Whispers & Screams
And Other Things
Vastly experienced, versatile senior technical asset with a broad range of highly evolved skills from team building to high-level technology solution implementations. A courageous and tenacious leader with proven experience in business development, organisational visioning, cutting edge information technology deployments, and as a senior management liaison. Experienced at working at all levels from Start-up to Corporate, I thrive on change and take the lead to engage and drive the engineering landscape in any business An outgoing personality, with high energy levels who is customer focused but understands the need for a structured approach to business. A mature and collaborative style provides excellent communication and presentation skills and, drawing on past experience, gives the credibility to build trust. A strategic thinker, who is innovative and creative and makes technically 'savvy' decisions and encourages others to do so, whilst totally focused on success and how this drives results.

The rise of the Network Plumber

As the worlds journey through the second industrial (Internet) revolution carries on apace, todays businesses face an emerging challenge. Unless your company has its own "in-house" network professionals it is likely that the demands the Internet places on your business, whilst clearly a massive opportunity are also the source of what can seem like spiralling overhead costs in terms of personnel and knowledge.

 

Back in the mists of history during the first industrial revolution, the electric light bulb was causing a stir. The new technology was clearly a fantastic opportunity for business of the time to increase productivity and improve working conditions. It was basically a new fangled technology which could enable businesses to "work smarter".  Now where have we heard that before?

The first electricity installation companies were small bands of highly educated and highly paid technical afficionados who were evangelists of the technology rather than being more akin to the matter of fact electricians of today. The technolgy has nowadays moved from invention to commodity to utility and that process probably took 10 to 20 years to fully complete. There are a lot of parallels that can be drawn between that revolution and this one.

Heres one cast iron fact. Businesses today need networks. Whether it is to connect their towering office blocks in each corner of the world into one great corporate network or just to connect their office computers to their printer and the internet to read their emails, they all need their networks. We have tried to think of one single business that wouldnt put itself at a disadvantage in todays world by ignoring everything related to the internet such as emails and websites and we have failed. From the sole trader window cleaner to the corporate giant, all of them now need their networks.

 

 The technology is now moving into the realms of utility rather than being "a great new invention". Nowadays your average Granny in Scotland is just as likely to switch on the laptop as they are to switch on their central heating. Ok thats a dubious fact I'll concede but you get the picture. The world has changed forever and the Scottish business community as well as the residential community now need their networks. The technology is now thought of more like a central heating boiler than the hubble telescope to the average consumer. They just want it to work.

Todays networks now need plumbers. Todays Scottish businesses now need network plumbers and not the techie evangelist types of the last 10-20 years. They need matter of fact network tradespeople who they can call upon to get things working properly when they arent. They dont need an inhouse plumbing enthusiast who does plumbing for a hobby and thinks theyre a bit handy with a pipe bender and they certainly dont need a plumbing department full of plumbers in their overalls ready to fix a boiler at a moments notice. 

 

Ok weve stretched the plumbing analogy a little too far here but I believe the point is made. When it comes to network plumbing and you need the system to just work. When you need a no nonsense expert in the trade to advise you on the best systems for your requirements or just to make your existing systems do the job that you need them to do for you, day in-day out, give us a call at Rustyice Solutions. The network plumbers.

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Could ants power Web3.0 to new heights? OSPF v’s ANTS

Having recently completed my latest M.Eng block on the subject of “Natural and Artificial Intelligence“, I became aware of advances made in the recent decade towards a new paradigm of network traffic engineering that was being researched. This new model turns its back on traditional destination based solutions, (OSPF, EIGRP, MPLS) to the combinatorial problem of decision making in network routing  favouring instead a constructive greedy heuristic which uses stochastic combinatorial optimisation. Put in more accessible terms, it leverages the emergent ability of sytems comprised of quite basic autonomous elements working together, to perform a variety of complicated tasks with great reliability and consistency.

In 1986, the computer scientist Craig Reynolds set out to investigate this phenomenon through computer simulation. The mystery and beauty of a flock or swarm is perhaps best described in the opening words of his classic 1986 paper on the subject:

The motion of a flock of birds is one of nature’s delights. Flocks and related synchronized group behaviors such as schools of fish or herds of land animals are both beautiful to watch and intriguing to contemplate. A flock … is made up of discrete birds yet overall motion seems fluid; it is simple in concept yet is so visually complex, it seems randomly arrayed and yet is magnificently synchronized. Perhaps most puzzling is the strong impression of intentional, centralized control. Yet all evidence dicates that flock motion must be merely the aggregate result of the actions of individual animals, each acting solely on the basis of its own local perception of the world.

