• 제목/요약/키워드: INVITE message

검색결과 8건 처리시간 0.025초

SIP 프록시에서 우선순위를 가지는 INVITE 메시지의 우회 방법 (A Bypass Scheme for INVITE Messages With Priority in SIP Proxies)

  • 권오준;장희숙;이종민
    • 한국시뮬레이션학회논문지
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    • 제19권4호
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    • pp.51-58
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    • 2010
  • SIP는 인터넷에서 사용되는 다른 프로토콜과 결합하여 음성 통신과 같은 다양한 서비스를 할 수 있는 유연성과 확장성이 있는 호 설정 프로토콜이다. 이러한 음성 통신은 사용자 간 통화를 목적으로 사용되는 일반 호와, 공중 안전망을 통하여 이루어지는 112, 119 등의 서비스를 해주는 긴급 호로 구분할 수 있다. 이러한 일반 호와 긴급 호를 인터넷과 같은 공중망을 통하여 효과적으로 처리해주기 위한 연구가 필요하다. 본 논문에서는 일반 호에 비하여 긴급 호를 보다 빠르게 처리할 수 있도록 INVITE 메시지에 우선순위를 부여하고 이를 SIP 프록시 큐에서 우선적으로 처리하는 방식을 제안한다. 성능 평가를 위하여 ns-2를 사용하여 시뮬레이션 연구를 수행하였다. 제안한 방법에 의하여 긴급 호 처리가 일반 호 처리에 비하여 빠르게 처리되며, 따라서 기존의 인터넷을 사용하여 국가 재난망과 같은 특수 목적의 망을 효과적으로 구축할 수 있을 것으로 기대된다.

SIP 프로토콜을 이용한 블랙박스 자동 영상 전송 구현 (SIP protocol use Black Box automatic image transmission)

  • 김명훈;김영길
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2016년도 추계학술대회
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    • pp.250-253
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    • 2016
  • 차량용 블랙박스의 저장된 영상은 교통사고 발생 시 사고 발생의 원인을 판별할 수 있는 중요한 기록이다. 현재블랙박스의 원격 감시는 차주 본인의 스마트폰으로 충격을 감시 하거나 전송 받을 수 있다. 이를 보완하여 차주가 사고로 인해 부상을 당하거나 정신을 잃었을 경우 SIP 영상 통신을 이용해 "INVITE" 메시지를 메신저 어플리케이션으로 보내고 응답을 하였을 때 "Notify" 메시지로 영상을 전송하여 지인에게 사고 소식을 알리고 영상을 확인 하여 위치 및 사고 상황을 파악하여 신속하게 대처할 수 있는 내용을 구현 및 연구 하고자 한다.

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SIP 프록시 큐의 비선형적 과부하 제어 방법 (A Non-Linear Overload Control Scheme for SIP Proxy Queues)

  • 이종민;전흥진;권오준
    • 한국시뮬레이션학회논문지
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    • 제19권4호
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    • pp.43-50
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    • 2010
  • 최근 인터넷 전화는 기존 유선 전화에 비해 적은 비용으로 통화를 할 수 있다는 장점으로 인해 많은 인터넷 사용자들에 의해 사용되어지고 있다. Session Initiation Protocol(SIP)은 인터넷 전화의 세션 설정 및 해제를 위한 응용계층 프로토콜 표준이다. SIP는 주로 전송을 위해 UDP를 사용하고 있다. 따라서 INVITE 요청 메시지가 유실되는 경우, UDP 메시지의 신뢰성 있는 전송을 위하여 그 메시지는 적절한 타이머에 의해 재전송된다. 재전송은 사용자에 의해 보내진 메시지의 신뢰성 보장을 위해 유용할 지라도, SIP 프록시(Proxy) 서버의 과부하를 초래하는 원인이 되기도 한다. SIP 프록시 서버의 과부하로 인하여 입력되는 메시지가 많이 유실될 수 있다. 본 논문에서는 프록시 서버의 과부하를 효율적으로 해결하기 위한 비선형 과부하 제어 알고리즘을 제안한다. 제안된 알고리즘은 ns-2 시뮬레이터를 이용하여 성능을 시뮬레이션하였다. 시뮬레이션 결과는 기존의 선형 과부하 제어 알고리즘에 비해 제안된 알고리즘의 프록시 서버의 처리율이 약 12%정도 향상됨을 알 수 있었다.

