Dial-up Broadband
Connection type Dial on demand Always on
IP address Changes on each call Static or infrequently changing
Relative connection speed Low High
Remote control potential Computer must be dialed in to control remotely Computer is always connected, so remote control can occur anytime
ISP-provided security Little or none Little or none

5. How is broadband access different from the network I use at work?
Corporate and government networks are typically protected by many layers of security, ranging from network firewalls to encryption. In addition, they usually have support staff who maintain the security and availability of these network connections. Although your ISP is responsible for maintaining the services they provide to you, you probably won’t have dedicated staff on hand to manage and operate your home network. You are ultimately responsible for your own computers. As a result, it is up to you to take reasonable precautions to secure your computers from accidental or intentional misuse.

6. What is a protocol?
A protocol is a well-defined specification that allows computers to communicate across a network. In a way, protocols define the "grammar" that computers can use to "talk" to each other.

7. What is IP?
IP stands for "Internet Protocol". It can be thought of as the common language of computers on the Internet. There are a number of detailed descriptions of IP given elsewhere, so we won't cover it in detail in this document. However, it is important to know a few things about IP in order to understand how to secure your computer. Here we’ll cover IP addresses, static vs. dynamic addressing, NAT, and TCP and UDP Ports. An overview of TCP/IP can be found in the TCP/IP Frequently Asked Questions (FAQ) at:

htp://www.faqs.org/faq s/internet/tcp-ip/tcp-ip-faq/part1/

and

h;tp://www.faqs.org/faq s/internet/tcp-ip/tcp-ip-faq/part2/

8. What is an IP address?
IP addresses are analogous to telephone numbers – when you want to call someone on the telephone, you must first know their telephone number. Similarly, when a computer on the Internet needs to send data to another computer, it must first know its IP address. IP addresses are typically shown as four numbers separated by decimal points, or “dots�. For example, 10.24.254.3 and 192.168.62.231 are IP addresses. If you need to make a telephone call but you only know the person’s name, you can look them up in the telephone directory (or call directory services) to get their telephone number. On the Internet, that directory is called the Domain Name System, or DNS for short. If you know the name of a server, say www.cert.org, and you type this into your web browser, your computer will then go ask its DNS server what the numeric IP address is that is associated with that name. Every computer on the Internet has an IP address associated with it that uniquely identifies it. However, that address may change over time, especially if the computer is

* dialing into an Internet Service Provider (ISP)
* connected behind a network firewall
* connected to a broadband service using dynamic IP addressing.

9. What are static and dynamic addressing?
Static IP addressing occurs when an ISP permanently assigns one or more IP addresses for each user. These addresses do not change over time. However, if a static address is assigned but not in use, it is effectively wasted. Since ISPs have a limited number of addresses allocated to them, they sometimes need to make more efficient use of their addresses. Dynamic IP addressing allows the ISP to efficiently utilize their address space. Using dynamic IP addressing, the IP addresses of individual user computers may change over time. If a dynamic address is not in use, it can be automatically reassigned to another computer as needed.

10. What is NAT?
Network Address Translation (NAT) provides a way to hide the IP addresses of a private network from the Internet while still allowing computers on that network to access the Internet. NAT can be used in many different ways, but one method frequently used by home users is called "masquerading". Using NAT masquerading, one or more devices on a LAN can be made to appear as a single IP address to the outside Internet. This allows for multiple computers in a home network to use a single cable modem or DSL connection without requiring the ISP to provide more than one IP address to the user. Using this method, the ISP-assigned IP address can be either static or dynamic. Most network firewalls support NAT masquerading.