• 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.

• Journal of Digital Contents Society
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• v.16 no.1
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• pp.173-177
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• 2015

This paper proposed an access control for computer-based integrated multimedia running on shepherd and SIP(Session Initiation Protocol). But, conventional framework for access control SIP environment has not yet fully progressed a shepherd and an access control for computer-based integrated multimedia running on SIP(Session Initiation Protocol). Session management include function of session creation, session end, late comer process, and access control. Therefore, this paper described access control based on a shepherd and SIP environment to maintain good session condition.

• Proceedings of the Korea Contents Association Conference
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• 2004.05a
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• pp.342-347
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• 2004

The VoIP(Voice over Internet Protocol) technology which is able to use a voice service through internet is more cheaper then existing telephone charges, and is easily accept the various of multimedia services from internet. Previous connection method of VoIP used H.323 protocol, but it is very complex to connection establishment. so, the SIP(Session Initiation Protocol) protocol that propose in SIP-Working Group Is in use recently. Therefore, we need new interworking methodology between H.323 and SW products. In this thesis, the progress interworking method between H.323 and SIP are propose, then interpret unnecessary packet delay for call setup and improved feature of message exchange.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.1 no.3
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• pp.17-20
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• 2008

This paper describes an access control which is running on SIP(Session Initiation Protocol) environment for computer supported cooperated works. Session management include function of session creation, session end, late comer process, and access control. But, conventional framework for access control SIP environment for computer supported cooperated works environment has not yet fully progressed. Therefore, this paper suggests an access control based on SIP environment for computer supported cooperated works environment to maintain good session condition.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.11
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• pp.2678-2684
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• 2014

In this paper a new message control method that can reduce server load and network traffic in XMPP/SIP presence service system has been proposed. This presence service system can process both XMPP(Extensible Massaging and Presence Protocol) based presence information and SIP(Session Initiation Protocol) based presence information. A new XMPP stanza architecture with added elements for presence stanza and IQ stanza has been designed, and a new presence information data processing method which can reduce size of SIP notification message and SIP PUBLISH message has been suggested. Furthermore a messages exchanging procedure that can transfer presence information between XMPP domain and SIP domain has been also suggested. The performance of the proposed system has been analysed by simulation.

• The KIPS Transactions:PartC
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• v.11C no.3
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• pp.371-378
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• 2004

SIP(Session Initiation Protocol) is a text based call signaling protocol that has characteristics such as flexibilities and extensibility for various application services over Internet. In this paper, we have implemented SIP based integrated Instant Messenger system which includes Presence Watcher Information service that can notify various current users status. In this system, voice and video communications are also possible as well as text based instant messages. For voice and video communication, we have newly proposed a method in which direct connection is possible between users without creation of SW INVITE dialog by extending PRESENCE TUPLE of presence information. In this case, PRESENCE TUPLE stores some informations necessary for the session.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.130-140
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• 2010

SIP (Session Initiation Protocol) is a signaling protocol to provide IP-based VoIP (Voice over IP) service. However, many security vulnerabilities exist as the SIP protocol utilizes the existing IP based network. The SIP Malformed message attacks may cause malfunction on VoIP services by changing the transmitted SIP header information. Additionally, there are several threats such that an attacker can extract personal information on SIP client system by inserting malicious code into SIP header. Therefore, the alternative measures should be required. In this study, we analyzed the existing research on the SIP anomaly message detection mechanism against SIP attack. And then, we proposed a Co-occurrence based SIP packet analysis mechanism, which has been used on language processing techniques. We proposed a association rule generation and an attack detection technique by using the actual SIP session state. Experimental results showed that the average detection rate was 87% on SIP attacks in case of using the proposed technique.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.6
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• pp.1022-1025
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• 2008

Session Initiation Protocol (SIP) has become the call control protocol of choice for Voice over IP (VoIP) networks because of its open and extensible nature. However, the integrity of call signaling between sites is of utmost importance, and SIP is vulnerable to attackers when left unprotected. Currently a herby-hop security model is prevalent, wherein intermediaries forward a request towards the destination user agent sewer (UAS) without a user agent client (UAC) knowing whether or not the intermediary behaved in a trusted manner. This paper presents an integrated security model for SIP-based VoIP network by combining hop-by-hop security and end-to-end security.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.286-288
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• 2002

SIP는 인터넷 텔레포니 신호(Internet Telephony Call)와 같은 멀티미디어 세션을 성립, 변경, 종료시킬 수 있는 응용계층의 호 제어 프로토콜이다. 또한, SIP 프록시 서버(Proxy Server)라는 네트일 호스트로 구축된 인프라를 통해 멀티미디어 통신을 원하는 네트윅상의 사용자를 찾아 멀티미디어 세션(Session)이 성립될 수 있도록 도와준다. SIP는 Request-Response 방식의 프로토콜이기 때문에 요청(Request)과 응답(Response)을 주고받는 일련의 트랜잭션(Transaction)으로 하나의 Task를 완성한다. 본 논문에서는 rfc2543을 기반으로 기본적인 SIP 트랜잭션을 위한 SIP 스택(Stack)의 설계 및 그 구현 방안을 제지한다.

• Journal of the Korea Society of Computer and Information
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• v.12 no.6
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• pp.187-192
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• 2007

Conference focus maintains and manages SIP(Session Initiation Protocol) signal connections with total conference participants, and it plays core functions of conference server. When the number of conference participants increases, conference focus restricts scalability of conference as increasing quantify of messages for processing. In this paper, to solve this problem. we propose a user system(conference information agent), which receives conference information from the conference focus and transfers them to the participants it manages. And we design and implement the total system including conference focus. When the conference information agent subscribe to the conference focus, it shows its possession of agent capability and capacity by using SIP SUBSCRIBE message. The conference focus informs to the other party by SIP response message that it was chosen as a conference information agent, and after that the conference focus sends all conference notification messages to it. So load of the conference focus can be reduced by this method. Finally, we have analyzed the performance of our system by experiments.