I found this guide:
Total Access 900e Series Hardware Installation Guide
Page 2:
Software Licensing Agreement
Each ADTRAN product contains a single license for ADTRAN-supplied software. Pursuant to the
Licensing Agreement, you may: (a) use the software on the purchased ADTRAN device only and (b) keep
a copy of the software for backup purposes. This Agreement covers all software installed on the system as
well as any software available on the ADTRAN website. In addition, certain ADTRAN systems may
contain additional conditions for obtaining software upgrades.
Third-Party Software
The software included in this product contains copyrighted software that is licensed under the GNU
General Public License (GPL). For a list of third-party software and their licenses, go to
http://www.adtran.com/software/EULA. You can obtain the complete corresponding source code of such
software components from ADTRAN for a period of three years after our last shipment of this product by
sending a money order or check for $5 to:
ADTRAN, Inc, P.O. Box 933638, Atlanta, GA 31193-3638
Please write GPL Source for product Total Access 900e in the memo line of your payment.
This offer is valid to anyone in receipt of this information.
Looks like just one license required.
Here is the
Adtran support site, looks like you need to create an account to go further but there is a license link there.