[Wylug-help] Linux and GPRS

[Jon Stockill]

On Wed, 22 Oct 2003 lists at mungewell.org wrote:

> Once working can you use the link as if it was a normal network
> connection, i.e. what ever port/service you want...

This depends on the network - some put less in your way than others.

> I assume that the phone allocates an IP for the PC end of the ppp link,
> is this a public IP - can it be reached from the outside world?

Again, see above.

On Orange you'll find yourself on an RFC1918 address, ICMP is heavily
filtered, UDP is broken, and your conenctions are forced through a web
proxy which reduces the quality of images to save bandwidth. Give up all
hope of ever making a sensible VPN working (about the only thing that will
is ppp over ssh, and why should you have to use something with such a high
overhead just to get around their network?)

HAving spoken to Vodafone it sounds like their network doesn't suffer from
such problems, so I may well be swapping to them in the near future.

> Is there anything that would prevent a 'evil doer' from ramping up your
> phone bill by sending loads of (unwanted) data to you (i.e flood ping)?

On Orange that shouldn't be a problem - I've no idea how it's handled on
other networks.

> PS. at 0.75p/KB its not much good for P2P Music, but IM might work quite
> nicely.... and be a lot cheaper than SMS :-)

I found GPRS to be very handy for email, irc, the odd bit of web browsing
(lynx or links will help keep the bandwidth down here). It's usable for
ssh, although the latency is quite high.

--
Jon Stockill
jon at stockill.org.uk