KR19990003702A - First Request Message Processing Method according to Delay Equalization Protocol in ISDN Network - Google Patents

Abstract

The present invention relates to a method of processing an initial request (INIT REQ) message after analyzing an 'information indication primitive' received from a DEQ multi-frame control layer to a delay equalization control layer in a delay equalization (DEQ) protocol structure.

This invention comprises the steps of: a) determining a message by analyzing it when an information display primitive is received; b) transitioning to a new lake state if the message determined in step a is an initial request message; c) stopping the TANULL timer; d) determining whether the received parameter is acceptable; e) assigning a new group ID (GID) and starting a TAINIT timer if the determination result is acceptable in step d; f) generating and transmitting an INIT ACK message and then transitioning to an INIT REC state; And g) if the determination result is not acceptable in step d, generates an initial request response (INIT ACK) message, starts a TADISC timer, and transitions to a DISC REQ state. The amount of code can be improved and the amount of code can be reduced when the present invention is implemented in software.

Description

First Request Message Processing Method according to Delay Equalization Protocol in ISDN Network

The present invention relates to a delay equalization protocol (Delay EQualization Protocol) for bonding a plurality of 56/64 kbit / s channels for delivering broadband data in the ISDN, in particular, DEQ In the protocol structure, the present invention relates to a method of processing an initial request message after analyzing an 'information indication primitive' received from a DEQ multi-frame control layer to a delay equalization control layer.

As the information society has progressed, communication demands have diversified, and the media handled by communication networks such as voice, data, and video have also diversified, so that individual networks established by services cannot provide efficient services. Therefore, the ISDN, which can integrate and digitize individual networks established by services and provide comprehensive services, has emerged. These ISDNs are designed to unify various terminals in order to accommodate users and manganese. The interface is standardized by Digital Subscriber Signaling System (DSS1), and the interface between the network and the network is also standardized by No.7 Common Line Signaling (CCS).

DSS1, which is a signaling method of the user-network interface (UNI) of ISDN, is implemented in layers 1 through 3 by an OSI (Open Systems Interconnection) reference model, as shown in FIG. The outlines and their relationship to the ITU-T Recommendations are given in Table 1 below.

Digital subscriber line signaling Layer Function Outline Corresponding recommendations Layer 1 Electrical physical conditions I.430, I.431 Layer 2 Link setting control and error control for message transmission Q.920, Q.921 Layer 3 Set up, opening Q.930, Q.931

Referring to FIG. 1, a first network terminal device NT1 located in a house (or building) is connected to an ISDN exchange located in a telephone station through a subscriber line, and an ISDN terminal TE1 is connected to an ISDN terminal in a building through an S / T point. Alternatively, the second network terminal device NT2 is connected to the first network terminal device NT1.

Here, 'NT1' (network terminal device 1) is a transceiver in a house for transmitting a digital signal to a subscriber line, and 'NT2' (network terminal device 2) is a device corresponding to a private branch exchange (PBX). The terminal TE1 can be accommodated, and the TE1 is an ISDN standard terminal that is directly connected to NT1 and may be connected via NT2, and an existing terminal that does not have an ISDN corresponding function, 'TE2' is not shown. It is connected to the ISDN network through a terminal adapter (TA).

In addition, the interface point between NT1 and NT2 is called 'T' point, and the interface point between NT2 and TE1 is called 'S' point. Since the interface specification of S point is determined to be based on T point, TE1 is The point to be connected is called the 'S / T' point.

In addition, the subscriber terminal, such as the ISDN terminal, is connected according to the above-described protocols of the layers 1 to 3 so as to be connected to the ISDN exchange, and the recommendations for defining such a connection are shown in Table 1 above.

In other words, in Table 1, Layer 1 is a user-network interface of the physical layer recommended by ISDN Recommendations I.430 and I.431, and has a basic interface of 2B + D access and a primary group speed interface of 23B + D or 30B + D. In the basic interface, the frame structure consists of 48 bits of 250 ms.

