This is a Counter64 preserving the total octets received by a now-expired control tunnel over its entire lifetime, per its description, the historical companion to the live cisgIpsSgTunInOctets. It gives an admin the final tally of inbound control-plane traffic for a since-closed connection, useful for judging how much signaling activity that tunnel handled before going away. An unusually high value for a tunnel that only lasted a short active time would suggest that connection experienced heavy retransmission or renegotiation churn right before it failed.