The Experts below are selected from a list of 29742 Experts worldwide ranked by ideXlab platform
Colin Agur - One of the best experts on this subject based on the ideXlab platform.
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negotiated order the fourth amendment telephone surveillance and social interactions 1878 1968
Information & Culture, 2013Co-Authors: Colin AgurAbstract:In the United States the words “telephone surveillance” bring to mind contemporary security concerns about smart phone tracking, the NSA warrantless wiretapping scandal, and the telecommunications provisions of the Patriot Act. Yet telephone surveillance is as old as Telephony itself, dating back to the nearly simultaneous commercialization of the telephone and phonograph. This article examines telephone surveillance by American law enforcement agencies from the inception of telephone service to the passage of the Federal Wiretap Law in 1968, focusing on the challenges an advancing, proliferating, and shrinking technology posed for Fourth Amendment law. To highlight the technological, institutional, and cultural interactions that have shaped Fourth Amendment jurisprudence, the article deploys Jack Balkin's theory of cultural software and Anslem Strauss's concept of a negotiated order and brings together major cases, federal legislation, and evidence of government surveillance. The article argues that duri...
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negotiated order the fourth amendment telephone surveillance and social interactions 1878 1968
Social Science Research Network, 2013Co-Authors: Colin AgurAbstract:In the US, the words ‘telephone surveillance’ bring to mind contemporary security concerns about smart phone tracking, the NSA warrantless wiretapping scandal, and the telecommunications provisions of the Patriot Act. Yet telephone surveillance is as old as Telephony itself, dating back to the nearly simultaneous commercialization of the telephone and phonograph in 1878. First put to use by users, so they would have a written record of business meetings held over the phone, recorders were later put to use by police for surreptitious recording of criminal suspects’ conversations. This article examines telephone surveillance by American law enforcement agencies from the inception of telephone service to the passage of the Federal Wiretap Law in 1968, focusing on the challenges an advancing, proliferating, and shrinking technology posed for Fourth Amendment law. To highlight the technological, institutional and cultural interactions that have shaped Fourth Amendment jurisprudence, the article deploys Jack Balkin’s theory of cultural software and Anslem Strauss’s concept of a negotiated order, and brings together major cases, federal legislation, and evidence of government surveillance. The article shows how telephone surveillance brought the Fourth Amendment into prominence and inspired many of its most contentious debates; the article argues that during the first 90 years of telephone usage in America, laws on search and seizure developed not from constitutional consistency or logic, but as the result of a complex negotiation process involving new media and human agency.
H. G. Schulzrinne - One of the best experts on this subject based on the ideXlab platform.
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reliable scalable and interoperable internet Telephony
2006Co-Authors: H. G. Schulzrinne, Kunda SinghAbstract:The public switched telephone network (PSTN) provides ubiquitous availability and very high scalability of more than a million busy hour call attempts per switch. If large carriers are to adopt Internet Telephony, then Internet Telephony servers should offer at least similar quantifiable guarantees for scalability and reliability using metrics such as call setup latency, server call handling capacity, busy hour call arrivals, mean-time between failures and mean-time to recover. This thesis presents a reliable, scalable and interoperable Internet Telephony architecture for user registration, call routing, conferencing and unified messaging using commodity hardware. The results extend beyond Internet Telephony to encompass multimedia communication in general. The architecture presented in this thesis deals with two aspects: at least PSTN-grade reliability and scalability of the Internet Telephony servers, and interoperable Internet Telephony services such as conferencing and voice mail using existing protocols. We describe the architecture and implementation of our Session Initiation Protocol (SIP)-based enterprise Internet Telephony architecture known as Columbia InterNet Extensible Multimedia Architecture (CINEMA). It consists of a SIP registration and proxy server, a multi-party conferencing server, a gateway for interworking SIP with ITU's H.323, an interactive voice response system and a multimedia mail server. CINEMA provides a distributed interoperable architecture for collaboration using synchronous communications like multimedia conferencing, instant messaging, shared web-browsing, and asynchronous communications like discussion forum, shared files, voice and video mails. It allows seamless integration with various communication means like telephone, IP phone, web and electronic mail. We present two techniques for providing scalability and reliability in SIP: server redundancy and a novel peer-to-peer architecture. For the former, we use DNS-based load sharing among multiple distributed servers that use backend SQL databases to maintain user records. Our two-stage architecture scales linearly with the number of servers. For the latter, we propose a peer-to-peer Internet Telephony architecture that supports basic user registration and call setup as well as advanced services such as offline message delivery, voice mail and multi-party conferencing using SIP. It interworks with server-based SIP infrastructures.
