KR19990047322A - How to Exchange Participant Information for a Multipoint Conference Controller - Google Patents

Abstract

The present invention relates to a method of exchanging attendee information of a multipoint conference controller.

In T.124, when a new node joins a conference, the new node transmits the information of the new node to the parent node in the tree structure, and the parent node includes the new node information in the information of the child nodes managed so far. After that, it adopts the method of passing all this information back to its next higher node. As described in T.124, there is an unreasonable increase in the processing performance of each node and the amount of data transferred between each node.

In the present invention, when new information is transmitted from a new node, the processing time is unnecessary because only the information received from the new node is transferred to the next higher node, instead of the new node. And the amount of unnecessarily transmitted data can be eliminated.

Description

How to Exchange Participant Information for a Multipoint Conference Controller

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conference controller for setting up a meeting or managing a participant in a data conference such as an electronic blackboard in a desktop multimedia conference.

One representative of the prior art for data conferencing controllers is the T.124 protocol defined by ITU-T. T.124 defines that each computer node participating in a conference be organized in a tree. When a new node joins a conference, the node's information is sent to its parent in the tree. T.124 specifies that the parent node that receives node information from the new node shares the information of all nodes by collecting all node information and new node information of another node that it already manages and delivering it to the next higher node. have.

As such, when new node information is delivered, this information is collected into the existing node information, and then repeated each time, and the existing node information is also transmitted to the upper node, so the processing time required to encrypt the node information and the amount of data to be transmitted This problem arises unnecessarily.

Therefore, when the new node participates in the data conference based on T.124, the present invention implies that the existing T.124 includes a problem of notifying all nodes participating in the conference. It aims to reduce unnecessary processing time and data transfer and to ensure compatibility with existing T.124 protocols.

According to the present invention for achieving the above object, when the node information is input from the node controller, generating a conference book modification notification protocol data unit and updating the selector of the protocol data unit, and the node number received from the node controller. Filling the update list of the protocol data unit with the selector of the node modification record of the update list, adding node information received from the node controller to the node information record of the node modification record of the update list, Encrypting the protocol data unit and transmitting the encrypted protocol data unit to its upper node, and decrypting the protocol data unit in the upper node received from the newly joined lower node. A first inspection step of checking the state of the selector of the protocol data unit, and if the selector of the protocol data unit is refreshed as a result of the first inspection, the node information record is read from the refresh list of the protocol data unit and And adding the modified conference book again to the conference book modification notification protocol data unit when the modification of the conference book is completed and re-encrypting the newly created conference book modification notification protocol data unit and encrypting the encrypted protocol data. Transmitting the unit back to its upper node, copying and storing the encrypted protocol data unit received from the lower node when the selector of the first test result protocol data unit is updated; A second checking step of checking the type of the selector of the node modification record of the update list in the decoded protocol data unit; and if the second checking result is to add the selector, the node information of the node modification record is added to its conference book. Adding, replacing the node information about the same node number of the existing conference book with the contents of the protocol data unit if the selector is replaced as a result of the second check; and moving the selector as a result of the second check. Deletes the node information corresponding to the node number of the node modification record in the existing conference book, and stores the encrypted reception protocol data unit stored when the conference book is modified from the decrypted protocol data unit. Send to parent node of It characterized by comprising, including.

1 is a block diagram of a multi-point data conferencing system to which the present invention is applied.

2 is a schematic diagram of a conference control module of a multipoint data conference system to which the present invention is applied;

3 is a multipoint data conference connection configuration diagram.

4 is a block diagram of a conference book.

5 is a structural diagram of a conference book modification notification PDU.

6 is a management chart of a meeting book during a meeting.

7 illustrates a conference book change when a new node joins a conference.

8 is a flowchart for explaining how a new node according to T. 124 creates a conference book modification notification PDU;

9 is a flowchart for explaining a method of modifying a conference book by a higher node of a new node according to T.124;

10 is a flowchart illustrating a method for creating a conference book modification notification PDU by a new node according to the present invention.

11 is a flowchart for explaining a method of modifying a conference book by a higher node of a new node according to the present invention;

<Description of the symbols for the main parts of the drawings>

101: node controller 102, 104 and 105: conference control module

103: network controller

201: Conference connection establishment and termination function module

202: Application Management Module

The present invention will be described in detail with reference to the accompanying drawings.

