22-05-2012, 02:05 PM
Accessing the Internet using a Cable Network
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Cable Access Q&A - Part One
Accessing the Internet using a Cable Network (and a cable modem) is becoming increasingly
more popular due to the much greater speed than is available through telephone-modem
access. Vicomsoft has gained valuable experience and knowledge about cable access and
would like to make this information available to those interested in the subject.
We are presenting the information in a Q&A (Questions and Answers) format that we hope will
be useful. Our current knowledge relates primarily to cable access in the USA and Canada
although we understand that cable access to the Internet is growing in a number of countries
world-wide. The explanations we provide should apply equally to cable access in most
countries. We welcome feedback and comments from any readers on the usefulness or content.
All aspects of the Internet, and especially access via cable networks, are constantly changing.
We are providing the best information available to us as at date of writing and intend to update it
at frequent intervals as things change and/or more information becomes available. However, we
intend this Q&A as a guide only and recommend that users obtain specific information from
local cable companies to determine applicability to their specific requirements. (This is another
way of saying that we cannot be held liable or responsible for the content).
The full Q&A is in two parts, each part divided into a number of sections. Part One is general in
nature and less technical, while Part Two deals with more technical matters.
Vicomsoft does not sell cable modems or access to the Internet via cable systems.
Furthermore, our products can be used with any type of Internet connection, be it modem dialup,
ISDN, T1, or cable modem. In other words, we are neutral on the subject of how people
connect to the Internet (but will admit to being biased to encouraging people to connect).
From our tests, from feedback we have received from users, from the recent progress made by
the cable companies and from what we have read, it would appear that accessing the Internet
via cable systems using cable modems is an option that is definitely worth considering for users
who have it available to them.
Part One: Questions
1. What is a Cable Network?
2. What does a TV cable system have to do with the Internet?
3. Why is access via a Cable Company faster?
4. Why has it taken cable companies so long to provide Internet access?
5. Can everyone have Internet access via Cable Services?
6. How do I get connected to a Cable Network for Internet access?
7. Do I need a separate cable for each service?
8. How do I access the Internet using the Cable Network?
9. How do I use the telephone services for Internet access?
Content of this page in its entirety is protected by US & UK Copyright
© 2002 Vicomsoft Ltd
Reproduction in electronic and written form is expressly forbidden without written permission.
10. What is a Cable Modem?
11. How do I get a Cable Modem?
12. How does a Cable Modem's speed compare with other connection methods?
13. What is the theoretical performance of a Cable Modem?
14. What is the real-world performance?
15. What is the point of having all this bandwidth available?
16. How should I choose between what type of connection to use?
17. How much does it cost?
18. How does a Cable Modem actually work?
19. How does the Cable Modem physically attach to my computer?
20. What is a Telco Return Cable Modem service?
21. What if I have more than one computer?
22. What's the downside of using Cable access?
23. What's the bottom line? What does Vicomsoft recommend?
Part 1: Answers
What is a Cable Network?
Cable Networks began in the USA over thirty years ago to provide TV access to locations that
had difficulty in receiving TV signals transmitted by normal transmission towers. This included
many inner city locations where TV reception was poor due to interference from buildings. In
addition, geographical conditions around some towns, and cities (such as mountains) made it
impractical for each building to have its own tall costly aerial. From a practical point of view, it
was also more efficient to have a TV signal 'delivered' to a central location in a building or a
community and then passed to individual TV sets than to have each TV set connected to its
own external aerial.
Cable Companies were formed that normally obtained a license or franchise for a specific
geographic location and sold access for a monthly subscription. Initially Cable Companies
rebroadcast signals from the major TV networks and did not provide any of their own content.
The communications industry is an ever changing and fast moving industry so it was not long
before Cable Companies began offering their own content and special content, often provided
at a premium price (such as movie channels or sports channels).
At this juncture in our explanation, its worth emphasizing two points that will be elaborated on in
more detail later.
Firstly, although Cable Companies had central distribution points, they also ran a unique
connection directly into each house, apartment or office (as in the case of a telephone line).
Secondly, the cable connection was intended to deliver TV signals which by their nature, require
high bandwidth (more on this later).
What does a TV cable system have to do with the Internet?
Content of this page in its entirety is protected by US & UK Copyright
© 2002 Vicomsoft Ltd
Reproduction in electronic and written form is expressly forbidden without written permission.
As Cable Companies began to proliferate and expand, they began to recognize that they could
provide services in addition to TV signals. Many began to offer telephone services which of
course they were able to do relatively easily because they already had a connection running
into premises. In this respect they were competing with traditional telephone companies who
also had a connection into premises. The recent spectacular growth of the Internet offers Cable
Companies a further opportunity, particularly since they can connect a user to the Internet at
much faster speed. As anyone who has used the Internet knows, the faster the speed of
access, the more useful and enjoyable the experience. Conversely, slow access can discourage
frequent use and even deter it. Some Cable Companies spotted the (now) obvious opportunity if
(1) they could provide Internet access and (2) if they could provide faster speed.
Why is access via a Cable Company faster?
Cable Companies by their very nature set up cabling and networks to provide TV signals which
required far more signal throughput (bandwidth) to be communicated. Modern Cable Networks
use fiber-optic cabling directly into the premises which cabling is theoretically capable of
delivering vast amounts of data. On the other hand, most telephone subscribers have old
'copper cable' connecting them to their telephone company's high speed network.
(Note: Not all Cable Company connections use fiber-optic cabling. Some older ones use coaxial
cabling which, although superior to 'copper wire' telephone cabling, does not provide the same
throughput as fiber-optic.)
Why has it taken cable companies so long to provide Internet access?
Cable Companies can provide Internet access in two ways - either by a 'telephone dial-up type'
of service or by a new high speed connection. Since they are able to provide telephone lines,
their subscribers can usually use tradition connection devices such as modems or ISDN. This
however is normally not much improvement over normal telephone dial-up access.
Cable companies had several problems to solve before being able to use their high bandwidth
capability and offer high speed Internet access. The first issue to be dealt with was that cable
networks were initially designed to deliver signals (i.e. TV) to subscribers and were usually not
designed to receive data (as they would if they were providing Internet access). To solve this
they would have to change equipment at both the subscriber end of the cable and at their own
end of the cable. At the subscriber end they would have to provide a new device called a 'cable
modem' while at their own end (called the 'head-end') they would have to change equipment to
be able to receive data from the subscriber. They would also have to arrange for their head-end
switch to be connected to the Internet backbone itself.