Tag Archives: 30 blogs in 30 days

Linux as a Switch Operating System: Five Lessons Learned

Although this post is nearly a year old, it is still gold. Ken Duda, the CTO of Arista Networks described five lessons learned along the way of supporting Enterprise Operating System (EOS), the Linux-based switching operating system. They are listed as:

  1. It’s okay to leave the door unlocked.
  2. Preserve the integrity of the Linux core.
  3. Focus on state, not messages.
  4. Keep your hands out of the kernel.
  5. Provide familiar interfaces to ease adoption.

Definitely worth a read.

Ethernet Alliance unveils five new speeds

This week Network World laid out some details of the work the IEEE group, the Ethernet Alliance, is doing with respect to new data rates. As mentioned in this blog post, while there are 5 shipping speeds of Ethernet (100 Mbps, 1 Gbps, 10 Gbps, 40 Gbps, and 100 Gbps), there are 5 new speeds that are currently being worked on (2.5 Gbps, 5 Gbps, 25 Gbps, 50 Gbps, and 400 Gbps). The last time Ethernet got this sexy was when promiscuous mode was introduced.

Some of the drivers for these new speeds are adoption rates of the older speeds. As detailed in the July 2014 IEEE Call for Interest , while the initial adoption for 10G, 40G, and 100G was in 2004, 2012, and 2015 (anticipated) respectively, because these speeds are turning out to be cost prohibitive, the transition to higher speeds has been slower than previously forecasted. For example, the 1G -> 10G transition has repeatedly moved out (from 2012 to 2014 to 2016 now). This creates a window where new technology can provide the higher port speed at lower cost. So, as an example, the SFP+ technology can be leveraged in 25 Gbps as a single lane and 50 Gbps as two lanes.

The 2.5 and 5 Gbps speeds (known as MGBASE-T) address the growing demands of BYOD in campus networks. Many of the newer APs nowadays ship with 802.11ac. This Wifi standard will have a second wave in 2015 whereby the uplinks (or backhauls) between the APs and the access switches will be multi-gigabit rates. The key requirement here is to be able to reuse the existing cabling infrastructure. So Cat 5e and Cat 6 would still be supported over the usual 100 meters and there would be no need to rip and replace cables.

Ethernet has come a long way since the days of the 2.94 Mbps flavor that Bob Metcalfe had invented. There is very little in common between the types of Ethernet standards we have today from the IEEE and the original specification. One thing that is common, however, is the ability to evolve according to market needs, from single-pair vehicular Ethernet to four-pair PoE and in between. More on this in another post.

QoS and SLA Guarantees in the Cloud

Ivan Pepeljnak’s makes an important point in his webinar on Cloud Computing Networking: as a customer, understand the QoS and SLA Guarantees that your public cloud provider offers. Whatever Tenant A does should not impact the performance of Tenant B. At a very minimum, there should be some guarantees on bandwidth, IO operations, and CPU cycles for every tenant. You don’t want to have the noisy neighbor who hogs up resources that leaves you no choice but to reboot your VM with the hope of getting reassigned to a physical server with less load. An AWS Small Instance is an example of an environment where you might encounter this scenario.

Applying Moore’s Law to Cricket Bats

TL; DR – They just follow the laws of Physics.

Moore’s Law states that the number of transistors per integrated circuit will double every two years. In a recent interview with Marketplace, Intel CEO Brian Krzanich, who is the sixth CEO of the company, expressed hope that Moore’s Law would remain alive on the watch of the next couple of CEOs. Currently, Intel can achieve 14 nm manufacturing processes. Krzanich said with the current technology, they can keep Moore’s Law alive for another 6-10 years.

Recently, I’ve been reading up on the science behind cricket bat manufacturing. Cricket has increasingly become a batsman’s game, highlighted not only by higher scores, but by bigger hits (more fours and sixes being hit). There are a few prevalent theories about bat manufacturing techniques improving and bats becoming heavier. A heavier bat can result in the ball being hit farther. However, as described by bat-maker Chris King, “the material and design have been pushed to their limits. Like Formula One cars, they operate at the outer edges of what’s possible.” Instead, the psychology of bat-owners is where the innovation lies. Bats, which have always been made of willow, aren’t necessarily getting heavier, but rather bigger and lighter, to give a batsman the impression that it’s heavier. Variations in the balance and the weight distribution make a huge difference. And that is what fives the batsman the sense of security and confidence to go for bigger hits. As King says, “What we’re up against is the belief that a big bat is more powerful than a bat of the same weight that’s smaller, which it isn’t. That’s against the laws of physics.”

30 Blogs in 30 Days – Let’s Do It!

I decided to jump on the bandwagon of the 30 Blogs in 30 Days challenge. Om Malik, of GigaOm fame, and Greg Ferro of Packet Pushers fame, are already on it. Let’s see if I can produce something original over 140 characters for a month.

For starters, here’s a photo I took yesterday from where I moved two weeks ago – Santa Cruz, California.

Natural Bridges State Beach from West Cliff Drive in Santa Cruz, California
Natural Bridges State Beach from West Cliff Drive in Santa Cruz, California, where I live