The ITU-T T.120 series defines a protocol for multipoint data conferencing, and the system configuration of the multipoint data conferencing according to the T.120 series is shown in FIG.

Since multi-point data conferencing is operated based on a computer network, each node participating in the conference requires a network controller 103 to exchange data, and in order to exchange information on the operation of the conference and the nodes participating in the conference. The conference control module 102 defined at 124 is required. The node controller 101 functions to control the basic operation of the conference control module 102. The conference control module 102 present in one node exchanges information with the conference control modules 104 and 105 present in the other node and manages the conference.

2 is a configuration diagram of a conference control module, which is composed of a conference connection establishment and termination function module 201 and an application management module 202. The subject matter of the present invention relates to the functionality of the conference connection establishment and termination function module 201.

The meeting connection setup and meeting termination function module 201 serves to create a data meeting, invite another system to the created meeting, or participate in the created meeting, and to terminate the meeting when the meeting is over.

The application management module 202 manages the information of the applications participating in the conference at the entire conference level.

Each node participating in the multipoint data conference has a tree-like connection structure as shown in FIG. 3. The node at the top of the tree structure is called the top node 301, and if there is no node connected to its child, it is called the end nodes 304, 305, and 306. Nodes that are neither top nodes nor end nodes are also referred to as intermediate nodes 302.

4 defines the structure of a conference book managed by the conference control module of each node. The conference ledger 401 is a data structure that systematically maintains information 402 of each node participating in the conference, and shows three node information. The node's information 402 has a node number, a higher node number, a node type, a node name, an attendee name, and the like.

5 shows a state in which the conference control module of each node manages the conference book when five nodes participate in the conference. Each end node 505, 507, and 509 only has its node information 506, 508, and 510 in the conference book. On the other hand, the intermediate node 503 also has its own node information and node information of its subordinate nodes 507 and 509 in the conference book 504 as well. The top node 501 has in the conference book 502 information of all nodes participating in the conference. When a new node joins a conference in a conference state as shown in FIG. 5, a connection is established on an existing tree connection structure, and its node information should be informed to other nodes.

FIG. 6 is a structural diagram of a protocol data unit (hereinafter referred to as PDU) used to inform its own node information to other nodes participating in a meeting when a new node joins a meeting. Such a PDU is called a conference book modification notification PDU. The conference book modification notification PDU 601 is a refresh-list and an update-list, which are lists of node information interpreted differently according to a selector and a selector indicating how to interpret the information of the PDU. Consists of If the selector is refreshed, only the node information contained in the refresh list is interpreted and the conference book is modified. If the selector is updated, only the node information contained in the update-list needs to be interpreted to modify the conference book. The refresh list 602 consists of a node number and a list of node information records 402, and deletes all information to the sender and sender sub-nodes of this PDU from the contents of the existing conference book. This means copying the PDU's refresh-list back to the conference book. Update-list 603 means that only the information of the nodes mentioned in the update-list in the existing conference book should be modified according to the selector of node modification record 604. In other words, if the selector is added, the node information record included in the node modification record must be added to the conference book. If it is replaced, the node information already existing in the conference book must be replaced with a new one. .

7 illustrates a process of changing a conference book managed by each node when a new node participates in an existing data conference. In FIG. 7, a node 6 707, which is a new node, is connected to node 5 705, which is an end node already participating in the conference, and participates in the conference. The newly joined node 6 707 stores its node information 708 in the conference book modification notification PDU and transmits it to node 5 705, which is a higher node. Receiving this PDU, node 5 (705) adds node information of node 6 (707) to its conference book (706). Node 5 705 then forwards the modified conference book 706 back to the next higher node, Node 2 703, in the conference book modification notification PDU. Node 2 703 also undergoes the same process as node 5 705 and is eventually modified to the conference ledger 702 of node 1 701, the highest node. Through this process, when a node newly joins a conference, node information is exchanged in a tree structure.

The method of exchanging the information of the participant nodes defined in T.124 is described in more detail.

