2-1
8000-A2-GB21-20
November 1997
Service Domain Features
2
Overview
This chapter describes the following features that are supported in the service
domain:
Protocols
Address Resolution Protocol (ARP) with Proxy ARP
Filtering
Protocols
The HotWire DSLAM and HotWire RTU forward IP packets between the end-user
system and the Network Service Provider using the following protocols:
Point-to-Point Protocol/High-level Data Link Control (PPP/HDLC)
Packets transmitted over DSL links on an 8546 DSL card are encapsulated in
PPP/HDLC frames. PPP/HDLC is not supported on the 8540 DSL card.
MAC
Packets transmitted over LAN ports are encapsulated in Ethernet II MAC
frames.
IP
IP packets arriving over the DSL interface are forwarded to the LAN interface.
IP packets arriving over the LAN interface are forwarded to the appropriate
DSL interface.
NOTE:
Directed broadcasts (also referred to as subnet broadcasts — all
1s (ones) in the host field) are forwarded upstream, but are not forwarded
downstream.
Also, multicasting is not supported.