The term broadband generally refers to the digital subscriber line (DSL) and Internet service provided by CATV companies (cable Internet). The first incarnations of both of these services were aimed at home users, but many companies now offer business-grade service as well (usually at a higher cost). While broadband is becoming more and more popular with consumers, downtime, fluctuating bandwidth, and capped upstream speeds often make consumer DSL and cable services unsuitable for running servers and other mission-critical tasks. Nonetheless, budget-minded IT managers are finding a place for business-class broadband services in their infrastructure.
In this article, I'll compare the advantages and disadvantages of broadband to help you decide which alternative will work for your business. I’ll also consider less common broadband solutions, such as fixed wireless and satellite, SDSL, IDSL, and VDSL.
For a look at the more traditional business offerings related to Internet access, check out my earlier article on dedicated leased line alternatives.
The bewildering varieties of DSL
DSL is a technology that allows high data transfer rates over regular copper phone wiring by using frequencies to send digital signals that can’t be used for analog signals. Most consumer-grade DSL offerings are of a type called asymmetric DSL or ADSL. This refers to the fact that upstream and downstream bandwidth is not equal. Typical download speeds are 1.5 to 6 Mbps, while upstream is generally much slower—anywhere from 128 to 768 Kbps. Many providers offer several different packages with different bandwidth offerings, so you can tailor what you buy to fit your needs.
Business-grade ADSL usually costs more than consumer-grade service, but less than frame relay or T-1 for comparable connection speeds. The difference between a provider’s consumer and business service usually isn’t the amount of bandwidth (connection speed), but rather the level of service. Business customers are paying for amenities such as 24/7 tech support and installation management. For better reliability and performance, some providers connect business-grade customers to a tier-one IP backbone while home customers are connected to a tier-two backbone. With ADSL, the same line can be used simultaneously for phone calls and data transfer.
ADSL may be a cost-effective option if you have a small office that needs Internet services consisting mostly of downstream traffic. Because of the low upstream bandwidth, it’s not the best choice if you want to run your own Web servers or other Internet-accessible servers.
Symmetric DSL (SDSL) is usually offered as a business product. Upstream and downstream speeds are the same (up to about 3 Mbps). This makes it a better choice if you need to run servers, but it’s more expensive and difficult to find SDSL providers in many geographic areas. Distance limitation is about 22,000 feet to the phone company central office (CO), and you don’t get the ability to use the phone for voice as with ADSL.
Very high bit-rate DSL
Very high bit-rate DSL (VDSL) is an extremely fast service, up to 52 Mbps downstream and 16 Mbps upstream. The problem is that distance limitations are very narrow; you must be within about 4000 feet of a CO to get this service. VDSL uses fiber optic cabling, so it costs considerably more than lower speed DSL services—if you can find a provider at all. However, it is excellent for large amounts of users, very high bandwidth applications, and running multiple servers.
Other DSL types
The above are the most common types of DSL, but businesses may find other offerings available in their areas. These include:
- IDSL (DSL over ISDN lines): This is available in some areas where ADSL is not (up to about 35,000 feet from the CO), but IDSL doesn’t give you much of a speed boost over regular ISDN (IDSL connects at 144 Kbps up and down).
- Rate adaptive DSL (RADSL): With this option, the modem can vary the speed based on the line quality/distance.
- Voice over DSL (VoDSL): Suited for telephony applications.
The negatives of DSL
Why hasn’t DSL made the more expensive T-1 service obsolete? There are several disadvantages to DSL. The biggest is the distance limitation for service. Customers must be within about 18,000 feet of a CO to get ADSL, and other varieties have distance limits as well. Also, if you have “fiber to the curb” (fiber optic cabling), you won’t be able to get ADSL. There are other types of DSL that run over fiber, but they’re more expensive and not offered by as many providers. You can get T-1 service just about anywhere you can get voice phone service.
DSL is an option you should consider if your business is located in an area where the type of service you need is available. Service guarantees vary widely from one provider to the next, so you should review contracts carefully and compare both cost and terms of service to those of your other access options.
Cable companies get into the “business” business
Although still primarily marketed to home users, cable access is slowly evolving into a business solution, as well. As with DSL, business-grade packages cost more than those intended for residential customers and usually include 24/7 tech support. Business-grade cable Internet services can be faster (it is possible to get speeds upwards of 10 Mbps with cable, although most residential services provide between 500 Kbps and 1.5 Mbps), and upstream bandwidth may not be throttled as it is with residential service. Terms of service for consumer cable usually prohibit running servers (and providers limit upstream bandwidth to 128 to 256 Kbps to enforce this). Business packages will often allow you to run Web servers over your cable connection.
