KR0133786B1 - Method of controlling call and connection uni of atm system - Google Patents

Abstract

The present invention relates to a method for identifying a user organizing unique identifier (OUI) by finding a BLLI information element stored in a setup message received through a signal adaptation layer from an ATM network. A first step of obtaining length information (Ls): A second step of obtaining a BLLI information element compared with 95 ₁₀ while increasing the count value of the counter: A third step of detecting an error by comparing whether the counter value exceeds the message length Step 4: Reading User Information Layer 3 Protocol (UIL3) data in which bits 7 and 8 are 11 and incrementing a counter from the BLLI information element: and read in step 4. If the user information layer 3 protocol data 11, ₁₀ increases after the counter 3 by one to read the data of the octet 8.1 and left shift, then the octet 8.2 Reads, adds, shifts left eight times, reads and adds the next 8.3 octets of data, outputs a 24-bit Organizing Unique Identifier (OUI), and reads the User Information Layer 3 protocol. A fifth step of outputting data 11 ₁₀ or 0 is provided.

Description

Call and Connection Control Method in ATM User Network Interface

1 is a conceptual diagram illustrating an ATM protocol reference model to which the present invention is applied;

2 is a diagram illustrating a mapping structure of an ATM PDU to which the present invention is applied;

3 is a structural diagram showing the format of an ATM cell shown in FIG.

4 is a diagram showing an example of a call processing related message flow in an ATM user network interface (UNI);

5 is a diagram illustrating a general format of call processing related messages in an ATM UNI;

6 shows a general format of information elements included in a message such as FIG. 5;

7 is a block diagram schematically showing a hardware configuration in which the present invention is performed;

8 is a structural diagram showing a format of a BLLI information element to which the present invention is applied;

9 is a flow chart illustrating a method of identifying an organizing unique identifier (OUI) from a setup message received in accordance with the present invention.

* Description of the symbols for the main parts of the drawings *

10: ATM unit 20: AAL5 receiver

30: microcomputer 40: memory

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling call and connection in a user transfer network (ATM) user-network interface (ATM), and in particular, a signal processing related message received from an opposite party. The present invention relates to a method of controlling signals and connections by reading and processing desired information by analyzing signaling messages.

With the rapid development of information society, B-ISDN emerged as the next generation communication network due to the increase of user's communication service demand. In B-ISDN, asynchronous so as to accommodate a wide range of services regardless of band and speed The ATM method, which is the transfer mode, is the basic means of delivery, and a signaling scheme such as Q.2931, B-ISUP, etc. has been proposed for the ATM processing.

That is, in the conventional ISDN (also referred to as narrowband (N) -ISDN), the transmission rate of a channel carrying user information was about 64 Kbps to about 2 Mbps, which made it difficult to satisfy broadband services such as moving pictures. On the other hand, B-ISDN can transmit data at high speed of 100Mbps or more, and can process various information sources such as voice, data, document, and video by using ATM technology.

In the conventional N-ISDN, a signaling method for realizing access control uses a Digital Subscriber Signaling System 1 (DSS1) in the subscriber line section and a NO.7 common line signaling method in the inter-station relay section. DSS1 implements the protocols of Layer 2 and Layer 3 on the D channel, also called Link Access Procedure on the D-channel (LAPD), and is recommended in ITU-T's standards Q.921 and Q.931. In B-ISDN, the Q.93B has been proposed into the draft by adding a function of asynchronous transfer mode (ATM) to Q.931 as a signaling procedure of user network interface (UNI). As a signaling procedure for B-ISDN (ISDN User Part), a draft was proposed.