SIP 시그널링 네트워크에서 지연 큐를 이용한 과부하 제어 방법 (The Overload Control Scheme Using a Delay Queue in the SIP Signalling Networks)

  • 이종민;전흥진;권오준
    • 한국멀티미디어학회논문지
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    • 제15권8호
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    • pp.1038-1047
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    • 2012
  • SIP(Session Initation Protocol)는 IP 전화의 호 설정 및 해제를 위한 응용계층 프로토콜이다. SIP 시그널링 네트워크에서 호 설정을 요청하는 UA(User Agent)의 수가 증가하게 되면 SIP 프록시 서버가 처리해야할 메시지의 수는 증가되어 과부하가 초래될 수 있다. 본 논문에서는 SIP 프록시 서버에 일반 큐와 지연 큐를 두어 SIP 프록시 서버의 과부하를 제어하는 방안을 제안한다. 입력되는 메시지가 일반 큐의 임계치를 초과하여 과부하가 예상될 경우 SIP 프록시 서버의 부하 감소를 위하여 신규 입력되는 INVITE 메시지를 지연큐에 배치하여 호 설정을 지연시킨다. 그 후에 일반 큐의 메시지가 하한 임계치 이하로 감소할 때 지연큐의 INVITE 메시지를 처리한다. 시뮬레이션 결과는 일반 큐의 메시지에 대한 빠른 처리로 인해 제안된 방법이 단일 큐 방법과 비교해 재전송 메시지의 수가 약 45% 감소함을 보여주었다. 그리고 시뮬레이션 결과에 의하면 제안 방법이 일반 큐 방법보다 평균 호 성공률이 약 2% 개선되었다.

Detection of SIP Flooding Attacks based on the Upper Bound of the Possible Number of SIP Messages

  • Ryu, Jea-Tek;Roh, Byeong-Hee;Ryu, Ki-Yeol
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제3권5호
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    • pp.507-526
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    • 2009
  • Since SIP uses a text-based message format and is open to the public Internet, it provides a number of potential opportunities for Denial of Service (DoS) attacks in a similar manner to most Internet applications. In this paper, we propose an effective detection method for SIP flooding attacks in order to deal with the problems of conventional schemes. We derive the upper bound of the possible number of SIP messages, considering not only the network congestion status but also the different properties of individual SIP messages such as INVITE, BYE and CANCEL. The proposed method can be easily extended to detect flooding attacks by other SIP messages.

광고 크리에이티브로서의 '부재 (absence)' 의 의미작용에 관한 연구 (The significations of 'The absence' as an advertising creative)

  • 박영원
    • 조형예술학연구
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    • 제4권
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    • pp.5-25
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    • 2002
  • It is not easy to get more attention as a prominent advertising expression among various types of numerous advertisements. Due to the voluminous expansion of advertising communications and the change of the media, new advertising creatives must be needed for serving to differentiate the message , inviting audiences to participate more positively in advertising communications This thesis aims at reviewing the absence as an advertising creative. And this thesis is about the significations of the absence. Chapter I describes the aim of this thesis about the absence as an advertising creative And Chapter II introduces the general concept, perception of the absence and its possibilities as an advertising creative And also mentions about the absence as one of paradoxical expressions with rhetorical theories as well as semiotics. Chapter III deals with the signification of the absence with introducing semiotic methods such as the theory of R. Barthes Chapter IV discusses the signification of the absence as an advertising creative talking into consideration of semiotic theories. And I categorize the types of the absence in advertising expressions. The absence is categorized into 5 types in this thesis. Type (1) is the absence of product which is supposed to be advertised, type (2) is the absence of product and make product image located out of main image of an advertising expression for introducing features of a product itself. And type (3) is the absence of the imaginary audience to invite an audience to participate more spontaneously. Type (4) is the absence of headlines, and type (5) is the absence of almost all visual images and verbal message but a corporate symbol or brand logo. The signification of S types of the absence can be described on the basic of semiotic theories, especially the theory of R. Barthes. It's my hope that this thesis about the absence as an advertising creative will serve as the basic theory for the empirical research about advertising expressions containing images of the absence.

