KR19990047467A - Phone Number Response Message Processing Method According to Delay Compensation Protocol of Integrated Communication Network - Google Patents

Abstract

The present invention relates to a delay compensation protocol (DEQ) for delivering broadband data in ISDN, and to a method for processing a master channel identification message that is sent to a called party when a call is set up or an additional channel / delete channel is set up.

The present invention compares the required number of channels with the number of telephone numbers when the current status of the calling party that has received the telephone number response message is a telephone number waiting state. Transmits = 1 over the entire bandwidth and transitions to the initial call setup CID = 1 state, and if the requested channel number of channels and the number of phone numbers are not the same, sends a phone number request message back to the called party and transitions to the phone number waiting state. do.

Conventionally, there is a disadvantage in that duplicate codes are generated by processing a message (primitive) around a state transition and a processing speed is slow. However, the present invention has a processing procedure of each state for the same primitive by processing the message (primitive). If they are similar or identical, it is easy to merge these processing procedures and the code size can be reduced to speed up the processing.

Description

Process of Directory numbers response message according to delay equalization protocol in ISDN

The present invention relates to a Delay Compensation Protocol (DEQ) for delivering broadband data in an ISDN. It is about a method.

Comprehensive information and communication network has emerged to provide comprehensive services by integrating and digitalizing individual networks established by services. In the Integrated Information Network (ISDN), the interface between the user and the network is standardized by Digital Subscriber Signaling System (DSS1) in order to uniformly accommodate various terminals, and the interface between the network and the network is also No. 7 It is standardized by common line signaling (CCS). DSS1, which is a signaling method of user-network interface (UNI) of ISDN, is implemented in layers 1 through 3 by an OSI (Open Systems Interconnection) reference model as shown in Table 1 below.

Digital subscriber line signaling Layer Feature Overview 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. Subscriber terminals, such as ISDN terminals, are connected according to the protocol of Layer 1 to Layer 3 in order to be connected to an ISDN exchange, and the recommendations defining such connections are shown in Table 1 above.

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 in 250us units. 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. The message is analyzed, and a call establishment 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 the ISDN terminal, the functions described above should be implemented. In this case, "protocol" is defined as an appointment between the same layers, and "primitive" is defined as a logical exchange between upper and lower layers. Each layer has entities that implement the functionality of that layer, and these entities are supposed to exchange information up and down through primitives.

These primitives are divided into four types: REQUEST, INDICATE, RESPONSE, and CONFIRM. Most primitives related to data transfer consist of a request primitive passed from a higher layer to a lower layer, and an INDICATE primitive passed from a lower layer to a higher layer. The CONFIRM primitive is a primitive that notifies the upper tier when a lower tier is obliged to respond to a particular request primitive from a higher tier, and the RESPONSE primitive is for a particular indication primitive from the lower tier. It is a primitive to inform the lower class when the higher class is obliged to respond.

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

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 key technology for multiple coupling is related to delay equalization, so follow the "Delay EQualization protocol" to provide N x 56/64 kbit / s. The delay compensation protocol, also called a bonding protocol, is a protocol for equalizing delay between channels when combining N 56/64 kbit / s channels.

As shown in FIG. 2, the delay compensation protocol is composed of a Call Control (25) layer, a DEQ negotiation control (22) layer, and a DEQ multiframe control (23) layer. The user data received from the APPLICATION layer 21 is transmitted, and various 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 an initial request (DQ_INIT_REQ), a connection request (DQ_CONN_REQ), a disconnect request (DQ_DISC_REQ), and a channel deletion request (DQ_DEL_CH_REQ). , Channel addition request (DQ_ADD_CH_REQ), abandonment request (DQ_ABORT_REQ), and the timers used in the DEQ negotiation control layer 22 include TCID_EXP, TCINIT_EXP, TAINIT_EXP, TANULL_EXP, TCADD01_EXP, and TAADD01_EXP. Primitives transmitted from the DEQ negotiation control layer 22 to the call control layer 25 include DQ_INIT_IND, DQ_DISC_IND, DQ_DISC_CONF, DQ_DEL_CH_CONF, DQ_LL_OFF_IND, DQ_RL_IND, and DQ_RL_OFF_IND.

In this case, xx_xxxx_REQ represents a request primitive, xx_xxxx_IND represents an indication primitive, xx_xxxx_RESP represents a response primitive, and xx_xxxx_CONF represents an confirm primitive. CC_xxxx_xxx is a primitive between the DEQ multiframe control layer 23 and the DEQ negotiation control layer 22, and DQ_xxxx_xxx is a primitive between the DEQ negotiation control layer 22 and the call control layer 25.

