You wonder when InfiniBand consolidation will stop, what with Cisco’s recent $250 million acquisition of Topspin Communications.

The number of InfiniBand companies swelled several years ago with Agilent, Libra Networks, Paceline Systems, JNI, HP, IBM, Intel and Microsoft in the crowd. A bunch of other companies - including Banderacom, Lane15, Voltaire, Mellanox and SBS Technologies - also joined the InfiniBand bandwagon.

InfiniBand was once touted as the be-all-and-end-all technology for speeding connections between servers, storage and a network. It fizzled as large systems vendors such as Intel and Microsoft withdrew support, and customers were wary of adoption. A slew of companies proclaimed bankruptcy, sold off their intellectual property to other struggling companies or rejiggered their direction.

Among the companies that restructured were Lane15, which became Vieo, a systems management appliance company, and Banderacom, which became 10 Gigabit Ethernet company NetEffect. JNI was swallowed up by AMCC, InfiniSwitch merged with Infinicon, Libra disappeared - and InfiniBand was relegated primarily to an interconnect for high-performance Linux clusters.

Nonetheless, a few InfiniBand companies still exist - Infinicon and Voltaire, which have found a place in high-performance computing, SBS Technologies and Mellanox, which makes the majority of the InfiniBand silicon used in host bus adapters and hubs.

One of the last of them was Topspin, which was not a pure-play InfiniBand company, but one that combined InfiniBand with Gigabit Ethernet and Fibre Channel interfaces.

Cisco says it will add Topspin’s technology to its Data Center, Switching and Wireless Technology Group, which is headed up by Senior Vice President Luca Cafiero. Topspin has a history with Cisco, among other vendors.

The acquisition will allow Cisco to provide InfiniBand server switching and complement its Ethernet-based Catalyst switches.

A variety of major server vendors have in the past year shown increased support for InfiniBand. The latest of these initiatives, the OpenIB consortium, consists of Dell, HP, IBM, NEC and Sun. All of them have previously announced relationships with Topspin.

While being consigned in the past to being a niche interconnect, Cisco’s acquisition could make InfiniBand a mainstream technology for the data center. Topspin’s InfiniBand, powered by Mellanox silicon, has come out on top. While many customers will find that 10 Gigabit Ethernet or Fibre Channel are satisfactory replacements for InfiniBand and proprietary interconnects like Myricom’s Myrinet, InfiniBand (with Cisco’s help and that of the major systems OEMs) may make it the customers’ number one choice.