1.3.6.1.4.1.1916.1.1.1.13 is the primary firmware image version, 1.3.6.1.4.1.1916.1.1.1.14 is the secondary, 1.3.6.1.4.1.1916.1.1.1.15 is the one to use on next reboot, and 1.3.6.1.4.1.1916.1.1.1.32 is the image that was booted (1=primary, 2=secondary).