A table that contains TLS PIP (Provider Internal Port) uplink
information. PIP is the virtual link between I and B components of PBB
(Provider Backbone Bridging) model. I component refers to a service
with svcVplsType set to 'iVpls (3)' and B component refers to a service
with svcVplsType set to 'bVpls (2)'. When any form of STP is enabled in
the iVpls domain, the PIP uplink is modeled as a regular STP port.