from anywhere in the Internet by means of IPv6/6LoWPAN.
Nodes collectively deliver their data to a sink node, which
represents the single point of contact for the external nodes.
Alternatively, each node might publish its own features and
data by running a CoAP server, though this feature is not yet
implemented in the testbed. In either case, a gateway is required to
bridge the 6LoWPAN cloud to the Internet and perform all the
transcoding described in the previous section.