An analogy with the way ant colonies function has suggested that the emergent behaviour of ant colonies to reliably and consistently optimise paths could be leveraged to enhance the way that the combinatorial optimisation problem of complex network path selection is solved.

The fundamental difference between the modelling of a complex telecommunications network and more commonplace problems of combinatorial optimisation such as the travelling salesman problem is that of the dynamic nature of the state at any given moment of a network such as the internet. For example, in the TSP the towns, the routes between them and the associated distances don’t change. However, network routing is a dynamic problem. It is dynamic in space, because the shape of the network – its topology – may change: switches and nodes may break down and new ones may come on line. But the problem is also dynamic in time, and quite unpredictably so. The amount of network traffic will vary constantly: some switches may become overloaded, there may be local bursts of activity that make parts of the network very slow, and so on. So network routing is a very difficult problem of dynamic optimisation. Finding fast, efficent and intelligent routing algorithms is a major headache for telcommunications engineers.

So how you may ask, could ants help here? Individual ants are behaviourally very unsophisticated insects. They have a very limited memory and exhibit individual behaviour that appears to have a large random component. Acting as a collective however, ants manage to perform a variety of complicated tasks with great reliability and consistency, for example, finding the shortest routes from their nest to a food source. 



These behaviours emerge from the interactions between large numbers of individual ants and their environment. In many cases, the principle of stigmergy is used. Stigmergy is a form of indirect communication through the environment. Like other insects, ants typically produce specific actions in response to specific local environmental stimuli, rather than as part of the execution of some central plan. If an ant’s action changes the local environment in a way that affects one of these specific stimuli, this will influence the subsequent actions of ants at that location. The environmental change may take either of two distinct forms. In the first, the physical characteristics may be changed as a result of carrying out some task-related action, such as digging a hole, or adding a ball of mud to a growing structure. The subsequent perception of the changed environment may cause the next ant to enlarge the hole, or deposit its ball of mud on top of the previous ball. In this type of stigmergy, the cumulative effects of these local task-related changes can guide the growth of a complex structure. This type of influence has been called sematectonic. In the second form, the environment is changed by depositing something which makes no direct contribution to the task, but is used solely to influence subsequent behaviour which is task related. This sign-based stigmergy has been highly developed by ants and other exclusively social insects, which use a variety of highly specific volatile hormones, or pheromones, to provide a sophisticated signalling system. It is primarily this second mechanism of sign based sigmergy that has been successfully simulated with computer models and applied as a model to a system of network traffic engineering.

In the traditional network model, packets move around the network completely deterministically. A packet arriving at a given node is routed by the device which simply consults the routing table and takes the optimum path based on its destination. There is no element of probability as the values in the routing table represent not probabilities, but the relative desirability of moving to other nodes.

In the ant colony optimisation model, virtual ants also move around the network, their task being to constantly adjust the routing tables according to the latest information about network conditions. For an ant, the values in the table are probabilities that their next move will be to a certain node.The progress of an ant around the network is governed by the following informal rules:

    • Ants start at random nodes.

 

    • They move around the network from node to node, using the routing table at each node as a guide to which link to cross next.

 

    • As it explores, an ant ages, the age of each individual being related to the length of time elapsed since it set out from its source. However, an ant that finds itself at a congested node is delayed, and thus made to age faster than ants moving through less choked areas.

 

    • As an ant crosses a link between two nodes, it deposits pheromone however, it leaves it not on the link itself, but on the entry for that link in the routing table of the node it left. Other ‘pheromone’ values in that column of the nodes routing table are decreased, in a process analogous to pheromone decay.

 

    • When an ant reaches its final destination it is presumed to have died and is deleted from the system.R.I.P.



Testing the ant colony optimisation system, and measuring its performance against that of a number of other well-known routing techniques produced good results and the system outperformed all of the established mechanisms however there are potential problems of the kind that constantly plague all dynamic optimisation algorithms. The most significant problem is that, after a long period of stability and equilibrium, the ants will have become locked into their accustomed routes. They become unable to break out of these patterns to explore new routes capable of meeting new conditions which could exist if a sudden change to the networks conditions were to take place. This can be mitigated however in the same way that evolutionary computation introduces mutation to fully explore new possibilities by means of the introduction of an element of purely random behaviour to the ant.

