Analysis

posted on 18 February 2008 12:19

Sun, like Brocade and Cisco, thinks there should be a single foundation unified datacentre interconnect. Cisco and Brocade are plumping for datacentre-class Ethernet; Sun is not; it's choice is InfiniBand.

A unified datacentre interconnect would allow for virtualised networking in which a single fat pipe to datacentre boxes: servers; storage products; and networking boxes, could be quickly and easily have its bandwidth carved up to suit dynamic resource requirements.

However, such a network must not drop data packets, and present day Ethernet can do that. Protocols like Fibre Channel over Ethernet (FCOE) and datacentre-class switches using Ethernet are awaiting an emerging datacentre-class Ethernet with re-jigged technology preventing packet loss and enabling predictable service levels. The packet-loss prevention features are being developed by an IEEE standards committee.

Sun says InfiniBand has these characteristics already.

InfinBand supplier Mellanox is near-finalising a 40Gbit/s InfiniBan switch and allied adapter chips. These should be faster than 10GigE Ethernet. InfiniBand has much less latency than Ethernet, say 60-70ns, which means the interconnect is both faster to respond and streams data much faster too. InfiniBand has congestion management features as well.

In the second half of this year we should see Mellanox release chips that can handle Ethernet and Fibre Channel. At that point a deliverable unified datacentre interconnect will be available, a long time in advance of datacentre-class Ethernet.

However, InfiniBand adoption will mean an extra interconnect to be installed and managed by datacentres, many of who are heavy adopters of Fibre Channel and Ethernet. Consolidation onto Ethernet looks quite realistic if, and it is a very significant if, datacentre-class Ethernet becomes a reality.

The likelihood is that Sun may well offer datacentre switching and clustering technology based on InfiniBand which will be able to carry both Fibre Channel and Ethernet traffic. Such networking will be virtualised and this could appeal to users needing to dynamically manage and optimise networking bandwidth.

There is no standardisation effort known about that addresses Fibre Channel over InfiniBand (FCoI).

Xsigo has a virtualising datacentre network switch and fabric based on InfiniBand.