• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.737-744
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• 2012

Recently VoIP has provided voice(both wired and wireless from IP-based) as well as the transmission of multimedia information. VoIP used All-IP type, Gateway type, mVoIP etc. Wired and wireless VoIP has security vulnerabilities that VoIP call control signals, illegal eavesdropping, service misuse attacks, denial of service attack, as well as wireless vulnerabilities etc. from WiFi Zone. Therefore, the analysis of security vulnerabilities in wired and wireless VoIP and hacking incidents on security measures for research and study is needed. In this paper, VoIP (All-IP type, and for Gateway type) for system and network scanning, and, IP Phone to get the information and analysis of the vulnerability. All-IP type and Gateway type discovered about the vulnerability of VoIP hacking attacks (Denial of Service attacks, VoIP spam attacks) is carried out. And that is a real VoIP system installed and operated in the field of security measures through research and analysis is proposed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.777-779
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• 2009

Study for VoIP in MANET is mainly focused on transmission performance or voice quality of VoIP traffic as single traffic. In this study, VoIP performance is analyzed of MANET which has several types of traffics. Diffserv scheme is used to process the traffics. It is showed that VoIP traffic performance is improved by differv scheme, as a result of analysis for VoIP and FTP traffic. Simulator, which is implemented with NS-2 package and VoIP patch, is used.

• Journal of Advanced Navigation Technology
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• v.17 no.4
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• pp.421-428
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• 2013

Voice over IP refers to technology that enables routing of voice conversations over the Internet or a TCP/IP network. VoIP communication costs cheaper than traditional analog phone. Phone calls can be made to anywhere / anyone: Both to VoIP numbers as well as people with normal phone numbers. VoIP protocol equipment available today follows the SIP standard. Older VoIP equipment though would follow H 323, MGCP, Megaco/H.248. A SIP server is the main component of an IP PBX, dealing with the setup of all SIP calls in the TCP/IP network. A SIP server is also referred to a Asterisk IP-PBX. A VoIP telephone, also known as a SIP phone or a softphone, allows the user to make phone calls to any softphone, mobile or PC by using App store. A VoIP telephone can be a simple software-based softphone. However, the SIP Server and the program is vulnerable to VoIP attacks. In this paper, eavesdropping attacks tested by using the Asterisk SIP server. Eavesdropping attacks and TLS security methods apply to VoIP system. TLS can be applied to determine whether the eavesdropping available for VoIP Environments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.5
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• pp.1109-1116
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• 2010

In this paper, some performance characteristics of VoIP(Voice over Internet Protocol) for MANET(Mobile Ad-hoc Networks) with simulation is studied and appropriate condition for implementation of VoIP service is suggested. VoIP simulator is implemented with NS(Network Simulator)-2. VoIP traffic for simulation is generated with some codecs of G.711, G.723.1, G.726-32, G.729A, GSM.AMR and iLBC. As simulation results for traffic transmission under $670{\times}670m$ 50node MANET environment, performance data for MOS(Mean Opinion Score), network delay, packet loss rate and transmission bandwidth are measured. Normalized analysis about measured results shows that maximum VoIP connection satisfying VoIP service quality condition is 15.

• The Journal of the Korea Contents Association
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• v.2 no.1
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• pp.98-103
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• 2002

Currently, VoIP service related companies have different telephone number system according to the problem of VoIP which Have no unique number system, and they develop/use different number bits, shortening button, and so on. In this paper, for solving this problem, we analyzed the standadization trend of ITU-T and IEIE, and reserched domestic trend of VoIP number system standardization trend and use case of number system of VoIP services. According to this, we proposes three number allocation plan that satisfies the globe trend, simpleness of number allocation, and VoIP service provider's actual conditions.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.839-843
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• 2002

In this paper, we present a next generation VoIP network architecture. Specifically, we present key components such as SoftSwitch and media gateway, and important protocols for VoIP services. We also present basic components and mechanisms for VoIP QoS. The architecture presented in this paper is able to support open interfaces and multimedia traffic, and therefore various multi-services can be supported efficiently using the architecture.

• Journal of the Korea Society of Computer and Information
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• v.17 no.3
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• pp.113-120
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• 2012

VoIP provides voice data service using existing IP networks and has received much attention recently. VoIP service has a variety of security vulnerabilities. Types of main attacks on VoIP service are tapping/interception, DoS attacks, spam, misuse of service attacks and the like. Of these, confidential information leak because of tapping/interception has been considered as a critical problem. Encryption techniques, such as SRTP and ZRTP, are mostly used to prevent tap and intercept on VoIP media information. In general, VoIP service has two service scenarios. First, VoIP service operates within a single private network. Second, VoIP service operates between different private networks. Both SRTP and ZRTP for VoIP media information within a single private network can perform encryption. But they can not perform encryption between different private networks. In order to solve this problem, in this paper, we modify SRTP protocol. And then, we propose an encryption method that can perform encryption of VoIP media information between the different private networks.

• Journal of the Korea Society of Computer and Information
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• v.10 no.5 s.37
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• pp.237-244
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• 2005

IP-Internet Telephony Service has not vet been achieved that of operating an IP-PBX service and a consumer Internet telephone services using VoIP technologies. In this paper, i suggest that the technologies of the VoIP Secure Gateway have connecting and securing for IP-Internet Telephony Service which makes If telephony protocols, firewall VPN tunneling, using Application Level Gateway, connection of the VoIP Secure Gateway. I suggest of telecommunication technologies that are enables an enterprise If-PBX service to interoperate with a consumer IP telephony service through a firewall. Also, I have proposed the solutions of security problems which was the security for VoIP Secure Gateway.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06d
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• pp.135-136
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• 2011

The more VoIP service is widely used, the more VoIP spam becomes threatened. Both VoIP spam violates the user's privacy and VoIP spam can cause money trouble. Therefore, it is important to reduce the VoIP spam but it is not easy to adopt some useful techniques to counter e-mail spam due to VoIP characteristics. We propose a technique using VoIP-RBL for countering SIP-based VoIP spam.

• Electronics and Telecommunications Trends
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• v.19 no.6 s.90
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• pp.66-73
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• 2004

2004년도 정보통신부의 IT839 전략에 따르면 8대 신규 서비스로 인터넷 전화(VoIP)와 3대 첨단 인프라로 광대역 통합망(BcN)을 선정한 바 있다. 이에 본 고에서는 9대 신성장동력에서 공동으로 활용하기 위한 VoIP와 BcN을 연계한 기술 동향을 설명한다. SIP 와 H. 323에 의한 VoIP 서비스가 제공되면서 네트워크 구조 변화가 시작되었다. 유선 네트워크, 무선 이동통신 네트워크, 인터넷 등을 통합하는 유무선 통합네트워크(BcN)는 VoIP 기술로 구축될 것이다. 본 고의 구성으로는 VoIP 기술 특성을 설명하고, VoIP 표준 동향을 분석한 후에 앞으로 구축될 BcN VoIP 의 발전 방향에 대하여 설명한다. VoIP 기술은 회선 정합및 인터넷 정합 기술과 H. 323, SIP, MEGACO 등의 프로토콜 기술과 VoIP 품질을 결정하는 코덱 기술이있다. VoIP 표준은 IETF에서 제정한 SIP를 중심으로 네트워크 특성을 고려하여 3GPP, 3GPP2, ITU에서개발하고 있다. BcN VoIP 는 기존의 VoIP 기술을 발전시켜 음성 품질이 오디오 수준으로 향상되고, 유선과 무선, 방송이 통합되는 제어 기술과 연계하여 실시간 멀티미디어 서비스를 제공할 것이다.