‘Ant net’ routing has been tested on models of US and Japanese communications networks, using a variety of different possible traffic patterns. The algorithm worked at least as well as, and in some cases much better than, four of the best-performing conventional routing algorithms. Its results were even comparable to those of an idealised ‘daemon’ algorithm, with instantaneous and complete knowledge of the current state of the network.

It would seem we have not heard the last of these routing antics…. (sorry, couldnt resist).

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Rapid Spanning Tree Protocol

The IEEE 802.1D Spanning Tree Protocol was designed to keep a switched or bridged network loop free, with adjustments made to the network topology dynamically. A topology change typically takes 30 seconds, with a port moving from the Blocking state to the Forwarding state after two intervals of the Forward Delay Timer. As technology has improved, 30 seconds has become an unbearable length of time to wait for a production network to fail over or "heal" itself during a problem.

The IEEE 802.1w standard was developed to used 802.1D's principal concepts and make the resulting convergence much faster. This is also known as the Rapid Spanning Tree Protocol (RSTP), which defines how switches must interact with each other to keep the network topology loop free, in a very efficient manner.

As with 802.1D, RSTP's basic functionality can be applied as a single instance or multiple instances. This can be done by using RSTP as the underlying mechanism for the Cisco-proprietary Per-VLAN Spanning Tree Protocol (PVST+). The resulting combination is called Rapid PVST+ (RPVST+). RSTP is also used as part of the IEEE 802.1s Multiple Spanning Tree (MST) operation. RSTP operates consistently in each, but replicating RSTP as multiple instances requires different approaches.

RSTP Port Behaviour
In 802.1D,each switch port is assigned a role and a state at any given time. Depending on the ports proximity to the Root Bridge, it takes on one of the following roles:

    • Root Port

 

    • Designated Port

 

    • Blocking Port (neither root nor designated)



Tge Cisco proprietary UplinkFast feature also reserved a hidden alternate port role for ports that offered parallel paths to the root but were in the Blocking state.

Each switch port is also assigned one of five possible states:

    • Disabled

 

    • Blocking

 

    • Listening

 

    • Learning

 

    • Forwarding



Only the forwarding state allows data to be sent and received. A ports state is somewhat tied to its role. For example, a blocking port cannot be a root port or a designated port.

RSTP achieves its rapid nature by letting each switch interact with its neighbours through each port. This interaction is performed based on a ports role, not strictly on the BPDU's that are relayed from the Root Bridge. After the role is determined, each port can be given a state that determines what it does with incoming data.

The Root Bridge in a network using RSTP is elected just as with 802.1D- by the lowest Bridge ID. After all switches agree on the identity of the root, the following port roles are determined.

    • Root Port - The one switch port on each switch that has the best root path cost to the root. This is identical to 802.1D. (By definition the root bridge has no root ports.)

 

    • Designated Port - The switch port on a network segment that has the best root path cost to the root.

 

    • Alternate Port - A port that has an alternative path to the root, different than the path the root port takes. This path is less desirable than that of the root port. (An example of this is an access-layer switch with two uplink ports; one becomes the root port, and the other is an alternate port.)

 

    • Backup port - A port that provides a redundant (but less desirable) connection to a segment where another switch port already connects. If that common segment is lost, the switch might or might not have a path back to the root.



RSTP defines port states only according to what the port does with incoming frames. (Naturally, if incoming frames are ignored or dropped, so are outgoing frames.) Any port role can have any of these port states:

    • Discarding - Incoming frames are simply dropped; no MAC addresses are learned. (This state combines the 802.1D Disabled, Blocking and Listening states because all three did not effectively forward anything. The Listening state is not needed because RSTP can quickly negotiate a state change without listening for BPDUs first.

 

    • Learning - Incoming frames are dropped but MAC addresses are learned.

 

    • Forwarding - Incoming frames are forwarded according to MAC addresses that have been (and are being) learned.

 

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How Wi-Fi works

If you want to know how to fix your Wi-Fi, first you need to understand how it works

Before you set about fixing your Wi-Fi, it helps to know how the technology works.

That way, you can make an informed decision about the equipment you need to solve your issues, or whether a change of settings might help.

It’s a complicated subject, and we won’t attempt to cover everything (such as packet data, TCP/IP, or the ins and outs of wireless security), but by the end of this section, you should have a firm grasp of Wi-Fi’s fundamentals.