FIG. 8 is a flowchart illustrating a process of creating a conference book modification notification PDU in order to notify the node information of a new node participating in a meeting as defined in T.124. The conferencing control module of the new node 6 707 waits for node information to be communicated from the node controller (801). It is specified in T.124 that the node controller passes meeting information to the conference control module to generate a conference book modification notification PDU and designate the selector as refresh. Therefore, the selector is designated as refresh (802). The generated PDU is filled with node number and node information in the refresh list of the PDU (step 803). The contents of the PDU are encrypted (804) for transmission of the completed PDU on the computer network. The encrypted PDU is transmitted to Node 5 (705), which is a higher node. This completes the process to be performed by the new node for exchanging attendee information.

FIG. 9 is a flowchart illustrating a case where a conference book modification notification PDU is received from a higher node of a new node as defined in T.124. If the conference book modification notification PDU is delivered from a lower node that is a new node (901), the PDU is already encrypted and delivered and then decrypted (902). Since the selector of this PDU is designated as refresh according to step 802 described in FIG. 8, it reads the node information record from the refresh-list of the PDU, and its conference book (706 in FIG. 7). (903). When the modification of the conference book is completed, the contents of the modified conference book are made back into the conference book modification notification PDU (904). At this time, the new PDU's selector is also refreshed as defined in T.124, and the PDU contains all the node information in its conference book. The newly created conference book modification notification PDU is again encrypted (905). The encrypted PDU is transmitted back to its parent node (906). As shown in FIG. 9, since all intermediate nodes between the newly joined node and the highest node have to re-create and encrypt the book modification notification PDU each time, unnecessary processing time is wasted. In addition, since not only the information of newly participating nodes but the contents of all conference books owned by intermediate nodes should be made as PDUs, unnecessary data that needs to be exchanged with existing node information unnecessarily to inform that a node has newly participated. The transfer occurs.

In order to improve this problem, the present invention proposed a new method for exchanging attendee information.

FIG. 10 is a flowchart illustrating a method in which a node newly attending a conference according to the present invention creates a conference book modification notification PDU using node information thereof. When node information is input from the node controller (1001), a conference book modification notification PDU is generated and the selector of the PDU is updated (1002). This is different from the content 802 that T.124 specifies to be refresh. The node number received from the node controller is filled in an update-list of the PDU (1003). The selector of the node modification record of the update list is designated as add (1004). The node information received from the node controller is filled in the node information record of the node modification record of the update list (1005). The created PDU is encrypted (1006) for transmission, and transmitted to its higher node (1007).

The difference between the method according to T.124 and the method according to the present invention is that the PDU selector is designated as an update and the node information is designated and added to an update-list.

11 is a flowchart illustrating a method of processing a PDU when receiving a conference book modification notification PDU according to the present invention. When the conference book modification notification PDU is transmitted from the newly participating lower node (1101), the received PDU is decrypted (1102). The state of the selector of the decoded PDU is checked (1103), and if the PDU selector is refreshed, the same operation as defined in T.124 is performed. That is, the node information record is read from the refresh list of the PDU and added to the conference book (1104). When the modification of the conference book is completed, the contents of the modified conference book are made back into the conference book modification notification PDU (1105). At this time, the new PDU's selector is also refreshed as defined in T.124, and the PDU contains all the node information in its conference book. The newly created conference book modification notification PDU is again encrypted (1106). The encrypted PDU is transmitted back to its higher node (1107).

If the selector of the PDU is updated as a result of the check in step 1103, the encrypted PDU received from the lower node is separately stored (1108). The reason why the PDU which is already encrypted is stored is that even if the PDU is sent back to the next higher node, the modification of the conference book is performed in the same manner as in T.124. At the same time, since the PDU does not need to be regenerated and encrypted, improvements can be made in terms of processing speed and amount of data to be transmitted.

According to the selector of the node modification record of the update-list in the decrypted PDU, only the conference book managed by the user needs to be modified (1109). If the selector is added, it indicates that a new node has joined, and thus, node information of the node modification record may be added to its conference book (1110). If the selector is to be replaced, the node information about the same node number of the existing conference book is replaced with the contents of the PDU (1111). If the selector is to be removed, the node information corresponding to the node number of the node modification record may be deleted from the existing conference book (1112). If the selector is replaced or removed, it is not the case that the new node is participating, but the information of the node already participating in the meeting is changed or withdrawn from the meeting. There is no. When modification of the conference book is completed from the decrypted PDU, the stored encrypted received PDU is transmitted to its higher node as it is (1113).

