The following is a fix for the Speedtouch 510 & 530 ADSL modem/router, as supplied by Telstra, for the engin service to work.

Note: If the firmware is an earlier version, you will need to re-install the latest firmware for the Speedtouch modem/router which is available from this link http://www.speedtouch.co.uk/530.asp before proceeding.
Here is how to correct the problem :

1. Open Finder
2. Go to Applications folder then open Utilities folder
3. Start the Terminal application
4. After the $ prompt type   telnet 10.0.0.138 (Where 10.0.0.138 is the default IP address of your router)
5. A username prompt will appear, just hit [enter] and it will let you in.
6. Please check you have the latest firmware which should be version 4.2.7x -- the version of firmware is given as "Software Version" once you have logged into the telnet screen.
7. From this screen you will need to place the mouse cursor next to the greater than sign (>)
8. Type: nat unbind application=SIP port=5060 then hit [enter]
9. Type: saveall then hit [enter]
10. Type: system reboot then hit [enter]
11. Once the cursor goes to the next line, please take note of your Speedtouch modem/router. The three lights will start flashing. This may take up to a minute. When the flashing of lights finishes, two lights will go hard green, and the light closest to the front, will go hard orange.

1. Open Finder
2. Go to Applications folder then open Utilities folder
3. Start the Terminal application
4. After the $ prompt type   telnet 10.0.0.138 (Where 10.0.0.138 is the default IP address of your router)
5. A username prompt will appear, enter the username: admin and password admin then press [enter] and it will let you in.
6. Please check you have the latest firmware which should be version 4.2.7x -- the version of firmware is given as "Software Version" once you have logged into the telnet screen.
7. From this screen you will need to place the mouse cursor next to the greater than sign (>)
8. Type: connection unbind application=SIP port =5060 [enter]
9. Type: saveall then hit [enter]
10. Type: system reboot then hit [enter]
11. Once the cursor goes to the next line, please take note of your Speedtouch modem/router. The three lights will start flashing. This may take up to a minute. When the flashing of lights finishes, two lights will go hard green, and the light closest to the front, will go hard orange.