Cable Modem Questions
is a cable modem?
A cable modem is a small box that connects your computer to
the Internet via your local cable television provider. A
cable modem has two connections, one that leads to the cable
lines outside your home and an Ethernet connection to your
computer. A one-way cable modem will also have a telephone
does a cable modem work?
Cable modems modulate and demodulate RF signals. The cable
modem receives data in what is known as the downstream
signal. This signal is modulated on television channels that
are six MHz wide at frequencies between 88 to 750 MHz. Using
QAM 64 technology, downstream speeds can reach up to 27 MBs
on the six MHz channel through which the data is
transferred. This signal usually runs adjacent to other
television signals. 5-1000MHz are required to use this
service along with RG6 100% shielded.
are the advantages of using a cable modem to access the
A cable modem will provide you with rapid download
transmission speeds. Downloading a file that would take
one-half hour using a telephone modem connection will take
only a few minutes with a cable modem connection.
A cable modem provides a
continual connection to the Internet. Two-way cable modems
do not require the use of a telephone line.
Your service will not be
interrupted or receive external static since the outer layer
of the cable line will not allow any noise to enter the
As a high-speed medium, you
will be able to view many different multimedia
presentations---"live" or streamed---such as
concerts, movies, etc.
does a cable modem connect to a computer?
There are three main components that connect a cable modem
to a computer: a coaxial cable, a Category 5 twisted pair
line, and a 10Base-T Ethernet network interface card (also
called a NIC card). The coaxial cable line from the outside
of the building connects to the cable modem. The Category 5
twisted pair line connects the computer to the cable modem.
The network interface card inside the computer enables the
cable modem to "talk" to the computer.
I watch television and browse the Internet at the same time?
Yes, you can. Since television and the cable modem operate
on separate frequencies of the available cable bandwidth,
you will be able to watch television and browse the Internet
at the same time.
fast will a cable modem download and upload data?
Cable modem speeds vary depending on network architecture,
your system configuration, and the number of users accessing
the network at the same time. Network speeds can reach up to
45 Mbps, but speeds will also depend on the service level to
which you subscribe. The asymmetric cable modem scheme is
the most common type of cable network setup, and will allow
for a faster data transmission rate (higher bandwidth) on
the downstream data path than the upstream data path. This
network setup works well since most cable modem users
download more information than they send. For example,
downloading web pages and multimedia files and participating
in newsgroups requires much more bandwidth than sending web
page requests or e-mail.
a telephone line still required when using a cable modem to
access the Internet?
You will not need a telephone line when using a two-way
cable modem. The cable line carries both upstream and
downstream signals. However, you will need a telephone line
if you are using a one-way cable modem. The upstream signal
travels via the telephone line to the cable office and then
to the Internet. Information that you request is sent back
to you via the cable line.
does a cable modem compare to a dialup modem?
Cable modems can connect to the Internet and download
information much faster than a dialup modem. For example, it
will take a cable modem user milliseconds to connect to the
Internet while it will take a dialup modem user about a
minute. Cable modems can also download information at speeds
up to 500 Kbps while a dialup modem will only download
information at 53 Kbps or less.
does a cable modem compare to xDSL?
Cable modems use a RF signal to carry data through your
television cable wire. Since cable modem users share a
single network connection to the Internet, speeds will
fluctuate depending on the number of customers online at the
same time. But we have designed our system so that our users
will not be affected and see a slow down.
xDSL uses the same copper
wire as your copper wire telephone line to carry data, but
the data is carried on a higher frequency than voice. In
order for the xDSL signal to work, the copper wire must be
less than 18,000 feet away from the Telephone Company's
Cable modem speeds and xDSL
speeds are similar, but xDSL is more expensive in most
I become a subscriber, will I still need an Internet Service
No, we will become your service provider. Your service
includes an Internet Service Provider as part of the cable
modem service package. Your service package also includes an
e-mail account(s), news, World Wide Web access and web
my browse time be monitored or restricted?
No, your browse time will not be monitored or restricted.
type of computer hardware and software do I need to use this
If you have a PC, you will need a minimum of a Windows 95
operating system, 50 megabytes of hard disk space, and 16
megabytes of RAM (although we recommend at least 32
megabytes of RAM). A processor of 133mhz or higher is also
If you have a Macintosh, you
will need a minimum of a System 8.0, 50 megabytes of hard
disk space, and 32 megabytes of RAM (although we recommend
at least 64 megabytes of RAM). However, if you are using a
one-way Com21 cable modem, you will need System 8.5 to 9.0
and IPNetRouter software.
many e-mail accounts can I have with my cable modem service?
The number of e-mail accounts included in your service
package will vary by market. Contact your local cable office
for more information.
great! What do I need to do to subscribe to this service?
Contact your local cable office for subscriber information.
network interface card is already installed on my computer.
Can it be used for this service?
Yes, if the network interface card is not already being used
for other purposes, such as supporting a home network. If
your network interface card is already being used, You will
have to provide another network interface card when we
install your cable modem.
I backup my files before the cable modem is installed?
Yes, you should copy and store all of the information on
your hard disk in a different location before the cable
modem is installed. We cannot guarantee the integrity of the
data on your hard disk during the cable modem installation
and Speed Related Questions
is faster---a PCI network interface card or an ISA network
Both the PCI network interface card and the ISA network
interface card provide users with the same Ethernet line
speed---10 megabits per second. However, a PCI card will
communicate with the PC's local bus at at faster speeds,
thereby providing faster through-pt to the user. USB is an
option to use only when no other option is present.
can I do to increase security and prevent hackers from
accessing information on my computer?
