Syngress - Eleventh Hour Network+ Exam N10-004 Study Guide (11 ...

More documents

Recommendations

Info

WAN Protocols and Properties <strong>11</strong>1 Crunch Time ■ At one time, X.25 was a popular standard for packet-switching networks, but new installations are few and far between these days. ■ X.25 is a WAN protocol that operates at Layers 1, 2, and 3 of the OSI model. ■ X.25 is very versatile, designed to operate in almost any environment. It is not as fast as other technologies but adds a very robust errorchecking mechanism that virtually guaranteed error-free delivery of data. When network communications were carried on a much poorer network media than that we enjoy today, this was a very important protocol for WAN transmission. ■ The terminology that stems from X.25 is still widely in use today. For example: • Packet-switching exchange (PSE) • Customer premises equipment (CPE) • Data circuit-terminating equipment (DCE) • Data terminal equipment (DTE) ■ An X.25 network is primarily made up of these three groupings: DTE, DCEs, and PSEs. ■ Synchronous optical network (SONET) SONET is an older, extremely highspeed network that provides a standard interface for communication carriers to connect networks based on fiber optic cable. ■ The SONET system uses fiber in dual counter-rotating rings. ■ The SONET is designed to handle multiple data types such as voice and video. ■ The SONET standard defines a hierarchy of interface rates that allow data streams at different rates to be multiplexed. ■ The SONET establishes optical carrier (OC) levels from 51.8 Mbps to 40 Gbps (as shown in Table 7.1). The OC is appended with a number, which indicates the speed of the medium. The base rate of OC-1 is 51.84 Mbps. Table 7.1 Optical Carrier Levels and Data Transmission Rates Optical Carrier Level OC-1 OC-3 OC-12 OC-24 OC-48 OC-192 OC-256 OC-768 Data Transmission Rate 51.84 Mbps 155.52 Mbps 622.08 Mbps 1.244 Gbps 2.488 Gbps 10 Gbps 13.271 Gbps 40 Gbps
<strong>11</strong>2 CHAPTER 7 Wide Area Networking INTERNET ACCESS METHODS In this section, we will look at Internet access technologies such as digital subscriber line (DSL), cable, Plain Old Telephone Service (POTS)/public switched telephone network (PSTN), satellites, and wireless. Digital Subscriber Line DSL is commonly denoted as xDSL, where the x specifies what type of DSL is in use. DSL is commonly used to access the Internet from both residential and business locations to provide high-speed access to the Internet. DSL became very popular as dial-up technologies become increasingly unable to meet the demand for fast access to the Internet. ■ ■ DSL and other high-speed technologies are slowly displacing dial-up service to the Internet. DSL is one of the most highly used because it can use preexisting phone lines in your home, so installation is a bit cheaper and less intrusive. DSL is not a shared medium, unlike cable networks, which use shared access. Shared access means that when there is heavy usage of the system, less bandwidth is available to individual users. DSL has dedicated bandwidth, so the only one using that bandwidth is you. DID YOU KNOW One drawback of DSL, however, is that the QoS is dependent on the user’s distance from the central office (CO).The CO is where the network endpoint is located and is generally run by your Internet service provider (ISP). The farther you are from the CO, the slower the service is. There are many forms of DSL. The most common forms of DSL are asymmetric DSL (ADSL) and symmetric DSL (SDSL). ASYMMETRIC DSL ADSL is the most widely deployed form of DSL technology. Most homes and small businesses currently using DSL technology use ADSL. Characteristics of ADSL are as follows: ■ ■ ■ ■ ■ ADSL is used to transmit digital information on preexisting phone lines. Unlike dial-up, ADSL provides an always on connection to the Internet. ADSL is able to place voice and data information on the same line. ADSL is asymmetric. This means that ADSL is designed to provide more bandwidth in one direction than in the other. ADSL generates downstream speeds of about 8 Mbps and upstream speeds of up to 640 Kbps. SYMMETRIC DSL SDSL is typically used in larger companies, and the upstream and downstream channels have the same size; that is, the download speed and upload speed are equal. SDSL operates at about 2 to 2.5 Mbps.
