"The benefits of open source are really clear to all the executives
I work with that report all the way up to [CEO] John Chambers," Cisco
engineer Roland Dreier told InternetNews.com. "There is no
question that open source is a key part of a modern engineering
organization. As budgets get tighter, I think that open source will be
one of the last things we would retreat from, since we see such huge
benefits from the participation that we have now."

Dreier is one of Cisco's most prolific contributors to the
Linux kernel and is one of the maintainers of the RDMA (remote direct
memory access) ( define) sub system of the kernel.

Dreier explained that RDMA is a relatively new technology that
is intended to improve latency and performance of network adapter
throughput. RDMA is a technology that is in the mainstream Linux kernel
and is a key part of Red Hat's recent Real Time Linux  MRG 1.1 release.

Cisco itself is benefiting from the RDMA technology in Linux
with the Cisco RAB (RDMA Accelerated Buffer) that brings Infiniband's
low levels of latency to Ethernet on the  Nexus 5000 switch line.

Though Cisco is a leading contributor to RDMA in Linux, Dreier was
quick to point out that the Linux RDMA effort is a broad collaborative
effort that includes the contributions of over 180 individuals and over
30 different organizations.

Cisco's Linux Distribution

According to Dreier, the RDMA stack on Linux represents the bulk of
Cisco's direct a contributions to upstream Linux kernel at the moment,
but that doesn't mean Cisco isn't doing more with Linux.

Cisco uses Linux in a number of its networking products, including the new  AXP(Application eXtension Platform), a Linux server on a blade that can be
plugged into a Cisco ISR router. At the time the AXP was released,
Cisco said that it was using its own hardened Linux to power the AXP.
But that doesn't mean Cisco has its own Linux distribution goals.

"We tend to emphasize having a good relationship with the
distribution providers," Michael Enescu, CTO of Open Source Initiatives
at Cisco told InternetNews.com. "We have both Red Hat and
MontaVista as supplier to us. Occasionally there are pieces of a distro
that we need to treat differently."

In those cases where Cisco has a need to do something
different, Enescu noted Cisco will sometimes start with a stock Linux
kernel and will build from there. In general, the goal is to work with
existing distributions in order to be more efficient.

"The initial condition is that we don’t want to burn cycles on
engineering and development to build from a stock kernel up," Enescu
said. "We start with a distribution and we have a very good
relationship with Red Hat and MontaVista."

Though Cisco does customize its own Linux for some uses, Cisco
is not about to enter the Linux distribution business itself. "We're
definitely not in that business and we don't want to compete with
them," Enescu commented.

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