This object reports the local send window size — the number of unacknowledged sequenced packets this router is allowed to have outstanding — for the VPDN session, and it reads as zero whenever sequencing is disabled for that session. Administrators check it to understand how much throughput headroom the tunnel's flow control currently allows before this end must wait for peer acknowledgements. For example, a local window size of zero on a session where sequencing should be enabled would indicate a misconfiguration rather than a deliberately unsequenced tunnel.