[plug] GPRS+IrDA Phones & Linux

[Paul Arch]

> Does anyone have much experience with getting mobile internet access
> via a Mobile with GPRS + IrDA? ie; Using a PDA or Laptop with IrDA as
> the console witht he Mobile as the internet connection.

I have had experience using my Nokia 3650 and IrDA port on laptop (but under
windows ;) ), but I am mostly experienced in using GPRS modems which connect
on a serial port of PC

> While it's expensive, at least GPRS isn't time-charged, so it's a more
feasible
> solution for remote administration.
>

Expensive is an understatement.  For peoples information (Telstra) charges
are ~ 2.2c per KB, traffic in both directions is counted.  You can go on a
plan (which we are on) for $85, which gives 10mb and reduces costs to 0.8c
per KB.

But alas, there seems to be some interesting developments on the pricing
front :

http://www.geekzone.co.nz/content.asp?contentid=3523

> I'm interested in feedback on:
>   *How easy it is to get going, and what Linux software is required
> (OpenZaurus support would be good ^_^)
>   *Whether Aus Mobile service providers (in particular Vodafone)
> support more than Web via GPRS (ssh would be useful. ^_^)
>   *Which phones support GPRS + IrDA for this purpose (preferrably
> Nokia, and not too expensive ^_^)
>

Whilst I cannot be too much help on the PDA front, with the mobile
phone/laptop, you use it exactly as you would a modem (on the serial port )
and dialup.  You just use a special dialup number (which for telstra, is
*99***1#).

 So under minicom:
    ATDT*99***1#

 would start ppp session.  With this in mind, its just a matter of setting
up your favourite dialing software (pppd) and pointing it to IrDA port ? No
username/password needed (under telstra).

 You need to 'inform' your gprs providers of your intent for using GPRS for
IP enabled services (eg. I want to access email from my mobile ) rather than
just MMS and WAP.  Vodaphone/Telstra are excellent in this respect, Optus I
have had trouble getting to the right people - but this is my own
experience, you may get a better run with them.  Be aware pre-paid services
from optus/vodaphone don't allow anything other than MMS/WAP (not too sure
about telstra, or if this is still the case )

 Telstras systems allocate your GPRS device a private address ( eg.
10.10.1.15 ), and this goes through some sort of NAT firewall system. If you
plan on having a remote device (we have embedded linux system monitoring wet
cooling towers ), CIPE is an excellent platform for creating VPN to internet
connected hosts.  But its a tricky situation - NAT f/w seems to timeout
after 2 minutes, hence needs flow of traffic (pings ) to keep alive == $$$

If you have the luxury of a serial port, might be easier to get GPRS modem
( http://www.intercel.com.au/ ).  I do believe you can get a cut down
version (non-industrialised) for ~ $225 ex.

Hope this is of some assistence.

cheers

Paul