Around Hamilton (Frankton and Te Rapa particularly), Telstra has it's own "circuits" - when you get broadband with them, it's a dedicated broadband circuit (ie. not re-sold Telecom ADSL).
You still use an ADSL modem to connect, but they specify that the connection is PPPoE. I haven't seen any specific instructions on the rest of the settings. When experimenting with a connection recently, I discovered that it would connect both with the Encapsulation set to LLC/Snap, and VC Mux.
Does anyone know whether this makes any difference whatsoever? And if it's meant to be VC Mux, do you still use the common 0/100 settings for VPI/VCI?
It's a known "quirk" of the network - http://www.geekzone.co.nz/forums.asp?forumid=44&topicid=53843 - Most ISAMs are capable of both but usually a provider will configure one or the other. There shouldn't be any discernable difference if you're talking about performance. The config's usually about security etc rather than what's going to give you better throughput…..and yep standard 0, 100 vc mux.