Sat Phone again and again

That's correct, Krakka.

Although the Iridium handset and operating frequency are different to the GSM/NextG handsets and frequencies, they all use the same sim-card technology to identify you and your account. This applies to Telstra services only - you cannot use a non-Telstra sim card (other than an Iridium sim) in an Iridium phone.

Not sure what you mean about the "prefixes" before dialling. I don't use the international codes on my device.

George

As you are using TR Telecom as your Iridium provider what works with an Iridium phone which has Telstra as the provider will/may not work.
If the same parameters apply then only a SIM provided by TR Telecom will work in your Iridium satphone.
The Telstra Next G and GSM SIM's work when enabled for international roaming because the PROVIDER is the same.
In a nutshell I don't think a Telstra Next G SIM or anyone elses SIM will work in your Iridium phone except for a SIM provided by TR Telecom.

An Iridium Satphone can ONLY work to Iridium satellites - it will not work to any national networks, even for emergency calls.

How it works depends on which SIMcard you put in it. Motorola 9500 can only receive SMS - 9505, 9505a, 9555 can receive and send SMS.

If you put a Telstra Mobilesat Simcard or a TR Telecom Iridium SIMcard in it, it works as a Satphone using International numbering no matter where in the world you are. These usually cost a minimum of $30 a month and you get assigned an International Number you can use anywhere in the world.

If you put a Telstra SIMcard (GSM or NextG) that is enabled for International Roaming, is not Prepaid and is not barred from 1900 calls, it will be recognised by the Iridium Network. You must be in Australia.
Outgoing calls to Australian numbers and INCOMING calls are charged at abt $3 a minute.
It will work like an Australian Mobile phone in terms of numbering - for incoming and outgoing voice calls you just use the normal national numbers (02 xxxx xxxx, 04xx xxx xxx).
You can send SMS to any phone in Australia, but you can ONLY receive SMS's from a Telstra Mobile - NOT from Optus, Vodaphone etc.

Krakka did you get my return MM Friday evening? If not i willl let you know how i got on.
Bob.