How to check your firmware version on Samsung Galaxy S2.
Type this code on your Galaxy S2 dial pad *#1234# and then you will get the firmware info.
Samsung Galaxy S2 Telstra Australia firmware update list.
Product Code: GT-I9100TLKJTEL
You can check the software updates tab on this page http://www.telstra.com.au/mobile/phones/smartphone
The below are the official stock ROMs that can be use to manually flash the Samsung Galaxy S2 by using Odin multi-downloader tool just in-case you want to upgrade, downgrade or return your Samsung Galaxy S2 into original stock firmware.
Firmware info: PDA:DVKF4| PHONE:DVKF2| CSC:TELKF3
DVKF4 Stock Kernel:http://www.multiupload.com/91ID4RZEMO
How to Update your Samsung Galaxy S2 Telstra via Kies server
All you need to have is Kies installed on your PC. Using the USB cable, connect your phone into your PC, when your phone is already connected the Kies application will launch automatically, if Kies doesn’t do that just open it manually in your PC. Go along with instruction to update your smartphone, and then Kies will do the job in searching appropriate update for your Galaxy S2, when found the update let Kies update your phone.
The above firmware links was compiled by Intratech at XDA-developer.
You can also help improved this list by adding additional firmware info on what you might had on your device.