I'm looking at a replacing an ISDN30 phone system. Our current supplier has let us down and the PBX equipment has gone belly up. We have a need for 5 desk based handsets. There are 2 different land-line telephone numbers routing to to the company plus an extra analogue line for our alarm system. This we can't change. Ideally I'd like to dump our current providers and get everything under one contract including the ADSL broadband we have on a dedicated telephone line. Phone usage is light at 90% UK & UK mobile based. Now here is the main issue. Our broadband is dreadful. 6mb/s at best and is unreliable. For this reason most small business systems are out as they use VOIP technology on an internet line. Anything that sucks bandwidth away from our internet access is automatically out. I've had a look at the BT One phone system which looks interesting. My understanding is it basically joins up mobile phones over a the EE 4G network. It allows you, via internet, to configure which phone rings at what time, voicemail & messaging etc. What's termed a cloud based phone system. The bonus being it's independent of office location. The issue is BT have been a bit evasive with us in the past and haven't been so transparent in pricing a quote up. Does anyone have any experience, recommendations of alternatives? I've tried the usual suspects, Vodafone, Three, O2 etc. but most seem to be ip / voip based. Any help & suggestsions much appreciated.