KR100243481B1 - Cut response message processing method according to delay compensation protocol of isdn - 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 truncation response message for a negotiated call between an originating party and a called party.

In the present invention, when the calling party receives the disconnect response message, the presenter determines the current state of the calling party, exchanges predetermined cut primitives between the upper and lower layers according to the cutting request 1 / cutting request 2 state, and then stops all timers of the call requested to be disconnected. And transition the next state to an invalid state. When the called party receives the cut-off response message, it grasps the current state of the called party, stops all timers related to the cut-off call according to the cutting request 1 / cutting request 2 state, and exchanges predetermined cutting primitives between the upper and lower layers of the called party. After that, the next state is changed to invalid state.

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

Description

Process of Disconnection Acknowledge message according to delay equalization protocol in ISDN

The present invention relates to a Delay Compensation Protocol (DEQ) for delivering broadband data in an integrated information communication network (ISDN), and in particular, a method for processing a truncation response message for a negotiated call between a calling party and a called party. It is about.

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 tier if the upper tier 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. 7, 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 call truncation response message, it has different processing routines according to various states for the truncation response 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. 7 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 problems of the prior art, and provides a truncation response message processing method that simplifies the message processing in consideration of the state based on the message (or primitive) in the delay compensation protocol. Its purpose is to.

Truncation response message processing method of the present invention for achieving the above object, (a) receiving a truncation response message; (b) determining a state of a calling party or a called party that has received the truncation response message of step (a); (c) in step (b), if the calling party's state is disconnect request 1, exchanging predetermined disconnect primitives between the upper and lower layers of the calling party, and stopping all timers of the requested call being disconnected and transitioning to an invalid state; (d) if the state of step (b) is cut request 2, exchanging predetermined cut primitives between the upper and lower layers of the calling party, and stopping all timers of the requested call being cut off and transitioning to an invalid state; (e) in step (b), if the called party's state is cut request 1, stopping all timers related to the requested call being cut, exchanging predetermined cut primitives between upper and lower layers of the called party, and then transitioning to an invalid state; (f) in the step (b), if the called party's status is cut request 2, stopping all timers related to the cut-off request, exchanging predetermined cut primitives between the upper and lower layers, and then transitioning to an invalid state; It is characterized in that the configuration.

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 illustrating a cut response message processing procedure according to the present invention;

7 is a flowchart illustrating a conventional primitive / message 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 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 initiation One Calling party sends INIT REQ on the first channel and waits for INIT ACK Initiate-CID1 Wait 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 INIT Receive 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 Active-Delete Initiation 8a Called party waits for response after requesting channel deletion Active-add start 8b-1 Called party waits for response after requesting channel addition Active-additional channel 8b-2 The receiver sets the additional channels after receiving a positive response to the channel addition. Active-CID1 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-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 a response after the called party requests to disconnect

In Tables 2 and 3, the called party and the called party disconnection request state is that each terminal side requests the other party to disconnect and waits for a response. If the current state is other than the invalid state and the disconnect request state 1 or 2, the next state is a request for disconnection when a DISC REQ message is sent to the other party or a disconnect request (DQ_DISC_REQ) primitive is received from the call control layer. The state transitions to 1 (DISC REQ 1), and when the DISC REQ message is received, the next state transitions to the DISC REQ 2 state.

Once data is exchanged over multiple channels of the established call, either the originating party or the called party wishing to disconnect can begin to disconnect. When the caller initiates the cut and the callee initiates the cut, the cut processing will be described as follows.

① Start cutoff

Note: The calling party initiates call truncation by sending an information message (cutting message) to all channels with CID set to 0 for all channels and RMULT and SUBMULT to 0 for starting the calling party disconnect timer TCdisc.

Ii: when the called party receives the truncation message of i, it sends a message to the calling party to accept or reject the truncation. The truncation accept message sets the CID to 0 and returns a value set to RMULT and SUBMULT to 0 to indicate that the truncation is accepted.The truncation reject message returns the cause code indicating CID = 0, the current parameter value, and the reason for rejection. Refuse to cut.

Note: The called party which has accepted the call truncation stops transmitting user data by the connection, waits for disconnection, and starts the called party truncation timer TAdisc.

Note: The originator receiving the truncation accept message initiates a channel truncation procedure for all channels combined in the call. And stop the calling party disconnect timer TCdisc.

Note: The originator receiving the truncation rejection message initiates a channel truncation procedure or maintains the current call for all channels combined in the call.

Note: The called party stops the called party disconnect timer TAdisc when all channels are disconnected.

② Start cutting on the called party

Note: The called party sends an information message (cutting message) that sets CID = 0, RMULT and SUBMULT areas to 0 on all channels to initiate call truncation and starts the called party truncation timer TAdisc.

Ii: when the calling party receives the truncation message of the above, the calling party sends a message to the called party accepting or rejecting the cutting. The truncation accept message sets the CID to 0 and returns a value set to RMULT and SUBMULT to 0 to indicate accepting the call truncation, and the truncation reject message returns the cause code indicating CID = 0 and the current parameter value and the reason for rejection. Refuse to cut.

Note: The calling party which has accepted the call cut off stops transmitting user data, waits for the cut and starts the calling cut-off timer TCdisc.

Ⅳ: The called party receiving the truncation accept message initiates a channel truncation procedure for all channels combined in the call. Then, the called party's disconnect timer TAdisc is stopped.

Note: The called party receiving the truncation rejection message starts the channel truncation procedure or maintains the current call for all channels combined in the call.

Note: The calling party stops the calling party disconnect timer TCdisc when all channels are disconnected.

