With the advancement of Urban Intelligence and Smart Cities, the importance of remote monitoring and data collection increased. Concerning monitoring, IP-Proxy is an important equipment to perform the interconnection between the sensors and the Internet. In the recent literature, several gateway architectures for network sensors have been proposed to integrate Wireless Sensor Networks (WSN) and Internet. Most  implementations of WSN gateways retrieve sensors data on the WSN and display the results to customers through the web. The disadvantage of these solutions is that they use specific protocols to connect the sensors, thereby prohibiting the direct interaction between customers and sensor nodes. As an option, the adoption of the SNMP protocol for sensor management has the potential to reduce the gateway complexity of most gateway.  For this reason, this article presents the design and implementation of a low-cost open platform IP-Proxy with the usage and modification of a commercial out-of-the-shelf wireless router, with serial connection to communicate with the sensors, that are connected to an expanded microcontroller Arduino Nano board. The results of the experiments showed that the IP-Proxy can successfully interconnect sensor networks and the Internet, where data can be worldwide broadcasted via Ethernet or WLAN. His features include ease of implementation, integration and robust operation.