The internet is designed to be resilient to failure. A patchwork of routers and cables span the globe, like a spiders web. There is no one route a message can take to get to its destination. Failure, or congestion is usually bypassed automatically without anyone being aware. Generally the weakest link are the two end-points.
Turbo Exchange servers are located in different secure data centres, using different hosting providers to minimise the possibility of total failure (you dont need all servers runnng for the system to be functional).
For a reliable connection, a risk assessment should be made. Typically, a small to medium size business may only have one connection to the internet. So that will be your weakest link should that connection fail. A second connection, to the same ISP, will lower the risk, but not sufficiently (what if the ISP fails, goes bankrupt, you forget to pay the bill, or your local telephone exchange burns down!). Two connections using different technologies is the best approach. Options include (in approximate reliability order):
ADSL & Cable
A suitable router installed at your premises can automatically switch between the services automatically for you. Of course, if your internet is reliable, and you are not concerned about occasional failure, then one connection will suffice.
Routers with 3G backup can be bought off the shelf. Providing you can supply a SIM from a mobile phone operator that has coverage in your area. It's the cheap and easy solution. If in doubt, it may be a good idea to seek specialist &/or local advice.
If your sharing the internet with other services, such as CCTV, or general web browsing/applications. Make sure your broadband connection is not saturated. Job messaging with Turbo Exchange uses relativity small amounts of data, so typically this is not an issue, but it can be.
If you have a firewall, and your blocking outgoing connections, make sure it's not blocking Turbo Exchange servers. There is more than one. Software firewalls, and anti-virus software installed on the PC's can often be a cause of unintentional connection blocking.