In our network we have 6 adtran routers spread over 3 geographical sites. Half of the users at Site2(they generate a lot of traffic) have a dedicated T1 to a server on Site1 and then the other half of Site2 and a small group of users at Site3 use the other T1 along with all of the traffic for the phones. We have been having troubles with the t1's going down periodically so we want to implement some fault tolerance/load balancing. We are thinking about adding a routing protocol that doesn't send a lot of traffic across the T1's so that's why we want to use OSPF. There are only about 200 users across the entire network with about 5 servers sitting on site1 and all are on the same domain(we are adding a mini domain controller on site2). If we use the basic configurations of OSPF would it automatically do load balancing across both T1's and use just one of the T1's if the other T1 went down or a period of time?
Any other suggestions?