So what are some of the basic technologies that they work with? One of them is called ISDN. ISDN stands for Integrated Services Digital Network. This is basically a telephone line made of copper wiring that provides extremely fast data transmissions. There are two types of ISDN. The first one is call the B-channel. This is used for the transfer of data, video, voice or any other multimedia. The B-channel runs at 64 kbps (kilobytes per second). The other type is called the D-channel. The D-channel will either run at 16 kbps or at 64 kbps depending on how you set it up. The D-channel is primarily used to switch your equipment in the ISDN network and the equipment at your ISDN site. Depending on the size of the corporation, the ISDN network can slow down a bit when more people are on the network downloading video, music or applications. Corporations also use this kind of connection for their video conferencing and for remote access to their computer networks.
A T1 line has the power to carry twenty-four digitized voices channels and a date rate of 1.544 megabits per second. A T1 connection can carry about sixty times the amount of data per second than a regular residential modem. The usual cost of a T1 line is around five hundred dollars per month, depending on who the company gets their service from. That may sound like a lot, but it's really nothing in the eyes of a medium sized company. The truth is that even a medium sized company needs more speed than that. Up one from the T1 is the T3 connection. A T3 connection can transmit 43.23 megabits per second and is the equivalent to twenty-eight T1s.
The next up from the T3 connection is the OC1. The OC1 stands for optical carrier because this uses fiber optics instead of copper telephone wiring. The number describes how many multiples of 51.84 megabits per second it can carry. The OC1 is basically a small step up from a T3 connection. Next is the OC3 which can deliver 155.52 megabits per second. Most large companies will use and OC12 connection because it's so strong and reliable.
This article introduces some key Internet service terms and will help you ask the right questions when choosing an Internet Service Provider.
This is how to Learn the Basic Terms
- Internet Service Provider (ISP): This is the company that provides your nonprofit or library with access to the Internet. In the U.S., the major providers of Internet access are phone companies, cable companies, and government entities. There are also smaller ISPs that rent equipment and services from larger companies.
- Broadband: This term doesn't refer to one specific kind of technology. Rather, it's a catchall term for a fast Internet connection. The U.S. Federal Communications Commission (FCC) currently defines broadband as 4 Mbps for downloads and 1 Mbps for uploads. DSL, cable, fiber-optic connections, and dedicated leased lines are all capable of providing broadband-level Internet access.
- Bandwidth and throughput: Both of these terms refer to the amount of data that can be transferred between two points on a network in a given period of time. Bandwidth generally refers to a theoretical maximum, while throughput is a real-world, practical measurement. These terms are sometimes used interchangeably, but they're not quite the same. The distinction is relevant because ISPs will usually advertise their bandwidth, which is often higher than the throughput that you'll actually receive.
- Internet connection types: The most common
connection types are DSL, cable, fiber-optic, and dedicated leased
lines. They vary in their speed capabilities (measured in megabits per
second, or Mbps) and in cost.
- DSL uses traditional telephone lines. Performance depends on how far you are away from the nearest telephone exchange. Residential DSL speeds can reach 20 Mbps for downloads and 1 Mbps for uploads.
- Cable Internet works over standard cable television lines. Residential speeds can reach 100 Mbps for downloads and 2 to 10 Mbps for uploads, and business speeds can be has high as 400 Mbps for downloads and 20 Mbps for uploads.
- Fiber-optic lines offer even better performance. Download speeds range from 15 to 150 Mbps and upload speeds from 5 to 35 Mbps. Experimental services such as Google Fiber can reach download and upload speeds of 1,000 Mbit/s.
- Dedicated leased lines are dedicated (meaning not shared) fiber-optic or copper lines you lease from an ISP. This is the most expensive — but also the most reliable — option because you do not share the line with anyone else, and service levels are guaranteed as part of your contract. Speeds range from 1.5 Mbps (T1 connections) to 4.5 Mbps (T3 connections).
- Uptime: Sometimes referred to as availability or responsiveness, this refers to the amount of time that a network connection is functioning and usable.