Layer 2 is commonly referred to as Link Access Procedure on the D channel (LAPD), which first adopts HDLC's BALANCE mode, which is the standard for the standardized data link layer, and its basic format is Flag. And an address field, a control field, an information field, a frame check sequence (FCS), and a flag.

Layer 3 controls the establishment, maintenance, and release of communication paths required by the network and packet switched services, and various additional service requests, which are received from the other side through layers 1 and 2. The message is analyzed and the call setup related message is formed and sent to the other party through the lower layer. General content relating to Layer 3 is described in Q.930, and call processing procedures for basic calls are recommended by Q.931.

In order to implement an ISDN terminal, the functions described above must be implemented. A protocol is defined between appointments in the same layer, and a primitive is defined in logical exchange between upper and lower layers. That is, each layer has entities that implement the functions of the layer, and these entities are configured to exchange information between upper and lower sides through primitives.

These primitives are divided into four types: REQUEST, INDICATE, RESPONSE, and CONFIRM. Most of the primitives related to data transfer are REQUEST passed from the upper layer to the lower layer. ) Primitives, and INDICATE primitives passed from the lower layer to the upper layer.

The CONFIRM primitive is a primitive that notifies the upper layer when the lower layer is obliged to respond to the specific request primitive from the upper layer, and the response primitive is a specific indication primitive from the lower layer. This is a primitive to inform lower layers when the higher layer is obliged to respond.

Channels provided by ISDN include 64 Kbps B channel, 16 Kbps D channel, 384 Kbps H0 channel, and 2.048 Mbps H1 channel. The basic interface provided by the combination of these channels is defined as 2B + D. The primary group interface is defined as 23B + D or 30B + D. However, when a wideband communication connection is required for a video service in narrowband ISDN, multiple (N) 56 or 64 kbit / s channels may be used in combination. That is, if the basic interface or the primary group interface has a fixed bandwidth but various bandwidths are required according to the service, the ISDN network may provide N x 56/64 kbit / s band.

Thus, in order to provide N x 56/64 kbit / s, bonding of 56/64 kbit / s channels set independently of each other is required. In this case, since each 56/64 kbit / s channels are individually connected by the digital switching network, each channel has an individual delay. Therefore, the core technology for multiple coupling is related to delay equalization, so to provide N x 56/64 kbit / s, the delay equalization protocol must be followed. That is, the delay equalization protocol is also called a bonding protocol, and is a protocol for equalizing delay between channels when combining N 56/64 kbit / s channels.

As shown in FIG. 2, the delay equalization protocol is composed of a Call Control (21) layer, a Delay Equalization Negotiation Control (22) layer, and a Delay Equalization Multiframe Control (23) layer. The user data is transmitted from the APPLICATION 21 layer, and primitives are transferred to each other as shown in FIG. 3. In FIG. 2, the DEQ multiframe control layer 23 is connected to the physical medium through each channel control and physical medium dependency (PMDL) layer 24a to 24c below.

Referring to FIG. 3, primitives transferred from the call control layer 25 to the DEQ negotiation control layer 22 include DQ_INIT_REQ, DQ_CONN_REQ, DQ_DISC_REQ, DQ_DEL_CH_REQ, DQ_ADD_CH_REQ, DQ_ABORT_REQ, DQ_RE_RES_REQ_, DQ_RL_RELL_REQ_, DQ_RL_RELL, and so on. The timers used include TCID_EXP, TCINIT_EXP, TAINIT_EXP, TANULL_EXP, TCADD01_EXP, and TAADD01_EXP. And a primitive transferred to the DEQ negotiation control layer (22) of the control layer 25 from the DQ_INIT_IND, DQ_DISC_IND, DQ_DISC_CONF, DQ_DEL_CH_CONF, DQ_DEL_CH_IND, DQ_DEL_CH_FAIL_IND, DQ_ADD_CH_IND, DQ_ADD_CH_CONF, DQ_ADD_CH_FAIL_IND, DQ_CID_FAIL_IND, DQ_LLOS_IND, DQ_RLOS_IND, DQ_ABORT_CONF, DQ_LL_IND, DQ_LL_OFF_IND , DQ_RL_IND, DQ_RL_OFF_IND, and so on. In this case, xx_xxxx_REQ represents a request primitive, xx_xxxx_IND represents an indication primitive, xx_xxxx_RES represents a response primitive, and xx_xxxx_CFM represents an confirm primitive. CC_xxxx_xxx is a primitive between the DEQ multiframe control layer and the DEQ negotiation control layer, and DQ_xxxx_xxx is a primitive between the DEQ negotiation control layer and the call control layer.

