Network emulators, network modelers and network simulators -- how do they differ? How do I know what solution would be right for my application? How do I compare an emulator vs a simulator?
Modelers, simulators, and emulators represent a continuum, that begins with pure mathematical software models and moves towards the physical reality of emulation.
A network modeler is a representation of a network based on a set of mathematical equations. With a network modeler, you mathematically define traffic volumes, flows, network architectures, etc. You can then visualize th...
How do you measure gravitational waves? How does that compare to counting bits in networking?
In June 2017, IWL Staff attended a fascinating lecture by Dr. Jess McIver of CalTech titled "Einstein Gravitational Waves and Black Holes". Dr. McIver described the operation of the LIGO project for...
Newcomers to IT network operations are often confounded by the complexity of managing, controlling, monitoring, diagnosing and repairing their networks. As we are all inclined to select the simplest tool, to a networking newcomer, the simplest tool for staying on top of network operations would be...
License IWL's stateful network impairment technology at a very reasonable price
IWL today announced a new patent licensing program for manufacturers and end users who use the technology of the Maxwell Patent.
Several years ago, an Israeli company called Shunra Software, offered a network simulator product. The product’s purpose: to help IT staff verify the performance of apps and devices, prior to deployment in production networks. The original developers had IT backgrounds, so they understo...
About a year ago we begin switching our various websites to use content management systems (CMS) that did not require SQL databases, or any database for that matter. We looked at GRAV and Hugo. The latter is highly portable and very fast, but for our more dynamic websites we decided to use GRAV.
In general we have been quite happy with GRAV, but recently we encountered a problem in which users began to see "Gateway Timeout" errors.
We dug into the issue - and found a solution.
The Washington Post recently published an article: "SpaceX wants to beam the Internet down to Earth. Here's How it will Start."
IWL believes the article doesn't give the whole story.
SpaceX is not proposing anything that is particularly new.
Low Earth Orbit (LEO) satellite networks have been around since the 1990's. There was Iridium and the former Soviet Union had a LEO satellite network for voice calls to remote locations (like Siberia).
The internet is a complex distributed process in which computers interact with one another over pathways that introduce delays and errors. There are many feedback loops. Some of those loops are simple to identify, such as the handshaking between the end points of a TCP connection. Other loops are harder to identify, such as the interaction of timers in ARP (address resolution), DNS (domain name system), and routing protocols (such as OSPF and BGP.)
Positive feedback loops are often merely annoying. But they can also cause more severe problems, such as connectivity failures.
Websites are a bit like fashion; what you wear says a lot about you as a person, and what your website looks like says a lot about your company. You don't want your clothes to make you look out of date, and you don't want your company to look out of date, either. So when it was time for IWL to up...
There's an old joke. It was said that English automobiles of the 1950's came equipped with a walnut inlayed toolbox containing many hammers. These ranged in size from a small jeweler's hammer up through a heavy, concrete shattering, sledge. It was said that when something in the automobile stopped working that one should begin by pounding on it with the smallest hammer. If that didn't solve the problem then one should move up to the next larger size. And so on, using ever larger hammers, until the sledge, which would reduce the automobile to a heap of shattered parts that could easily be hauled away – because the original problem was obviously insolvable.
Fuzz testing of software is somewhat like that old English automotive technique, but often without the benefit of an orderly sequence.
The question of “how many bits” were sent and received clearly is a matter of interest when measuring data rates or data quantities.
Mobile providers, consumer ISP's, consumers, and regulators talk a lot about their speed and (not so often) about their data caps. But rarely, if ever, are sufficient details provided:
And it is not just a consumer issue: ISPs that exchange data with one another under contractual peering and transit arrangements need common ground when they discuss how much data each party is delivering to the other.