.

And for efficient bandwidth availability, the operator can set different timeslots according to the application services.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

FIG. 1A is a block diagram of a system configuration to which the present invention is applied and includes a LAN 11 which is a local area communication network in a relatively small area, an ATM switch 13 for asynchronous transmission, and the LAN 11 and ATM of different protocols. 5 is provided with a router / interlock 12 for connecting the exchange 13.

1B is a schematic conceptual diagram of the present invention, where T is a timeslot, N is the number of packets, and BW is an allocation band.

As shown in the figure, in the present invention, when the LAN packet arrives in the state where the router / interlock device 12 does not have an ATM connection, an ATM connection is established to allocate a timeslot T. LAN packets arriving during the assigned timeslot T are counted, and information on the number and length of packets is recorded in the virtual channel connection table of the band management.

In addition, the bandwidth BW is allocated. The bandwidth management virtual channel connection table is modified by comparing the bandwidth required for a predetermined time slot with the bandwidth allocated to all time slots, and the band is variably allocated.

That is, since the number of LAN packets passed in the first timeslot T1 is N (1) = 3 and the number of LAN packets passed in the second timeslot in T2 is N (2) = 5, T2 is equal to N (2) -N ( It is necessary to increase the bandwidth for 1) = 2 packets. In this way, the bandwidth is variably allocated according to the connected virtual channels by the number of LAN packets passed for each timeslot T. At this time, if the band difference is less than 5Kbps, the time for new band allocation is reduced by allocating to the existing band without sending a signal message for allocating a new band.

In addition, when the band to be allocated to a predetermined timeslot T is less than the first call setup band BW (def), the first call setup band is maintained and the LAN packet arrived during the allocated timeslot T. If no, disconnect ATM.

2 is a configuration block diagram of a variable band allocation apparatus according to the present invention, where 501 is a timer, 502 is a variable band detection and allocation unit, 503 is a band management and virtual channel connection table, 504 is a disk, and 505 is a band allocation signal protocol. The processing unit 506 denotes an ATM cell generation and processing unit, respectively.

As shown in the figure, the variable band allocation apparatus includes a timer 501 for notifying a time slot T of a predetermined time and a LAN packet arriving from the LAN 11 for each time slot allocated by the timer 501. A variable band detection and allocating unit 502 for allocating virtual bands by counting a number and a variable band detection and allocating unit 502, and a packet passed through each connection virtual channel with the disk 504 as an auxiliary means. A band management and virtual channel connection table 503 for storing information on the number, average packet length, and band used, and the variable band detection and allocation unit 502, and the current band allocation information and a band for new band allocation. A band allocation signal protocol processing unit 505 for providing information to an external higher-bandwidth signal protocol processing unit (Q.2931), and the variable band detection and allocating unit (5) connected to the external wideband signal protocol processing unit (5). An ATM cell generation and processing unit 506 is provided for processing a LAN packet input from 02) as an ATM cell and outputting the packet to an ATM switch 13 through an external ATM link.

Looking at the operation of the variable band allocation process configured as described above, the timer 501 has the same timer value of about 1 to 2 seconds throughout the system in a time slot T of a predetermined time or an application service by ATM connection. It may have a different timer value defined according to the quality of service of, and there is a timer alarm number for each ATM connection instructs the variable band detection and allocation unit 502 to allocate a time slot. The variable band detection and allocation unit 502 counts the arriving LAN packet during the indicated timeslot and, upon receiving the timeout signal, calculates the band for the current timeslot and compares the bandwidth for the entire timeslot with the newly allocated time slot. The bandwidth is notified to the band allocation signal protocol processing unit 505.

In the band management and virtual channel connection table 503 composed of a memory device (CAM) having a very fast access time, information of a used band is read during each time slot, and a new allocated band is written. Each time a LAN packet arrives, the packet length corresponding to the virtual channel and the number of arrivals are recorded, and information of the band management and virtual channel connection table 503 is stored on the disk 504 at a command of an administrator or at a predetermined time. . This stored information can be used by the administrator to analyze network traffic or to extract accurate network tuning parameters.

