A Brief History of Wires in the Brain

Metaphors have formed a significant part of the development of neuroscience, often linked with technology. A metaphor that has been widely used for the past two centuries is that of the nervous system being like wires, either as a telegraph system or telephone exchange, or, more recently, in the more abstract metaphor of a wiring diagram. The entry of these terms into scientific writing is traced, together with the insights provided by these metaphors, in particular in relation to recent developments in the study of connectomes. Finally, the place of the wiring diagram as a modern version of Leibniz’s “mill” argument is described, as a way of exploring the limits of what insight the metaphor can provide

Recursion applied to the Erlang B formula for determining the telephone exchange Grade of Service

This paper describes how it is possible to apply a recursion to the original formula of Erlang B., to solve the problem of evaluating large numbers in that formula, using mathematical assistants, in applications designed to determine the grade of service in telephone exchanges.

Recursion applied to the Erlang B formula for determining the telephone exchange Grade of Service

This paper describes how it is possible to apply a recursion to the original formula of Erlang B., to solve the problem of evaluating large numbers in that formula, using mathematical assistants, in applications designed to determine the grade of service in telephone exchanges.

An Overview of Telephony Development in Zagreb (1881-1981)

Within a mere hundred years from the appearance of the first telephone in Zagreb in 1881 until the establishment of the first electronic telephone exchange in 1981, telephony in Zagreb went through several formative periods to assert itself. Zagreb was transformed from a provincial town in the Austrian-Hungarian Monarchy to the economic and cultural centre of Croatia. In that period, due to technological development, many changes took place that influenced the accessibility and price of the most popular telecommunications technology in the 20th century. At first a status symbol reserved for the wealthiest citizens, telephone gradually became accessible to all inhabitants of the city. In the decades after World War II, the new telephone infrastructure was constructed under the unfavourable conditions of technological underdevelopment, scarcity of professionals, and meagre financial resources. Nevertheless, despite all the aggravating circumstances, telephony managed to become an inevitable part of Zagreb’s everyday life. Modern telecommunications rest on these very steps that fixed telephony took in its development, and are therefore an indicator of the technological as well as cultural development of Zagreb.

Warrnambool Exchange Fire — Resilience and Emergency Management

Effective emergency management of a disaster at a single point of failure is vital if the effects of the disaster are to be mitigated. The immediate impacts of a disaster highlight stakeholder perspectives. There is no one-size-fits-all solution to every disaster. Nevertheless, analysing features, aftermath, impact and interim services made available after a disaster provide lessons that can be utilised to avert or mitigate the effects of similar events in the future. This paper provides lessons learnt from a fire that occurred in 2012 in the Warrnambool telephone exchange located in Victoria, Australia and proposes a strategy that provides increased network resilience and more effective emergency management once the copper-based core switching in exchanges is progressively replaced by fibre service area modules.

The Guilty Secret

This chapter studies the use of the controversial surveillance method called ‘Special Facilities’ (SF), the use of which historically MI5 to this day seems keen to conceal. SF was the code name for telephonic electronic eavesdropping, and sometimes for the use of microphones by MI5 for covert purposes in any circumstances. SF in this former sense was often, but not always, used in conjunction with a telephone interception, which was almost invariably set up at the telephone exchange, or at least outside the target’s home or office. The legal questions raised by the use of SF were never properly addressed until 1989. At the heart of it, however, is the question of whether the placing and use of covert listening devices was lawful.

Initial setup of PBX server based on Asterisk

The development of information technology is very dynamic, in particular, actively developing computer networks, which are increasingly used for telephone conversations. Recently, there has been increased interest in IP-telephony technologies, in other words PBX, the use of which can significantly reduce the cost of telephone communication within the company. PBX (Private Branch exchange) is a system of devices that provides automatic connection and support of telephone communication between subscribers of this PBX, who use special end devices — telephones. A virtual PBX is a powerful telephone system that uses an Internet connection as opposed to standard telephone services. A standard PBX is used to transfer calls from the Internet to a public telephone switching network. Virtual PBX can be considered as a more economical version, because no equipment is involved, everything is virtual and hosted by the service provider. Currently, the open communication platform Asterisk occupies almost 85% of the open source PBX market. The Asterisk automatic telephone exchange supports both IP-telephony protocols and traditional communication lines. All basic and advanced PBX functions are supported: voice menu, call recording, call statistics, voicemail, queuing and operator distribution. Video communication is directly supported. The latest versions of Asterisk support call encryption. Asterisk has simple and well-documented interfaces for integration with other systems, making it easy to embed communications in business processes and business applications. There are a large number of various graphical tools for administering Asterisk, both paid and free, among which the most popular is the free WEB interface FreePBX.