This chapter examined cable modem technology and presented VPN services, including IPSec.
Cable modems offer the administrator an alternative low-cost technology for remote access,
and they can provide longer-range connections than DSL. Although cable modems use a
shared medium, the overall performance is comparable to the switched DSL in real-world
deployments. The key to cable modem services is DOCSIS and the incorporated security and
other services that this standard provides.
Most remote access users will map IPSec tunnels over the cable modem network to allow
for corporate access. Although not the only VPN technology, IPSec is currently the most
popular and provides for encrypted tunneling of IP data between locations. We also briefly
noted a number of other tunneling technologies that provide solutions for remote access.