How to Choose an Internet Service Provider

You have a growing array of ISPs to choose from, offering
a wide range of services and pricing structures. An ISP can
be a commercial business or a local university, state agency,
or nonprofit organization. You can find out about ISPs in
your area through the Internet, from advertisements or
the yellow pages, and from Internet books and guides.
You also will find a list of Internet service providers on the
World Wide Web at http://thelist.internet.com
Factors to consider when evaluating ISPs include:
Price
Some ISPs offer access at a fixed rate per month or year.
Others offer service at an hourly rate or by charging per
megabyte of data transferred or archived. If you’re not certain
what your usage level will be, it makes sense to begin with
a fixed-rate plan and then monitor usage. Generally, campus
budgets can handle a fixed commitment of a known amount
more easily than a variable commitment.
Support
If your campus does not have its own networking staff or is
not supported by a central office staff, extra support from
the ISP is a necessity. Ask the provider about onsite configuration
services, training, startup software supplied with the
service, and whether the provider operates a help desk with
phone or e-mail consultation. In addition, peer assistance
can prove invaluable, and some service providers organize
user meetings and similar gatherings to help their customers
use the Internet more effectively.
Access
If the ISP offers dialup access, be sure to ask about the size
of the modem pool and the number of customers the ISP is
serving. Ask the following questions:
• Does the ISP enforce maximum session times and provide
password-protected access?
• Does the ISP use a single access number or a pool of numbers?
• What connection speeds are available? (For example, make
sure the ISP can connect high-speed analog modems—
33.6 K and 56 K—or ISDN digital modems—128 K—if
you have this service. Also note that as of this writing, standards
for 56-K modems were still not solidified. Make
sure your 56-K technology is compatible with your ISP’s.)


Performance
It is important to know how the service provider is connected
to the Internet. For example, it is not effective to have a
T1 leased-line connection from your campus to an ISP if the
ISP is connected to the Internet via a T1 connection or less,
especially if the ISP supports several customers. Generally,
higher connection speeds allow a service provider to
accommodate many users and operate more efficiently.
Additional Services
Internet connectivity requires ongoing network administration
configuration and maintenance. Your ISP may offer
these services, so be sure to ask.
For dialup users: ask your ISP if maintenance of a user
account and mailbox is offered on your behalf, with ample
mail spool space for the number of users who can receive
e-mail at your address. The spool space is very important
because it determines how much content your mailbox
will hold before rejecting new messages.
For direct access users: ask if your ISP offers registration
of network identifiers, such as Internet domain names and
IP addresses. You will also need an Internet server computer
that performs the following functions:
• Domain Name System (DNS)—Provides translation
from URL addresses (for example, www.cisco.com) to
numerical addresses (for example, 198.92.30.31)
• Electronic mail service—Establishes e-mail accounts and
allows campus users to receive and send e-mail
• USENET news—Maintains a local usenet news
conferencing system
• World Wide Web or Gopher publishing—Allows you
to publish information and make it accessible to the
Internet community
Commercial Internet server packages that run on a variety
of platforms are available, or your ISP can assist with many
of these services (see right—“How to Create Your Own
Web Site”).

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How to Connect to the Internet

How to Connect to the Internet

How to Connect to the Internet
The Internet is a global network of thousands of computers,
growing by leaps and bounds each year. It allows a worldwide
community comprising tens of millions of people to
communicate over any distance, access information from
anywhere in the world, and publish text and images instantly.
The Internet is a link to the information resources of
campuses, libraries, and businesses, assisting in research
projects and cross-cultural studies and permitting a free
flow of ideas and studies between students, faculty, and
their peers.
Remarkably, however, a large majority of classrooms
still lack Internet connections. If your campus is among
them, you will be pleased to hear that connecting to the
Internet is easier than ever.

Where connections once required costly special services,
you now have a range of options. Commercial online
services such as America Online and the Microsoft network
offer dialup Internet access for $20 or less per month. ISPs
offer dialup and shared access connections for a variety of
prices, based on a range of line speeds up to T3 (45 Mbps)
for environments with heavy demand or a large number
of users.
On the hardware side, you can make a dialup connection
with a modem attached to one computer or a router
attached to your local-area network, allowing multiple
users to access the Internet.
Modem connections are inexpensive and easy to acquire,
so they are a good idea if you’re just starting out or if your
campus has only a few computers. However, only one person
can use a modem at any given time, leading to heavy
competition for Internet access. A single router can provide
a shared-access solution, accommodating multiple users
and multiple simultaneous Internet connections. It connects
you directly to a router at your ISP’s location.
However you choose to connect, your window on the
Internet is a browser such as Netscape Navigator or
Microsoft Internet Explorer: easy-to-use programs that link
you to any active site on the Internet

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A Wide-Area Network for a Small District

A Wide-Area Network for a Small District
To improve communications between campuses and their central office, the campuses decide to install a wide-area network. The upgrade economizes on Internet connectivity
by offering all campuses a connection through a central high-speed line

.

A Community College WAN
A growing community college system sees rising network traffic at its three campuses. It wants to install future-ready local networks to support multimedia applications and to
provide high-speed WAN links that will allow south and west campus students to take advantage of north campus courses via the network (distance learning). In addition,
because many students commute from great distances, the college wants to allow students at all three campuses to dial up their local servers from home and retrieve assignments
and communicate with professors.

