Stateless configuration of routers can be achieved with a special router renumbering protocol. This is achieved with firewall software running on the network's gateway router. Appliances built this way can provide an inexpensive alternative to expensive router and firewall hardware. Wi-Fi USB Connector or a wireless router. A Wi-Fi capable device connected to the wireless router. The BT Home Hub 2.0 was a combined wireless router and phone. A single wireless router combining these functions may suffice. SDB may require changes to intermediate router configuration. IGMP operates between a host and a local multicast router. Integrated femtocells (which include both a DSL router and femtocell) also exist. The packet is then passed on to the next hop router for this tunnel. The packet contains source and destination, not all router hops. Router Discovery and Router Redirect protocols for IPv4. Communication within the virtual router takes place periodically. Such connections are maintained by an interconnecting router, known as an area border router (ABR).