|Introduction to Physical Security and Security of Services|
Network access, such as internet access, tends to be at the mercy of large organisations which run the local internet 'backbones' (the main routes). Even if you buy your connection through a small provider, their own connection is usually with one of the larger organisations.
The reliability of your local providers can be a significant issue to the success of your business - or it might not be, depending on what your business is. If it is important to have reliable access, you might want to either write reliability (and penalties) into your contract with them, or to have two different providers, who themselves, preferably, are connected to two different backbones.
If you have the two providers, you will probably need to have a specialist configure your network so that in the event of one provider failing you, your network automatically cuts over to the other. And that when the first resumes connectivity, the network routing switches back to a dual-route.