Research And Development Of Encoder/Decoder In Network Protocol Test System

With the development of the Next Generation Internet technology based on IPv6 protocol, the IPv6 supported devices are extensive installing but IPv4 is still the core protocol for present Internet system and therefore the transition from IPv4 to IPv6 is a very long term process. As the only networking relay device supporting heterogeneous and homogenous IP version, the router plays a key role when Network environment is transiting from IPv4 to IPv6. So the research and design technology for the router testing becomes very promising in the near future.The technique background of this dissertation is Multi-Port router testing technology and the subject investigated is the Encoder and Decoder (E/D) which is a sub-module of the Two-Port Tester (TPT) being part of the Distributed Multi-port Concurrent Testing System (DMC-TS), which is investigated by SC-Netcom Lab.DMC-TS, which is investigated by SC-Netcom Lab, takes two-layer architecture: at the top layer, a PC acts as the Multi-Port Concurrent Tester (MPCT) and at the bottom layer, multiple TPTs test a pair of ports with either LTM or TTM.This dissertation focuses on the extended design and implement action of the Encoder/Decoder (E/D), which is an important component in TPT and acts as the peer entity (in a test system) of the protocol implementation under test in a router. An E/D is not only capable of encoding PDUs (Protocol Data Unit) conforming to relevant protocol specifications, but also capable of encoding PDUs with errors inside to check the reaction of the router under test to an erroneous PDU. The author's contribution in this dissertation can be summarized as:1. Extended design of the E/D is provided, which represents better operationality and expansibility and achieves general design framework.2. An adaptation module is introduced between an E/D and supporting layers to cope with the diversity of underlying protocols and make the E/D for a given protocol independent of lower layers.3. The author has developed an RIP E/D and an IPv4 E/D in a Win32 environment based on the general design framework and unit tests carried out to show they have designed behave.