ShoreTel Building Reliable IP Telephony Systems

File Size1.66 MB
Create DateApril 24, 2015

The public telephone networks built decades ago have been incredibly reliable. Legacy enterprise telephony equipment can also achieve high reliability. IP telephony systems are now expected to delivery high reliability despite their newer technology, different implementations, and different features. This paper provides a tutorial that quantifies reliability, and describes industry techniques for achieving reliability, along with the difficulties encountered. The following are highlights of the topics covered:

  • The meaning and measure of five-nines of mean time between failure (MTBF) reliability
  • The contrast between delivering high uptime - availability - versus the statistics of reliability
  • The superiority of n+1 redundancy versus traditional one to one redundancy
  • No single point of failure as a guiding principal
  • How networks provide the most difficult challenge to reliability
  • Achieving five-nine availability with four-nine availability servers

ShoreTel’s approach to reliability and its advantages are detailed in the following discussions:

  • ShoreTel’s 60-year demonstrated MTBF is approximately ten times higher than a typical PBX
  • ShoreTel Voice Switch modular design is superior to chassis, daughter boards or server designs
  • ShoreTel’s use of n+1 redundancy vs. typical 1:1 redundancy
  • ShoreTel distributed architecture solves lack of network reliability
  • ShoreTel fallback adds resiliency

These aspects of ShoreTel’s architecture and design deliver unprecedented reliability at low cost with brilliant simplicity.