1. The service network ports on the S5100 and the network ports on the switch are not uniquely mapped. Moreover, error codes persist even after these ports are uniquely mapped. Therefore, the problem is irrelevant to the link between both devices. 2. R&D engineers find that the rates and working modes of the S5100 and the megabit switch are inconsistent. Specifically, the S5100 network adapter works at the rate of 100 Mbit/s in half-duplex mode, while the megabit switch works at the rate of 100 Mbit/s in full-duplex mode.