The handoff locator is used to
deploy OpenADN as an overlay over IP. It needs to be
discussed in the context of two specific requirements:
OpenADN as an overlay over IP (Middlebox sequence):
To switch through a middlebox-sequence distributed over
an IP network, an OpenADN switch might put its own IP
address (or an anycast group address) in the handoff-
locator before forwarding it to the middlebox.
The middlebox just copies this to the destination IP address
field in the IP header in return packets. The packets are sent
back to the originating OpenADN switch (or any switch in
the anycast group) that then switches it to the next
middlebox in the sequence.