What firmware are you running?
I have a number of TA900s deployed without any issues.
The T1 goes down when the carrier is doing maintenance and then comes back up.
We have tried many different firmware versions to try to solve this issue with no luck and, because of this, many of the AdTrans have different versions on them. Too many to post, I'm afraid, but alot of them are running older firmware packs and some (the testing ones) are on newer packs and them some in between, but same result. The Adtran will freeze up and become unreachable till power cycle. We have to have customer power cycle our equipment, which becomes a big hassle.
I have been running R10.3.3, R10.9.3 both did not experience this issue.
One customer had their T1 go down every time it rained and did not have this issue.
I wonder if there is something else going on.
Thanks for posting. I'm not aware of any hardware or software issue that would necessitate the unit needing to be power cycled for any type of T-1 outage. The ADTRAN unit should be constantly trying to reestablish the connection. It's important to note that a power cycle also resets the interface on the far end, and this is what sometimes restores service.
I believe the troubleshooting should focus on the state of the unit when the link is in the down state. I would start by having the end user report the status of the LEDs on the front of the unit while it is down. This may give us some important data, but accessing the unit is the best way to determine exactly what is happening. This can be done on the craft port with a serial connection, or a Telnet/SSH connection on the customer side of the unit. The output of "show interfaces" will be most important as it will show us the current state, which types of errors the unit is seeing, and on which layer (T-1, PPP, frame-relay, IP, etc.) the unit is down. Feel free to respond to this post if you have the output of "show interfaces" during an outage. We would be glad to look it over with you. Also, feel free to call ADTRAN Technical Support at 888-423-8726 if you would like to create a trouble ticket.
I went ahead and marked an answer for this post. However, if you are still having problems, ADTRAN would be happy to assist you.