e is at its peak carrying information more bandwidth can be made available. Also switched virtual circuits allow charges for connection to be made only for what the customer uses, unlike leased lines where you have to pay a flat rate (828-829).In the May 1999 issue of "Computerworld", a trading company decided to change its networking architecture. DCH (Da Chong Hong), in the past, used a multiple leased line architecture consisting of over 50 separate lines (See Figure 1). Figure 1 proves the fact that when transferring data between multiple sites, frame relay decreases the amount of lines that need to be leased. DCH knew it had to change its architecture to keep up with data rate technological advances. DCH decided to switch to a networking architecture that consisted of ATM and frame relay. This venture saved DCH over $129,000 per year. ATM is another form of a packet-switching data communication method.One problem with transferring information over a frame relay network is the fact at times the network can become congested. The LAN Times Encyclopedia of Networking reports the fact that "when a frame relay network becomes congested, frames are arbitrarily discarded". The end nodes are responsible for retransmitting the message frames or either they can be discarded permanently if the customer wants them to (387). Frame relay also offers a security features that help control access to the network: only private lines can access the network, passwords are required to access the network, and a time-out feature logs off inactive stations (388). These delaying tactics help insure the quality of transmission and help prevent hackers from accessing the network resources.Frame relay use addresses to signify which site or node the message frame is being sent to. In the CCNA Exam Certification Guide, it establishes the fact that frame relay uses a header and a trailer to get the message over the network. The DLCI is the frame rela...
