In 1985, the U.S. FCC adopted regulations that specify the availability of license-free frequency bands in the 900-MHz, 2.4-GHz, and 5-GHz portions of the frequency spectrum. To be compliant with the rules for these bands, however, equipment must use spread spectrum or OFDM methods to spread the signal power over a relatively wide portion of the frequency spectrum. This approach promotes frequency reuse—otherwise known as sharing—of these bands by multiple users, with a l..
As discussed in Chapter 4, "Network Topology and Design," accounting of data traffic is not only important for customer billing, but is a crucial part of traffic engineering. For example, knowing the relative size of flows between routers in the network core can help you calculate the most cost-effective topology and circuit size of the core network. In terms of operation, Netflow switching is similar to the fast-switching cache: The first packet of any fl..
Using an Internal ISDN PRI Module
You can configure an ISDN PRI controller module by using the controller T1 command set as follows: Router8#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router8(config)#isdn switch-type primary-dms100 Router8(config)#controller T1 0 Router8(config-controlle)#framing esf Router8(config-controlle)#clock source line primary Router8(config-controlle)#linecode b8zs Router8(config-controlle)#pri-group timeslots 1-24 Router8(config-controlle)..
For both Frame Relay PVC and SVC, access to a Frame Relay network is generally made through private leased lines at various speeds ranging from 56 kbps to 45 Mbps. From the Frame Relay user's perspective, the leased line terminates at the Frame Relay service providers' Frame Relay switch. When SVC is employed, the service provider does not provision a dedicated virtual circuit between the end points of the connection. A SVC through a Frame Relay network is set up to the dest..
The FTP protocol includes IP address information in the packet payload. Normally, Cisco's NAT implementation rewrites IP address information in the payloads of FTP packets by looking in every packet sent on TCP port 21, which is the port that FTP uses to pass session control information by default. So when an FTP server uses a nonstandard TCP port number for session control, you have to configure the NAT router to expect FTP packets on this new port number: Router#configure ..
