The value of vRtrMvpnSpmsiType specifies the type of the
selective provider tunnel.
When the value of vRtrMvpnSpmsiType is set to 'rsvp', the selective
provider tunnel is used for RSVP. When the value is set to 'pim',
the selective provider tunnel is used for PIM. When the value is
set to 'ldp', the selective provider tunnel is used for LDP.