The possibility of your computer being "hacked" is
slim to none. Although illegal entry into computer systems
happens every day, it generally occurs in large
corporations. Hackers commonly "sweep" a range of
IP addresses looking for possible "holes" to
exploit. These "holes" are generally provided by
oversights in software development, such as telnet servers,
mail servers, ftp servers, chat servers, etc. Most of our
customers have no need to run these types of services, and
are therefore not vulnerable to such exploits.
However, for your added
security, we recommend you disable "File & Print
Sharing" on your TCP/IP connection. If sharing on your
home network is necessary, we recommend File & Print
sharing be enabled on another protocol that is not
accessible via the Internet, such as NetBEUI. If File &
Print Sharing from the Internet is needed, we recommend you
password protect your shared resources. Other hardware
and/or software solutions exist to protect your computer and
home network from possible Internet attack. It is at your
discretion to use such devices, but they are not supported
by our Customer Care Center.
my IP address change when I start using a cable modem to
access the Internet?
Your IP address may change, but it depends on how the
network is setup.
is a home network?
A home network connects two or more computers together with
network interface cards and network line, and enables the
computers to have file and print sharing capabilities.
you support home networking?
No, we currently support one computer per cable modem
I fax through a cable modem?
Unfortunately, it is not possible to fax through a cable
modem because a fax requires an analog fax/modem to operate.
However, with the correct software, much of which is freely
available, it is possible to send and receive faxes through
an Internet connection without the need of an analog phone
line and fax/modem device.
I host a server with this service?
Unfortunately, hosting servers is not allowed with our
residential cable modem service. This includes, but is not
limited to, web servers, ftp servers, and mail servers. If
you want to run a server, contact your local cable provider
for information about obtaining a commercial subscription.
Internet filtering software (i.e. NetNanny) work when using
a cable modem?
Filtering software that is running locally on your own
system will filter out undesired content. For additional
information about this type of product, contact the vendor.
type of Macintosh hardware and software do I need to use
You will need a minimum of a System 8.0 to 8.5, 50 megabytes
of hard disk space, and 32 megabytes of RAM (although we
recommend 64 megabytes of RAM). If you are using a one-way
Com21 cable modem, you will need System 8.5 to 9.0 and
This cable modem service
utilizes Dynamic Host Configuration Protocol (DHCP) to
assign the IP address to your Macintosh computer. DHCP in
versions of MacOS prior to System 8.0 do not work properly
with our cable modem service.
browsers can I use?
All versions of Netscape and Internet Explorer work well
with our cable modem service.
e-mail programs can I use?
Netscape Communicator, Microsoft Outlook Express, and Eudora
are the most common e-mail programs on Macintosh and work
well with our cable modem service. Other mail programs that
support POP3 e-mail will work, but are not officially
use MacOS 9. Can I perform File Sharing using TCP/IP?
Yes, however for security purposes, we recommend that you
disable the guest access feature when you are not using it.
can I do to increase security and prevent hackers from
accessing information on my Macintosh?
Although the chances of a hacker accessing information on a
PC are slim, the chances of a hacker accessing information
on a Macintosh are even more unlikely. Besides the fact that
we have safeguards in place on our headend equipment to
prevent this type of activity, most hackers try to access
information on PCs simply because there are more of them.
However, to increase security, you can disable the file
sharing over TCP/IP feature when you are not using it and
install security hardware and/or software to make your
system more secure.
have two (or more) Macintosh computers. Can they all use the
same cable modem?
Although it is possible to network Macintosh computers and
connect a single cable modem to your existing LAN, we do not
support this type of configuration
is IPNetRouter and why do I have to use it?
IPNetRouter is a software package that you will need to
install if you are using a one-way Com21 cable modem. MacOS
is not able to simultaneously handle network connections
from a telephone modem and the Ethernet port without the
there any alternatives to IPNetRouter?
Vicomsoft's SoftRouter Plus will perform the same functions
as IPNetRouter but is more expensive.
is a cable modem?
A cable modem is a small box that connects your PC to the
Internet via your local cable TV provider. A cable modem
will typically have three connections, one to the coaxial
cable wall outlet coming in from your local Cable TV
provider and the other two to connect to your PC and your
is cable telephony?
Cable telephony is transmitting anything other than TV
pictures over a cable TV system. That "anything' might
be anything from a data connection to the internet to
simple, standard, analog voice phone calls – local, long
distance and international. Typically, transmitting anything
other than TV over the standard coaxial cable installed at
your house requires a cable modem.
is Direct Broadcast Satellite (DBS)?
Direct Broadcast Satellite is a digital satellite system
transmitting TV programs, which can be received by small
dish antennas typically mounted on either roofs or side of
houses. The receiving dish is stationary, being locked in on
the position of the DBS service provider.
DSL is a term for Digital Subscriber Line. DSL technologies
provide extremely high bandwidth over the twisted-pair
(telephone wire) that runs from your phone company's central
office to your office or home. DSL technology is being
installed by local phone companies in order to provide
faster access for their subscribers to the Internet and also
to counter the competition from the cable TV industry with
its cable modem.
Simply, bandwidth is the capacity to move information.