HP and Cisco bury hatchet on virtualised datacentre comms

Hewlett-Packard and Cisco have compromised on proposed competing standards for managing communications in virtualised datacentres.


Hewlett-Packard and Cisco have compromised on proposed competing standards for managing communications in virtualised datacentres.

The IEEE 802.1 group, the ethernet technical standard committee, will vote on the proposals this month.

The compromise means that instead of having either distributed or centralised management of network communications in a datacentre, both forms will be supported.

Paul Congdon, vice-chairman of the committee and CTO of HP's ProCurve network technology unit, said the compromise extends the standard to include Cisco's view of how to include legacy systems to be incorporated in virtualised datacentres.

Congdon said there was previously a difference in philosophy between HP and Cisco. HP, he said, believed in an open, distributed network management system that allowed switches to find ports to integrate new and legacy systems, whereas Cisco preferred a centralised approach. "HP believes Cisco's approach, which means redefining the systems and their relationships from scratch, is overkill," he said.

The new standard has been forced on switch makers because of virtualisation. Hypervisor software running on servers or PCs has started to take over some of the tasks usually handled by network appliances. These include firewalls, access control, load balancing, deep packet inspection and other network functions.

This wastes CPU cycles and system bandwidth, and users can no longer see how these functions are working because they are hidden in virtual machines managed by the hypervisor.

Cisco and HP each want to tag data so that networking functions are handled by direct communications between network interface cards and datacentre switches, speeding up communications and improving overall system efficiency.

HP's proposal for a virtual Ethernet port aggregator (VEPA) creates data tags that set up a virtual link between network interface cards on server and edge switches, such as HP's ProCurve, and uses expanded media-access control addressing tables on both ends of the link.

Cisco's proposal builds on VEPA by automating replication across multiple systems from a central point. It does this by adding a tag that lets packets travel across multiple systems as needed to a final destination without expanding address tables. This so-called port extender is likely to call for a larger switch that aggregates traffic from many edge switches.

The two proposals complement each other, but systems using them may compete in the market, said Congdon.

Congdon said that in the next five years much more attention would be paid to automating datacentre management. At present, there are separate systems to manage processing, storage and networking, but there is a crying need for a single system to manage all the elements, he said.

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