Resilience and survivability in communication networks: Strategies, principles, and survey of disciplines

Peer-to-peer VoIP calls are becoming increasingly popular due to their advantages in cost and convenience. When these calls are encrypted from end to end and anonymized by low latency anonymizing network, they are considered by many people to be both secure and anonymous.In this paper, we present a watermark technique that could be used for effectively identifying and correlating encrypted, peer-to-peer VoIP calls even if they are anonymized by low latency anonymizing networks. This result is in contrast to many people's perception. The key idea is to embed a unique watermark into the encrypted VoIP flow by slightly adjusting the timing of selected packets. Our analysis shows that it only takes several milliseconds time adjustment to make normal VoIP flows highly unique and the embedded watermark could be preserved across the low latency anonymizing network if appropriate redundancy is applied. Our analytical results are backed up by the real-time experiments performed on leading peer-to-peer VoIP client and on a commercially deployed anonymizing network. Our results demonstrate that (1) tracking anonymous peer-to-peer VoIP calls on the Internet is feasible and (2) low latency anonymizing networks are susceptible to timing attacks.

https://cs.gmu.edu/~xwangc/Publications/CCS05-VoIPTracking.pdf

Tracking anonymous peer-to-peer VoIP calls on the internet

Last mile

There is growing interest in capturing and analyzing Internet traffic characteristics in pursuit of insights into its evolution. We present a study of one of the few sources of publicly available long-term Internet traffic workload data, namely the NLANR PMA archive of packet header traces. Trace samples were collected at a number of academic, research, and commercial sites during years 1998--2003. We consider four metrics of traffic: bytes, packets, flows, and number of source-destination pairs. We also analyze the composition of traffic by protocol.

Longitudinal study of Internet traffic from 1998-2003

An open architecture platform bypasses data from the facilities of a telecommunications carrier, e.g. an incumbent local exchange carrier, by distinguishing between voice and data traffic, and handling voice and data traffic separately. An SS7 gateway receives and transmits SS7 signaling messages with the platform. When signaling for a call arrives, the SS7 gateway informs a control server on the platform. The control server manages the platform resources, including the SS7 gateway, tandem network access servers (NASs) and modem NASs. A tandem NAS receives the call over bearer channels. The control server determines whether the incoming call is voice traffic or data traffic, by the dialed number, and instructs the tandem NAS how to handle the call. Voiced traffic is transmitted to a switch for transmission from the platform. Data traffic is terminated at a modem NAS, where it is converted into a form suitable for a data network, such as a private data network or an Internet services provider (ISP). The converted data is sent by routers to the data network. The data network need not convert the data, as the function has already been provided by the platform. In lieu of a conversion, the modems can create a tunnel (a virtual private network) between a remote server and the data network.

System and method for bypassing data from egress facilities

Internet Telephony

Internet traffic, as epitomized by Web browsing behavior, is very bursty, or equivalently, the ratio of the peak to average data rate is quite high. To handle the offered traffic, the network must be sized to handle the peak load. Because the peaks of individual users are typically uncorrelated, the network peak load grows much more slowly than the sum of the peak loads of the individual subscribers whose traffic is carried by the network. This implies there are provisioning scale economies associated with aggregating traffic. That is, service providers that are able to aggregate the traffic of a larger number of users are likely to have lower capital and operating costs and there may be a minimum efficient scale of operation for Internet Service Providers (ISPs). In the current environment where users are accustomed to a relatively poor grade of service (i.e., long packet delays are tolerated) and when most users access the Internet via dial-up modems that limit the possible peak to average load ratio, the impact of these scale economies on industry structure are likely to be small. However, with increased quality of service (QoS) expectations (e.g., addition of delay-intolerant real-time services) and the spread of broadband services offering the potential for much higher peak to average load ratios, the provisioning problem may grow in importance. Although models of aggregate traffic flows have been developed [Kelly, 1998] and others have speculated about the nature of interconnection agreements across the Internet hierarchy [Bailey and McKnight, 1997; Lehr, 1998], we are unaware of any work that attempts to argue from traffic characteristics to industry structure. 1 The simulations on which this paper are based were prepared by Ian Liu in the course of completing his Master's Thesis at MIT (see Ian Liu, 1999), but Mr. Liu did not participate in the preparation of this draft. Drs. Clark and Lehr would like to acknowledge the support of the MIT Internet and Telecoms Convergence Consortium (http://itel.mit.edu).

Provisioning for bursty Internet traffic: Implications for industry and Internet structure

Access to broadband is widely recognized as a prerequisite for a community's economic welfare and the delivery of local government services. In communities where the private sector is perceived as having failed to deliver adequate and affordable broadband services, municipal and county governments face pressures to stimulate broadband deployment. However, no systematic data documents the nature and status of municipal broadband initiatives, the comparative effectiveness of alternative policies for promoting broadband access, or their implications for local economic development, private provisioning of infrastructure, and the operation of municipal and county government. As a result, hundreds of communities are proceeding independently to develop their own strategy, without the benefit of the accumulated experience of those that have gone before, and with no assurance of success. The objectives of this project are to collect, analyze, and disseminate data about the nature and effectiveness of local government initiatives to stimulate broadband deployment, adoption and use, as well as the effects of such initiatives on local e-government and economic development.

/pdf/local-government-stimulation-of-broadband-effectiveness-e-3ofbbszg72.pdf

Local Government Stimulation of Broadband: Effectiveness, E-Government, and Economic Development

: This report describes an effort to understand how the Internet might be designed today if we could make a fresh start. The goal is to understand the current set of requirements that drive the Internet, and to offer long-term directions to help guide the evolution of the Internet in response to these requirements.

Future Generation Network Architecture (New Arch)

The Internet is a network of networks that realizes its global reach by being able to route data from source nodes on one network to destination nodes that may be across town or on the other side of the globe, and in many cases, are on networks that are owned and operated by different Internet service providers (ISPs). Along the end-to-end path, the data may need to cross the networks of still other ISPs. Supporting the end-to-end, global connectivity, which is a hallmark of the Internet’s value proposition, requires that the ISPs be interconnected both physically (i.e., there exists an electronic pathway for transporting packets) and via business relationships. These business relationships impact both the flow of traffic and the flow of money across the Internet value chain. Historically, most traffic was exchanged between the largest ISPs on the basis of revenue-neutral peering agreements that routed traffic but not dollars across ISP interconnections. The explosive growth of video traffic, the increased socio-economic importance of the Internet, and the rise of business disputes over who should pay for the increased costs of traffic have raised questions about whether the time has now come for Internet interconnection to be regulated. In this chapter, we focus on the growing challenge posed by the rise in traffic/usage-related costs for Internet interconnection – attributable today to the rise in entertainment video traffic from content delivery networks (CDNs) – and what this may mean for policy-makers.

David D. Clark

Papers

Internet Telephony

Provisioning for bursty Internet traffic: Implications for industry and Internet structure

Local Government Stimulation of Broadband: Effectiveness, E-Government, and Economic Development

Future Generation Network Architecture (New Arch)

Interconnection in the Internet: peering, interoperability and content delivery