We have abandoned a phone system.  Everyone uses their cell phone.

Allen Stout - for office......wish I could suggest.

Most of the agents have their direct contact number listed on the listings.

The thing I love about the one in my office is that, if I don't answer at my desk, the call goes right to my mobile phone. 

This is the VOIP system I have myself, not my office, but what I like about it is that I have an app on my phone so if I am not at the physical phone I can still take all the calls on that number while on the go.

Transfer calls to my cell.

All calls for me to my cell phone, that would be all I want. However our signage here already only has our cell numbers, no office number, so it is rare I get a call at the office anyway.

For me it would be the ability to transfer all calls coming to me to my cell phone.

Very reliable network and providers with reasonable rates.

 I just converted home office to VOIP, $19.95/mo. Quality is very clear. No time limit, no out of the area cost same price in Canada, Guam, 50 states and US territories. I think you need to maintain a land line for FAX..... Not aware of any new digital fax machine accepting.

Let me know if there is a VOIP digital fax machine....

Sam Shueh

Over 12 years I use Vonage. Works for me.

Vonage. 

We use it for over 12 years

Reliability, we use Gvoice.

Depends on the size of the office.  Have you checked Ooma?  We use it for our home office.  Excellent quality.

I have no idea. I only ever use my cell phone for business and if they should happen to call my brokerage, they are immediately transferred to my cell.

 Good morning Alan. The only downside of VoIP is if the Internet goes down, so does your phone service.

Redundancy and latency. You want a robust and realiable network with the shortest hops possible.