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services for internet Telephony
2004Co-Authors: H. G. Schulzrinne, Jonatha LennoAbstract:Internet Telephony—voice transmission and call signalling over IP networks—can provide services far beyond those of the circuit-switched telephone network. This thesis discusses Internet Telephony services in four broad areas: user-location services; multi-party conferencing; the interworking of Internet Telephony and mobile Telephony; and Internet Telephony feature interaction. User-location services are services which modify how a Telephony server locates a user. Service authors need a way to control this process; this thesis presents two of them. The SIP Common Gateway Interface (SIP CGI) is a low-level server interface which allows fine-grained control of message processing in Session Initiation Protocol (SIP) servers. The Call Processing Language (CPL) is a protocol-independent, inherently safe high-level language for describing services in a way that is easily created and edited. The thesis also describes a general service framework providing a straightforward and powerful API atop which these and other service execution environments can be implemented, and an event thread architecture that makes implementation of transaction-based protocols such as SIP efficient and scalable. Multi-party conferencing involves calls in which three or more people communicate simultaneously. This thesis presents a new approach to conferencing in which a fully-distributed, decentralized protocol establishes a fully connected mesh of signalling and media connections between conference participants. Internet Telephony needs to be able to connect to circuit-switched mobile Telephony networks. The thesis presents a family of system architectures which allow SIP and UNITS networks to be connected directly, allowing traffic to flow directly to the mobile switching center handling a user's mobile terminal. These architectures eliminate triangular routing, transcoding, and other inefficiencies of indirect connections. Finally, whenever services are defined, the issue arises of feature interaction, in which several features or services interact in unexpected and potentially undesirable ways. This thesis explains how Internet Telephony alters the feature interaction problem, discusses the applicability of existing resolution techniques, and presents some new approaches for resolving interactions in the Internet environment.
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providing emergency services in internet Telephony
ITCom 2002: The Convergence of Information Technologies and Communications, 2002Co-Authors: H. G. Schulzrinne, Knarig ArabshiaAbstract:Assisting during emergencies is one of the important functions of the telephone system. Emergency communications has three components: summoning help during emergencies, coordinating emergency response and notifying citizens and public officials of local emergencies. As we transition to an Internet-based telecommunications system, these functions need to be provided, but there is also an opportunity to add new functionality and improve scalability and robustness. We discuss three aspects of Internet-based communications related to emergencies: First, we describe how Internet Telephony can be used to provide emergency call (``911'' or ``112'') services. Secondly, Internet Telephony needs to be enhanced to allow prioritized access to communications resources during emergency-induced network congestion. Finally, Internet event notification can be a valuable new mechanism to alert communities to pending or on-going emergencies such as hurricanes or chemical spills.
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integrating internet Telephony services
IEEE Internet Computing, 2002Co-Authors: Wenyu Jiang, H. G. Schulzrinne, Jonatha Lenno, Sankara Narayana, Kunda SinghAbstract:Cost savings and the ease of developing and adding new services have motivated great interest in Internet Telephony, which integrates services provided by the Internet with the public switched telephone network (PSTN). Internet Telephony relies on several protocols, including the real-time transport protocol (RTP) for multimedia data transport and the session initiation protocol (SIP) or H.323 for establishing and controlling sessions. SIP can integrate with other Internet services, such as email, the Web, voice mail, instant messaging, conference calling, and multimedia collaboration. We have implemented a SIP-based software suite called the Columbia Internet extensible multimedia architecture (Cinema), which we installed and integrated with the existing private branch exchange (PBX) infrastructure in the computer science department at Columbia University. The Cinema environment provides interoperability with the PSTN, programmable Internet Telephony services, and IP-based voice mail. It also integrates Web access and e-mail for unified messaging and supports multiparty multimedia conferencing. The setup lets us extend our PBX capacity and will eventually let us replace it while keeping our existing phone numbers. It also provides an environment in which we can easily add new services and features, including interoperation with existing multimedia tools, e-mail access from standard. telephones, network appliance control, and instant messaging support.
