Hello,

Active Directory Schema is updated at each Windows Server release. Each of those schema updates brings us some new features to our forests. This is the same for Exchange and Skype (formerly known as Lync or Office Communication Services). Those schema updates bring new attributes and classes in your Active Directory Schema, you can identify which version of those update are injected in your schema by looking at a special location in your forest.

Active Directory Schema

You need to look at the “ObjectVersion” on the schema naming context :

Get-ADObject (Get-ADRootDSE).schemanamingcontext -Properties objectversion

Active Directory Schema

Here, the object version is 85, to get the friendly name you can use that table :

Exchange Schema

For Exchange, you need to look out for for the “RangeUpper” attribute on an Exchange object on the schema naming context :

Get-ADObject "CN=ms-Exch-Schema-Version-Pt,$((Get-ADRootDSE).schemaNamingContext)" -Properties RangeUpper

Active Directory Schema for Exchange

Again, to get the friendly name of the Exchange schema version you can use that table :

Skype Schema

For Skype, this is also the “RangeUpper” attribute, but on a Skype object in the schema naming context :

Get-ADObject "CN=ms-RTC-SIP-SchemaVersion,$((Get-ADRootDSE).schemaNamingContext)" -Properties RangeUpper

Active Directory Schema for Skype

And here is the final table :

All of those tables are in constant change, nearly each new product version releases bring new schema modifications.