VPDN (Virtual Private Dial-up Network) uses L2TP or GRE tunnel technology to build a virtual private network isolated from the public Internet for customers to meet the requirement of their wireless terminals to access the internal network.

○   The IoT card terminal directly dials into the enterprise intranet through the operator's network to realize communication with enterprise intranet applications;

○   The VPDN channel can be used as the backup of the wired link to supplement the broadband VPDN access;

○   The VPDN service of the Internet of Things can be flexibly networked through the operator's network to realize the intranet communication between the branch and the headquarters;

○   It can restrict customers from accessing the public network and only allow access to the intranet, which improves the security of VPDN services;

○   A fixed IP address can be issued for each IoT card terminal;

○   With multi-level security control, customers can build their own AAA (authentication, authorization and accounting) to realize the authentication and binding of the IoT card;;