• Journal of the Korea Society of Computer and Information
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• v.14 no.5
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• pp.85-91
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• 2009

The centralized conference architecture has a restriction in scalability due to the performance reduction as the number of conference participants increases. To solve this problem several distributed conference architectures have been studied recently. In these architectures new conference servers are added dynamically to the conference environment. In this paper, We have proposed a new conference information data model which can be used in these distributed conference architectures. In our newly proposed conference information data model. several components has been added for exchanging conference information between primary conference server and multiple secondary conference servers. We also proposed a procedure of conference information exchange between these conference servers. And the management of conference informations and SIP(Session Initiation Protocol) notifications to the total conference participants can be processed distributedly with these conference servers, therefore the load to the primary conference server can be decreased by using this method. The performance of our proposed model has been evaluated by experiments.

• Journal of the Korea Society of Computer and Information
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• v.17 no.6
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• pp.67-73
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• 2012

A distributed conference architecture with a new load control method has been suggested in this paper. A new event package in this paper enables to control conference load. Some additional elements for exchanging SIP messages between server and participants, and for distributing the load, have been added to new conference information data format. Furthermore to lessen the load, all conference servers share the processing of conference information data which should be transferred periodically to all participants. The suggested load control event package makes each server can get current load status of the overall servers. When load increases in one server SIP client requests are distributed by selecting a server which has the lowest load value, or new server is created to share the load. The performance of the proposed system has been evaluated by experiments. They shows 21.6% increase in average delay time, and 29.2% increase in average SIP message processing time.

• Journal of the Korea Society of Computer and Information
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• v.13 no.7
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• pp.199-205
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• 2008

The centralized conference model has advantage of conference management and control. however it's scalability has been limited as performance degrades largely with increasing number of conference users. So new distributed conference models which improve scalability of centralized conference model have been suggested recently. In the distributed conference model. as conference users exceed a predefined maximum number, a new conference server is added to the conference dynamically. In this paper, We have proposed a new method which increases efficiency of conference event package processing that primary conference server should charge in the distributed conference environment. The primary conference server exchanges informations with each secondary conference servers and conference users by using conference event package. And from the conference information database it selects SIP(Session Initiation Protocol) UA(User Agent) which will share notification to the conference users, and transfers lists to each conference servers. The conference servers make the selected UAs share processing of conference event package, so loads of SIP signal processing decrease, and improve scalability of distributed conference model. The performance of our proposed model is evaluated by experiments.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.224-230
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• 2019

In this paper, a new multiple servers conference service system using media control channel/distributed conference manipulation architecture has been presented. This conference service system can handle loads effectively from many conference participants. In this suggested architecture, media control channels are established between conference server, and distributed conference manipulation messages for distributing system loads are exchanged through this channels. These messages are transported between servers using media control channel created after stable transport sessions, and can be used to process server loads according to participants effectively. So this method can be used to implement large scale conference service system. For these purposes, formats of distributed conference manipulation messages which transmitted through media control channels are designed. and messages exchange procedures between conference servers are also presented. The performance of the proposed conference service system has been analysed by experiments, and the results show that the performances are improved according to participants.

• Journal of the Korea Society of Computer and Information
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• v.16 no.9
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• pp.123-129
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• 2011

In this paper, We have proposed a new distributed conference architecture which can reduce largely SIP(Session Initiation Protocol) messages exchanged between servers and participants in distributed conference environment by using resource lists which consist of conference participants URIs. This architecture can also reduce processing time and loads of conference servers. In our proposed method, the number of SIP messages required for participating in the conference can be largely reduced, and the number of SIP messages required for subscription of conference event package and maintaining sessions can also be largely reduced by using resource lists. Therefore expandibility of the conference system increases and network traffic can be reduced by using our conference architecture. And We also have proposed in this paper a new conference information data format with some added elements that are necessary for processing resource lists. Furthermore the procedure for dynamically adding conference servers to the conference environment has been suggested, and the exchanging process of SIP messages and conference information data between conference servers and conference participants has been also suggested. The performance of our proposed system has been evaluated by experiments.

