Brian LeeLTEC 4550

Network System AdministrationMr. John West

Purpose of this Presentation

Hub - is a device used to connect multiple network devices together and make them behave as a single network segment.

This device is also know as an Ethernet hub, active hub, network hub, repeater hub, multiport repeater or just a hub.

Hubs neither provide security, or identification of connected devices. This means that messages have to be transmitted out of every port of the hub, greatly degrading the efficiency of the network.

The effective range of a hubs signal is dependent on the media installed. The signal could be as limited to 15 meters for coaxial cabling or as efficient as several kilometers for fiber optic.

A typical, small 4-5 port unmanaged hub costs between $10 – $20. The range is dependent on the type and speed of the needed install application.

Historically, the main reason for purchasing hubs rather than switches was their price. This motivator has largely been eliminated by reductions in the price of switches, but hubs can still be useful in special circumstances.

Switch - (sometimes known as a switching hub) is a computer networking device that is used to connect devices together on a computer network.

Switches exist for various types of networks including Fiber Channel, Asynchronous Transfer Mode, InfiniBand, Ethernet and others.

Each connected switch device can be identified using a MAC address, allowing the switch to regulate the flow of traffic. This maximizes security and efficiency of the network. A switch is often considered more "intelligent" than a hub because of these features.

The effective range of a switches signal, similarly to a hub, is dependent on type of media installed. Typically between 100 and 300 meters. The Appendixes detail more uses and distances

4 -5 port, unmanaged switches costs the same as a hub between $10 – $20. However the next level, managed, 8 port switch costs between $15 – $55. Larger commercial switches typically with 16 up to 50 ports can cost a few hundred dollars.

A switch is considered more advanced than a hub because a switch will only send a message to the device that needs or requests it, rather than broadcasting the same message out of each of its ports.

Router - is a device that forwards data packets between computer networks, creating an overlay internetwork. . A router is connected to two or more data lines from different networks.

A router has interfaces for different physical types of network connections, (such as copper cables, fiber optic, or wireless transmission).Routers also contain firmware for different networking communication protocols. Each network interface port uses this firmware, or specialized computer software, to enable data packets to be forwarded from one protocol transmission media to another.

The effective range of a router depends on how the network devices are connected.

Are they directly wired to one of the router’s ports as seen in the diagram?

Or, are they connected wirelessly through the router’s antennae?

Wired connection ranges typically are limited to between 15 – 100 meters. Wireless connections range between 20 – 250 meters distance.

Please use the corresponding appendix to address the appropriate standard’s range.

An example of a router would be the owner's cable or DSL modem, which connects to the Internet through an ISP.

Home wireless router cost between $10 – 100. A Gigabit, built-in firewall secure router can cost over $1000.

More sophisticated routers, such as enterprise routers, connect large business or ISP networks up to the powerful core routers that forward data at high speed along the optical fiber lines of the Internet backbone.

Bridge - A network bridge, operating at the data link layer, may interconnect a small number of devices in a home or the office. This is a trivial case of bridging, in which the bridge learns the MAC address of each connected device.

Single bridges also can provide extremely high performance in specialized applications such as storage area networks.

A bridge works by connecting like networks effectively extending or bridging individual network segments. Bridging is distinct from routing which allows the networks to communicate independently as separate networks.

The effective range of a bridge signal is dependent on the media installed. The minimum signal media limit would be 15 meters versus several kilometers over fiber optic.

Classic bridges may also interconnect using a spanning tree protocol that disables links so that the resulting local area network is a tree without loops. In contrast to routers, spanning tree bridges must have topologies with only one active path between two points.

This device costs the same and is marketed as an unmanaged switch or hub. The prices range between $10 – $55.

Gateway - is a node (a router) on a TCP/IP network that serves as an access point to another network. A “default” gateway is the node on the computer network that the network software uses when an IP address does not match any other routes in the routing table.

In home computing configurations, an ISP often provides a physical device which both connects local hardware to the Internet and serves as a gateway. Such devices include DSL routers and cable routers.

A default gateway provides an entry point and an exit point in a network.

In organizational systems, a gateway is a node that routes the traffic from a workstation to another network segment.

The default gateway commonly connects the internal networks and the outside network (Internet). In such a situation, the gateway node could also act as a proxy server and a firewall.

The gateway is also associated with both a router, which uses headers and forwarding tables to determine where packets are sent, and a switch, which provides the actual path for the packet in and out of the gateway.

If you have an external hardware-based gateway, as the picture depicts, then the range is based on any other wired or wireless network component. Please use the corresponding appendix to address the appropriate standard’s range. However, most modern gateways are built into a company’s internet router

A separate gateway device typically costs between $45 - $100. This is the same price range as most gateway enabled internet routers.

Firewall - is a software or hardware-based network security system that controls the incoming and outgoing network traffic by analyzing the data packets and determining whether they should be allowed through or not, based on an applied rule set.

On inspecting all packets for improper content, firewalls can restrict or prevent outright the spread of networked computer worms and Trojan virus’.

A firewall establishes a barrier between a trusted, secure internal network and another network (e.g., the Internet) that is not assumed to be secure and trusted.

The effective range of a firewall would be defined by the distance travelled by the data packets being analyzed. The sky is the limit in the case of an Internet-based data packet!

Firewalls often have network address translation (NAT) functionality, and the hosts protected behind a firewall commonly have addresses in the "private address range", as defined in RFC 1918.

An external hardware security appliance will cost between $65 - $500. An enterprise-ready, gigabit bundled firewall appliance can start at $10,000 up to $100,000

Wireless AP - a wireless access point (WAP) is a device that allows wireless devices to connect to a wired network using Wi-Fi, or related standards.

The WAP usually connects to a router (via a wired network) as a standalone device, however it can also be an integral component of the router itself.

A WAP normally connects directly to a wired Ethernet connection and the WAP then provides wireless connections using radio frequency links for other devices to utilize that wired connection.

The effective range of a wireless access point is determined by environmental interference, frequency used, and 802.11 standard programmed.

Wireless access point (WAP) prices range based on features exactly similar to routes because typically routers will have wireless capabilities built into them and vice versus. Therefore, basic home WAP prices range from $25 - $100. While feature-rich wireless routers based on the all-new 802.11ac standard start at $100 - $275.

World Wide Web

Firewall Router

Switch Wireless Access Point

Hub

BridgeHub

Terminal

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Terminal

Overall Network Diagram

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