4.Stations on wireless LANs normally use CSMA/CA.5.Network Allocation Vector (NAV)forces other stations to defer sending their dataif one station acquires access. In other words, it provides the collision avoidanceaspect. When a station sends an RTS frame, it includes the duration of time that itneeds to occupy the channel. The stations that are affected by this transmissioncreate a timer called a NAV.6.A Bluetooth network is called a piconet. A scatternet is two or more piconets.7.The following shows the relationship:8.A Bluetooth primary and secondary can be connected by a synchronous connec-tion-oriented (SCO)link or an asynchronous connectionless (ACL)link. An SCOlink is used when avoiding latency (delay in data delivery) is more important thanRadio layer → Internet physical layerBaseband layer →MAC sublayer of Internet data link layerL2CAP layer→ LLC sublayer of Internet data link layer
2integrity (error-free delivery). An ACL link is used when data integrity is moreimportant than avoiding latency. 9.The primary sends on the even-numbered slots; the secondary sends on the odd-numbered slots.10.In all types of frames, a duration of 259μs is used for hopping.Exercises11.In CSMA/CD, the protocol allows collisions to happen. If there is a collision, itwill be detected, destroyed, and the frame will be resent. CSMA/CAuses a tech-nique that prevents collision.12.See Table 14.1.Table 14.1Exercise 12Fields802.3field size (bytes)802.11field size (bytes)Destination Address6 Source Address6Address 16Address 26Address 36Address 46FC2D/ID2SC2PDU Length2Data and Padding46 to 1500 Frame Body64-15180 to 2312FCS (CRC)44
1CHAPTER 15Connecting LANs, Backbone Networks, and Virtual NetworksSolutions to Review Questions and ExercisesReview Questions1.An amplifieramplifies the signal, as well as noise that may come with the signal,whereas a repeaterregenerates the signal, bit for bit, at the original strength.2.Bridgeshave access to station physical addressesand can forward a packet to theappropriate segment of the network. In this way, they filtertraffic and help controlcongestion. 3.A transparent bridgeis a bridge in which the stations are completely unaware ofthe bridge’s existence. If a bridge is added or deleted from the system, reconfigura-tion of the stations is unnecessary. 4.A signal can only travel so far before it becomes corrupted. A repeaterregeneratesthe original signal; the signal can continue to travel and the LAN length is thusextended.5.A hubis a multiport repeater.6.A forwarding portforwards a frame that it receives; a blocking portdoes not.7.In a bus backbone, the topology of the backbone is a bus; in a star backbone, thetopology is a star.8.A VLANsaves time and money because reconfiguration is done through software.
- Fall '15
- Networking, Bit rate, Frame rate, data rate