The value of tmnxL2tpTuL2tpV3PubTcpMssAdjust specifies the Maximum Segment Size (MSS) for the TCP traffic in a L2TP tunnel of this group which is sent from the public network to the private network. The system may use this value to adjust or insert the MSS option in the TCP SYN packet packet. A value of '-1' specifies that the TCP MSS adjustment functionality on the private side is disabled. A value of '-2' specifies that the TCP MSS must be derived from the MSS (i.e., tmnxL2tpV3TgPubTcpMssAdjust) of the associated L2TPv3 tunnel group. When the system receives a TCP SYN packet from the public network and the packet contains an MSS option, the system replaces the MSS option value with tmnxL2tpTuL2tpV3PubTcpMssAdjust when the value of tmnxL2tpTuL2tpV3PubTcpMssAdjust is smaller than the MSS option value. When the system receives a TCP SYN packet from the public network and the packet does not contain an MSS option, the system inserts one whose MSS is equal to tmnxL2tpTuL2tpV3PubTcpMssAdjust.