Primitives transmitted from the DEQ negotiation control layer 22 to the DEQ multiframe control layer include CC_ADD_REQ, CC_INFO_REQ, and CC_DEL_REQ. The timers used in this layer include TAFA_EXP, TXDEQ_EXP, and DEQ negotiation control layer in the DEQ multiframe control layer. Primitives to be transmitted include CC_LSYNCH_IND, CC_RSYNCH_IND, CC_RSYNCH_FAIL_IND, CC_INFO_IND, CC_FAIL_IND, CC_LLOS_IND, and CC_RLOS_IND. These primitives are described in detail in the Interoperability Specification for Nx56 / 64 kbit / s, version 1.1, issued by the Bonding Consortium, dated September 2, 1993, so further explanation is omitted.

Next, when an information indication (CC_INFO_IND) primitive for delivering a message is received, all received messages must be analyzed / processed in order to process a message according to each mode. When an initial request message is received, as shown in FIG. If is not acceptable, there is a problem that the processing procedure is complicated and the time is delayed because the processing flow is divided into two branches. That is, referring to FIG. 9, in the conventional first request message processing procedure, if the parameter received from the other party cannot accept, the called terminal determines in step 908 to perform step 909 or performs step 910, step 911, and step 912. .

Accordingly, the present invention has been proposed to solve the above-mentioned conventional problems. When the information request primitive is received and the initial request message is determined, the first request message processing is quickly performed in a single path after determining whether the parmable is acceptable. The purpose is to provide a method.

In order to achieve the above object, the present invention provides a call control scheme in which a delay equalization protocol for multiplexing N 56/64 kbit / s channels and equalizing the delay of the combined channels to provide a broadband required for service. When the calling terminal transfers the information primitive to the called terminal for call setup, including the layer, the delay equalization negotiation control layer, and the delay equalization multi-frame control layer, the information primitive received by the delay equalization negotiation control layer of the called terminal is analyzed. A comprehensive information communication network adapted to process a message, the method comprising: a) analyzing an information display primitive to determine a message; b) transitioning to a new lake state if the message determined in step a is an initial request message; c) stopping the TANULL timer; d) determining whether the received parameter is acceptable; e) assigning a new group ID (GID) and starting a TAINIT timer if the determination result is acceptable in step d; f) generating and transmitting an INIT ACK message and then transitioning to an INIT REC state; And g) starting the TADISC timer after generating an initial request response (INIT ACK) message if the result of the determination in step d is not acceptable, and transitioning to a DISC REQ state. do.

1 shows a user-network connection of an ISDN;

2 shows a reference architecture of a delay equalization protocol;

3 is a schematic diagram illustrating primitives carried between three layers for implementing a delay equalization protocol in ISDN,

4 illustrates a frame structure in a delay equalization protocol;

5 shows an information message format;

6 is a flowchart illustrating a process of establishing a call in a delay equalization protocol;

7 is a schematic diagram illustrating a flow of processing information display primitives in a delay equalization protocol;

8 is a flowchart illustrating a method of processing an initial request message according to the present invention;

9 is a flowchart illustrating a conventional method of processing an initial request message.

