L2TPv3 protocol support any two layer link load transmission in core IP packet forwarding on the network, it’s a protocol widely used to obtain. L2TPv3 protocol formulate by IETF, it combines advantage of L2F and PPTP, the third edition L2TP extended packaging ability of data of the second layer protocol, defines a set of basic L2TP protocol so that separated second layer load which packaging in the tunnel , enhanced the interoperability, make VPN applications more simple and flexible. L2TPv3 includes two types of packets, control packets and data packets. Control packets used in consultation, maintenance and release control connections and sessions connections. These kind of packets transport packets by control channel of L2TPv3 to ensure its reliable transmission. Data packets transmit use the second layer encapsulation through L2TPv3 conversation. Unlike the control packets, if you have lost data packets they are not retransmitted. Control packets is the core of L2TPv3. L2TPv3 control packets run on two phases:
Protocol testing is part of network testing, the origin of software testing in software engineering. Protocol testing generally includes four kinds of test: conformance testing, performance testing, interoperability testing and sturdiness testing. Conformance testing detects whether achieved system and protocol specifications accord or not, an important aspect of protocol testing, and is the basis for the other three kinds of testing, as a method to ensure that protocol implement and consistent protocol specification.