Just some conclusions to follow up my earlier post:
First:
Thanks for all the replies and discussion.
In the end I went for the cable modem option: It is the option offered
by my Telstra, and I already have a cable connected to my house.
Second:
I was surprised to find the the ISP situation has changed drastically in
the last three years. There are now essentially 4 ISPs in New Zealand:
Telecom, Telstra, Vodaphone and Slingshot:
Paradise and Clearnet are just brands for Telstra clear. Telstra has
completely integrated the operation of these companies with its own
TelstraClear service. While the old Paradise and Clearnet domain names
still exist, all new users get TelstraClear accounts.
IHug is now Vodaphone.
I am sure there are still some small ISPs around, but it seems like the
top end is well and truely shaken out.
Third:
As regards PPP over modem, I downloaded the relevant RFC's and looked
pretty carefully at the PPP problem I was having. The problem I was
having was in the LCP setup layer. It seems that Slingshot's state
machine and the pppd state machine go out of sync when the Slingshot
peer tries to renegotiate the LCP layer. The pppd peer ( the only side
that I can see in detail ) looks to follow the RFC specification, but
the whole thing is so complicated that I cannot conclude that the
Slingshot peer is at fault. It may well be that the right combination of
options to pppd will overcome this problem, but it is really a sticking
plaster solution.
The underlying issue is that PPP is a complicated protocol that involves
extensive negotiation of parameters between the two peers at several
protocol layers. While I am sure that whoever writes the ISP's peers
could do better with their testing, I doubt if it is possible to come up
with a test suite that guarantees the implementation is compliant with
standard under all circumstances. I doubt that PPP over modem
connections to any ISP will ever be truely Linux friendly in a set and
forget sense.
When you go to a broadband connection, the ISP controls both sides of
the link since they provide you with a stand-alone modem that usually
connects to you computer via a TCP/IP link over Ethernet. That is a much
easier set of protocols to design to. In addition, it is easy to put a
firewall router between the modem and your machines to give you
additional security.
Bernie Frankpitt
