Clients. The port number is the identification number of the application software with network function. A software can have multiple port numbers, which proves that the software has more than one network function. Shell Branch is a leading online and offline real estate transaction and service platform in China, with the slogan of "professional brokers lead shell branches with higher shell branches" as the tob end and enterprises as the tob end. Shell is a housing rental transaction information service platform, which has a large number of housing information, covering second-hand houses, new houses and rental information in various provinces and cities, and the data is updated in real time. The platform also provides users with VR house viewing service, allowing users to personally watch the house structure.