- Latency: This is the number of milliseconds it takes for data to travel from one location to another across a network. It is sometimes also referred to as delay.
- IP Address: This is the unique identifier for a computer or other device. If your organization needs to host services such as web, mail, or VPN (virtual personal network), use static IP addressing. If not, use dynamic IP addressing.
Factors to Consider When Choosing an ISP
Business or residential?
ISPs usually distinguish between the services they offer to business users and to home users. Business-class connections provide more reliability, greater upload speeds, and other advantages important to some organizations. However, they'll usually cost a lot more. If your needs are limited, your organization might not need a business-grade connection.How reliable? Are there Service Level Agreements?
Most business-class Internet connections come with assurances regarding uptime, latency, and other metrics. For example, your ISP might guarantee that 99.9 percent of the time your connection will work and, if it doesn't meet that target, it will refund some of your money. These promises are usually captured in a formal document known as a Service Level Agreement (SLA). An example of a Service Level Agreement can be found at Speakeasy.net.How long does the contract last?
ISPs will sometimes offer reduced rates in exchange for a long-term contract. Be cautious about any contract that lasts for more than two years. Services, prices, providers, and technologies are changing all the time. You don't want to be locked into a long-term contract when a cheaper, faster service shows up in your community a year from now.What are the terms of the contract?
Some ISP contracts restrict what you can use your Internet connection to do. For example, some ISPs expressly forbid customers with residential service contracts from hosting websites or other online services. There may also be caps on the amount of data you can upload and download over the course of a month.What are the upload and download speeds?
While you probably spend most of your time on the Internet downloading files and information, you should still pay attention to upload speeds. This is especially true if you host your own website or other online services, or make frequent use of cloud-based services such as file storage and online backup. Most broadband connections marketed to home users are asymmetric. In other words, the upload speed is much lower than the download speed. Business-class broadband connections will usually provide more bandwidth for uploading than residential connections.What are your redundancy options?
Sooner or later, your Internet access will go down. So it's helpful to plan ahead by thinking about other ways you can access critical online resources and information in the event you lose your primary Internet connection. For example, if your cellular phone network is still up and running, you can use mobile devices to access information online, even if your organization's Internet connection is down.Understanding Your Bandwidth Requirements
So how much bandwidth do you need for your Internet connection? Well, that depends on your current usage and your future needs.Current Usage
Does the ISP offer integrated voice and data service?
It's becoming more and more common to get both voice and data services from the same vendor, over the same lines, sharing much of the same equipment. Integrated services can be less expensive and less complicated to manage than separate voice and data services.Are there equipment and installation costs?
Residential plans usually have low equipment and installation costs. In contrast, for business-class Internet connections, the installation and setup fees will usually be much higher, and the equipment can be hugely expensive. You may be able to roll some of these initial costs into your monthly bill by renting equipment from your ISP, but you'll trade lower up-front costs for higher ongoing costs.Understanding your current usage includes:
- Knowing your users. Think carefully about the applications and websites your staff and your clients or patrons use today. What sorts of functionality do you think they'll be asking for in three years or five years?
- Monitoring your network traffic. How fast is demand for bandwidth growing in your organization? How much bandwidth did you use six months ago, and how much are you using today? Network monitoring tools can help you track this information. ABC: An Introduction to Network Monitoring explains what network monitoring tools can do. The Stanford Linear Accelerator Center has an exhaustive list of free and commercial solutions.
Future Usage
The following are some potential changes that would have a major impact on what type of connection you need:- Increasing use of video and audio. Video and audio files are big, and transmitting them over a network takes a lot of bandwidth. As your organization looks to engage your constituents with multimedia, sufficient bandwidth to manage large files is important.
- Adopting cloud solutions. When you are accessing cloud services, you will require a more robust Internet connection.
- Switching to VoIP. VoIP, or voice over Internet protocol, refers to the transmission of phone calls over data lines and Internet connections. If you want to use your Internet connection to carry phone calls, you'll probably need more bandwidth.
0 comments:
Post a Comment