3 is a diagram illustrating a buffer configuration of a variable band allocation device according to an embodiment of the present invention. A protocol for receiving LAN packets from a plurality of LAN ports and converting them into service date units (SDUs) of ATM-5 (ATM-Adaptation Layer-5) A plurality of first queues 601 used for LAN packet counting and SDU conversion in the translation layer, and for generating 48 bytes of segment and reassembling PDU (SAR-PDU) than Convegence Sublayer Protocol Data Unit (CS-PDU) A plurality of second queues 602 corresponding to SARs of the AAL-5 layer, and multiplexing queues 603 of the ATM layer to output to the ATM link according to bands allocated by the respective service schemes of the second queue 602. It is provided.

The variable band detection and allocating unit 502 configured as described above allows the buffer to output LAN packets inputted from a plurality of LAN ports during the predetermined timeslot T to an ATM link that converts them into ATM cells. In addition, it is possible to analyze the state of the queues in each stage to measure the performance of the traffic state of the ATM network and the user traffic characteristics of the LAN packet.

4 is a flowchart of a process of variably allocating a band by a timeslot according to the present invention.

First, when the contents of the band management and virtual channel connection table 503 are all initialized (201), and the timer 501 for allocating the timeslot T is operated (202), the LAN is assigned to the allocated timeslot T. Check if the packet arrives (203).

As a result of the check, if there is a LAN packet arriving in the time slot T, information such as a related LAN packet length and the number of arrivals is recorded in the band management and virtual channel connection table 503 (204). When a new band is allocated from the ATM switch 13 by processing the band allocation signal protocol according to the number of packets arrived 205, the timer 501 transitions to operation 202.

On the other hand, if the LAN packet does not arrive during the assigned timeslot T, the ATM connection is released (206).

FIG. 5 is a detailed flowchart of a process of updating the band management and virtual channel connection table of FIG.

As shown in the figure, the band management and virtual channel connection table 503 checks whether the arrived LAN packet is an ATM connection (301), and if the LAN packet arrives in a new state without a connection, a new virtual channel as a base band. (302), and record the number and length of LAN packets in the allocated virtual channel table (303).

If there is an ATM connection in which the arrived LAN packet is already formed, the number and length of LAN packets are recorded in the pre-allocated virtual channel table (304).

6 is a flowchart of a band allocation signal protocol according to the present invention, in which a LAN packet 1 (LAN-Pkt1-req) is transmitted from the LAN 11 in a new state in which there is no ATM connection during an assigned time slot T. Upon arrival, the router / interlocker 12 first sends a baseband call connection request signal (Cell-CONN-Req (BWdef)) through an ATM-UNI and a baseband call connection response signal (Call-CONN-Conf (BWdef)). After receiving the call, the call is connected to the ATM switch 13 to the baseband (401), and the LAN packets (LAN-Pkt1-req, LAN-Pkt2-req, and LAN-Pkt3) arrive at the allocated timeslot T1. -req) is sent to the ATM switch 13 (402).

Then, according to the number of packets that are time slotted and counted, the bandwidth increased or decreased in the next time slot T2 is allocated (403), and the received LAN packets (LAN-Pkt4-req, LAN-Pkt5-req, LAN-Pkt6-req). ) Is transmitted to the increased / decreased band BW1 (404).

That is, when the time slot is timed out, the band is requested according to the observed band information, and during the band allocation request, the band is used as the band used before the observation. Therefore, without waiting for a new band allocation, the existing band is serviced, and when a new band is allocated, the service is immediately provided to the allocated band. In addition, the observed bandwidth can be calculated in various ways. As a conventional method, the average LAN packet length that has been passed is multiplied by the number of arriving packets and divided into timeslots.

