When the user accesses different PDNs, the user can carry the same APN that serves as the virtual APN.
The actual APN is the matching APN based on the configuration rule of the
virtual-apn-rule command.If the APN supports the virtual APN, it indicates that
the APN carried by the user is the virtual APN. The users actual APN is the
matching APN based on the configuration rule of the virtual-apn-rule command.