As described above, the disconnect timer Txdisc is driven when the call is disconnected, and the disconnect timer is stopped when all channels related to the call are disconnected. If the truncation timer expires before all channels are disconnected, appropriate processing is performed, such as an end primitive.

6 is a flowchart illustrating a DISC ACK message processing procedure according to the present invention. Either the calling party or the receiving party initiates the call truncation, sends a DISC REQ message to the other party, and receives a DISC ACK message. FIG. 6 briefly illustrates the process at the calling party (CU) and called party (AU) for the truncation response message (DISC ACK) using the SDL diagram.

① Calling party receives cut response message

When the disconnect response message DISC ACK is received by the calling party CU 600, it is determined whether the calling party state is the disconnect request 1 DISC REQ 1 or the disconnect request 2 DISC REQ 2.

If disconnect request 1 (DISC REQ 1) state (620) sends a disconnect instruction primitive (DQ_DISC_IND) from the DEQ negotiation control layer to the call control layer (621), all channels from the DEQ negotiation control layer to the DEQ multiframe control layer. A channel delete request (CC_DEL_REQ) primitive for deleting is sent (622). Subsequently, all timers associated with the disconnect requested call are stopped (623) and then transitioned to an invalid state (660).

In the case of the DISC REQ 2 state (630), a confirmation of disconnection (DQ_DISC_CONF) primitive is sent from the DEQ negotiation control layer to the call control layer (631), and the channel deletion request from the DEQ negotiation control layer to the DEQ multiframe control layer. (CC_DEL_REQ) sends a primitive to delete all channels (632). Subsequently, all timers associated with the disconnect requested call are stopped (633) and then transitioned to an invalid state (660).

② The called party receives the disconnect response message

When the disconnect response message DISC ACK is received at the called party AU (600), it is determined whether the called party is in the disconnect request 1 (DISC REQ 1) or the disconnect request 2 (DISC REQ 2).

If it is in the DISC REQ 1 state (640), all timers related to the disconnect requested call are stopped (641). Then, after transmitting the DISC ACK message to the calling party (642), the DEQ negotiation control layer sends a disconnect instruction (DQ_DISC_IND) primitive (643), and the DEQ negotiation control layer to the DEQ multiframe control layer. In step 644, the channel delete request (CC_DEL_REQ) primitive is sent to delete all channels. Finally, the state of the DEQ negotiation control layer transitions to an invalid state (660).

If it is in the DISC REQ 2 state (650), all timers related to the disconnect requested call are stopped (651). After returning a disconnect response (DISC ACK) message to the calling party (652), send a disconnect acknowledgment (DQ_DISC_CONF) primitive from the DEQ negotiation control layer (DQ_DISC_CONF) (643), the channel from the DEQ negotiation control layer to the DEQ multiframe control layer A delete request (CC_DEL_REQ) primitive is sent to delete all channels (644). Finally, the state of the DEQ negotiation control layer transitions to an invalid state (660).

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

Claims (5)

A method of processing a DISC ACK message for truncating a negotiated call 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 truncation response message; (b) determining a state of a calling party or a called party that has received the truncation response message of step (a); (c) in step (b), if the calling party has a disconnect request 1, exchanging predetermined disconnect primitives between upper and lower layers of the calling party, and stopping all timers of the requested call being disconnected and transitioning to an invalid state; (d) if the state of step (b) is cut request 2, exchanging predetermined cut primitives between the upper and lower layers of the calling party, and stopping all timers of the call requested to cut and transition to an invalid state; (e) If the called party's status is cut request 1 in step (b), all timers related to the called-out call are stopped, and then, the predetermined cutoff primitive is exchanged between the upper and lower layers of the called party, and then the transition is made to an invalid state. Doing; (f) If the called party's status is cut request 2 in step (b), all timers related to the requested call are stopped, and then, the predetermined cutoff primitive is exchanged between the upper and lower layers of the called party, and then transitioned to an invalid state. Truncation response message processing method according to the delay compensation protocol of the integrated information communication network, characterized in that comprising a step. The method according to claim 1, wherein the predetermined truncation primitive of step (c) sends a truncation indication primitive (DQ_DISC_IND) from the DEQ negotiation control layer to the call control layer, and a channel deletion primitive (DEQ multicast control layer) from the DEQ negotiation control layer to the DEQ multiframe control layer. A method of processing a truncation response message according to a delay compensation protocol of an integrated information communication network, characterized by sending CC_DEL_REQ). The method according to claim 1, wherein the predetermined truncation primitive of step (d) sends a truncation acknowledgment primitive (DQ_DISC_CONF) from the DEQ negotiation control layer to the call control layer, and a channel deletion primitive (DQ_DISC_CONF) from the DEQ negotiation control layer to the DEQ multiframe control layer. A method of processing a truncation response message according to a delay compensation protocol of an integrated information communication network, characterized by sending CC_DEL_REQ). The method according to claim 1, wherein the predetermined truncation primitive of step (e) sends a truncation response message (DISC ACK) to the calling party, and then sends a truncation indication primitive (DQ_DISC_IND) from the DEQ negotiation control layer to the call control layer. A method of processing a truncation response message according to a delay compensation protocol of an integrated information communication network, wherein a channel deletion request primitive (CC_DEL_REQ) is sent from the negotiation control layer to the DEQ multiframe control layer. The method according to claim 1, wherein the predetermined truncation primitive of step (f) sends a truncation response message (DISC ACK) to the calling party, and then sends a truncation acknowledgment primitive (DQ_DISC_CONF) from the DEQ negotiation control layer to the call control layer. A method of processing a truncation response message according to a delay compensation protocol of an integrated information communication network, wherein a channel deletion request primitive (CC_DEL_REQ) is sent from the negotiation control layer to the DEQ multiframe control layer.

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