• The Journal of the Korea Contents Association
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• v.14 no.7
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• pp.10-17
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• 2014

The focus maintains and manages conference session in the conference service. Load of focus increases by the number of participants and it becomes the major reason that limits the extendability of the large-scale conference service. In this paper, a new distributed focus control method has been proposed to solve this problem. Load of focus has been distributed to several conference nodes to implement large-scale conference service in this architecture. Conference nodes which have focus function subscribe to conference server's conference information database, and focus hae been allocated dynamically to process participants needs according to total numbers of the conference participants. For this purpose a new conference control event package for focus load control has been suggested. Furthermore the exchange procedure of SIP messages between focuses and participants also been suggested. The performance of the proposed system has been evaluated by simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.12
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• pp.2252-2258
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• 2016

CCMP(centralized conferencing manipulation protocol) enables adding and removing conference participants, changing their roles, adding and removing media streams in conference system. In this paper, by using extended CCMP, a new distributed conference system architecture which can be used to multiple servers distributed conference system in SIP(session initiation protocol) environment has been presented. In this study, according to increasing number of participants, a new extended CCMP architecture which can distribute conference system loads to multiple servers dynamically to decrease loads of servers has been designed. This extended CCMP architecture also can add dynamically new servers from the prepared servers pool. Furthermore, new conference information data format which can represent extended CCMP has been designed, and exchange procedures of extended CCMP control messages which can distribute loads between servers have also been presented. The performance of the proposed system has been analysed by simulation.

• Journal of the Korea Society of Computer and Information
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• v.17 no.10
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• pp.71-77
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• 2012

In this paper, We have proposed an efficient SIP(Session Initiation Protocol) messages control which can be used to reduce conference servers load in distributed conference model. Each conference participant can control the amount of event notification messages from the conference server in real time according to its processing capacity and network circumstances. And the amount of SIP messages needed to maintain session with the conference servers can also be controlled actively in our system. The amount of SIP messages which should be processed by the conference servers can be reduced largely by using our suggested method. Therefore the conference system can be more easily expandable and total network traffic can be reduced largely in SIP environment. We have suggested new conference event packages and conference information data model with some added elements that are necessary for efficient SIP messages control. The performance of the proposed system has been evaluated by experiments.

• The Journal of the Korea Contents Association
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• v.8 no.5
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• pp.1-8
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• 2008

The centralized conference architecture, one of the conference architectures in SIP(Session Initiation Protocol) environment, is widely used as it has the advantage of conference management and control. However it has been limited in scalability. Therefore we have proposed an efficient distributed conference architecture to improve scalability of centralized conference model. In our architecture, if the number of conference participants exceeds the predefined maximum number, a new conference server is added to the conference dynamically. In this case, the focus of existing server acts as primary focus and the focus of added server acts as secondary focus, and dynamic reallocation of participants between servers is done to equally divide the loads. This process is repeated as the number of conference participants increases. For this behavior, we have proposed procedure of adding the conference server, SIP call signal exchange, signaling procedure for RTP(Real Time Transport Protocol) sessions between conference servers, and procedure of conference event package between conference servers. The performance of our proposed model is evaluated by experiments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.7
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• pp.1335-1341
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• 2017

In this paper, a new architecture of multiple conference servers which use extended control channel framework in SIP(session initiation protocol) session has been presented. For this purpose, in this study, a new extended control channel framework architecture which can distribute total conference system loads to multiple servers effectively has been presented. In the implementation, extended control channels have been connected by using SIP sessions that was established between each conference servers, and extended control channel messages which can be transferred through control channels have been designed in this study. These extended control channel messages can distribute system load effectively between multiple conference servers, and conference information data format that can represent extended control channel framework has also been designed. Furthermore, exchange procedures of extended control channel messages have also been presented. The performance of the proposed system has been analysed by simulation. The analysis results show that average SIP messages delay time and average media stream delay time have improved.