* Explanation of symbols for main parts of the drawings

21: Application Layer 22: Delay Equalization Negotiation Control Layer

23: delay equalization multi-frame control layer 24a, 24b, 24c: channel control physical layer

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

FIG. 2 is a diagram illustrating a reference architecture of a delay equalization protocol, FIG. 3 is a schematic diagram illustrating primitives transmitted between three layers for implementing a delay equalization protocol in ISDN, and FIG. 4 is a diagram illustrating a frame structure in a delay equalization protocol. Figure is shown. 5 is a diagram illustrating an information message format.

Referring to FIG. 2, as described above, the delay equalization protocol is implemented by the call control layer 25, the delay equalization negotiation control layer 22, and the delay equalization multiframe control layer 23. As shown, various primitives are being delivered.

In order to deliver the serial bit stream coming down from the application layer by multiple combinations of N 56/64 kbit / s channels, as shown in FIG. 4, framing is required, and the framed data is allocated to each bearer channel. Will be delivered.

As shown in FIG. 4, the framing structure according to the delay equalization protocol is composed of 256 octets, and 64 frames are gathered to form one multiframe. The octets in each frame are numbered from 1 to 256, and four overhead octets are used for information exchange and framing. That is, in one frame, octet 64 is assigned to a frame alignment word (FAW), octet 128 is assigned to an information channel (IC), and octet 192 is assigned to a frame count (FC). Is assigned. Octet 256 is assigned to the CRC.

Looking more closely at each overhead octet, the FAW (octet 64) has a fixed value of 0001,1011, the IC (octet 128) is used for information exchange between terminals, and the FC (octet 192) is used between individual channels. It is used to measure relative delay changes and is a modulo 64 counter (6 bits), which is incremented by 1 per frame. In CRC (octet 256), bit 1 and bit 8 are defined as 1, bit 2 is defined as A, bit 3 as E, and bits 4 to 7 are used for CRC4. Here, A is an alignment bit, indicating that the remote terminal has lost framing, and E is an error bit, indicating that the remote terminal has detected a CRC4 error.

This overhead distributes the overhead octets across all channels as evenly as possible by allowing them to be distributed over each channel at 125usec intervals.

On the other hand, the information channel message format is composed of 16 octets, as shown in Figure 5 to transfer control information between the two terminals. Referring to FIG. 5, the first octet of the information channel frame has an integer value of 0111 1111 as an alignment, and the second octet is a channel identifier (Channel ID: CID). Used to identify individual channels in the setup. CID is a 6-bit binary number encoded with a number in the range of 0 to 63, and a CID of 0 indicates parameter negotiation.

The third octet of the information channel message is the group identifier (GID), which is used to uniquely identify a group of bearer channels that associate a particular call. Octets 4 (bits 2 through 4) indicate an operation mode (MODE), where 0 represents an operation mode 0, 1 represents an operation mode 1, 10 represents an operation mode 2, and 11 represents an operation mode 3. In octet 5 (bits 2 to 4) of FIG. 5, RMULT is a rate multiplier, which, together with SUBMULT in octet 6, defines the bandwidth of the application for the call, and BCR represents the bearer channel rate, with 0 being 56 kbit / s-based, 1 indicates 64 kbit / s. In octet 6, the MFG, if set to 1 as the manufacturer ID flag, indicates that the manufacturer ID is loaded in the digit fields of octets 10-16. In octet 8, RI is a remote indicator for informing the counterpart of whether the delay equalization has been completed. In octet 7, RL REQ represents a remote loopback request and RL IND represents a remote loopback indication. REV represents the revision level, octet 8 represents the subaddress, and octet 9 represents the transfer flag as XFLAG. Octet 10 to octet 16 indicate telephone number dial digits (Digit-1 to Digit-7).

On the other hand, Figure 6 is a sequence diagram showing the flow of messages in call setup, Figure 7 is a flow chart illustrating a process of setting up a call in the delay equalization protocol.

