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Cable and DSL

Cable

Cable is a great cost-effective connection for a small office or home office or SOHO. Here are afew cable network terms:

Headend This is where all cable signals are received, processed and formatted. The signalsare then transmitted over the distribution network from the headend.

Distribution Network These are relativel small service areas that usuall range in si!efrom "## to $,### customers. The%re tpicall composed of a mi&ed fiber-coa&ial or H'C

architecture with optical fiber substituting for the distribution network%s trunk portion. The fiber

forms both the connection from the headend and an optical node that changes light to radio

fre(uenc )*'+ signals that are then distributed through a coa&ial cable throughout the specificarea being serviced.

DOCSIS (data over cable service interface specification) ll cable modems and like devices

have to measure up to this standard.

In cable network we have to share the bandwidth with all the other subscribers.

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DSL (Digital Subscriber Line)

S re(uires a phone line, a S modem )often included with service+, either an /thernet card

or a router that has an /thernet connection. S group tpes fall into two categories based uponthe upstream or downstream speed connections:

Smmetrical S The speed for both downstream and upstream connections are e(ual orsmmetrical.

smmetrical S ifferent transmission speeds occur between two ends of a networkdownstream speed is usuall faster.

The term &S covers a number of S variations, such as S, high-bit rate S )HS+,

*ate daptive S )*S+, Snchronous S )SS+, 0S1 S )0S+ and ver-high-data-rate S )2S+.

S flavors that don%t use the voice fre(uencies band, like S and 2S, allow S lines to

carr both data and voice signals simultaneousl. Others, like SS and 0S, that occup thecomplete fre(uenc range, can onl carr data. The speed that S service can offer depends on

how far ou are from the CO- the closer the better.

ADSL

S supports both voice and data at the same time, but it was created to allot more bandwidth

downstream than upstream because it%s best for residential subscribers that usuall need moredownstream bandwidth for doing things like downloading video, surfing and email checking etc.

S will give ou downstream rate from $34 5bps to 6.7 8bps, but anthing going upstream

is onl going to reach around " 8bps. O!Sprovides a channel for analog voice transmissionand can transmit without a problem with S over the same twisted-pair telephone line.

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Cabling t"e Serial #ide Area Network

Serial !rans$ission

91 serial connectors use serial transmission, something that take place " bit at a time over a

single channel. C0SCO routers use a proprietar 4#-pin serial connector that ou have to get from

Cisco or a provider of Cisco e(uipment. The tpe of connector ou have on the other end of thecable depends on our service provider and their particular end-device re(uirements. There are

several different tpes of ends:

/0T0-$7$

/0T0-;;6

2.73 )used to connect to a CS