This example features a simple application sending udp packets on port 0xF0B0, 
from port F0B1, to a udp receiver. It must be used in conjonction with a node 
running the udp-receiver-ipv6 example.

We use this example to test UDP, and most particularly UDP header compression
with IPv6 and 6lowpan support. When IPv6 is used over an 802.15.4 link, 
6lowpan acts as an adaptation layer between IPv6 and MAC. In particular, 
it can compress IP headers and UDP headers.

With both HC1 and HC01 header compression schemes, UDP 16-bit ports are 
compressed to 4 bits if they are between F0B0 and F0BF.

sender behavior:
The sender is implemented in examples/udp-sender-ipv6/example-udp-sender.c 
and acts in the following way:
it waits 15 seconds (to be sure the node configures a global address, in case
a router on the link sends router advertisements usable for address 
autoconfiguration) , then sends 5 UDP packets to the receiver address 
entered hard-wired in the source code.

receiver behavior:
When receiving a packet, the receiver answers with a simmilar packet.

To run this example, contiki-conf.h must have at least the following flags 
values:
#define UIP_CONF_UDP             1
#define UIP_CONF_IPV6            1

You must configure addresses example-udp-sender.c and 
examples/udp-receiver-ipv6/example-udp-receiver.c which match your 
platforms addresses.