Network+ Exam Objectives 1.7

1.7 Compare the characteristics of wireless communication standards

Within the last decade, wireless communication and its uses have continued to grow and advanced. Nowadays computers, cell phones, PDAs, and more all make use of wireless communication. Today’s wireless communications continue to be engineered to be even faster to meet the fast-paced world of today, with growing networks classified as 3G, 4G, and even 5G. Security of wireless communication is also a growing concern that engineers all over the world continue to study and upgrade.

802.11 a/b/g/n

802.11 is the IEEE specification that is used by wireless LAN communications. 802.11 is needed in order to specify an interface between two wireless clients or communication between a wireless client and a base station. Today’s 802.11 is much different from those versions used in the past.

•   802.11a – 802.11a, which is not very widely used today, requires a 5GHz radio band and is capable of transmitting upwards to 54Mbps. To increase bandwidth, 802.11a uses orthogonal frequency division multiplexing.

• 802.11b – 802.11b is one of the more commonly used wireless communication standards. It is able to transmit up to 11Mbps with fallback rates of 1Mbps, 2Mbps, and 5.5Mbps. It uses a 2.4GHz band with DSSS.

•   802.11g – 802.11g is often referred to as an enhancement to 802.11b. It also uses DSSS on a 2.4GHz band and is able to transmit with speeds upwards of 54Mbps. 802.11g is just as commonly used, if not more commonly used than 802.11b.

• 802.11n – 802.11n too uses DSSS on a 2.4GHz band. It is an upgrade and enhancement of 802.11g and is able to transmit 600Mbps but devices today generally only use 300Mbps. 802.11n is not very widely used, yet.

Authentication and encryption

The authentication and encryption of wireless communications has been a long-time issue that has yet to be perfected. However, as newer and more advanced technologies continue to be created, the authentication and encryption aspect of wireless communication has grown stronger. 

•  WPA – Wi-Fi Protected Access (WPA) was created in order to fix some of the security flaws and weaknesses with WEP. WPA offers dynamic encryption key generation, meaning that the keys are given on a per-use and per-session basis. WPA also offers an integrity-checking technology through the temporal key integrity protocol (TKIP) which adds a 128-bit encryption key which was secure for awhile but in today’s world is seen as highly unsecure.

•   WEP – Wireless Equivalent Privacy (WEP) is one of the first attempts at creating secure wireless communications on 802.11 networks. To provide security, WEP was designed to encrypt the data transfer. However, the flaw existed in the fact that the technology used to encrypt the data transfer was not encrypted. WEP also only works on the lower end of the OSI model in the data link and physical layers and cannot be used for end-to-end security purposes. The encryption key used with WEP is static and shared and there is no way to authenticate users, leaving them prone to spoofing attacks.

• RADIUS – Remote Authentication Dial In User Service (RADIUS) provides centralized authentication, authorization, and accounting management when computers are connected to a network. RADIUS runs in the application layer using UDP transport methods. Using RADIUS, there is the ability to authenticate users or devices before giving them network access, authorize those users and/or devices for specific network services, and to account for the usages per user/device. RADIUS too is considered to be insecure.

• TKIP – Temporal Key Integrity Protocol (TKIP) was created as a solution for replacing WEP without having to replace hardware. Using TKIP, the technology was able to implement a key mixing function that combined a secret root key with an initialization vector. TKIP also allowed for protection against replay attacks since out of order packets were rejected at access point. TKIP also introduced the 64-bit message integrity check (MIC). TKIP also ensures that every data packet received has its own unique encryption key. However TKIP is still prone to attacks.

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