First, the terms used in the present invention are briefly defined as follows. The answering terminal is a terminal for receiving a call, and the calling terminal is a terminal for initiating a call. The bearer channel is a channel provided by a network used for data transmission, for example, a B channel of BRI or PRI, a T1 DS0, etc., and an information message is a 16 octet message as shown in FIG. It is conveyed through the information channel of the multiframe structure or by the full bandwidth of the master channel during the initial parameter negotiation. Master channel is a channel used to communicate control information between each end. This channel is called call setup, channel delete, channel addition, remote loopback. It provides a path for initial parameter negotiation for loopback, call disconnection, etc.

In case of using the delay equalization protocol, four operation modes are defined. Operation mode 0 supports initial parameter negotiation and DIRECTORY NUMBER exchange in the master channel. When call setup is completed, data is transmitted without delay equalization. This mode is useful when the calling endpoint requires a phone number, but delay equalization must be done by other means. That is, in operation mode 0, no delay equalization is performed.

Operation mode 1 is a basic (common) mode of the delay equalization protocol that supports the user data rate multiplied by the bearer rate, and does not provide an in-band monitoring function for an error. Thus, the overhead octets for detecting errors are eliminated after the call is aligned, and one or more on-channel error conditions that prevent all system synchronization are not automatically recognized after the call is ACTIVE.

Mode 2 supports user data rates that are 63/64 times the bearer rate. This mode of operation provides in-band monitoring and the user data rate is the remaining band after the insertion of the overhead octets. That is, the error is checked while the multiframing structure is maintained even after being activated.

In operation mode 3, user data rates are integer multiples of 8 kbit / s, including Nx56 and Nx64. All channels use the same bearer channel rate and provide in-band monitoring to support continuous equalization (CRC) for delay equalization and end-to-end bit error test. The overhead octets required for error monitoring are provided with additional bandwidth. Thus, a sufficient user data rate can be provided, and an overhead octet is included in each bearer channel.

Based on the understanding of such a definition, a process of actually setting up a call according to a bonding protocol and transmitting data will be described with reference to FIG. 6.

When a high speed serial data stream comes down from the application layer, data is transmitted through N bearer channels. Each bearer channel is then individually connected by digital network exchange. On the originating terminal side, the user data is framed according to the framing structure as shown in FIG. 4 and then delivered to each bearer channel. On the destination terminal side, the received data is synchronized and aligned to restore the original bit stream. do. Framing and synchronization should be transparent to all applications.

In the delay equalization protocol, the entire operation is performed by the call establishment process, the process of adding the bandwidth to the existing call after the channel connection is established by the call establishment, and the bandwidth is deleted from the existing call in order to reduce the user data without sudden degradation of the entire call. There is a process.

The call setup process involves establishing an initial channel (called a master channel), establishing N-1 other channels by multiple combining after the initial channel is established, and implementing delay equalization when each channel is connected. There is a delay equalization (DEQ) process.

6 is a flowchart illustrating a call setup process, wherein the initial channel setup includes steps 601 to 604, the multiple combining process includes steps 605 and 606, and the DEQ process includes steps 607 to 609. After the call setup is made, user data of the application layer is allocated to each channel through a predetermined framing process and transmitted.

The initial call setup procedure begins with the connection of the first channel on an N x 56/64 kbit / s call. This channel is called the master channel (601). The parameter negotiation process is performed by this channel, and the originating terminal makes additional calls after the complete negotiation process is completed. Once the originating terminal is connected to the master channel, the originating terminal repeatedly transmits an information message (see FIG. 5) with a channel identifier (CID) set to 0 to start a negotiation process (602). The TCINIT_EXP timer is then started. At this time, the originating terminal transmits by setting each parameter of the information message to a specific value. The group identifier (GID) is set to 0, and RI = 0 and RL = 0, respectively. In the first information message, the calling terminal sets the MFG to 1, transmits the manufacturer's ID by including the ID in the digit field, and the XFLAGs are all set to 1. If the calling terminal fails to transmit the manufacturer ID, the MFG flag is set to 0 and the digit fields are all set to 1. If the calling terminal supports sub-addressing, the sub-address area includes the sub-address, and if not, the corresponding area is set to all zeros.

