Sometimes when I'm at home, my iPhone connects to the Sure Signal and shows full reception, but it won't receive phone calls. People calling me go straight through to voicemail, and I will get a txt later telling me that I've missed calls. Turning the phone off and on seems to fix the problem. My flatmates are also having issues (and are also on iPhones, but different models).
The second issue is that the system light on the Sure Signal will occasionally start flashing and it will drop all cellphone connections for a few minutes. It doesn't seem to be an issue with our internet connection, which has been rock solid for the last couple of weeks
Not sure if the two problems are related.
I'm not using a Vodafone supplied ADSL modem; my setup is a Draytek Vigor 120 controlled by a pfSense box (ALIX 2D13). The firewall is setup to allow the Sure Signal to make any external connection, and it generally doesn't seem to have had any problem connecting and configuring itself.
Any suggestions appreciated!