On the other hand, apart from the B-ISDN standardization centered on ITU-T, the computer and telecommunications industry, academia, government agencies, and research institutes to promote the development of ATM technology and accelerate the development of ATM products and services. A participating ATM Forum was established in October 1991 and worked closely with standardization bodies (ANSI, IEEE, ITU-T, etc.) to support ATM UNI Specication V3.0 (93.9),: ATM B-ICI Specification V1. Draft drafts such as 0 (93.8) and ATM DXI Specication V1.0 (93.8) were enacted. The role of the ATM Forum is not to duplicate the work of international standards bodies, but to complement and accelerate the standardization process by establishing standards that can be implemented in a short period of time.

The present invention is to implement the Q.93B protocol for call and access control in the ATM network according to the ATM User Network Interface Specication announced by the ATM Forum as described above. Its purpose is to provide a way to identify an Organizing Unique Identifier (OUI) after receiving a message.

Organizing unique identifier (OUI) identification method of the present invention for achieving the above object,

Identifying a user organizing unique identifier (OUI) by storing the setup message received through the signal adaptation layer from the ATM network in memory and finding the BLLI information element stored in the setup message using a counter. In the method for

First step of obtaining the length information (Ls) of the setup message:

A second step of obtaining a BLLI information element compared with 95 ₁₀ while increasing the count value of the counter:

A third step of detecting an error by comparing whether the counter value exceeds the message length:

A fourth step of reading a User Information Layer 3 Protocol (UIL3) data having a counter 7 and bit 8 of 11 from the BLLI information element by incrementing a counter; and

If the user information layer 3 protocol data read out in step 4 is 11 _{10, the} counter is increased by 3 to read data of 8.1 octets, shifted to the left, and then read and added to the next 8.2 octets. After shifting, the next 8.3 octets of data are read and added to output a 24-bit organizing unique identifier (OUI), and 0 if the read user information layer 3 protocol data is not 11 _10. It is characterized by having a fifth step.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram illustrating ATM protocol reference models to which the present invention is applied, and is composed of a management plane, a control plane, and a user plane, and the management plane is again hierarchical management and plane It is divided into management. Here, plane management refers to overall management of the system, and hierarchical management refers to management of resources and usage variables and OAM information management.

In addition, the control plane manages call control and access control information, and the user plane manages the transfer of user information. Protocols of control plane and user plane are divided into upper layer, ATM adaptation layer, ATM layer, and physical layer. The functions of each layer are shown in Table 1 below.

[Table 1] Function of each layer in protocol standard model

As shown in Table 1, the ATM method is divided into vertical structures such as a physical layer, an ATM layer, an ATM adaptation layer (AAL), and a higher protocol layer. The AAL layer is divided into a segmentation and a recombination sublayer (SAR). And Reassembly sublayer) and the hunting (CS: Convergence Sublayer) sublayer is divided again, the physical layer is divided into sublayers of physical media (PM) and Transmission Convergence (TC).

In addition, Layer 3 of the control plane is implemented as Q.93B to control CALLs and connections between ATM networks and users. Q.93B is Q.931, ISDN's Layer 3 protocol. The B-ISDN User-network Interface Layer 3 Specification for basec call / bearer control is used to extend the BALL-Bearer protocol.

2 is a diagram illustrating a mapping structure of a protocol data unit (PDU) in an ATM scheme to which the present invention is applied, in which a Q.93B message of layer 3 passes through SSCF, SSCOP, CPCS of a signaling adaptation layer (Signalling AAL 5). It is segmented to 48 bytes (bytes, hereinafter referred to as octets) and is mapped to a number of 53-byte ATM cells after a five-byte header is added to the ATM layer.

3 is a diagram showing the format of an ATM cell shown in FIG. 2, which is divided into a 5-byte header and a 48-byte payload, and is used in a user network interface (UNI). The header structure of the first byte is composed of 4 bits of Generic Flow Control (GFC) and 4 bits of Virtual Path Identifier (VPI), and the second byte of 4 bits of Virtual Path Identifier (VPI). VPI) and 4-bit Virtual Channel Identifier (VCI), and the third byte consists of 8 bits of the virtual channel identifier (VCI), and the fourth byte contains 4 bits of the virtual channel identifier (VCI). 3 bits of payload type (PT) and 1 bit of cell loss priority (CLP: Cell Loss Priority), and the fifth byte of 8 bits of header error control (HEC: Header Error Control). 4 is a flow of messages related to call processing in ATM User Interface (UNI). Such as illustrated figure shows a call processing process between the caller (calling user) and a network (network) and the called party (called rser).