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Modems vs. Routers

Modems vs. Routers

When choosing between modems and routers for remote
access to a central network or the Internet, consider the
following pros and cons:
Modems
• Inexpensive
• Good for one user or limited remote access for a small group
• Portable, so they can be used remotely from any location with
a phone line
• Compatible with existing telephone lines
• Connections can be made at a relatively low cost (essentially
the same as a local or long-distance phone call)
Routers
• Support faster WAN connections than modems
• Support multiple users
• Many routers have a “live” connection (so you don’t
get busy signals), and you save time not having to dial up
the connection
• The connections are more reliable than with telephone lines
but may be more costly than ordinary phone lines and may not
support voice calls
• Offer data encryption (for enhanced security) in addition to
data compression (for enhanced performance)
Dial-on-demand routing” (DDR) is sometimes used as a
compromise between the dialup method of connecting and fullfledged
routing. “Dial-on-demand” means the router establishes
(and is charged for) a connection only when the connection is in
use. This solution uses a basic router paired with either a modem
or an ISDN line, which makes the calls as needed, when the
router requests a connection.

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ISDN

ISDN

ISDN is a service that operates at 128 Kbps and is available

from your phone company. Charges for ISDN connections

usually resemble those for analog lines—you pay per call

and/or per minute, usually depending on distance. ISDN

charges also can be flat rate if linked to a local Centrex system.

Technically, ISDN consists of two 64-Kbps channels

that work separately. Load-balancing or “bonding” of the

two channels into a 128-K single channel is possible when

you have compatible hardware on each end of a connection

(for instance, between two of your campuses). What’s more,

as a digital service, ISDN is not subject to the “line noise”

that slows most analog connections, and thus offers actual

throughput much closer to its promised maximum rate.

You can make ISDN connections either with an ISDNready

router or with an ISDN terminal adapter (also

called an ISDN modem) connected to the serial port of your

router. Again, modems are best for single users, because

each device needs its own modem, and only one “conversation”

with the outside world can happen at any one time.

Your ISDN router, modem, or terminal adapter may come

with analog ports, allowing you to connect a regular

telephone, fax, modem, or other analog phone device. For

example, a ISDN router with an analog phone jack would

allow you to make phone calls and send faxes while staying

connected via the other ISDN digital channel.

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Analog Lines

Analog Lines

Using analog lines to dial out to other networks or to
the Internet—or to allow remote users to dial into your
network—is a straightforward solution. Most ordinary
phone lines are analog lines. Connect a modem to your
computer and to a wall jack and you’re in business. You
pay for a connection as you would pay for a phone call—
by the minute, or a set rate per local call (long distance
charges are the same as for a long distance telephone call).
At present, the fastest analog modems operate at
56 Kbps for transferring data. With today’s larger file sizes
and graphically sophisticated World Wide Web sites on the
Internet, you should look for modems that operate at a
minimum of 33.6 Kbps (also called V.34) and have
V.42 (error correction) and V.42bis (data compression)
capabilities for better performance.
While modems offer a simple solution for dialout
connections to other LANs and the Internet, they do not scale
well as your network grows. Each modem can support only
one remote “conversation” at a time, and each device that
wants to connect with the outside world needs a modem.
See the examples in the next section for ways to overcome
this limitation by installing a router for wide-area communications

and your Internet link.


Analog vs. Digital

The difference between analog and digital signals is very important
for data communications. The most familiar “analog”
communication is a phone call. Varying electrical voltage reflects
the variations in the volume and tone of the human voice. By
contrast, digital communications use a series of 1s and 0s to
carry information from point to point. Modems actually convert
the digital data of one computer into an analog signal for transmission
over the phone lines. On the receiving end, another
modem converts the analog signal back into a series of 1s and 0s,
so the receiving computer can interpret the transmission. Today,
phone companies can offer fully digital service between LANs
(leased lines such as 56 K, 384 K, and T1s are digital services), or
Integrated Services Digital Network (ISDN) which allows dialup
connections on an as-needed basis. When it comes to moving
data, digital communications are less susceptible to errors and
faster than analog signals because they are not susceptible to

problems such as electrical “noise” on transmission lines.

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Remote Access and Wide-Area Networks

                 Remote Access and Wide-Area Networks

LANs accommodate local users—people within a building
or on a campus. WANs connect users and LANs spread
between various sites, whether in the same city, across the
country, or around the world. “Remote access” refers to
a simple connection, usually dialed up over telephone lines
as needed, between an individual user or very small
branch office and a central network.
Your campus gains access to the Internet through
some type of remote connection. A single user can use a
modem to dial up an Internet service provider (ISP). Multiple
users within a campus might choose to rely on a router
to connect to the ISP, who then connects the campus to
the Internet.
In general, LAN speeds are much greater than WAN
and remote access speeds. For example, a single shared-
Ethernet connection runs at 10 Mbps (mega means “million”).
Today’s fastest analog modem runs at 56 kilobits per second
(Kbps) (kilo means “thousand”)—less than one percent of
the speed of an Ethernet link. Even the more expensive,
dedicated WAN services such as T1 lines don’t compare (with
bandwidth of 1.5 Mbps, a T1 lines has only 15 percent of
the capacity of a single Ethernet link). For this reason, proper
network design aims to keep most traffic local—that is,
contained within one site—rather than allowing that traffic

to move across the WAN.

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