Exercise 4. Match each network type to a definition.

a) WAN b) LAN c) MAN d) Peer-to-peer	1) A network that connects devices within the range of an individual person. All of these devices are dedicated to a single host.
e) WLAN f) Client-server g) PAN	2) A network that has no hierarchy among the computers, nor are there any dedicated servers. Each client has equivalent capabilities and responsibilities.
	3) A network that spans across a large campus or city and consists of various buildings interconnected through wireless or fiber optic backbones.
	4) A network that uses radio waves to transmit data between wireless devices. This network can operate in infrastructure or ad hoc mode.
	5) A network that connects multiple networks that are in geographically separate locations and is owned by a service provider.
	6) A network that encompasses a small geographical area, typically owned by an individual or wholly managed by an IT department.
	7) A network where hosts request information or services from a server. The server provides the requested information or service to the hosts.

Lesson 19. Wireless security

Exercise 1. Read the text and translate it into Russian.

Wireless security.

The best way to secure a wireless network is to use authentication and encryption. Two types of authentication were introduced with the original 802.11 standard, as shown in the figure:

· Open system authentication - Any wireless device can connect to the wireless network. This should only be used in situations where security is of no concern.

· Shared key authentication - Provides mechanisms to authenticate and encrypt data between a wireless client and AP or wireless router.

The three shared key authentication techniques for WLANs are as follows:

· Wired Equivalent Privacy (WEP) - This was the original 802.11 specification securing WLANs. However, the encryption key never changes when exchanging packets, making it easy to hack.

· Wi-Fi Protected Access (WPA) - This standard uses WEP, but secures the data with the much stronger Temporal Key Integrity Protocol (TKIP) encryption algorithm. TKIP changes the key for each packet, making it much more difficult to hack.

· IEEE 802.11i/WPA2 - IEEE 802.11i is now the industry standard for securing WLANs. The Wi-Fi alliance version is called WPA2. 802.11i and WPA2 both use the Advanced Encryption Standard (AES) for encryption. AES is currently considered the strongest encryption protocol.

Since 2006, any device that bears the Wi-Fi Certified logo is WPA2 certified. Therefore, modern WLANs should always use the 802.11i/WPA2 standard.

 

Exercise 2. Give the definitions to the next terms:

Router, Modem, Firewall, Switch, Patch panel, Wireless access point, Repeater, Hub, PoE switch

 

Exercise 3. Match each description to a device from the ex. 2.

1) Regenerates weak signals to effectively extend the distance a signal can travel.

2) Resides between two or more networks and protects data and equipment on a network from unauthorized access.

3) Uses IP addresses to forward traffic to other networks.

4) Converts a computer’s digital data into a format that can be transmitted on the ISP’s network.

5) Transfers small amounts of DC current over Ethernet cable, along with data, to power special devices.

6) Filters and segments network traffic by sending data only to the device to which it is sent.

7) Receives data on one port and sends it out to all other ports.

8) Provides network access to devices that use radio waves to communicate with other devices.

9) A place to collect incoming cable runs from the various networking devices throughout a facility.

 

Lesson 20. Brief history of connection technologies.

Exercise 1. Read the text and translate it into Russian.