Cant access mycloud outside of home network

Hi, I have got mybooklive working great in my home wifi network and can access everything or all devices, however i cannot access my device outside of my network.

as soon as I leave home my device cannot be found and thats using either the apps or from a pc.

any help would be great, thanks

steve

Have you checked the complete online manual for your device for any clues. settings etc? You can download it for your device from WD support at wdc.com

I have followed all the steps from the setup manual, and tried some tips from WD without luck.

Could my modem be blocking any ports that the device may use?