CompactPCI (cPCI) was formed in the late 1990s to offer a ruggedized, Eurocard-based form factor around PCI. The specification is based on the 2mm connector standard and the IEEE 1101.10/11 mechanicals. PCIbus was a proven bus with an enormous installed base in different market segments like telecom, industrial automation, etc. The CompactPCI architecture could also leverage off the lower cost, widely available PCI silicon and the omnipresent WinTel (Windows/ Intel) architecture.
PICMG released a series of specifications in the late nineties that addressed critical requirements in the Telecommunications industry like Hot swap and five nines availability (99.999). PICMG 2.1 (Hotswap), PICMG 2.5 (H110 Telephony bus), PICMG 2.7 (Dual system slot) and PICMG 2.9 (System management bus) were some of the specifications that made using cPCI bus a compelling reason for new products catering to computer telephony, VoIP and a myriad other applications.