If I recall, the CTI integration out of the box only worked with a couple of systems which are probably no longer in existence these days. What you needed to do was get a 3rd party module that allowed CRM to work with a standard TAPI stream for many systems. The problem with TAPI is that it is supposed to be a standard but sadly everyone seems to have a different standard of TAPI with their systems in my experience. You need to look at getting QGate's intelli-CTi although looking at their website now they're called QWare. If you can't get a VOIP system to connect to Sage CRM using this software, then I'd walk away from it

And I have used QGate's (sorry QWare's) software on a couple of projects in the past where CTI was required and it works. It isn't cheap but you get what you pay for. Enbu used to have a CTI wrapper for CRM but I don't think they're still going any more. I assume Gretrix bought them out so you could check out Greytrix's site. I've not used that though.

We developed our own integration with 3CX and Horizon (We are a Gamma and 3CX partner) and have customers successfully running Mitel systems with Xarios.
You are right , QGates offering was extortionate 

Sean from Spire have you 'productised' the integration?  If it is something that other partners can use we can put it either here: https://community.sagecrm.com/add_on_store/default.aspx or get it listed on the Marketplace

Hi Sean, All they want is when an incoming call rings, they have a lookup on screen that is automatically populated based on the phone number (checks for company, person and a number stored against an opportunity) and when 'clicked' moves them to the record n CRM so they can enter a communication whilst talking!! 
Dial out, would just use the 'tel' hyperlink as they are already on the correct record in CRM...
Not complex but something more sites are looking for!!

Thanks

Hi RBC_1, thats exactly what we did with 3CX, Incoming call shows any matching numbers (against a Company/Person/Lead) with the ability to display the CRM record before you answer and then when navigating to the CRM record, we embedded a quick communication block within the summary to record 'phone in' as you are on the call.

We all used it internally up until 6 months ago before we had to move away from Sage CRM.

We also hooked Sage CRM into the 3CX CDR Sockets. So even if a member of staff didn't log the actual call details, we stored a record of all Inbound/Outbound, DDI, Duration, Answered, Missed calls made to and from matched customers in Sage CRM. This was useful to get an idea of call frequency to our support department. We had some dashboards showing average durations and volumes.