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programming internet Telephony services
IEEE Network, 1999Co-Authors: Jonatha Rosenberg, Jonatha Lenno, H. G. SchulzrinneAbstract:Internet Telephony enables a wealth of new service possibilities. Traditional Telephony services such as call forwarding, transfer, and 800 number services, can be enhanced by interaction with e-mail, Web, and directory services. Additional media types, like video and interactive chat, can be added as well. One of the challenges in providing these services is how to effectively program them. Programming these services requires decisions regarding where the code executes, how it interfaces with the protocols that deliver the services, and what level of control the code has. In this article we consider this problem in detail. We develop requirements for programming Internet Telephony services, and we show that at least two solutions are required-one geared for service creation by trusted users (such as administrators), and one geared for service creation by untrusted users (such as consumers). We review existing techniques for service programmability in the Internet and in the telephone network, and extract the best components of both. The result is a common gateway interface that allows trusted users to develop services, and the call processing language that allows untrusted users to develop services.
Jonatha Rosenberg - One of the best experts on this subject based on the ideXlab platform.
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programming internet Telephony services
IEEE Network, 1999Co-Authors: Jonatha Rosenberg, Jonatha Lenno, H. G. SchulzrinneAbstract:Internet Telephony enables a wealth of new service possibilities. Traditional Telephony services such as call forwarding, transfer, and 800 number services, can be enhanced by interaction with e-mail, Web, and directory services. Additional media types, like video and interactive chat, can be added as well. One of the challenges in providing these services is how to effectively program them. Programming these services requires decisions regarding where the code executes, how it interfaces with the protocols that deliver the services, and what level of control the code has. In this article we consider this problem in detail. We develop requirements for programming Internet Telephony services, and we show that at least two solutions are required-one geared for service creation by trusted users (such as administrators), and one geared for service creation by untrusted users (such as consumers). We review existing techniques for service programmability in the Internet and in the telephone network, and extract the best components of both. The result is a common gateway interface that allows trusted users to develop services, and the call processing language that allows untrusted users to develop services.
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signaling for internet Telephony
International Conference on Network Protocols, 1998Co-Authors: H. G. Schulzrinne, Jonatha RosenbergAbstract:Internet Telephony must offer the standard Telephony services. However the transition to Internet-based Telephony services also provides an opportunity to create new services more rapidly and with lower complexity than in the existing public switched telephone network (PSTN). The Session Initiation Protocol (SIP) is a signaling protocol that creates, modifies and terminates associations between Internet end systems, including conferences and point-to-point calls. SIP supports unicast, mesh and multicast conferences, as well as combinations of these modes. SIP implements services such as call forwarding and transfer placing calls on hold, camp-on and call queueing by a small set of call handling primitives. SIP implementations can re-use parts of other Internet service protocols such as HTTP and the Real-Time Stream Protocol (RTSP). We describe SIP, and show how its basic primitives can be used to construct a wide range of Telephony services.
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the session initiation protocol providing advanced Telephony services across the internet
Bell Labs Technical Journal, 1998Co-Authors: H. G. Schulzrinne, Jonatha RosenbergAbstract:During the past few years, Internet Telephony has evolved from a toy for the technically savvy to a technology that, in the not too distant future, may replace the existing circuit-switched telephone network. Supporting the widespread use of Internet Telephony requires a host of standardized protocols to ensure quality of service (QoS), transport audio and video data, provide directory services, and enable signaling. Signaling protocols are of particular interest because they are the basis for advanced services such as mobility, universal numbers, multiparty conferencing, voice mail, and automatic call distribution. Two signaling protocols have emerged to fill this need: the ITU-T H.323 suite of protocols and session initiation protocol (SIP), developed by the Internet Engineering Task Force (IETF). In this paper we examine how SIP is used in Internet Telephony. We present an overview of the protocol and its architecture, and describe how it can be used to provide a number of advanced services. Our discussion of some of SIP's strengths - its simplicity, scalability, extensibility, and modularity - also analyzes why these are critical components for an IP Telephony signaling protocol. SIP will prove to be a valuable tool, not just for end-to-end IP services, but also for controlling existing phone services.
