Voip Board Reliability And Design For Testability

Along with the fast development of the IP technology,the requirement for multi communication service is quickly increasing.It makes the access network to provide more and more broadband and integration service for customers.NGN will be the next generation network technology consequentially.How to protect the existing investment,and promise the old user who using POTS services still be supported in new communication environment will be a real challenge for us.The technology of the VOIP has solved this challenge perfectly. Alcatel-sbell has designed one high density VOIP card which supports 72-1ine subscribers in the ISAM(Intelligent Service Access Manager) system.It uses the advanced technic and is the highest number of the port which is provided in one card in the world.All functions are based on the high quality of the product.This document will be focused on how to deal with the series problems which are come out because of the high density,and guide you how to design a high density card with high quality and manufacture the production effective.It has done deeply analysis on the layout and thermal,and makes the thermal alarm strategy to solve the layout and thermal issue.According the signal integrity and timing analysis and simulation for the critical signals,it can ensure the quality of the signal.The strategy for the clock,ground,filter and protection design ensure this card can meet the EMC/EMI and resistibility requirement.Based on package selection,boundary scan strategy,power monitor and test point etc,it can increase the production effective.The final test result verifies the correctness of the previous analysis,simulation and design.