Primitives transmitted from the DEQ negotiation control layer 22 to the DEQ multiframe control layer 23 include CC_ADD_REQ, CC_INFO_REQ, and CC_DEL_REQ. The timers used in the layer include TAFA_EXP and TXDEQ_EXP. Primitives transmitted from the DEQ multiframe control layer 23 to the DEQ negotiation control layer 22 include CC_LSYNCH_IND, CC_RSYNCH_IND, CC_RSYNCH_FAIL_IND, CC_INFO_IND, CC_FAIL_IND, CC_LLOS_IND, CC_RLOS_IND, and the like. These primitives are described in detail in the "Interoperation Specification for Nx56 / 64 kbit / s (Version 1.1)" issued by the Bonding Consortium, dated September 2, 1993, and will not be described in detail.

On the other hand, the conventional scheme for handling such primitives in Layer 3 has been proposed in Appendix A (ANNEX A) of the recommendation, which is roughly summarized as shown in FIG.

Referring to FIG. 8, the conventional method first determines a state of a corresponding layer (S1), and when a primitive or a message is received (S2), the corresponding primitive or message processing routine according to the determined state is driven (S3). If the message received in step S2 is a DN RESP message, it has a different processing routine according to various states for the DN RESP message in step S3. As such, there is a hassle to separate processing routines according to the current state and find another processing procedure according to the message of the state.

Therefore, the primitive processing as shown in FIG. 8 is duplicated if the processing is similar or the same in different states for the same message (or primitive) in a finite state machine (FSM) structure in which state transition rules are defined. Can be. Even if code duplication is avoided by a subroutine call method, it is difficult to construct a subroutine that is appropriately divided over several states, and there is a problem that the processing speed decreases according to the subroutine call procedure.

Accordingly, the present invention has been proposed to solve the above-mentioned conventional problems, and the processing procedure for the same message (or primitive) in the delay compensation protocol is similar to or similar to the state using the same point. In view of the above, an object of the present invention is to provide a method for processing a telephone number response message, which simplifies the processing procedure.

The telephone number response message processing method of the present invention for achieving the above object comprises the steps of: (a) receiving a telephone number response message; (b) determining a current state of the calling party that has received the telephone number response message; (c) when the calling party is in a phone number waiting state, increasing the number of telephone numbers by +1 and comparing the required number of channels with the number of telephone numbers; (d) If the number of channels requested is the same as the number of telephone numbers, the channel identification message CID = 1 is transmitted over the entire bandwidth and the initial call setup CID = 1 state is transmitted. The requested number of channels and the number of telephone numbers are not the same. If not, characterized in that it comprises a step of sending a phone number request message to the called party and transition to the phone number waiting state.

1 shows a user-network connection of an ISDN;

2 is a diagram illustrating a reference architecture of a delay compensation protocol;

3 is a schematic diagram illustrating primitives carried between layers to implement a delay compensation protocol in ISDN,

4 is a diagram illustrating a frame structure in a delay compensation protocol;

5 shows an information channel format;

6 is a flowchart schematically illustrating a call setup process in a delay compensation protocol;

7 is a flowchart illustrating a phone number response message processing procedure according to the present invention;

8 is a flowchart illustrating a conventional message / primitive processing procedure.

Explanation of symbols on the main parts of the drawings

21: application layer 22: delay compensation negotiation control layer

23: delay compensation multiframe control layer 24a, 24b, 24c: channel control physical layer

25: call control layer

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

2 is a diagram illustrating a reference architecture of a delay compensation protocol, and FIG. 3 is a schematic diagram illustrating primitives carried between three layers for implementing a delay compensation protocol in ISDN. 4 is a diagram illustrating a frame structure in a delay compensation protocol, and FIG. 5 is a diagram illustrating an information channel format.

Referring to FIG. 2, the delay compensation protocol is implemented by a call control (CC) layer 25, a delay compensation negotiation control (DEQ NC) layer 22, and a delay compensation multiframe control (DEQ MC) layer 23. As shown in FIG. 3, various primitives are transmitted between the layers.

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 compensation 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 a cyclic redundancy check (CRC).

In particular, the information channel (IC) message 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 a constant value of "0111,1111" as an alignment (ALIGN), and the second octet may dial N calls simultaneously as a channel ID (Channel ID: CID). It is used to identify individual channels in each call 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 a group identifier (GID), which is used to uniquely identify a group of bearer channels associated with a particular call. Octet 4 (bits 2 through 4) indicates the operation mode (MODE), where "0" indicates operation mode 0, "1" indicates operation mode 1, "10" indicates operation mode 2, and "11" indicates operation mode. 3 is shown, respectively.

