tMacFilterParamsFwdSapPortId specifies the sap port identity of the
destination for this Mac filter entry. A value of 0 indicates that
there is currently no SAP destination defined.
A value different from 0 can only be specified if the
tMacFilterParamsFwdSvcId object also has a non-zero value,
and if the the value of the tMacFilterParamsAction object of this
entry is 'forward'. In addition a non-zero value can only be given if
the object tMacFilterParamsFwdSdpBind has a zero value.