Almost a year ago, I configured a customer with two T1 point-to-point circuits between two of thier offices. Used cisco routers on each end with CSU/DSU wic cards. I setup EIGRP for load balance and fail over. The load balance and fail-over fuctionality was working fine for a long time. The custoemr even experienced the first T1 having some trouble and the second taking up the full load untill the repair was made. This was evidence that in an actual event a T has problems, his compuetre systems in the remote office would continue to communicated over the network to the servers at the main site.
I received a call from another vendor that does on demand remote desktop support online over the Internet for custom medical software for the same customer and they said they were experiencing some packet loss. I trust this other company. Although their core technical experience and background isn't networking, if they say they saw this happening then I belive them and I have to investigate the network problem. They were onsite which was different at first since they normally remote in using Inquerio software.
I went to the remote side first and found that the smartjack LEDs weren't even lit. Checked all connections and they were fine - just the way I left them way back. the status on the routers is just plain old status down and protocol down. This usually means there is no live circuit. Did all I can at that moment. I wrote down the circuit ID and called into my office. I email the office manager lettng him know that the T1 cards in the telco smartjack weren't even lit and he checked his side. his side were lit but they didn't seem correct. I'll be out there next week to see what's happening.