The Internet's Coming of Age (2001) / Chapter Skim
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4 Collisions Between Existing Industries and Emerging Internet Industries: Telephony as a Case Study
4 Collisions Between Existing Industries and Emerging Internet Industries: Telephony as a Case Study
Pages 151-176
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From page 151... ...
For reasons that range from reducing the costs of conventional telephony by using less expensive technology, to bypassing the tariff structure of the existing public switched telephone network (PSTN) , to innovating new forms of telephony services and applications, many efforts are under way to use the Internet and its technology components to provide voice services.
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From page 152... ...
.~ Telephony over IP networks is also being deployed within enterprises (generally replacing PBX functionality) , with the goal of achieving lower costs by operating a single network carrying both data and voice.2 These developments are emblematic of a broader trend toward Internet services that overlap and potentially exceed or even supersede communications services that have long existed as distinct industries with distinct policies and regulations governing them.
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From page 153... ...
Another function that is generally provided in any telephony application is a directory lookup service that associates a phone number or other identifier with a particular telephone line or IP device.4 Some designs amount to little more than a substitution of IP technology for transport within the network. For instance, IP may be substituted for other means of transporting communications within the networks of telephony providers; this internal substitution of IP technology for transport within the network raises few policy issues that are distinguishable from those raised by the introduction of other new technologies or the entry of new players into the "traditional" PSTN business.
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From page 154... ...
For example, telephony services may be provided by a single vendor in a centrally managed way (perhaps over a dedicated network) or provided as a distributed service with individual users placing calls end-to-end over the Internet, perhaps making use of services such as directory lookup provided by a third party.
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From page 155... ...
is the public Internet approach adopted by a number of IP telephony start-up companies. It uses the same generic form of entry a gateway between the PSTN and an IP data networkbut replaces packet transport over dedicated IP links with transport over the public Internet.
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From page 156... ...
1997. A Taxonomy of Internet Telephony Applications.
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From page 157... ...
TELEPHONY AS A CASE STUDY 157 IP Device ~J IP \Trans~ IP Device (it Class 3: IP to IP. Computer telephony devices are used at both ends and the connection is made solely through IP networks or the Internet.
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From page 158... ...
Using the public Internet THE INTERNET'S COMING OF AGE Billing and Customer Care System En ' I Router Router Ed ~3 ~3 EM Router Router I nternet Seoul Company Private IP Network NOC En ETCH PTT FIGURE 4.2 Two examples of class 1 IP telephony configurations. LEC, local exchange carrier; IGN, IP gateway node; and PTT, Post, Telegraphs, and Telephones.
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From page 159... ...
The opening up of the PSTN service creation architecture is aimed at increasing the flexibility of the infrastructure and enabling a greater number of parties to create useful services. In the AIN, the service creation environment and the applications are provided by the service provider
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From page 160... ...
Also, local access is evolving to support higher data speeds as datacentric communications are introduced in the local loop in the form of DSL and digital optical fiber deployments closer to end users in telephone networks and in the form of hybrid fiber coax deployments in cable networks. PSTN's evolution from a predominantly circuit-switched to a packetswitched architecture is producing a significant change in architecture construct and concomitant operations.
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From page 161... ...
Telephony is understood to refer to communication between devices attached to the public switched telephone network (e.g., telephony regulations do not apply to two-way radios or in-building intercom systems)
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From page 162... ...
Many industry analysts predict that the rapid growth of data networks, particularly the Internet, will lead to the melding of voice and data networks, and that voice traffic will increasingly be carried using IP technology. There are a number of practical reasons why IP telephony could over time supplant traditional PSTN voice services.
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From page 163... ...
The latest trend is the significant increase in the number of players as new competitors emerge in the local telephone market (the competitive local exchange carriers, or CLECs) , with entrants such as Qwest and Level 3 challenging the incumbent longdistance telecommunications carriers.
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From page 164... ...
