• Journal of Communications and Networks
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• v.11 no.1
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• pp.72-83
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• 2009

We have studied the effect of head of the line blocking (HOLB) on session initiation protocol (SIP) session establishment delays. Our results are based on experiments performed in a test bed and on the public Internet. We used the stream control transmission protocol (SCTP) as a transport for SIP because SCTP can be configured to suffer or to avoid HOLB. Our experiments show that the effect of HOLB on session establishment delays generally starts to be significant starting at fairly low packet loss rates. However, there are scenarios where network conditions are good enough to make the effect of HOLB insignificant.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.4
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• pp.312-333
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• 2005

SIP(Session Initiation Protocol) has been proposed for session control protocol of Internet multimedia communication system like VoIP(Voice over IP). SIP has complicated session control steps to support various kinds of audio and video formats and to assure service quality of real time data communication. Up until now, existing protocol analyzers can not provide such detailed information of SIP based communication system. In this paper, therefore, we propose a new protocol analyzer as a tool that can analyze and diagnose SIP based multimedia communication system throughout the session initiation, data exchange and session change steps. The propose traffic analyzer, which is called STAT(SIP based Traffic Analysis Tool), Is implemented on Winder's environment so that it is generally usable and extensible. Since STAT analyze low level packets captured via Ethernet broadcasting property, it is able to provide session status and real time traffic monitoring information without any affection to the communication system. The STAT which is implemented in this paper. therefore, is expected to be a useful tool for developing and managing of a SIP based multimedia communication system.

• Journal of Korea Multimedia Society
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• v.20 no.11
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• pp.1768-1775
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• 2017

The SIP(Session Initiation Protocol) is an application layer call signaling protocol which can create, modify and terminate the session of user, and provides various services in combination with numerous existing protocols. However, most of cryptosystems for SIP cannot prevent quantum computing attack because they have used ECC(Elliptic Curve Cryptosystem). In this paper, we propose a NTRU based authentication and key distribution protocol for SIP in order to protect quantum computing attacks. The proposed protocol can prevent various attacks such as quantum computing attack, server spoofing attack, man-in-the middle attack and impersonation attack anonymity, and our protocol can provide user's anonymity.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.1119-1122
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• 2008

본 논문에서는 세션 초기 프로토콜(SIP: Session Initiation Protocol)에서 멀티미디어 응용 개발 프레임워크를 위한 네스티드 세션 관리에서의 오류 제어 방식에 대하여 기술한다. 네스티드 세션이란 하나의 부모 세션 아래에 여러 개의 자식 세션이 존재하는 것을 말한다. 제안하고자 하는 오류 제어는 오류 중에서 소프트웨어 오류인 경우에만 복구할 수 있으며 먼저 메시지와 스택을 이용하여 세션 초기 프로토콜 기반 네스티드 세션에서 검사점 설정(check point)을 한 후에 오류 감지 발생하면 그 검사점까지 되돌아서 재 수행하는 방식을 제안한다.

• 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 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.

• Journal of Digital Contents Society
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• v.17 no.1
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• pp.65-70
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• 2016

This paper suggests an environment of a CSCW(Computer Supported Cooperative Works) for industry safety service. A good example of industry safety service is gunpowder. This paper proposed a computer-based integrated multimedia for industry safety service running on shepherd and SIP(Session Initiation Protocol). But, conventional framework has not yet fully progressed a shepherd 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 an environment of integrated multimedia based on a shepherd and SIP environment to maintain good session condition.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.289-291
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• 2002

본 논문에서는 SIP(Session Initiation Protocol)을 사용하는 VoIP(Voice over IP) 네트워크에서 SIP 트래픽을 감시, 분석하는 관리 도구인 SIPMan 을 설계하고 구현하는 연구를 소개한다. 구현하는 SIPMan 은 실시간으로 SIP 패킷을 캡처하여 call 에 대한 다양한 정보를 분석하여 DB 에 저장할 수도 있다. VoIP 망 관리자는 SIPM무의 web GUI를 사용하여 call detail record, SIP 트래픽 정보 등을 모니터링말 수 있다.

• The KIPS Transactions:PartC
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• v.15C no.2
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• pp.87-92
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• 2008

This paper proposes a session control model for the P2P(Peer to Peer) IPTV(Internet Protocol Television) services and presents the IPTV session control procedures based on the proposed model. Since, while public IPTV traffic is usually processed via a separate network, P2P IPTV traffic is processed together with the conventional Internet access traffic, the P2P IPTV control mechanism needs to provide multi-stream processing for the constituent TPS(Triple Play Service) traffic and corresponding QoS(Quality of Service) control functions. Besides, P2P IPTV session control mechanism should provide appropriate multicast control functions in order to support effective transmission of video traffic generated by personal IPTV broadcasters. The P2P IPTV session control model proposed in this paper is designed to be based on the standard SIP(Session Initiation Protocol), IGMP(Internet Group Management Protocol), and COPS(Common Open Policy Service) protocol so that it can contribute to the easy and prompt deployment of inter-operable P2P IPTV platform.

• Journal of Internet Computing and Services
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• v.9 no.2
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• pp.83-88
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• 2008

Session initiation protocol (SIP) is an application-layer prolocol to initiate and control multimedia client session. When client ask to use a SIP service, they need to be authenticated in order to get service from the server. Authentication in a SIP application is the process in which a client agent present credentials to another SIP element to establish a session or be granted access to the network service. In 2005, Yang et al. proposed a key exchange and authentication scheme for use in SIP applications, which is based on the Diffie-Hellman protocol. But, Yang et al.'s scheme is not suitable for the hardware-limited client and severs, since it requires the protocol participant to perform significant amount of computations (i.e., four modular exponentiations). Based on this observation. Huang and Wei have recently proposed a new efficient key exchange and authentication scheme thor improves on Yang et al.'s scheme. As for security, Huang and Wei claimed, among others, that their scheme is resistant to offline dictionary attacks. However, the claim turned out to be untrue. In this paper, we show thor Huang and Wei's key exchange and authentication scheme is vulnerable to on offline dictionary attack and forward secrecy.