First, a virtual channel connection (VCC) is always formed through a signaling adaptation layer (Signalling ALL) for call and access control, and the messages used for call / access control through the virtual channel are shown in Table 2 below. As shown in the following Table 3, the message for ATM CALL / access control, the message used for the Global Call Reference as shown in Table 3, and the ATM multipoint call / access control as shown in Table 4 below. Separated by the message used.

[Table 2] Messages Used for ATM Call and Access Control

[Table 3] Messages Used for Global Numbers

Table 4. Messages Used for ATM Multipoint Call and Connection Control

Referring to FIG. 4, the call / access control process shows that the originator generates a SETUP message to set up a call, delivers it to the network, starts the timer T303, and enters a call initiated state. .

In this case, the setup message includes a call reference, various information elements required for call processing (for example, called part number, ATM user cell rate, broadband bearer capability, quality of service parameters, etc.) have. If there is no response for the time set by the timer T303, the setup message is retransmitted, and if there is no response even after repeating the predetermined number of times, the call processing is stopped.

After receiving the setup message, the network selects and assigns a valid connection identifier (VPCI / VCI) and then sends a setup message back to the called party.

After receiving the setup message, the called party creates a CALL PROCEEDING or CONNECT message and sends it to the network. If not, the receiver sends a RELEASE COMPLETE message. In this case, the call procedure message is delivered to the network when the call procedure message cannot be reached until the expiration time of the timer T303 after receiving the setup message.The network stops the timer T303 when the call procedure message is received. It enters the Proceeding state, and when the called party transmits the Connect message, it starts the timer T313 and enters the Connect Request state.

Upon receiving the Connect message, the network stops the timer T303 or T310, delivers the Connect Acknowledgment message to the called party, and then delivers the Connect message to the caller and becomes active.

When the called party receives the Connect Acknowledgment message, the receiver stops the timer T313 and becomes Active. When the called party receives the Connect Message, the called party sends the Connect Acknowledgment message and becomes Active.

Through the call processing process as described above, a communication path (connection) given by a connection identifier (VPCI / VCI) is formed between the caller and the called party to exchange data.

On the other hand, the user (receiver or caller) who wants to disconnect from the data transmission is finished or during transmission, generates a release message and starts the timer T 308 to request the network to release the connection and then release it. (Release Request Staste) state, the network, upon receiving the release message, disconnects the virtual channel, informs the other side, delivers the release completion message to the user side, and becomes null.

When the user (sender or called party) requesting the disconnection receives the RELEASE COMPLETE message, the timer T308 is stopped, the pseudonym, the call number, etc. are released, and the status is null.

At this time, the user or the network can generate a status request message at any time to request information about the status of the network or another user, and the user or the network receiving the status request message is the status. ) Create a message to indicate your status.

On the other hand, when adding another party to an existing channel connection, this is requested by an ADD PARTY message, and the user's connection is established in an existing point to multipoint connection. Send DROP PARTY message when released.

5 is a diagram showing a general format of call processing control-related messages in an ATM user interface (UNI), where 1, ..., 8 at the top represents bits, and 1, 2, ... at the right side. ..9, etc represents a byte (octet).

As shown in FIG. 5, the first byte is a protocol discriminator and is 1001 in the ATM UNI, bits 5 to 8 of the second byte are 0, and bits 1 to 4 are CALL REFERENCE. Indicates the length in bytes and is usually 11. The third to fifth bytes indicate the call number, in particular, bit 8 of the third byte indicates a message sent from the sender side as 0 as a flag and a message sent to the caller side as 1 Indicates. The sixth and seventh bytes indicate a message type and a message is allocated according to the sixth byte value as shown in Table 5 below.

