Wireless Mesh Network at Carleton University

DSTM (Dual Stack Transition Method)

DSTM is the mechanism to carry IPv4 traffic over IPv6 only network. It consists of three main parts:u

v Tunnel End Point: Border router between IPv6-only network and IPv4 Internet or intranet.

v DSTM Clients: Dual-stacked nodes, create tunnels to Tunnel End Pont (TEP).

v DSTM Address Server: Allocates IPv4 addresses to DSTM clients.

In our IPv6-only mesh network, DSTM is deployed to provide IPv4 support. The mesh node works as DSTM server and a TEP. When the client needs to communicate with the IPv4 world, it acquires a global IPv4 address from the DSTM server, then it creates the DTI (Dynamic Tunnelling Interface). All the IPv4 packets are encapsulated into IPv6 packets and transmitted t hrough the DTI interface to the mesh node (TEP). The DTI module on the mesh node decapsulates the IPv6 packet and forwards the original IPv4 packet.

On the mesh node, proxy ARP is deployed on the ethenet port which connects to the IPv4 network, to solve the return route problem