The Design And Implementation Of A TDM Over IP Prototype System

TDM over IP is a kind of new technology, which is designed to carry TDM traffic on IP network. It is transparent to protocols and signalings. It has the capacity of carrying all kinds of TDM traffic, supporting any kind of signalings adopted by TDM network. With TDM over IP, carriers can support new data traffic as well as original circuit traffic without abandoning legacy PBX and other existing TDM equipments;Packet network providers also benefit from supporting multi services on IP network, such as voice and video.About the standardization of TDM over IP technology, IETF has achieved some successes for this stage. In this thesis, the author will introduced the design and implementation of a TDM over IP prototype system based on embedded technology, which can carry one line of E1 link over LAN. The protocol design complies with SAToP, a draft from IETF. This prototype system will be good to boosting the exploration of TDM over IP technology, accumulating some ideas for the company which the sytem belongs to, and preparing the process of production. The hardware platform and software platform are ARM7 processor developing board and VxWorks real-time operating system. This combined developing platform will provide flexibility to the next stage development of TDM over IP. Analysis of architecture, protocol layer model and requirements of a certain real-time application for this system will be introduced in detail in this thesis. Furthermore, some key problems such as jitter buffer and clock recovery will be focused on detailly.Particularly, a certain control word designed by the author is included among protocol layer, which has the capacity of indicating packet loss and mis-order, carrying the LOS signal of E1. Besides this, a dynamic jitter buffer mechanism used to smooth the jitter of IP network is introduced.Moreover, introduction to future markets of TDM over IP and some related products from different manufacturers as well as fully comparison between two different TDM over IP drafts from IETF is also included in this thesis. As a kind of new technology of IP multi services, the feasibility, prediction of market and the position in NGN is highly regarded in this thesis.