<Li> DSL analog chip and line driver </Li> <P> Apart from connecting to a DSL service, many modems offer additional integrated features, forming a residential gateway: </P> <Ul> <Li> Router functionality that includes Network Address Translation (NAT) to share a single IPv4 address . </Li> <Li> An 802.11 n or 802.11 ac wireless access point </Li> <Li> A built - in switch (typically 4 ports) </Li> <Li> Virtual Private Network termination </Li> <Li> Dynamic Host Configuration Protocol (DHCP) server </Li> <Li> DNS (Domain Name System) caching, a relay or proxy DNS cache which queries DNS servers on the Internet </Li> <Li> Voice over Internet Protocol functionality including Quality of Service (priority control for data flows between users) </Li> </Ul> <Li> Router functionality that includes Network Address Translation (NAT) to share a single IPv4 address . </Li>

Systems that use digital subscriber lines (dsl) do not require modems