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RDD with Follow-Up Texting: A New Attempt to Build a Probability-Based Online Panel in South Korea

  • Dong-Hoon Seol;Deok-Hyun Jang;Sarah Prusoff LoCascio
    • Asian Journal for Public Opinion Research
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    • 제11권3호
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    • pp.257-273
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    • 2023
  • Conducting face-to-face surveys is difficult and cost prohibitive, necessitating a new attempt to build a probability-based panel in South Korea. Since 99.9% of adult Koreans own a mobile phone, mobile phone numbers provide a viable sampling frame. Random digit dialing (RDD) surveys were conducted August-December 2021. Of the 288,056 valid phone numbers dialed, 13,655 respondents between the ages of 19 and 69 completed a phone survey. These respondents were later invited by text message to join a panel; 3,202 of these (23.4% or 1.2% based on the number initially contacted) joined the panel. When compared to official government statistics like resident registration data, the census, or the Social Survey, this new probability-based panel can be said to be representative of the Korean population on the basis of age, gender, location, marital status, and household size after weighting is applied. However, even after weighting, panel members are more educated than the general population, white-collar workers and self-employed people are overrepresented, and blue-collar workers are underrepresented. As of February 2023, this panel has grown to 10,471 participants with plans to continue to invite more panel members in the same way. Based on the comparisons in this paper, we can regard this panel as a cost-effective, probability-based panel that may be used for various kinds of public opinion research, by researchers both within and outside of Korea. As we continue to refine and grow this panel, we hope it will become more widely used by researchers as well as provide a model for those building similar panels in other countries.

"무역상무(貿易商務)에의 역사적(歷史的) 어프로치와 무역취인(貿易取引)의 전자화(電子化)" (E-Commerce in the Historical Approach to Usage and Practice of International Trade)

  • 춘홍차
    • 무역상무연구
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    • 제19권
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    • pp.224-242
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    • 2003
  • The author believes that the main task of study in international trade usage and practice is the management of transactional risks involved in international sale of goods. They are foreign exchange risks, transportation risks, credit risk, risk of miscommunication, etc. In most cases, these risks are more serious and enormous than those involved in domestic sales. Historically, the merchant adventurers organized the voyage abroad, secured trade finance, and went around the ocean with their own or consigned cargo until around the $mid-19^{th}$ century. They did business faceto-face at the trade fair or the open port where they maintained the local offices, so-called "Trading House"(商館). Thererfore, the transactional risks might have been one-sided either with the seller or the buyer. The bottomry seemed a typical arrangement for risk sharing among the interested parties to the adventure. In this way, such organizational arrangements coped with or bore the transactional risks. With the advent of ocean liner services and wireless communication across the national border in the $19^{th}$ century, the business of merchant adventurers developed toward the clear division of labor; sales by mercantile agents, and ocean transportation by the steam ship companies. The international banking helped the process to be accelerated. Then, bills of lading backed up by the statute made it possible to conduct documentary sales with a foreign partner in different country. Thus, FOB terms including ocean freight and CIF terms emerged gradually as standard trade terms in which transactional risks were allocated through negotiation between the seller and the buyer located in different countries. Both of them did not have to go abroad with their cargo. Instead, documentation in compliance with the terms of the contract(plus an L/C in some cases) must by 'strictly' fulfilled. In other words, the set of contractual documents must be tendered in advance of the arrival of the goods at port of discharge. Trust or reliance is placed on such contractual paper documents. However, the container transport services introduced as international intermodal transport since the late 1960s frequently caused the earlier arrival of the goods at the destination before the presentation of the set of paper documents, which may take 5 to 10% of the amount of transaction. In addition, the size of the container vessel required the speedy transport documentation before sailing from the port of loading. In these circumstances, computerized processing of transport related documents became essential for inexpensive transaction cost and uninterrupted distribution of the goods. Such computerization does not stop at the phase of transportation but extends to cover the whole process of international trade, transforming the documentary sales into less-paper trade and further into paperless trade, i.e., EDI or E-Commerce. Now we face the other side of the coin, which is data security and paperless transfer of legal rights and obligations. Unfortunately, these issues are not effectively covered by a set of contracts only. Obviously, EDI or E-Commerce is based on the common business process and harmonized system of various data codes as well as the standard message formats. This essential feature of E-Commerce needs effective coordination of different divisions of business and tight control over credit arrangements in addition to the standard contract of sales. In a few word, information does not alway invite "trust". Credit flows from people, or close organizational tie-ups. It is our common understanding that, without well-orchestrated organizational arrangements made by leading companies, E-Commerce does not work well for paperless trade. With such arrangements well in place, participating E-business members do not need to seriously care for credit risk. Finally, it is also clear that E-International Commerce must be linked up with a set of government EDIs such as NACCS, Port EDI, JETRAS, etc, in Japan. Therefore, there is still a long way before us to go for E-Commerce in practice, not on the top of information manager's desk.

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