If you need to access internal DCC private pages (anything on http://staff.devon.gov.uk) from outside school you can by changing the address to use the DCC secure. e.g: https://staff.devon.gov.uk
You will then be asked to login with your DCC account.
If you do not already have a DCC account you will need to register for one at http://www.devon.gov.uk/login
Please be aware it takes a few days for an account to be validated and created.
Note: This method also works for accessing the pages whilst logged into the Hosted Application Service (SIMS Terminal Server)