This counts notification payloads sent by this specific Phase-1 tunnel, per its description, the outbound per-tunnel companion to cisgIpsSgTunInNotifys. It shows how many status/error notifications this device itself is generating toward one specific peer, which - if unusually high compared to other tunnels - would suggest something about this device's handling of that particular connection is triggering more notifications than normal, rather than a peer-side issue. An admin noticing this spike on one tunnel right after a local configuration change to that tunnel's crypto map would suspect the change introduced a mismatch generating extra notifications.