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.