This attribute defines the object type to be returned. 

The following abbreviations are used for the object type names:
MD - management domain
ME - managed element
EH - equipment holder
EQ - equipment
PTP - physical termination point
FTP - floating termination point
CTP - connection termination point
TPPool - termination point pool
EPGP - equipment protection group
PGP - protection group
SNC - subnetwork connection
RT - route 
CC - cross connection
SN - subnetwork
TL - topological link
OS - operations system
TMD - transmission descriptor

Readable by Requesting OS? No
Writeable by Requesting OS? Yes
Invariant? Yes