In octet 5 (bits 2 to 4) of FIG. 5, "RMULT" is the rate multiplier, which, together with "SUBMULT" in octet 6, defines the bandwidth of the application for the call, and the BCR represents the bearer channel rate. 0 indicates 56kbit / s base and 1 indicates 64kbit / s base. In octet 6, " 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 7, " RI " is a remote indicator for informing the counterpart of whether the delay compensation is completed, and a value of 1 indicates an equal delay (delay compensation completion). In octet 7, "RL REQ" indicates a remote loopback request and "RL IND" indicates 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).

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 a call establishment process, a process of adding bandwidth to an existing call after a channel connection is established by call establishment, and deleting bandwidth from an existing call in order to reduce user data without sudden degradation of the entire call. There is a process.

The call setup process is largely the process of setting up an initial channel (this is called a master channel), adding N-1 channels by multiple combining after the initial channel is established, and implementing delay equalization when each channel is connected. It consists of three parts of the DEQ process.

6 is a flowchart schematically illustrating a call setup process in a delay compensation protocol.

In FIG. 6, 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, the user data of the application layer is allocated to each channel through a framing process in an active state.

Initially, the master channel is initialized (601), and call parameters are negotiated (602).

The initial call setup procedure begins with the connection of the first channel on an N x 56/64 kbit / s call. This first channel is called the master channel. The parametric negotiation process is performed through the master channel, and the calling terminal makes an additional call after the complete negotiation process is completed. Once the calling terminal is connected to the master channel, the calling terminal repeatedly transmits the information message with the channel identifier (CID) set to 0 and starts the negotiation process (602). At this time, the calling terminal transmits each parameter of the information message to a specific value. The group identifier GID = 0, RI = 0, and RL = 0, respectively. In the first information message, the originating terminal transmits the manufacturer's ID with MFG = 1, including the ID in the digit field, and the XFLAG is 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 receives a call and is connected to the other party, it sends all 1s to the channel, starts the destination null timer TANULL_EXP, and searches for multiframe information or information message. Once the terminating end detects a valid information message, the channel is considered the master channel of the new call and the terminating null timer TANULL_EXP is stopped. If a multiframe is detected, the called terminal considers the current call as an additional channel, stops the called party's null timer TANULL_EXP, and uses the GID to identify the current call.

In the master channel of the new call, if the called terminal accepts the requested parameter, it returns the same value as the received value to the calling terminal and starts the called party initial timer TAINIT_EXP. If the requested parameter is not accepted, RMULT and SUBMULT = 0 are returned with the valid mode value in the information message, and the called party disconnection procedure is started or a setting value different from the received parameter is returned.

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 region. The call can be identified among the calls received by the called terminal by this GID. 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, the ID is put in the digit field, and the calling terminal returns the information message along with other parameters as the initial response. If the called 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.

The calling terminal and the called terminal now exchange telephone numbers (DN) (603). The calling terminal requests an initial directory number (DN) by sending an information message with CID = 0, a transmission flag set to 1, and a digit field all set to 1. After the initial response, when the called terminal receives the information message with the XFLAG set to 1, the destination terminal sets the XFLAG of the information message to 1 and carries the telephone number in the digit field and returns the information message again. If the number of channels is N, exchange N-1 phone numbers (DNs). That is, when DQ_CONN_REQ is received from the call control layer to the DEQ negotiation control layer at the calling terminal, the DEQ carries an INIT REQ message on the CC_INFO_REQ primitive and delivers it to the called terminal. When the called terminal receives the INIT REQ message through CC_INFO_IND, the called terminal forwards the INIT ACK message to the called terminal. The calling terminal forwards the DN REQ message to the called terminal and requests a phone number. When the receiving terminal receives the DN REQ message, the called terminal generates a DN RESP message and delivers the telephone number to the calling terminal. This telephone number exchange operation is repeated N-1 times (603).

After the telephone number exchange is completed, the calling terminal sends an information message with CID = 1 to signal the end of the negotiation process.When the called terminal receives an information message with CID = 1, the calling terminal returns an information message with CID = 1 to the additional channel. Inform that the reception is ready At this time, the called terminal stops the called party initial timer TAINIT_EXP and starts the called channel addition timer TAADD01_EXP (604, 605).

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

Once each additional channel is connected, each terminal stops the channel addition timer TXADD01. When each channel is ready, the terminating terminal starts the delay equalization timer TXDEQ_EXP and uses the 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 CID arriving 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 delay equalization timer TXDEQ_EXP is stopped and user data transmission is started (609, 610).

