Compare and contrast Internet connection types, network types, and their features: CompTIA A+ 220-901 sub-objective 2.7
Detailed (and official) description of CompTIA A+ sub-objective 2.7
2.7 Compare and contrast Internet connection types, network types, and their features.
> Internet Connection Types
Line of sight wireless internet service
> Network Types
Welcome to CertBlaster ExamNotes! This section will cover CompTIA A+220-901 sub-objective 2.7. When you are finished you will have been exposed to everything covered by the objective statement. We will look at internet connection types and features. Let’s get to it.
Internet Connection Types
Once limited to the POTS dial-up connection, internet connectivity has woven its way into our daily existence. It’s hard for some of us, now, to imagine having to go home to access a webpage or email. Here is how it breaks down.
The cable internet connection is a broadband high speed internet connection that is always on. It uses a cable modem that communicates over the same line that carries your cable television signal. It is capable of very high speeds depending on your service agreement. Cable modems can support voice and data and can be wired or wireless based on your preference. Typically your cable modem can give you up to 160Mbps depending on your plan.
DSL (Digital Subscriber Line) uses the existing ordinary copper telephone lines (POTS. In its basic configuration it feeds three signals to and from your DSL modem there are two 64Kbps channels providing 128Kbps for data that can be split to carry voice on one line and data over the other allowing you to use internet services and talk on the phone at the same time. The third line carries command and control data consuming very little bandwidth. This is an “always on” connection type and there is no need to dial-up the connection. There is a variety of DSL technology available but all use the same infrastructure cabling for communication. The later versions of the technology use different techniques to achieve higher speeds. One method is Symmetric Digital Subscriber Line (SDSL) the symmetry referred to in its name applies to equal upload and download rates. SDSL can reach theoretical speeds up to 22Mbps. Another method Asymmetrical Digital Subscriber Line (ADSL) where the upstream and downstream speeds are not the same. This allows the provider to adjust the data rate according to what the customer is willing to pay for, maxing out at 640Kbps upstream and up to 24Mbp downstream. A variation of SDSL is VSDL (very-high-bit-rate Digital Subscriber Line) which is capable of up to 70Mbps over short distances.
Dial-Up technology has been around since the beginning. It uses POTS lines as does DSL but the connection is not persistent. Dial-up requires a modem (modulate/demodulate) to modulate the digital signal from a PC to the analog waveform used by the phone lines then on the receiving end the signal is converted back to digital or demodulated. Dial-up modem speeds began at 14.4Kbps, increasing to 28.8 and ultimately with v92 technology achieved a blistering 56Kbps. Each of those speed increases were greatly anticipated and considered groundbreaking in the pro-broadband era.
Fiber optics provide the highest bandwidth currently available in a range up to 43 terabit per second depending on your provider. This is made possible mainly by the capacity of the media and also by the fact that you are on a dedicated line. It is yours and yours alone, point to point. This requires fiber to the premises, directly from the ISP to the building and on to the device, no copper.
Satellite communication takes advantage of satellites orbiting the earth in a geosynchronous orbit, meaning at any point in time the satellite will be in the same location relative to your position on Earth. There are over 400 satellites orbiting in this manner. Most are communication satellites delivering voice, data, video and internet. Typically these connections max out at 15Mbps. The necessary equipment is a roof mounted satellite dish aimed at the target satellite and a receiver (or transceiver) to send and receive data.
Line of Sight
Satellite and long range wireless internet transmissions requires an obstruction free line of sight between the devices. They can also be impacted by severe weather and are not the best choice for live streaming.
Chances are slim that you will encounter ISDN (Integrated Services Digital Network) in the field. ISDN was aimed at the business class user in the pre-broadband era. You need to know what it is and its bandwidth which is up to 128Kbps.
Cellular communication takes place over a CDMA (Carrier Sense Multiple Access) network of fixed antennae placed strategically to provide the best coverage areas in North America. Internationally satellites in conjunction with are used in the GSM (Global System for Mobile Technology) standard prevails in the rest of the “covered” world. Consider cellular service in any of the varieties (later) as the largest wireless internet connection type in the world. So here it goes. 2G cellular is actually slower than dial up on paper, your results may vary but don’t expect more than 50Kbps on this connection. The next advance was 2G E or 2G EDGE (Enhanced Data for GSM Evolution) which brought the speed up to 384Kbps. Then came 3G which is a noteworthy improvement when properly implemented. You will see speeds between 200K and 4Mbps. Check for the latest revision of the standard. And now the hands down winner 4G (LTE or WiMAX) this will get you between 100Mbps and 1Gbps. 4G LTE is the fastest combination and you are likely to encounter more LTE implementations than WiMAX.
This technique allows you to connect your cellphone to a laptop or tablet through USB or Bluetooth enabling devices using the phone’s cellular connection to provide mobile connectivity to another device. This connection is a one to one connection share. Good for essential connectivity this connection type offers limited bandwidth and if used over a Bluetooth connection your battery will take a big hit.
Your own wireless phone can in all likelihood be turned into a hotspot depending on the device’s capabilities. You can have a completely supported wireless business meeting with a small group at a park or a lake anywhere but that conference room. Importantly in most cases the device sharing the hotspot will have its internet capability disabled. Bandwidth will not reflect the full capacity of the host and battery life will be impacted.
Networks are classified by several factors in order to identify their purpose. Technically a network can consist of as few as two computers, as long as they can communicate with each other they are a network. In the smallest scale you could connect to your desktop that has its printer shared and print content from your laptop. That’s a small LAN. The network types shown can be wired or wireless or both.
A Local Area Network (LAN) when one or more PCs or wireless devices are connected and share resources and services with each other. Good examples of this network type are business that can interconnect one or more buildings and the users (hosts) within. There may be one printer on each floor that the users can access.
A Wide Area Network (WAN) is the polar opposite of a LAN. A WAN can have many users and small networks. The key is that they are spread over a large geographical area. The most extreme version of a WAN is the internet where billions of users can access the resources made available by millions of networks and resources.
A Personal Area Network (PAN) is a very short range network consisting of personal devices. Generally this is a Bluetooth configuration and could be made up of personal heart and activity monitors connected to a cell phone. The cell phone can in turn connect to a laptop‘s Bluetooth and create another PAN. The key here is the short range and personal nature of the connection.
A Metropolitan Area Network (MAN) covers a large geographical area such as a city or metropolis. MANs are created by cities and municipalities to provide essential connectivity during power outages or other catastrophic events that would interrupt a traditional WAN. They are reliable and redundant.
And that wraps up our ExamNotes for A+ Sub-objective 2.7 – Good luck at the exam!