Why Broadband ISDN?

The carriers knew they had to packetize their networks, and that they needed a new architecture (B-ISDN) supported by a number of new protocols. Here are some of the functions carriers thought they wanted to support.
§  Add a note hereSet up a multimedia video-telephony call between two or more people (involves signaling).
§  Add a note hereCarry the call between two or more people (involves media transport).
§  Add a note herePermit access to music, TV programs and varied computer applications.
§  Add a note hereAllow computers to communicate efficiently at high speeds.
Add a note hereEach of the above functions would be a chargeable service, leading to billing the customer. Carriers also needed to provision, operate, assure, manage, and monitor their networks as per usual.
Add a note hereWhen carriers contemplate network transformation or modernisation, they like to huddle amongst themselves in the standards bodies to agree their target services and design a standardized architecture. The latter consists of a number of components, implemented using switches and servers, plus standardized message formats (protocols) to provide the intercommunication. It’s easy to see why this ends up as a monolithic and closed activity—it all has to be built by the vendors, slotted together and then work properly. Getting the architecture into service is usually a highly complex and multi-year activity, and the cost will have to be covered by more years of revenue-generating service. Supporters of the model have pointed to the scalability and reliability of modern networks, the accountability, which comes from centralized control, and the sheer functionality that can be put in place by organizations with access to large capital resources and internal expertise.
Add a note hereCritics point to the monopolistic tendencies of capital-intensive industries with increasing returns to scale, the resistance of carriers to innovation and the overall sluggishness and inflexibility of the sector. They note that circuit-switched networking began in the 1860s and that it had taken a further 130 years to automate dialling and digitise calls. By the time I was asking my question in Canada, B-ISDN had already been in gestation for around 15 years with no significant deployment.
Add a note hereThe Internet, of course, also took its time to get started. TCP/IP came into service in 1983 and by the late eighties research groups were using e-mail and remote log-in. The fusion of hypermedia and the Internet gave us Web browsers and Web servers in 1993–94 and launched the explosion in general Internet usage. By 1996 there was already a debate within the vendor and carrier community: was the future going to be IP and was the B-ISDN vision dead? It took a further ten years for the industry to completely take on board the affirmative response.
Add a note hereThe Internet always ran on carrier networks. More precisely, the basic model of the Internet comprised hosts (computers running an IP stack and owned by end users) and routers (sometimes called gateways) forwarding IP packets to their correct destinations. The routers could be operated by any organization (often maverick groups within carriers) and were interconnected using standard carrier leased lines. Almost all hosts connected to the routers by using dial-up modems at each end across switched telephone circuits. So from a carrier perspective, the Internet was simply people buying conventional transport and switched services—the specificity of the Internet was invisible. In truth, the Internet was beneath the radar of the B-ISDN project.

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