|
Residential access, connecting home end systems into the network.
Refers to connecting a home end system to an edge router. One form of residential access is the dial-up modem orver
an ordinary analog telephone line into a residential ISP. There are two common types of brodband residential access: digital
subscriber line (DSL) and hybrid firer-coasial cable. While DSL and dial-up modems use ordinary phone lines, HFC
access metworks are extensions of the currect cable network used for bradcasting cable television. HFC requires special modems,
called cable modems. One of the attractive features of DSL and HFC is that the services are always on.
Company access, connecting end systems in a business or educational
institution into the network. On coporate and university campuses, a local area metwork (LAN) is typically used to connect
an end system to the edge router. Ethernet technology is currently by far the most prevalent access technology in comapny
networks. The dege router is responsible for routing packets that have destination outside of that LAN.
Wireless access, connecting end systems (that are often mobile)
into the network.Accompanying the current Internet revolution, the wireless revolution is also having a profound inpact on
the way people work and live.In a wireless LAN, wirieless users transmitt.receive packets to.from a base station within
a radius of a few tens of meters. The base station is typically connected to the wired Internet and thus serves to connect
wireless users to the wird network. In wide-area wireless access networks, the base station is managed by a telecommunications
provider and serves users within the radius of tens of kilometers
|
