Security for Broadband Internet Access Users

BROADBAND ACCESS METHODS High-speed access is becoming increasingly popular for connecting to the Internet and to corporate networks. The term “high-speed” is generally taken to mean transfer speeds above the 56Kbps of analog modems, or the 64 to 128Kbps speeds of ISDN. There are a number of technologies that provide transfer rates from 256Kbps to 1.544Mbps and beyond. Some offer asymmetrical uplink and downlink speeds that may go as high as 6Mbps. These high-speed access methods include DSL, cable modems, and wireless point-to-multipoint access. DSL services include all of the so-called “digital subscriber line” access methods that utilize conventional copper telephone cabling for the physical link from customer premise to central office (CO). The most popular of these methods is ADSL, or asymmetrical digital subscriber line, where a existing POTS (plain old telephone service) dial-up line does double duty by having a higher frequency digital signal multiplexed over the same pair. Filters at the user premise and at the central office tap off the digital signal and send it to the user’s PC and the CO router, respectively. The actual transport of the ADSL data is via ATM, a factor invisible to the user, who is generally using TCP/IP over Ethernet. A key security P A Y O F F I D E A