# Affordable Broadband with Software Defined IPv6 Network for Developing Rural Communities
## 4 Affordable Broadband Services with SoDIP6 Network
We consider smart sleeping and traffic load-based energy variance in this experimental analysis to evaluate the energy efficiency of the proposed testbed. The overall steps of experimental activities are depicted in Figure 3. Custom end-access network topology as mentioned in Figure 2 was loaded and executed in the Mininet emulator after starting the Open Daylight SDN controller. The network hosts generated random IPv6 traffic in a periodic manner. The traffic with power consumption status of data plane devices was continuously monitored via a power monitoring daemon. Similarly, the sleep/wakeup daemon instructed data plane devices based on traffic status to sleep or wakeup accordingly. The pattern of energy consumption recording during 24 h of monitoring is presented in Algorithm 1. In the running of the SoDIP6 network, at the beginning, a list of source hosts and destination hosts was randomly generated to establish IPv6 traffic exchange using a traffic generator tool like 'iperf' and 'ping6'. Source hosts periodically generated IPv6 traffic to the destination, while the iperf tool generated traffic every 2 min and the ping6 tool generated traffic every 3 min. This situation created continuous traffic flow in the network. The device and link power monitoring daemon continuously monitored the IPv6 traffic status at the switch and links then activated the smart sleeping and wakeup daemon accordingly. We also consider that a switch has 110 Watt power consumption in normal conditions [55] and full load links consumes 40 Watt [56]. Similarly, per port power consumption by switch ports per Mbps was 0.01 Watt [57; 58] and active CPE consumes 7 Watt. While considering the 7 h (10 pm to 5 am) sleeping habit of rural people, the data plane devices can be entered into sleep mode during idle situations and the corresponding links can be shut down. Figures 4 and 5 show the pattern of power consumption by all switches and links over the period of 24 h. The outcome of this empirical analysis indicates that switches and access points (APs) frequently entered into sleep mode whenever there was no traffic entering into the device and links. This leads to the total energy consumption rarely reaching peak value, except in some moments which look like spikes in the graphs. We simplified the results to total annual energy consumption based on the 24 h of power utilization pattern by the network nodes and links. We achieved an annual energy saving of 31.50% on nodes and 55.44% on links with SoDIP6 network deployment. Note that nodes and switches/routers are used interchangeably in this article. Per unit charge of electricity in Nepal is almost equal to one cent. An annual energy bill to be paid by ISPs that have a different number of switches and links in their end access networks with respect to the legacy IPv4 network and the SoDIP6 network as per assumptions provided in our experiment is estimated and the comparative chart is shown in Figure 6. Hence, an ISP with 400 switches and 1800 links at its access network can have annual cost savings of up to three million USD. Most of the ISPs and Telcos of Nepal use Cisco, ZTE, and Huawei routers in  
Figure 2: End access network in the ISP (Internet Service Provider) network infrastructure. ```
1. /*(V, Ed) = G, where switches and CPEs as nodes (V) and links (Ed) in network topology graph G*/
2. /*(V,\" initialize network, assign IPv6 address, set remote controller */
3. src_list = random (V) /*V belongs to CPEs. This identify source hosts for random ipre6 traffic generation. */
4. dst_list = random (V)/*V belongs to CPEs. This identify destination hosts to send IPv6 traffic generated form source hosts. */
5. while (running_network (G)):
6. /*(every 2 min, Generate_IPv6_ipperf(src_list) /*generate IPv6 traffic every 2 min using iperf*/
7. /*(every 3 min, Generate_IPv6_ping6(src_list) /*generate IPv6 traffic every 3 min using ping6*/
8. /*(every 2 to 3 min, /*record the power of nodes and links*/
9.