For a growing business, one location is typically not enough. With enough personnel and capital, many businesses prefer to set up multiple offices to attract different regions of customers.

With separate offices, how can your business install a network so all the locations can work, communicate, and share information easily, instantaneously, and effectively? For your main post, assume the following:

A business has two locations in different states. Both locations have their own T1 internet connections. How do you join these two networks together so every computer can see every other computer?

Your solution should provide a suggested overview to achieve the end goal of integrating the networks. Be sure you address important issues like maintaining security, reliability, end-user operations, and network speed.