According to the method of the present invention, the node information can be exchanged to all nodes participating in the conference using only the conference book modification notification PDU generated by the new node, and the intermediate node may experience a separate PDU encryption process or an increase in the size of the PDU. It can be removed.

The numerical effects are summarized as follows. First of all, the variables necessary for the numerical expression should be defined as follows.

L: Depth of the tree constituting the conference (L> 0),

P: Average number of bytes of PDU when the node information of one node is encrypted by making conference book modification notification PDU,

T: the number of maximum direct descendants in the tree (T> 0), i.e. T value is 2 for binary tree and T value for n-ary tree.

K: level of each node in the tree (0 ≦ K <L−1), where the K value of the most significant node is L−1 and the K value of the end node is zero.

l. Number of PDU Encryption Processes: When a new node is connected to an end node of an existing tree and participates in a conference, and the depth of the entire tree reaches L, when the conference book modification notification PDU is generated and the number of encryptions is C, As can be seen, the method proposed in the present invention can reduce the unnecessary PDU encryption process of L-2 times.

Method of T.124: Since the PDU must be encrypted repeatedly at the intermediate node of the tree, the number of encryption processes is as shown in Equation 1.

C _T.124 = L-1

Method of the Invention: Since the PDU needs to be encrypted only at the node newly participating in the conference, the number of times of the encryption process is necessary only once as in [Equation 2].

C _ours = 1

2. Size of PDUs exchanged: The size of the ledger notification PDU to be transmitted to its parent node by the intermediate node existing at level K on the route of the top node and the new node participating in the conference is given by the following equation. Similarly, in the case of the T.124 method, the size of the PDU increases as a function of the tree's depth to the tree's width. However, in the case of the method of the present invention, the size of the PDU is simply fixed to one node information size. Thus, comparing Equations 3 and 4, the method of the present invention can reduce the transmission amount of about P (T ^k -1) bytes in each layer.

Method of T.124: Since each intermediate node has to make all the node information about its subordinate node into PDU again and transmit it to the parent node, the size of PDU to be transmitted to the parent node in the case of complete tree is [Equation 3] Same as

Method of the Invention: Since only node information of a newly participating node needs to be repeatedly transmitted to each intermediate node, the size of a PDU that an intermediate node of each layer needs to transmit to its upper node is constant as shown in [Equation 4].

S (ours) _k = P

Claims (1)

When the node information is input from the node controller, generating a conference book modification notification protocol data unit and updating the selector of the protocol data unit; Assigning a node number received from the node controller to an update list of the protocol data unit and adding a selector of the node modification record of the update list; Filling node information received from the node controller into a node information record of a node modification record of an update list, encrypting the protocol data unit, and transmitting the encrypted node to its higher node; A first checking step of checking a state of a selector of the decoded protocol data unit after decoding the protocol data unit in an upper node received from the newly joined lower node; Reading the node information record from the refresh list of the protocol data unit and adding it to its conference book if the selector of the protocol data unit is refreshed as a result of the first inspection; When the modification of the conference book is completed, the modified contents of the conference book are made into the conference book modification notification protocol data unit again, and the newly created conference book modification notification protocol data unit is re-encrypted, and the encrypted protocol data unit is again Transmitting to a higher node, Copying and storing the encrypted protocol data unit received from the lower node when the selector of the protocol data unit is updated as a result of the first inspection; A second checking step of checking the type of the selector of the node modification record of the update list in the decoded protocol data unit; Adding node information of a node modification record to its conference book if the selector is to be added as a result of the second check; Replacing the node information about the same node number of the existing conference book with the contents of the protocol data unit if the selector is replaced as a result of the second inspection; Deleting the node information corresponding to the node number of the node modification record from the existing conference book if the selector is moved as a result of the second inspection; And when the modification of the conference book is completed from the decrypted protocol data unit, transmitting the stored encrypted received protocol data unit to its higher node.