This parameter specifies the expected IPv6 TCP MSS clamping value, if supported by the DUT. If this parameter is set to the keyword default, CDRouter will automatically compute the expected IPv6 MSS based on the LAN MTU setting.
Note that in some cases it may be necessary to adjust the expected MSS clamping value. Some DUTs use MSS clamping to modify the IPv6 TCP MSS option when traffic is routed over WAN interfaces with MTUs smaller than the LAN MTU (such as when PPPoE is used as the WAN connection mode). DUTs may also modify the MSS value when TCP sessions are routed over VPN tunnels.
This testvar was added in CDRouter 9.1