I'm sure someone from Cisco will correct me if I'm wrong but, IIRC, SDEE is actually an evolution of Cisco's RDEP.
RDEP was developed first by Cisco as an in-house replacement for the less secure UDP-based “PostOffice” protocol. Then, in association with the other industry partners in the SDEE consortium, the new "standard" was developed with RDEP as the basis.
As an aside, SDEE is an industry attempt to standardize security device reporting in response to a lack of action from the IETF IDMEF effort. Also, RDEP v2 (again, Cisco will correct me if I'm wrong) will be fully SDEE compliant.
I hope this helps,
Alex Arndt
