Message Queuing Middleware on VPN and Its Traffic Control Scheme - Modeling Asynchronous Message Queuing Communication on MPLS VPN

A battery electrolyte level indicator constructed for substitution of a battery cap on a multi-cell battery. The electrolyte level indicator has an outer housing construction in the shape of a cap to be screw mounted into the open upper end of the port leading into the battery cell. A probe extends from the housing or cap, into the battery electrolyte. A light indicator, such as a light emitting diode, is mounted on the exterior of the cap housing and will become automatically energized in a fail-safe condition if the electrolyte is at a sufficient level within the cell. However, if the level of the electrolytes should drop below the depth of the probe, then the indicator light will be deenergized, thereby immediately providing an advisory signal to the operator of an unsafe battery condition. The probe is constructed so as to operate as an anode in combination with a cathode of the battery. Moreover, the probe is formed of a material which, when connected in this arrangement, is highly resistant to corrosion.