Identifies the type of stream, and according to it uses filter table.
It can not be changed after a filter table is attached to it.
The following types of streams are supported:
ip: IP filter. The exact definition is a row in
hh3cLIIPStreamTable.
mac: MAC filter. The exact definition is a row in
hh3cLIMACStreamTable.
userConnecton: User connection filter. The exact definition
is a row in hh3cLIUserStreamTable.