If noise at the radio card is high, the radio card will have difficulty recovering the signal, which results in bits errors and retransmissions. An important signal measurement is the signal-to-noise ratio (SNR). The SNR (in dB) at a particular point in the network is simply the signal power (in dBm) minus the noise power (in dBm). A signal power of –65 dBm and noise power of –90 dBm yields an SNR of 25 dB. The noise power is anything other than signals corresponding to t..
The first approach utilizes a single CPU-controlled shared bus that connects a number of slave interface cards. This arrangement can be based on a general-purpose computer, such as a PC running UNIX or Windows NT. Various bus communication strategies (such as shared memory, DMA, and bus mastering), together with high-performance RISC CPUs, can result in a router of significant forwarding capabilities. A large number of dedicated-purpose centralized CPU router pl..
This section provides guidelines for building a secure WLAN. These recommended practices are offered as tried and tested methodologies for addressing this challenging topic. Every enterprise comes with its own unique environment, infrastructure, and security challenges, but by following these suggestions and tailoring them to your specific needs, you can be sure that you have addressed the most common security issues encountered today. Trusted Versus Untrusted Wireless Netwo..
The EXEC level command to look at the entire IP routing table is: Router>show ip routeCodes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP ..
Enabling Frame Relay Encapsulation
On a Cisco router, Frame Relay can be configured only on the supported interfaces; it's most commonly supported on synchronous serial interfaces. A single Cisco IOS command is all that is required to enable Frame Relay on the serial interface. The encapsulation frame-relay interface configuration command, as follows, is used to enable Frame Relay encapsulation and to allow Frame Relay processing on the supported interface. R1(config)#interface serial4/2 R1(config-if)#encapsu..