Cost for business-grade cable is generally comparable to that of business-grade DSL (although prices for both can vary widely depending on the geographic area and provider). You usually don’t have multiple CATV providers to choose from within an area, as you may have with DSL, so the lack of competition sometimes drives prices up. An important consideration with cable Internet is to recognize that it is a shared technology. The more customers there are on an area of cable (in physical proximity), using it at the same time, the lower performance will be. There are also security considerations. It may be possible for other customers in your area to see your computers on their networks if you have a computer directly connected to the cable modem (rather than a router) and you have file and print sharing enabled on the computer’s interface to the Internet. This is easily fixed by properly configuring the interface, but can be a problem in a small business that doesn’t have trained IT personnel.
Cable may be worth checking into if you’re in an area where DSL is not available, you need high speed access, you can’t afford the high cost of T-1, and you don’t need guaranteed bandwidth. If you’re considering using cable Internet for your business, I recommend that you talk to other customers who’ve used the service and ask how well the service has performed for them.
Wire-free alternatives worth checking into
Newer technologies free you from the need for wiring, using the airwaves to send and receive network signals and transfer data. These include satellite and fixed (ground-based) wireless.
Satellite goes professional
Satellite Internet uses geosynchronous satellites, which stay in the same position in relation to the ground at all times. Thus, at your location, you can have an antenna (dish) that stays in a fixed position, which is used to send signals to the satellite and receive signals from it. The satellite provider’s network is connected to the Internet backbone, and also is connected to a dish that transmits the signals to the satellite, which in turn transmits them to you. With most satellite systems, IP data is converted to digital video broadcast (DVB) by equipment at the sending location and goes to the satellite in that format, and is then converted back to IP at the recipient’s end.
The biggest advantage of satellite is the fact that you can locate your office anywhere that has a view of the sky where the satellite is located. This means you can have Internet access out in the middle of a desert where there are no phone lines (assuming your provider offers two-way satellite access; as with early cable modem, some satellite services are one-way only).
Another use of satellite is as a mobile technology, providing Internet access to a company van or RV. Equipment for mobile use is much more expensive, due to the complexity of keeping the dish positioned correctly in a mobile environment. For an example of a mobile satellite provider, see the Internet Anywhere Web site.
There are a large number of companies providing satellite access. These tend to be focused on either residential customers (with speeds of around 400 Kbps, in many cases one-way) or large enterprise-level companies (with service costs of thousands of dollars per month). Some of the consumer-oriented companies such as Hughes Network (DirecPC) also offer business services.
Is the fix in for fixed wireless?
Fixed wireless technology uses ground-based broadcast towers to communicate between the service provider (called a wireless Internet service provider or WISP) and the customer. Fixed wireless is a viable option if your business is located in an area close to where the towers are located. Companies can provide wireless Internet and phone service using the same technology, and in some cases, the signals can be broadcast as far as 35 miles. The speed of the wireless connection depends on the provider’s connection to the Internet backbone, the number of customers using that connection, and whether the provider throttles bandwidth. Cost varies, averaging $100-200/month to connect a small LAN.
A variation on the WISP is the “hotspot” wireless provider. These companies set up short-range wireless access points at airports, restaurants/coffee shops, hotels, and so on. You can connect your Wi-Fi (802.11) equipped laptop to the network and Internet at these locations by paying a fee for the session or by subscribing to a service that gives you unlimited usage of a particular provider’s network. You can find a list of “hotspots” in various geographic areas by using the WiFinder Web site.
Bandwidth aggregation: Making the most of multiple connections
One way to get more speed at a relatively low cost is by aggregating the bandwidth from two or more connections. For example, if you need more than 1.5 Mbps downstream but don’t need high upstream, you could purchase two DSL lines and combine them (using software such as Rainfinity’s RainConnect) for a total downstream bandwidth of 3 Mbps. You can do the same with multiple T-1 lines, multiple cable connections, or even a combination of different types of lines. This has the added advantage of providing redundancy; if one line goes down, you still have one or more working lines for backup.
Debra Littlejohn Shinder, MCSE, MVP is a technology consultant, trainer, and writer who has authored a number of books on computer operating systems, networking, and security. Deb is a tech editor, developmental editor, and contributor to over 20 additional books on subjects such as the Windows 2000 and Windows 2003 MCSE exams, CompTIA Security+ exam, and TruSecure's ICSA certification.