Allied Telesis AT-S39 - Manual (Page 208)

Section III: Web Browser Management
208
Bridge Hello Time
The time interval between generating and sending configuration
messages by the bridge. The default is 2 seconds. This value
cannot be changed from this window. To change this value, refer
to earlier in this procedure.
Port State
The current STP status of the port. A port’s STP status can be
forwarding, listening, learning, or blocking. This setting cannot be
changed.
Root Bridge
The MAC address of the bridge functioning as the root bridge in
the spanning tree domain. This value is for display purposes only
and cannot be changed.