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internet Telephony gateway location
International Conference on Computer Communications, 1998Co-Authors: Jonatha Rosenberg, H. G. SchulzrinneAbstract:Although the Internet was designed to handle non-real time data traffic, it is being used increasingly to carry voice and video. One important class of contributors to this growth are Internet telephones. Critical to more widespread use of Internet Telephony is smooth interoperability with the existing telephone network. This interoperability comes through the use of Internet Telephony gateways (ITGs) which perform protocol translation between an IP network and the public switched telephone network (PSTN). In order for an IP host to call a user on the PSTN, the IP host must know the IP address of an appropriate gateway. We consider the problem of finding these gateways. An analysis of a number of protocol architectures is presented, including hierarchical databases, multicast advertisement, routing protocols, and centralized databases. We propose a new protocol architecture, called Brokered Multicast Advertisements (BMA) which serves as a lightweight, scalable mechanism for locating ITGs. The BMA architecture is general, and can be applied to location of any service across a wide area network.
D Smyk - One of the best experts on this subject based on the ideXlab platform.
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an architecture for residential internet Telephony service
IEEE Network, 1999Co-Authors: Christian Huitema, J Cameron, Petros Mouchtaris, D SmykAbstract:A new architecture that can be used for offering an Internet Telephony service to residential customers is introduced. The architecture addresses scalability and availability requirements of mass-market deployment of carrier-grade services and supports interconnection with SS7 for Internet Telephony calls to the public switched telephone network. The architecture is based on the concept of a gateway decomposition that separates the media transformation function of today's H.323 gateways from the gateway control function of the gateways and centralizes the intelligence in a call agent. The media gateway control protocol is introduced as the protocol between the call agent that assumes the gateway control function and the gateway that provides just the media transformation function. Interworking between the architecture and the public switched telephone network, the session initiation protocol, and H.323 are also discussed.
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an architecture for residential internet Telephony service
IEEE Internet Computing, 1999Co-Authors: Christian Huitema, J Cameron, Petros Mouchtaris, D SmykAbstract:Network gateways are used to set up calls between the public switched telephone network (PSTN) and the Internet, but existing gateways support a relatively small number of lines. To meet the scalability and availability requirements of mass-market deployment of carrier-grade Telephony services, the authors propose an architecture based on the decomposition of Internet gateway functionality. The media transformation function of today's H.323 gateways is separated from the gateway control function, and intelligence is centralized in a call agent. The Media Gateway Control Protocol is introduced; MGCP is an Internet draft currently under discussion by the IETF for standardizing the interface between a call agent and the media transformation gateway.
Eric Neumayer - One of the best experts on this subject based on the ideXlab platform.
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the ties that bind the role of migrants in the uneven geography of international telephone traffic
Global Networks-a Journal of Transnational Affairs, 2013Co-Authors: Richard Perkins, Eric NeumayerAbstract:Recent work suggests that migrants have been a major driving force in the dramatic growth of international Telephony over recent decades, accounting for large rises in telephone calls between countries with strong immigrant/emigrant connections. Yet, the existing literature has done a poor job of evaluating the substantive importance of migrants in explaining large disparities in levels of bilateral voice traffic observed between different countries. It has also failed to go very far in examining how domestic and relational factors moderate (namely amplify or attenuate) the influence of migrant stocks on international calling. Our contribution addresses these gaps in the literature. For a sample, which includes a far larger number of countries than previous studies, we show that, together with shorter-term visitors, bilateral migrant stocks emerge as the relational variable with one of the substantively largest influences over cross-national patterns of telephone calls. We also find that the effect of bilateral migrant stocks on inter-country telephone traffic is greater where the country pairs are richer and more spatially distant from one another.
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the ties that bind the role of migrants in the uneven geography of international telephone traffic
Social Science Research Network, 2010Co-Authors: Richard Perkins, Eric NeumayerAbstract:Recent work has suggested that migrants have been a major driving force in the dramatic growth of international Telephony over recent decades, accounting for large rises in telephone calls between countries with strong immigrant/emigrant connections. Yet the existing literature has not done a good job of evaluating the substantive importance of migrants in explaining large disparities in levels of bilateral voice traffic observed between different countries. Nor has it gone very far in examining how the influence of migrant stocks on international calling is moderated (i.e. amplified or attenuated) by domestic and relational factors. Our contribution in the present article addresses these gaps in the literature. For a sample which includes a far larger number of countries than previous studies, we show that, together with shorter-term visitors, bilateral migrant stocks emerge as the relational variable with one of the substantively largest influences over cross-national patterns of telephone calls. We also find that the effect of bilateral migrant stocks on inter-country telephone traffic is greater where the country pairs are richer and more spatially distant from one another.
