Hi friend!
The value is an integer ranging from 1 to 65535.
The user-based NAT session number limitation is enabled by default. The default maximum number of user-based NAT sessions for each type of protocols is as follows:
TCP or UDP: 10240
ICMP: 512
Summation of TCP, UDP and ICMP: 8192. If the maximum number of NAT sessions of all protocols is set, this setting takes preference over the setting for a specific type protocol.