When a call is established by multiple coupling, each state of the DEQ negotiation control layer is defined as shown in Tables 2 to 3 below.

Status of the DEQ negotiation control layer (calling side) State name Mark Contents Null state 0 No call exists Call settings One Calling party sends INIT REQ on the first channel and waits for INIT ACK Call setup CID = 1 on hold 1a Waiting for CID = 1 after completing parameter negotiation and DN exchange at the calling party and sending CID = 1 Wait for phone number 2 The calling party waits for receiving after requesting additional DN Additional channels 3 Status of setting remaining channel after completing parameter negotiation and DN exchange activation 8 All channels are set up so that DEQ multiframe can transmit data Active-Delete Initiation 8a Waiting for response after calling party requests channel deletion Active-additional initiation 8b-1 Waiting for response after calling party requests to add channel Active-additional channels 8b-2 The originator sets up additional channels after receiving a positive response to the channel addition. Active-CID1 Wait 8c The calling party waits for a response after sending CID = 1 as a signal of completion of adding or deleting a channel. Active-mode1 8d Mode 1 is active and information messages are not exchanged and messages are transferred between CC and DEQ MC. Cutting requirements 9 Waiting for response after calling party requests to disconnect

Status of DEQ negotiation control layer (receive side) State name Mark Contents Null state 0 No call exists Receive call 4 The called party receives the channel connection request Receive initialization 5 Received INIT ACK and received INIT ACK Additional Channel Standby 6 Waiting for setting for the rest of channel after parameter negotiation and DN exchange are completed at called party activation 8 All channels are set up so that DEQ multiframe can transmit data Initiate Active Delete 8a Called party waits for response after requesting channel deletion Active additional start 8b-1 Called party waits for response after requesting channel addition Active additional channels 8b-2 After the called party receives a positive response to the channel addition, the called party waits for the setting of the additional channel. Active CID = 1 wait 8c The called party waits for a response after sending CID = 1 as a signal of completion of adding or deleting a channel. Active mode 1 8d Mode 1 is active and information messages are not exchanged and messages are transferred between CC and DEQ MC. Cutting requirements 9 Waiting for a response after the called party requests to disconnect

In Table 2, the telephone number response message (DN RESP) is valid in the calling party's telephone number waiting state (2). In other words, before the call negotiation process is completed, the calling party analyzes the parameter requested by the called party and exchanges the telephone number (DN) when accepting the parameter (see FIG. 6). The calling party requests an initial directory number (DN), and the called party sends back a phone number (DN) in the digit field of the information channel. If the number of channels is N, N-1 numbers will be exchanged. 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 calling party generates a DN RESP message and transmits the telephone number to the calling party.

7 is a flowchart illustrating a phone number response message processing procedure according to the present invention. 7 briefly shows the process of the caller response message of the calling party using the SDL diagram.

When the calling party sends a DN REQ message to the called party and receives a DN RESP message in response (700), the current state of the calling party is determined. If the current state of the calling party is AWAIT DN state (710), after increasing the received telephone number counter (d) by +1 (720), the requested number of channels (N) and the increased The number of telephone numbers d is compared (730).

If the requested number of channels and the number of telephone numbers are the same (N = d), the channel identifier is set to 1 and CID = 1 message is transmitted over the entire bandwidth (740), and the initial call CID = 1 setting (CALL INIT WAIT CID = 1) state transition (750). If the requested number of channels and the number of telephone numbers are not the same (N ≠ d), the telephone number request message is transmitted to the called party (760), and the state transitions to the standby number (AWAIT DN) state (770).

Conventionally, there are disadvantages in that a duplicate code is generated by processing a message centered on a state and a processing speed is slow. According to the present invention, when the processing of each state is similar or identical to the same primitive, the present invention can easily merge these processing procedures and reduce the code size, thereby improving the processing speed.

Claims (1)

A method for processing a telephone number response message (DN RESP) in a delay compensation protocol for equalizing delays of combined channels by multiplexing N channels to provide a broadband required for a service, (a) receiving a telephone number response message; (b) determining a current state of the calling party that has received the telephone number response message; (c) when the calling party is in a phone number waiting state, increasing the number of telephone numbers by +1 and comparing the required number of channels with the number of telephone numbers; (d) if the requested number of channels and the number of telephone numbers are the same, send channel identification message CID = 1 over the entire bandwidth and transition to the initial call setup CID = 1 state; If the required channel number of channels and the number of telephone numbers are not the same, a telephone number according to the delay compensation protocol of the integrated information communication network, comprising the step of sending a telephone number request message to the called party and transitioning to the telephone number waiting state. How to handle number response messages.