One possibility is that IP telephony networks will be melded together using IP, so that calls are carried end-to-end over IP. It is also possible that there will be many IP telephony networks built by a variety of players (both traditional local and interexchange carriers)
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From page 165... ...
INTEROPERATION BETWEEN IP TELEPHONY AND THE PSTN Whatever the course of change for the Internet and the PSTN,itis clear that for the foreseeable future, dedicated IP networks, the public Internet, the PSTN, and hybrids of these will all play a role in delivering telephony services. From a customer perspective, a smooth transition will depend on the extent to which telephony networks remain interconnected (anyone can continue to place a call to anyone else)
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From page 166... ...
7See IETF IP Telephony working group charter, available online at |
From page 167... ...
This suggests that Internet service providers and other Internetbased telephony providers should be able to issue new telephone numbers to their customers, even to those who do not have conventional telephone service, so as to provide compatibility across calls originated or terminated on conventional and IP-based telephones. Additional issues arise when a given household uses both PSTN and Internet services.
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From page 168... ...
and different types of devices? What is required to meet the needs of telephony that runs over the public Internet in contrast with telephony that runs over private networks using IP technology, and what are the implications for the signaling and control infra~5Unlike the old naming schemes for telephone exchanges te.g., '~Jacksonville 6-500 i, in which there was a fixed mapping between name and exchange, a naming scheme that provides indirection allows the number with which a name is associated to be easily changed, perhaps at the direction of the telephone user.
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From page 169... ...
The committee foresees some interesting complications. For instance, a household of the future might well employ both conventional PSTN telephone and IP telephony equipment, with the latter making use of one or more local access technologies (e.g., IP over DSL or IP over a cable modem)
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From page 170... ...
How do the provider-proprietary applications for specific customers affect the service creation environments? If networks carrying voice networks are to continue to meet stringent performance requirements in the face of opening them to a diverse set of providers, the ability to control against overload and provide enhanced robustness will need to be included.
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From page 171... ...
The potential inconsistency between the assumptions underlying existing regulations and those that would be applicable to new forms of telephony is well illustrated by one concern raised by local exchange carriers that has been the subject of FCC regulatory attention: Would local termination tariffs be applied to phone calls carried on the Internet? Internet telephony services (or the ISPs that carry the data associated with the phone call)
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From page 172... ...
requirements (see Box 4.1~.19 CALEA required telecommunications carriers to provide assistance for law enforcement in carrying out wiretaps. In its ruling, the FCC mandated that cable television and IP services inasmuch as they provide telecommunications services and are a telecommunications carrier and thus a common carrier, at least for the purpose of CALEA are subject to CALEA.
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From page 173... ...
TELEPHONY AS A CASE STUDY 173 Robustness and quality are also expected of telephony services, manifested in state and federal regulatory attention to carrier performance. The relative ease with which the Internet can offer voice services means that many businesses will be in a position to offer voice services, probably over a broad spectrum of service quality and reliability, from robust and high quality to fragile, unreliable, and low quality.
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From page 174... ...
Three such issues are as follows: · In Internet telephony, there are no meaningful distinctions between local and interexchange carriers. The existing regulatory regime, in which local and long-distance services are separated and in which customers select a particular long-distance carrier to carry calls outside their local area, does not map onto Internet telephony because the architectures of the two networks are so different.
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From page 175... ...
If ISPs were required to ensure that voice traffic carried over their networks falls under a particular set of rules, it would become necessary for them to examine all the traffic over their network to screen out "unacceptable" voice communications. Because telephony providers are free, in keeping with the Internet's edge-based innovation model, to design their own protocols for telephony, it can be impossible to reliably identify which traffic is associated with telephony applications.
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From page 176... ...
The result may be large transformations and dislocations in existing markets; the result may also be stressful for the Internet, its design principles, and its service providers. One predictable trend is the use of existing regulation by incumbents to protect a legacy industry position.
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