OLSR HNA Message

There are two radios on each mesh node. The routing protocol OLSR is running on one interface to establish the mesh backbone. The other interface does not join in the routing process. It provides access to wireless client in the local footprint. To anounce the reachability of wireless clients in local footprints to the mesh back bone, the Host and Network Association (HNA) message in OLSR is employed to provide connectivity from the OLSR interface(s) to those non-OLSR interface(s). A mesh node injects route information of an associated network in the local footprint into the OLSR mesh network by periodically multicasting HNA messages, with the following information:

• Network Address: The network address of the associated network.
• Netmask: The netmask, corresponding to the network address immediately above.

When other mesh nodes receive HNA messages, they generate correspondent entries in the routing tables. Therefore, the mesh back bone and local footprints are fully integrated. In order to generate the HNA message, we need to determine the IP addresses of arriving wireless clients.

Dynamic Host Configuration Protocol for IPv6 (DHCPv6)

Our mesh network is based on IPv6. DHCPv6 is deployed as the address autoconfiguration mechanism. The DHCPv6 protocol is a client server model. Through the DHCPv6 message exchange, a client acquires configuration information from the server. DHCPv6 messages are carried by UDP packets. The IP address allocated by the DHCPv6 server is carried in the Reply message.