The tmnxEthTunnelSAPMemberEntry contains the SAP information pertaining
to an Ethernet Tunnel Group member.
Entries in the tmnxEthTunnelSAPMemberTable are created and destroyed by
setting the tmnxEthTunnelSAPMemberRowStatus object.
Entries in this table corresponding to control SAPs, those with the
index sapEncapValue set to 8191 (0x1FFF), are not writable.
For a data SAP that is sharing the fate of a control SAP, these entries
allow the configuration of the tag values for the corresponding path in
the Ethernet Tunnel port.