The NETLINK 423 Network Transmission Quality Tester is a portable, battery operated handheld instrument which enables field staff to perform end-to-end network tests from one end.   The NETLINK 424 network test responder provides an answer base for test calls originated from the NETLINK instruments, and can also be used to generate test calls for network verification and fault finding.   The NETLINK 430 Digital Line Test Set is a portable, multifunctional, highly integrated instrument which tests analogue and digital subscriber line services.     The COMLINK suite of Windows application programs that provide a cost effective integrated system to analyse and report on telecommunications network quality and performance. The exciting new product family from EDL/Extron the Netlink Connect series, brings new flexibility and functionality to the Netlink family. The new connect family consists of a main display unit running Windows CE with instrument operational software and a instrument testing POD. The pods are available for a variety of testing and new pods are currently under development.