A+ Exam Objective 2.2 Compare and contrast common networking hardware
Welcome to CertBlaster ExamNotes! Here we will look at 220-1101 Sub-objective 2.2 Compare and contrast common networking hardware devices. We will look at the evolution of interconnectivity and the roles these devices play.
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Router /Access Point
Here they all are rolled into one device! Most reputable ISPs provide a device like the one shown. For this image, we took the most fully featured non-ISP related modem available. My guess is that most of you have seen a variation of this in your travels. This device is a Cable Modem, Router, Firewall, and Wireless Access Point as well as a Switch/Bridge.
Think of the Router as your network traffic cop. Ultimately, the router and the firewall which have the final say, decide which traffic does and does not get onto your network.
The router is useful for finding the quickest path for your data to take while finding its way through the maze of routers and servers from point to point. Shown here is a combination Router/ Wireless Access Point. It is responsible for routing and also access to the Wireless Network among other functions.
Switch/ Managed/ Unmanaged
A switch determines whether or not a destination Hardware (MAC) or network (IP) address is attached to the switch itself. A switch uses MAC or IP addressing knowledge about the devices connected to it and the device-oriented environment it exists in. Switches utilize packet switching and the information contained in each packet to determine if the destination for the packet is connected locally or needs to be forwarded upstream. Unlike a hub, an unmanaged switch uses the information gained to direct traffic to the correct port. Switches operate as MAC Bridges.
The goal of a switch is to enable efficient traffic management. A managed switch has features not found in an unmanaged switch such as VLAN support and traffic prioritization. Managed switches can use the SNMP protocol to enable remote management.
Cable management is always important. It is especially important when there are a large number of users assigned and the cable closet is not particularly roomy. The purpose of a patch panel is to connect and manage inbound and outbound cables in a central area. Typically, the destination would be labeled on the panel and lead to a wall jack. Presented below is a good example of a well-organized patch panel. Take a good look. Notice the really precise cable routing and management of four switches in a well-kept server space. Most installations start out like this.
Firewalls can be a hardware device, software, or both. Naturally, you can address more threats with the combination approach by using your hardware firewall as the first line of defense. Next, your software firewall will provide additional protection and possibly even malware scans.
The hardware firewall device’s placement is important. It should be between the external network, in most cases the internet, and your private network or LAN.
Power over Ethernet – PoE
The PoE (Power over Ethernet) system uses an Ethernet cable as its primary carrier. This impacts the effective Volt/Amp delivery as the RJ grade cable is not rated to carry the higher voltages some devices require. It is however ideal for a low-voltage operation such as a security monitor or a baby monitor.
PoE Injectors vs. PoE switch
A PoE injector provides data and power to a single device. A PoE switch on the other hand is capable of distributing power and data to all connected devices.
The smallest network you can create is a one-to-one (Peer to Peer) relationship between two computers or devices. A hub is designed to distribute multiple signals to multiple hosts. Communications are managed by CSMA (Carrier Sense –Multiple Access), where the host will check the cable to see if it is clear before transmission is initiated. When a signal is distributed by a hub, it is sent to all connected devices, causing a burst of communications if left unchecked.
Your cable modem is usually provided by your ISP, although it can be purchased separately. The cable line into your premise carries video signals, Internet access, and VoIP signals. The cable modem is capable of splitting these signals and delivering them to the intended devices. Today’s cable modems can also provide network management services including those found in your wireless router like firewall, parental controls, and device management.
Digital subscriber line DSL
DSL (Digital Subscriber Line) uses the existing ordinary copper telephone lines (POTS). In its basic configuration, DSL feeds three signals to and from the DSL modem. The first two 64Kbps channels provide 128Kbps for data. These can be split to carry voice on one line and data over the other, allowing internet and phone services to be used at the same time. The third line carries command and control data, consuming very little bandwidth.
DSL 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 DSL use different techniques to achieve higher speeds. One method is Symmetric Digital Subscriber Line (SDSL) which allows for equal upload and download rates. SDSL can reach theoretical speeds up to 22Mbps. Another method is 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 24Mbps downstream. A variation of SDSL is VSDL (very-high-bit-rate Digital Subscriber Line) which is capable of up to 70Mbps over short distances.
Optical network terminal (ONT)
An Optical Network Terminal (ONT) is a device that converts fiber optic signals into digital ones. This allows digital devices like your router to interpret fiber optic signals. The fiber optical signal consists of pulses of light that would be unintelligible to a digital device without the ONT conversion.
Network interface card
Devices connect to hubs and switches either wirelessly or through RJ-45 UTP cabling. The wired connection requires a Network interface card (NIC) as shown below.
Software-defined networking (SDN)
Cloud resources and even entire virtual networks can be accessed using Software Defined Networking (SDN). Network management can be delegated to cloud resources to provide centralized management. This technique can be used to create virtual WANs.
That will do it for Sub-objective 220-1101 2.2! Good Luck on the test!!!
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