| 摘要 |
Power over Ethernet (PoE) communication systems provide power and data communications over the same communications link, where a power source device (PSE) provides DC power (for example, 48 volts DC) to a powered device (PD). The DC power is transmitted simultaneously over the same communications medium with the high speed data from one node to the other node. For data-only switches (i.e. non-PoE), a midspan device is connected between the data-only switch and the PD devices so as to inject the DC power for the PD devices. The midspan device includes a combination data and management port that communicates both high speed data packets and management packets with the data-only switch. The combination data/management port obviates the need for a dedicated management port on both the midspan and the data-only switch. This eliminates the need to use an extra port on the data switch thus making better port utilization at the data switch as well as lowing the cost of the midspan.
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