When the called terminal is received and connected with the other party, it transmits all 1s to the channel, starts the TANULL_EXP timer, and searches for multi-frame information or information message.

Once the incoming call detects a valid information message, the channel is considered the master channel of the new call and the TANULL_EXP timer is stopped. If multiple frames are detected, the called terminal regards the current call as an additional channel, stops the TANULL_EXP timer, and uses a group identifier (GID) to identify the current call.

On the master channel of the new call, if the called terminal accepts the requested parameter, it returns the same value as it received and starts the TAINIT_EXP timer. If not accepted, the RMULT and SUBMULT = 0 return with the valid mode value in the information message, start the TA DISC primitive or return a different set of parameters, and start the TAINIT_EXP timer. In the additional channel of the current call, the called terminal allocates the group identifier (GID) of the call and returns the call in the group identifier (GID) area. The call can be identified in the call received by the group identifier to the called terminal. At this time, the XFLAG region of the information message is set to one.

When the called terminal determines the manufacturer ID return, the MFG flag of the information message is set to 1, puts the ID in the digit field, and returns the information message with other parameters as the initial response to the calling terminal. If the destination terminal does not want to return the manufacturer ID, the MFG flag of the information message is set to 0 and the digit field is set to 1.

The calling terminal detects that the response is from the called terminal when CID = 0 from the called terminal and the MODE receives a valid information message. Therefore, the calling terminal analyzes the parameters of the received information message and performs the truncation procedure if it cannot accept or cannot accept the parameters requested by the called terminal. If the MFG flag of the received information message is 1, the manufacturer ID contained in the digit field is received. If the MFG flag is 0, the digit area is ignored, and the XMFG flag is ignored.

Subsequently, the calling terminal sets the CID = 0 and the transmission flag to 1 and transmits an information message with all the digit fields to 1 to request the initial telephone number (603).

After the initial response, when the called terminal receives the information message with XFLAG set to 1, it sets the XFLAG of the information message to 1 and carries the information number again with a telephone number in the digit field. In this way, the calling terminal and the called terminal exchange telephone numbers. If the number of channels is N, exchange N-1 numbers.

That is, when the calling party receives DQ_CONN_REQ from the call control layer to the DEQ negotiation control layer, the DEQ carries an INIT REQ message on the CC_INFO_REQ primitive and delivers it to the called party. When the called party receives the INIT REQ message through CC_INFO_IND, the called party sends the INIT ACK message to the called party. The calling party sends a DN REQ message to the called party and requests a phone number. When the called party receives a DN REQ message, the called party generates a DN RESP message and sends the telephone number to the calling party. This telephone number exchange operation is repeated N-1 times (603).

Subsequently, when the telephone number exchange is completed, the calling terminal transmits an information message of CID = 1 to signal the end of the negotiation process, and when the called terminal receives an information message of CID = 1, the calling terminal returns an information message of CID = 1 and adds it. Announce that the channel is ready for acceptance. At this time, the called terminal stops the TAINIT_EXP timer and starts the TAADD01_EXP timer (604, 605).

When the originating terminal receives the information message with CID = 1, the TCINIT_EXP timer is stopped, the TCADD01_EXP timer is started, and connection to the additional channel is started (606).

Once each channel is connected, each terminal stops the TXADD01 timer. When each channel is ready, the terminating terminal starts the TXDEQ_EXP timer and uses a frame counter (FC) to measure the relative delay balance between individual channels of Nx56 / 64 kbit / s (607). In addition, since the incoming call arrival order cannot be guaranteed to be the same as the call establishment order, each terminal uses the received CID to align the channel (607). Each terminal is rearranged, and if the delay is equalized between channels for the call, RI = 1 of the information message is transmitted in all channels of other terminals (608). In each of the modes 2 and 3, when each terminal receives RI = 1 as an information message in all channels, it will assume that call setup is completed, and the TXDEQ_EXP timer is stopped and user data transmission is started (609, 610).

