CertiGuide to Network+  9  Chapter 0111: Wide Area Networking       9  VII  Wide Area Networking Technologies

Point-to-Point Leased Line 1 Frame Relay

The X.25 standard is an analog means of connecting sites. What makes the X.25 standard interesting is the fact that like the Internet, no packet must follow a specific path. When designers are laying a ‘battle plan’ involving X.25, the connections follow a specific path, right up to hitting the phone company. At that point, the data goes into what is called and looks like, a cloud. At the other end of the cloud, the data pops out and follows a specific path. X.25 is still used in older telephone systems. In more advanced phone companies, X.25 has been replaced by frame relay.

X.25 is limited to 56Kb/sec. This sounds very slow at a time when even 56Kb/sec dial-up modem access is barely acceptable to many home users. However, X.25 has been around for a very long time. In its heyday, consumers had 300 or 1200 baud modems (if they had modems at all), and X.25 was quite speedy in comparison.

Point-to-Point Leased Line 1 Frame Relay