Online proxy IP is a way to change a user's IP address and hide their identity on the internet. However, it can be slow and may pose security risks, especially with free proxy IPs. Paid proxy IP services provide higher security and stability, and can help ensure the validity and availability of proxy IPs. While many broadband operators in China support PPTP and L2TP protocols, it is important to choose a reliable and secure proxy IP service to protect your privacy and security.