Managing Performance In SDN And NFV Environments
Gauging service quality in an SDN/NFV network requires looking at every layer that makes up your application.Transforming ideas into light bulbs – LiFi
About 4 years ago, Harald Haas, a physicist and professor of mobile communications at the University of Edinburgh, was the first to coin the term Li-Fi, at a TED Talk during TEDGlobal 2011. Since then, millions of bits about this technology roamed the Internet, and many companies already started implementing it.
Who’s doing this already?
The history begins with a company named Velmenni, which has produced a light bulb that works with Li-Fi technology on a small scale. They are not the first to prove the technology works, nor the first to conduct a real-world experiment, but here’s their Jugnu Lighbulb demo.
Philips has developed a VLC (Visible Light Communication) system for shoppers at stores. People have to download an app on their smartphone and then it will interact with the LEDs in the store. The LEDs can pinpoint their location in the store and give them corresponding coupons and information based on which aisle they are on and what they are looking at.
ByteLight has developed a system similar to Philips’ lighting network, making LEDs “talk” to any smartphone and tablet with a camera and/or Bluetooth Smart technology that is “opened to listen”.
The first VLC smartphone prototype was Continue reading
CPLANE Networks on Software Gone Wild
When I wrote a blog post explaining the difference between centralized control and centralized control plane, John Casey, CEO of CPLANE Networks wrote a comment saying “yeah, that’s exactly what we’re doing.”
It took us a while to get the stars aligned, but finally we managed to sit down and chat about what they’re doing, resulting in Episode 46 of Software Gone Wild.
Custom metrics with Cumulus Linux
Host sFlow version 1.28.3 adds support for Custom Metrics. This article demonstrates how the extensive set of standard sFlow measurements can be augmented using custom metrics.
Recent releases of Cumulus Linux simplify the task by making machine readable JSON a supported output in command line tools. For example, the cl-bgp tool can be used to dump BGP summary statistics:
cumulus@leaf1$ sudo cl-bgp summary show json
{ "router-id": "192.168.0.80", "as": 65080, "table-version": 5, "rib-count": 9, "rib-memory": 1080, "peer-count": 2, "peer-memory": 34240, "peer-group-count": 1, "peer-group-memory": 56, "peers": { "swp1": { "remote-as": 65082, "version": 4, "msgrcvd": 52082, "msgsent": 52084, "table-version": 0, "outq": 0, "inq": 0, "uptime": "05w1d04h", "prefix-received-count": 2, "prefix-advertised-count": 5, "state": "Established", "id-type": "interface" }, "swp2": { "remote-as": 65083, "version": 4, "msgrcvd": 52082, "msgsent": 52083, "table-version": 0, "outq": 0, "inq": 0, "uptime": "05w1d04h", "prefix-received-count": 2, "prefix-advertised-count": 5, "state": "Established", "id-type": "interface" } }, Continue reading
I use SNMP SETs and I’m not afraid to admit it.
Do you remember back in CCNA school when we learned all sorts of great things that we very rarely followed. One of the favourites was that we are supposed to put meaningful descriptions on all of our interfaces so we know what the other side is connected to.
How many people actually follow that advice?
Yeah, I never do it either. There’s always just too many things on the list that need to get done and it seems like that extra 5 seconds it would take me to update the description to the interface just doesn’t seem like it’s worth the effort. Of course, then I later check the port and end up knocking out my XYZ services and cause myself an outage.
This is where a little python and a decent NMS can help to solve a problem.
Understanding ifIndex
Before we get into the code. We need to understand a little about ifIndex values and how they relate to the physical interfaces of the devices. If you’re REALLY interested, you can do some reading in RFC 2863. But in a nutshell, each interface on a device, whether physical or logical has a specific numeric value assigned to it Continue reading
Blue Planet Won’t Drive Ciena Revenue in 2016
Blue Planet did add two new Tier 1 customers in late 2015.
Citrix White Paper: Cisco ACI & Citrix NetScaler Accelerate Application Deployment & Propel Agile Application-Driven Networks
Citrix outlines a joint solution with Cisco that provides a flexible way to link network services to applications, improving security, and accelerating application deployment.
Worth Reading: The Marriage of the Ecosystem
The post Worth Reading: The Marriage of the Ecosystem appeared first on 'net work.
Network Automation, Programming, And Scale
How do you write custom network automation programs that will endure? Here are some ideas.HTTP/2 For Web Developers
HTTP/2 changes the way web developers optimize their websites. In HTTP/1.1, it’s become common practice to eek out an extra 5% of page load speed by hacking away at your TCP connections and HTTP requests with techniques like spriting, inlining, domain sharding, and concatenation.
Life’s a little bit easier in HTTP/2. It gives the typical website a 30% performance gain without a complicated build and deploy process. In this article, we’ll discuss the new best practices for website optimization in HTTP/2.
Web Optimization in HTTP/1.1
Most of the website optimization techniques in HTTP/1.1 revolved around minimizing the number of HTTP requests to an origin server. A browser can only open a limited number of simultaneous TCP connections to an origin, and downloading assets over each of those connections is a serial process: the response for one asset has to be returned before the next one can be sent. This is called head-of-line blocking.
As a result, web developers began squeezing as many assets as they could into a single connection and finding other ways to trick browsers into avoiding head-of-line blocking. In HTTP/2, some of these practices can actually hurt page load times.
The New Web Optimization Continue reading
The Grumpy Old Network Architects and Facebook
Nuno wrote an interesting comment to my Stretched Firewalls across L3 DCI blog post:
You're an old school, disciplined networking leader that architects networks based on rock-solid, time-tested designs. But it seems that the prevailing fashion in network design and availability go against your traditional design principles: inter-site firewall clustering, inter-site vMotion, DCI, etc.
Not so fast, my young padawan.
Let’s define prevailing fashion first. You might define it as Kool-Aid id peddled by snake oil salesmen or cool network designs by people who know what they’re doing. If we stick with the first definition, you’re absolutely right.
Now let’s look at the second camp: how people who know what they’re doing build their network (Amazon VPC, Microsoft Azure or Bing, Google, Facebook, a number of other large-scale networks). You’ll find L3 down to ToR switch (or even virtual switch), and absolutely no inter-site vMotion or clustering – because they don’t want to bet their service, ads or likes on the whims of technology that was designed to emulate thick yellow cable.
Want to know how to design an application to work over a stable network? Watch my Designing Active-Active and Disaster Recovery Data Centers webinar.
This isn't the first Continue reading