The Quintum gatekeeper is very limited, with emphasis on the limited.
If you have devices that change I.P. and re-register, the quintum have a hard time following up, either give you a false double registration or no registration at all.
Also, the built in gatekeeper on the gateway is very limited on the number of devices that could handle.
A A400 could only registrer four devices, and does not tell you anything when it reach the maximun, only stop taking registrations.
Only use if for other quintum devices and only as a last resort.
Think of it as something that you got for free, and you got what you paid for.