Table 5 Message Coding

Further, the eighth and ninth bytes may indicate a message length and may have a maximum length of 64K (2 ¹⁶ ) bytes, followed by a variable length information element from the tenth byte.

6 is a diagram showing the general format of information elements included in an ATM UNI message, where 1, ..., 8 on the top represents bits, and 1, 2, .. 5, ect on the right side are bytes. (Octet).

In FIG. 6, the first byte is an information element identifier, and information elements are classified according to the values as shown in Table 6 below.

[Table 6] Information identifier coding

In the second byte, bit 8 is 1, bits 6 and 7 are coding standards, and bits 1 to 5 are IE instruction fields.

The third byte and the fourth byte indicate a length of information element, followed by the contents of the information element after the fifth byte.

7 is a block diagram schematically showing a hardware configuration in which the present invention is performed, and checks and assembles an error by processing the cells received from the ATM unit 10 and the ATM unit 10 receiving the ATM cells from the ATM network. AAL5 receiver 20 for restoring the message and the message assembled from the AAL 5 receiver 20 for storing the memory in the memory 40 and reading the necessary information by applying the method of the present invention. Is done.

FIG. 8 is a diagram illustrating a format of a BLLI information element to which the present invention is applied, and BLLI (Broadband Low Layer Information) has information of a lower layer for checking compatibility with a higher entity accessed by an originator's address. .

In FIG. 8, the first octet is 1011111, which indicates that it is a BLLI information element as shown in Table 6 above. In the fifth octet, bit 7 and bit 6 are 1, indicating the first layer, and user information in bits 5 to 1 The protocol of layer 1 is recorded, bit 7 and bit 6 are 10 in the sixth octet to indicate the second layer, and the protocol of user information layer 2 is recorded in bits 5 to 1. Also, the 6a and 6b octets are added when indicating the HDLC mode to which the protocol of the user information layer 2 of the 6th octet is applied, where bit 8 of the 6a octet is an extension and bits 7 and 6 represent a mode. Bits 5, 4, 3 and 0 are 0, bits 2 and 1 indicate the use of Q.933, bit 8 of octet 6b represents extension and bits 7 to 1 represent window size. In addition, when the user information layer 2 of the sixth octet is a user specific layer 2 protocol, a sixth octet indicating user specific layer 2 protocol information appears after the sixth * octet. Bit 8 of the seventh octet represents the extension, bits 7 and 6 represent the ID of the third layer as 11, and bits 5 through 1 represent the user information layer 3 protocol. The 7a, 7b, and 7c octets are added when the layer 3 protocol of the seventh octet is a protocol based on X.25, ISO / IEC 8208, or X.223 / ISO 8878 to add bits 7, bits of the 7a octet. 6 indicates a mode, bits 4 to 1 of the 7b octet indicate the default packet size, and bits 7 to 1 of the 7c octet indicate the packet window size.

In addition, if the seventh octet indicates a user specific three-layer protocol, a seventh a * octet indicating the user-specific layer three protocol information is added after the seventh octet.

In addition, when the seventh octet represents ISO / IEC TR 9577, bits 7a ** and 7b ** octets are added, and bits 7 to bit 1 of the 7a ** octet correspond to ISO / IEC TR 9577 IPI (8−8). 2 bits), and bit 7 of the 7b ** octet indicates IPI (1 bit).

The eighth, 8.1, 8.2, 8.3, 8.4, and 8.5 octets are used when the seventh octet represents ISO / IEC TR 9577, and the seventh a ** and sevenb ** octets represent IEEE 802.1 SNAP. Bit 7, bit 6 are SNAP ID, 8.1 octet is OUI octet 1, 8.2 octet is OUI octet 3, 8.3 octet is OUI octet 3, 8.4 octet is PID (Protocol Identifier) octet 1, Eighth octets represent PID octets 2.

