CHAPTER 1
ERX System Overview
1-6
Where the ERX System Fits In

Figure 1-5 and Figure 1-6 illustrate the position of the system as an edge

router in an end-to-end Internet network. Communications with the

system can take place over a variety of media. In Figure1-5, the

customers are businesses using T1/T3 communication lines. In

Figure 1-6, the customers are using digital subscriber lines (DSLs) with a

DSL access multiplexer (DSLAM).

Figure 1-5 ERX system communicating over T1/T3 lines
Figure 1-6 ERX system communicating over DSL lines
Desktop
Remote
access router
Hub
Hub
Remote
access
router ERX system
Desktop
Internet
Core router
OC3
T1/T3
Home office
Remote
access router
Hub
Desktop
Internet
DSLAM
DS3
OC3
ERX system Core
router