A more scalable solution is to connect branch offices using a site-to-site virtual private network (VPN)..
The VPN Solutions uses the fact that both your central office local area network and the branch office networks are connected to the larger network (the Internet) to provide connectivity between the LANs. Of course, the Internet is a public network, full of hackers and attackers, so the key concern with sending communications across the Internet that are confidential within the company is security.
VPN Solutions resolve this problem by creating a "tunnel" through the Internet from one office (site) to another. The traffic that goes through this tunnel is encrypted to protect any sensitive data.