Neon-komputadórComputer Users Manual, Ministry of Foreign Affairs and Cooperation, Democratic Republic of East Timor
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Languages EnglishPortuguese Índice IntrodcutionChapter II: Networks and Communications Basic ConceptsModems Integrated Services Digital Network(ISDN) Leased-Lines CATV ("Cable Modems") Direct Subscriber Lines Network Interface Cards Network Typologies Repeaters, Hubs and Switches Bridges, Routers and Brouters Wireless Ethernet Modem Protocols OSI and TCP/IP Other Network Protocols TCP/IP Lower and Middle Layers TCP/IP Upper Layer: Applications The Internet Chapter III: Operating Systems Chapter IV: Applications Chapter V: Basic Coding and Programming Chapter VI: Basic System Administration Appendicies: Ministry Policy Ministry Hompage |
Leased-Lines (aka T-1 and T-3 connections) Leased-lines are a dedicated, 24-hour a day, digital service between two location with extremely high bandwidth. A T-1 connection leased-line is recommended for those who need to connect to high bandwidth networks in distant locations, for networks that support a large number of Internet users or for those that will be hosting their own Internet service. Running at more than ten times faster than an ISDN link at 1.55mbps, a T-1 can be split depending on use, up to 24, 64kbps lines. An individual user on a leased-line is using the Internet directly - as such leased lines are sometimes called the 'backbone cable'. When a user calls up an Internet Service Provider, they share a portion of a T-1, which is referred to as a Point of Presence (POP). Depending how many users accessing that ISP or region network connectivity may appear fast or slow even though modem speed is the same. Cable or Cabal? One of the terms you may here, in hushed tones and a wink, is the existence of the "Internet Cabal". This is an allegedly secret group that is really actually in control of the network. As silly as it may sound, it does have a kernel of truth to it. Administrators of sites that have higher bandwidth and more connections have significantly more leverage over content that those that a relatively bandwidth and connection poor. The term arose in the 1980s during a period called 'the Great Renaming' in Usenet, the Internet public news services. Proposed changes were able to be implemented only with the support of the hosts of major sites. The term is a pun on the word 'cable', as these site hostmasters were invariably connected with leased-lines. T-3 leased lines have the equivalent of roughly 28 T-1 lines running at a total of 45mbps. They are only appropriate for large university campuses and very large networks. They are well and truly out of the price range of most individuals and indeed most organizations. |
Ministry of Foreign Affairs and Cooperation, GPA Building #1, Ground Floor, Dili, East Timor
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