The value of the object tlsMstiPriority specifies the
priority of this spcecific Multiple Spanning Tree
Instance for this service.
It is used as the highest 4 bits of the Bridge ID
included in the MSTP BPDU's generated by
this bridge.
The tlsMstiPriority can only take-on values which
multiples of 4096 (4k). If a value is specified which
is not a multiple of 4K, then this value will be
replaced by the closest multiple of 4K which is lower
then the value entered.