Why VPN monitoring? Let’s imagine a company that have a network of branch offices in most of the largest cities of the country. The offices are interconnected using both public networks (i.e. Internet) and dedicated operator networks (i.e. MPLS). In order to provide secure communications, on top of both types of links the company runs VPN tunnels, that are used for to carry the actual data. Also, in order to make the connectivity more reliabile, the company employs multiple VPNs from each site — one main (over MPLS) and two backup (over the Internet); in case of link failure the re-routing is handled using OSPF. As our experience shows, network  failures and service degradations may occur even in case of a very reliable network such as this one. In case of RDP and VoIP-based services (i.e. the remote office doesn’t have any servers and PBXes), the network failure will bring the office to a dead stop. More »