In operation mode 1, when each terminal receives RI = 1, it will transmit a ready indication for data transmission to A = 0 in all bearer channels. When A = 0 is transmitted, each UE waits for A = 0 reception on each bearer channel. When each terminal receives A = 0 in the bearer channel, it stops transmitting the framing pattern and considers the call setup to be completed. At this time, each terminal will remove the multiframe structure from all channels. In addition, after transmitting RI = 1 and A = 0, if the frame synchronization loss is detected in all bearer channels before the UE receives A = 0, the call setup is considered complete and the multiframe structure is removed from the bearer channel. In modes 2 and 3, each terminal continuously monitors each channel of the call for delay equalization and frame alignment. Each terminal also monitors bit errors between terminals. Each terminal transmits RI = 1, and upon detecting RI = 1, each terminal stops the TXDEQ_EXP timer.

On the other hand, when a call is set up by multiple combining in this way, when the information display primitive is received from the DEQ multiframe control layer to the DEQ negotiation control layer, the flow of processing this is shown in FIG. 7.

Referring to FIG. 7, when an information display primitive (CC_INFO_IND) is received from the DEQ multiframe control layer (701), the received message is analyzed / determined in the message analyzing step 702, and the corresponding processing routine is determined according to the determined message. 710 to 729 are driven to process the corresponding message. In this case, the types of messages used for call control are as follows: INIT REQ, INIT ACK, DN REQ, DN RESP, CID = 1, ADD CH, ADD CH ACK, ADD CH REJ, DISC, DISC ACK, DEL CH, DEL CH There are approximately 19 species such as ACK, DEL CH REJ, RL REQ, RL IND, RL OFF REQ, RL OFF IND, IC TOO LONG, and C FILD ERR.

When the message is determined by receiving the information display primitive as described above, if it is determined as the first request message, the flow of the present invention shown in FIG. 8 is performed.

Referring to FIG. 8, if an information display primitive is received from the calling terminal to the called terminal and an INIT REQ message is received in step 801, the terminal transitions to a call reception state in step 802 and then TANULL in step 803. Stop the timer. In step 804, it is determined whether the received parmator is acceptable. If it is acceptable, a new group ID is assigned in step 805, and the TAINIT timer is started. In step 806, an INIT ACK message is generated and transmitted to the called party, and in step 808, the terminal transitions to the INIT REC state. If the parameter is not acceptable in step 807, an INIT ACK message is generated in step 808, and then the TADISC timer is started in step 809, and the state transitions to the DISC REQ state in step 810.

As described above, when the initial request message is received through the information indication primitive in the delay equalization protocol, the response speed can be improved in a single path according to the present invention, thereby improving the processing speed when setting up the call, and implementing the present invention in software. This has the advantage of reducing the amount of code.

Claims (1)

Delay equalization protocols for multiplexing N 56/64 kbit / s channels to equalize the bandwidth required for service and equalizing the delay of the combined channels include call control layer, delay equalization negotiation control layer, and delay equalization multiframe. In the integrated information communication network including the control layer, when the calling terminal transmits the information primitive to the called terminal for call establishment, the information primitive received by the delay equalization negotiation control layer of the called terminal is analyzed to process the corresponding message. a) analyzing the information indication primitive when it is received to determine a message; b) transitioning to a new lake state if the message determined in step a is an initial request message; c) stopping the TANULL timer; d) determining whether the received parameter is acceptable; e) assigning a new group ID (GID) and starting a TAINIT timer if the determination result is acceptable in step d; f) generating and transmitting an INIT ACK message and then transitioning to an INIT REC state; And g) starting the TADISC timer after generating an initial request response (INIT ACK) message if the result of the determination in step d is not acceptable, and transitioning to a DISC REQ state. First request message processing method according to delay equalization protocol in ISDN communication network.