'aos' seems to have various different sysDescr

1)
Alcatel-Lucent OS6400-P24 6.4.3.717.R01 Service Release, February 11, 2011.

2)
Alcatel-Lucent 6.4.4.342.R01 GA, April 18, 2011.

3)
6.6.1.679.R01 GA, November 01, 2009.

3rd one is not very good target for sysDescr discovery