9 is a flowchart illustrating a method of identifying an organizing unique identifier (OUI) from a BLLI information element of a setup message received according to the present invention.

In FIG. 9, in step 100, the SETUP message is received in the ATM network by the hardware as shown in FIG. 7 and stored in memory, and then the eighth octet data m7 is stored in the temporary variable a. After storing, shift to the left eight times and add the result to the ninth octet data m8 to obtain the message length Ls. Here, the messages stored in the memory are sequentially indicated by m0, m1, m2, ... from the first octet data, and the length Ls of the message is shown in FIG. 5 in the eighth and ninth octets. Information is contained (100-110).

Subsequently, after loading 9 into the counter and incrementing by 1, it is determined whether the octet data indicated by the counter is 95 ₁₀ , and then the BLLI information element is searched (Search) .In this case, the counter value is 9 to the length of the message obtained in step 110. An error is detected by determining whether the value is greater than the added value (Ls + 9) (120 to 150). That is, the Organizing Unique Identifier (OUI), which is an object of the present invention, is located in the BLLI information element. Find it.

Subsequently, since the current counter indicates an information element identifier (IEI) which is the first octet of BLLI, the current counter value is increased by 2 to store the octet data indicated by the counter in temporary variable a. After shifting left and right, the temporary variable a is added again to the octet data indicated by the counter having the count value increased by one, and the length La of the BLLI information element is calculated (160). ) Is two octets behind the IIE, as shown in Figure 6, so that the counter value is increased by two to read the first byte of the information length, and then the counter is incremented by one to read the second byte of the information length. do.

Subsequently, 01100000₂ is stored in the temporary variable b1 and b2dp 00011111₂ in the temporary variable, and the counter value is increased by 1, the octet data read by the counter is masked, and the end operation is performed with the temporary variable b1. _A ULI3 octet equal to ₁₀ (seventh octet of FIG. 8) is found, and the read data is masked with b2 to determine whether the result is 11 ₁₀ (170 to 230). Here, the meaning of the layer 3 protocol according to the UIL3 data is shown in Table 7 below.

[Table 7] UIL3 protocol

Subsequently, if the UIL3 data is 11 ₁₀ in step 230, the counter is incremented by 3, the data of the 8.1 octet indicated by the counter is read and shifted 8 times to the left, and then the data of the next 8.2 octet is read and shifted. In addition, the added result is shifted 8 bits to the left again, the next 8.3 octets of data are read and added to the shifted result to obtain a 24-bit organizing unique identifier (OUI), and if the USL3I data is 11 ₁₀ . Otherwise, the OUI value is set to 0 and output (240 to 280).

As described above, by analyzing the message received from the ATM network and reading the call and connection control related information, the call and connection control according to the Q.93B protocol can be efficiently executed in the ATM user network interface. have.

Claims (1)

Identifying a user organizing unique identifier (OUI) by storing the setup message received through the signal adaptation layer from the ATM network in memory and finding the BLLI information element stored in the setup message using a counter. In the method for First step of obtaining the length information (Ls) of the setup message: A second step of obtaining a BLLI information element compared with 95 ₁₀ while increasing the count value of the counter; A third step of detecting an error by comparing whether the counter value exceeds the message length: A fourth step of reading a User Information Layer 3 Protocol (UIL3) data of bit 7 and bit 8 from the BLLI information element by incrementing a counter; and If the user information layer 3 protocol data read out in step 4 is 11 _{10, the} counter is increased by 3 to read the data of 8.1 octets and then shifts to the left, and after reading and adding the next 8.2 octets to the left 8 times. After shifting, it reads and adds the next 8.3 octets of data to output a 24-bit organizing unique identifier (OUI), and outputs 0 if the read user information layer 3 protocol data is not 11 ₁₀ . Call and connection control method in the ATM user network interface characterized in that it comprises five steps.