User`s manual

50
Some ISP/WISP has special inquire for TTL feature that did not decrease the TTL
value when pass the first router of ISP/WISP.
When using PPPoE for WAN access, WH-5420CPE provides flexible configuration for
TTL value. The default value is 255 and does not have to change in a normal situation.
You can check with your ISP/WISP if TTL value causes connection problem.