What You Should Know about Wired WANs to Get a Networking Job
You will need to know about wired WANs if you plan to be a networking professional. You must connect to a WAN and not a LAN if you want to connect to the computers on a property. Historically, the easiest way to connect from here to there has been a dial-up circuit over telephone lines using a modem.
The first modem, the Bell 101, transmitted data at 110 bits per second. This speed was far superior to what a skilled Morse code operator could deliver (20 bps) and was comparable to what a skilled typist could key in a Teletype machine (50 bps).
Even better, the pair of Bell 101 modems would also be on duty at all times, never needing a vacation or a break. For an investment of a few thousand dollars, you could avoid paying a human operator $2 per hour.
Modems added intelligence over the years, so that from the early 1960s to the late 1990s, they could eke out up to 56kbps from a single phone line. This is the greatest speed you can practically get from a single phone line, called a DS-0 in telephone lingo.
Speeds available on a DS-0 and below are called narrowband. Anything above DS-0 is broadband. These days, networking professionals think of narrowband as quaint. Broadband signals available from service carriers include DS-1, T-1, E-1, DSL, SONET, DOCSIS, MPLS, and dark fiber. Older technologies you don’t need to be too concerned with anymore (unless you’re a technology history buff) include ISDN, ATM, Frame Relay, X.25, and PSTN.
Buying service from LECs and CLECs
Many data connection services are available from your local phone company. The “local phone company” refers to the company that used to have a monopoly in your particular area. Until the last few decades, some telecommunications companies were given exclusive rights to provide phone and other WAN services in a particular region, such as a city or a specified unincorporated area.
The deal, forced primarily by the Federal Communications Commission (FCC), was that local phone companies would provide local voice telephone service, and other companies would provide long-distance services. The local phone company in your area was called a local exchange company (LEC).
To make a long story short, the LECs wanted to get into providing longdistance voice service. The deal struck enabled existing LECs to offer long-distance services if they allowed other companies to provide local phone service. These were called competitive LECs (CLECs).
Some CLECs ran copper wires to provide service in areas with significant new construction. This practice was the exception rather than the rule. For the most part, CLECs carried high-capacity fiber-optic cable and would provide services to large building and corporate campuses.
Considering the cloud and managed service
An organization can buy individual links to connect the main office to a remote office. These can come from either a LEC or a CLEC. Another option is to buy networking services from a company that specializes in this area.
It is common practice to contract with an Internet service provider to provide Internet connectivity for organizational use and for web hosting. The extreme case of outsourcing network services involves relying upon the cloud. At this point, the only network access you need is a large pipe for Internet access. The cloud provider manages all server storage and security access. The use of cloud-based services is a viable strategy for startups.
Many LECs and CLECs offer managed networking services for their clients. Several IT companies, such as IBM, HP, and Level 3 Communications, provide this kind of service for organizations.