The result is that - with less difficulty than an integrator could 10 years ago, specify a standard non-redundant PC server to house non-hot-swappable voice cards - you can "dial in" an IPnexus configuration that will seamlessly house a wide range of components and support your application with 99.999% uptime.
In effect, you get most of the benefits of purpose-built hardware, with the effort/expertise-, cost-, availability, and time-to-market features of (admittedly high-end) off-the-shelf equipment.
PT's IPnexus family has recently been enhanced by the addition of the ZT5085e Redundant Host platform. This is a 12U, 19 inch rackmount chassis with 21 6U slots (over/under), including 18 node slots, two redundant fabric slots (letting you build dual stars for full backplane-network fallback), and two 3U PICMG 2.9 IPMI-compatible intelligent shelf manager slots (the latter arranged over/under in one 6U slot). Everything's serviceable from the front, and dual everything. This is a hard system to kill, and if something breaks, you can fix it in minutes.
The ZT5085e can be configured with several midplane options, too. You can have it set up with two CPCI bus segments, with 32/64-bit, 33/66MHZ bus support. You can have up to four hot-swappable host slots (compatible with the Redundant Host specification), enabling active/standby and active/active configurations. There's a single H.110 telephony bus, too.
Power to each slot is isolated - up to 50W per node slot and 70W per fabric slot, power and cooling. Fan trays are redundant and hot-swappable, as are the (N+N) power supplies. The system as a whole is NEBS Level 3/ETSI compatible.