As described above, according to the present invention, in interconnecting LANs in a remote area through an ATM network, the bandwidth per time slot is varied according to the amount of information of a higher application service, thereby avoiding wasting bandwidth, a communication resource. By applying this to LAN connection router or interworking device of ATM network, economical network operation and implementation are simple, so it is easy to apply practically, especially for remote LAN contact service such as virtual LAN connection in the early stage of ATM network, It can be applied to all LAN and ATM network access devices.

In addition, by storing the information on the band in the auxiliary disk, it is possible to extract the traffic information according to the tuning parameters and application services for allocating the dynamic band to the network.

Claims (5)

A router / interlock device 12 connecting LAN 11, a relatively small area-area communication network, ATM switch 13 for asynchronous transmission, and LAN 11 and ATM switch 13 of different protocols. In a variable band allocation apparatus applied to a system having a system, a timer 501 for notifying a timeslot T and a LAN packet arriving from the LAN 1 for each timeslot allocated by the timer 501 are counted. A variable band detecting and allocating unit 502 for allocating a virtual band, and a packet which is connected to the variable band detecting and allocating unit 502 and passed according to each connected virtual channel using the disk 504 as an auxiliary means; A band management and virtual channel connection table 503 for storing information on average packet length and used bands, and the variable band detection and assignment unit 502 to allocate current band allocation information and band information for new band allocation. External upper broadband A band allocation signal protocol processing unit 505 provided to a signal protocol (Q.2931) processing unit, and a LAN packet input from the variable band detection and allocation unit 502 connected to the external wideband signal protocol processing unit to an ATM cell; And an ATM cell generation and processing unit (506) for processing and outputting the same to an ATM exchanger (13) through an external ATM link. 2. The band management and virtual channel connection table 503 stores the number of LAN packets passed during timeslots and ATM connection information using a CAM memory, which is a fast access memory, and calculates the stored information in a predetermined manner. A time slot type variable band allocation apparatus for LAN-to-LAN access, which is stored in a disk 504 for use in network operation and network state analysis. The LAN frame of claim 1, wherein the buffer of the variable band allocator receives LAN packets from a plurality of LAN ports and converts the LAN packets into service data units (SDUs) of an ATM adaptation layer-5 (ALL-5). A plurality of first queues 601 used for counting and SDU conversion, and SARs of the AAL-5 layer to generate a segment PDU (Segment And Reassemly PDU) of a predetermined byte rather than a Convegence Sublayer Protocol Data Unit (CS-PDU). And a plurality of second queues 602 corresponding to the multiplexing queues 603 of the ATM layer that output to the ATM link according to a band allocated by the service schemes of the respective second queues 602. A time slot type variable band allocation device for inter-LAN connection. In the variable band allocation method applied to the time slot type variable band allocation apparatus for LAN connection of the present invention, a first step of initializing the contents of the band management and virtual channel connection table 503 and a timer 501 ) And a second step of checking whether there is a LAN packet when the time slot T is allocated, and a third step of updating the band management and virtual channel connection table 503 if there is a LAN packet arriving as a result of the checking. And a fourth step of transitioning to the second step after receiving the new band from the ATM switcher 13 by processing the leased signaling protocol according to the number of packets arrived after performing the third step. And a fifth step of releasing the ATM connection when the LAN packet does not arrive in the allocated timeslot (T) after performing the second step. 5. The method of claim 4, wherein the third step comprises: a sixth step of checking whether the arrived LAN packet is an ATM connection; and if the LAN packet is already connected to the ATM after performing the sixth step, the LAN is added to a pre-allocated virtual channel table. After the seventh step of recording the number and length of the packets, and after performing the sixth step, in the case of LAN packets not connected to the ATM, the new virtual channel is allocated to the baseband and the number and length of the LAN packets are recorded in the allocated virtual channel table. And a time slot type variable band allocation method for inter-LAN connection, comprising: an eighth step.