Physical layer end-to-end availability in next generation networks

In this paper the end-to-end physical layer availability in NGN (Next Generation Networks) will be analyzed. The case study will be presented and physical layer availability for this case will be calculated. All typical NGN architecture entities are considered in availability calculation, such as core network availability, access network, softswitch, edge routers, etc. The influence on ETE (end-to-end) availability of some network elements will be discussed.