Page 2 and 3:
Syngress is an imprint of Elsevier
Page 4 and 5:
xii About the Authors Technical Edi
Page 6 and 7:
2 CHAPTER 1 Network Fundamentals Ne
Page 8 and 9:
4 CHAPTER 1 Network Fundamentals re
Page 10 and 11:
6 CHAPTER 1 Network Fundamentals
Page 12 and 13:
8 CHAPTER 1 Network Fundamentals Wh
Page 14 and 15:
10 CHAPTER 1 Network Fundamentals d
Page 16 and 17:
12 CHAPTER 1 Network Fundamentals
Page 18 and 19:
14 CHAPTER 1 Network Fundamentals T
Page 20 and 21:
16 CHAPTER 1 Network Fundamentals T
Page 22 and 23:
18 CHAPTER 1 Network Fundamentals I
Page 24 and 25:
20 CHAPTER 2 Network Media DID YOU
Page 26 and 27:
22 CHAPTER 2 Network Media Table 2.
Page 28 and 29:
24 CHAPTER 2 Network Media ■ Perf
Page 30 and 31:
26 CHAPTER 2 Network Media Table 2.
Page 32 and 33:
28 CHAPTER 2 Network Media LAN TECH
Page 34 and 35:
30 CHAPTER 2 Network Media CONNECTO
Page 36 and 37:
32 CHAPTER 2 Network Media EXAM WAR
Page 38 and 39:
34 CHAPTER 2 Network Media problems
Page 40 and 41:
36 CHAPTER 2 Network Media electrom
Page 42 and 43:
38 CHAPTER 3 Network Devices Table
Page 44 and 45:
40 CHAPTER 3 Network Devices some o
Page 46 and 47:
42 CHAPTER 3 Network Devices ■
Page 48 and 49:
44 CHAPTER 3 Network Devices ■
Page 50 and 51:
46 CHAPTER 3 Network Devices EXAM W
Page 52 and 53:
48 CHAPTER 3 Network Devices ■ Du
Page 54 and 55:
50 CHAPTER 3 Network Devices Proxy
Page 56 and 57:
52 CHAPTER 3 Network Devices Top Fi
Page 58 and 59:
54 CHAPTER 3 Network Devices the co
Page 60 and 61:
56 CHAPTER 4 Wireless Networking
Page 62 and 63:
58 CHAPTER 4 Wireless Networking
Page 64 and 65: 60 CHAPTER 4 Wireless Networking Ta
Page 66 and 67: 62 CHAPTER 4 Wireless Networking WE
Page 68 and 69: 64 CHAPTER 4 Wireless Networking Th
Page 70 and 71: 66 CHAPTER 4 Wireless Networking us
Page 72 and 73: 68 CHAPTER 4 Wireless Networking
Page 74 and 75: 70 CHAPTER 4 Wireless Networking si
Page 76 and 77: 72 CHAPTER 4 Wireless Networking co
Page 78 and 79: 74 CHAPTER 5 The OSI Model and Netw
Page 94 and 95: 90 CHAPTER 6 TCP/IP and Routing ■
Page 96 and 97: 92 CHAPTER 6 TCP/IP and Routing For
Page 98 and 99: 94 CHAPTER 6 TCP/IP and Routing UND
Page 100 and 101: 96 CHAPTER 6 TCP/IP and Routing ■
Page 102 and 103: 98 CHAPTER 6 TCP/IP and Routing Sub
Page 104 and 105: 100 CHAPTER 6 TCP/IP and Routing co
Page 106 and 107: 102 CHAPTER 6 TCP/IP and Routing
Page 108 and 109: 104 CHAPTER 6 TCP/IP and Routing al
Page 110 and 111: CHAPTER 7 Wide Area Networking 107
Page 112 and 113: WAN Protocols and Properties 109 In
Page 116 and 117: Internet Access Methods 113 EXAM WA
Page 118 and 119: Internet Access Methods 115 Wireles
Page 120 and 121: Internet Access Methods 117 Top Fiv
Page 122 and 123: Internet Access Methods 119 with th
Page 124 and 125: 122 CHAPTER 8 Security Standards an
Page 146 and 147: 144 CHAPTER 9 Network Management
Page 148 and 149: 146 CHAPTER 9 Network Management Wi
Page 150 and 151: 148 CHAPTER 9 Network Management Cr
Page 152 and 153: 150 CHAPTER 9 Network Management
Page 154 and 155: 152 CHAPTER 9 Network Management An
Page 156 and 157: 154 CHAPTER 9 Network Management Lo
Page 158 and 159: 156 CHAPTER 10 Network Troubleshoot
Page 164 and 165:
162 CHAPTER 10 Network Troubleshoot
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
Page 178 and 179:
Glossary 177 Access Determines who
Page 180 and 181:
Glossary 179 Extensible Authenticat
Page 182 and 183:
Glossary 181 Oscilloscope A cable t
Page 184 and 185:
Glossary 183 Wireless Network A net
Page 186 and 187:
186 Index Data link layer, 74-75 fu
Page 188 and 189:
188 Index Network troubleshooting,
show all

Syngress - Eleventh Hour Network+ Exam N10-004 Study Guide (11 ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?