It is likely something to do with the User-defined Type not being present locally. Even though I have dbo.SampleDataType defined locally defined the same as the remote server I still cannot pass it across the Linked Server boundary using 4-part naming.

This:

declare @p1 dbo.SampleDataType

insert into @p1 values(N'99',99)

insert into @p1 values(N'98',NULL)

insert into @p1 values(N'97',99)

EXEC [SomeServer\SQL2008R2].test.dbo.SampleProcedure @Sample=@p1

Yields this:

This works OK though which should be expected as it parallels what .NET is doing by passing the table declaration and population within batch to be executed on the remote server:

DECLARE @sql NVARCHAR(MAX) = '

use test;

declare @p1 dbo.SampleDataType

insert into @p1 values(N''99'',99)

insert into @p1 values(N''98'',NULL)

insert into @p1 values(N''97'',99)

EXEC dbo.SampleProcedure @Sample=@p1'

EXEC(@sql) AT [SomeServer\SQL2008R2];