Signals and spectrum

Wi-Fi’s core premise is pretty simple – routers and adapters send and receive data using radio waves. It’s the same basic technology that’s used by radio and TV to receive terrestrial signals, mobile phones to make and receive calls, as well as video senders, baby monitors, and all sorts of other wireless devices.

In effect, all a wireless router or adapter does is translate the data it receives into a radio signal, which is decoded back into data at the other end.

Specifically, wireless routers use frequencies of 2.4GHz (or the range 2.412GHz-2.484GHz to be more precise) and, in the case of more expensive dual-band routers, 5GHz (4.195GHz-5.825GHz) to send and receive information.

But there’s far more to it than simply slinging streams of data to and fro. Each of these bands is further divided into channels, of which your router can use one or two simultaneously (when two are used simultaneously, it’s called channel bonding – see below for more details). In the 2.4GHz band there are up to 14 channels available, and up to 42 in the 5GHz band.

The idea is that by using different channels, neighbouring networks avoid stepping on each other’s toes. In an ideal world, for maximum performance and stable operation, your router should be running on a channel that no other network in range is using.

In reality, the true number of available channels is lower than these theoretical maximums, depending on where you live and which router you’re using.

In the UK and Europe, you’re legally allowed to use only channels 1 to 13 in the 2.4GHz space, and you’re restricted to 18 of the 42 in the 5GHz space. A Netgear router we use in our office, meanwhile, makes only four channels in the 5GHz space available for use.

This is compounded by the fact that when your router transmits on each channel, the effective width of its signal is about 20MHz, which, in the 2.4GHz space, means it can overlap up to eight neighbouring channels.

It doesn’t take a genius to work out that when more than three wireless networks are in close proximity to one another, co-channel and adjacent channel interference can become a problem.



Channel bonding (the ability some routers have to group two channels together, doubling the potential throughput) makes the congestion even worse – with several 40MHz wide channels hogging such a narrow spectrum, it’s like trying to squeeze several 21-stone men into a small lift.

Why 5GHz?

There is a solution to hand, however – 5GHz wireless. The advantages it holds over 2.4GHz are threefold. First, it’s far less congested. Fewer people own dual-band 5GHz routers and devices, so the chances are you’ll be able to set up your network on a completely congestion-free channel, which you perhaps wouldn’t over 2.4GHz.

Second, since the channels are further apart than in the 2.4GHz band (with 20MHz between each, compared with 4MHz or 5MHz) there’s much less opportunity for adjacent channel overlap. Even in the unlikely event that many 5GHz routers and devices are in close proximity to each other, maintaining a steady signal should be much easier.

Finally, and potentially the biggest bonus of all, there are relatively few non-networking devices currently using the 5GHz space.

Where users of 2.4GHz must contend with all manner of domestic interlopers, from microwaves to cordless phones, 5GHz networks are comparatively clutter-free.



Physical barriers

It isn’t all rosy in the 5GHz garden, though. Since the signal is of a higher frequency than 2.4GHz, it deals less well with walls, windows and floors, and this hits its ability to transmit and receive speedily at long range.

In Rustyice tests, we’ve routinely seen routers perform well over 2.4GHz, flawlessly transferring files wirelessly at a distance of about 40m, with two walls in the way.

When tested in the same location over 5GHz, most suffer a significant drop in transfer speed and weaker signal reception. Some fail to maintain a solid connection entirely. That means the more objects blocking your signal path, the worse the reception in the 5GHz band gets. It isn’t only building materials that get in the way – everything from humans to heavy rain can attenuate a wireless signal.

Choosing a 5GHz router

Restricted range isn’t the only problem afflicting 5GHz routers. Many devices, such as smartphones, internet radios and games consoles, don’t send or receive signals in that band.

It’s really only laptops and PCs with premium wireless cards that will take advantage of the 5GHz band.

That’s why high-end routers typically offer the choice of 2.4GHz and 5GHz bands, but you should take care when choosing a dual-band router.

Some routers can transmit on both bands simultaneously, while others require you to manually flick between the two. Needless to say, the former is the better choice.
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Wi-Fi security luddite? The ICO is coming for you!

The Information Commissioner's Office today published new guidance for home Wi-Fi security after a YouGov report found that 40% of home users did not understand how to manage the security settings on their networks.

The survey also found that in spite of most ISPs now setting up and installing security on Wi-Fi equipment, 16% of the people surveyed were unsure whether or not they were using a secured network, or were aware they weren't, but didn't give a toss either way.

The new guidance includes information on managing encryption settings and how to think of a secure password. Top tip? Don't use pa55w0rd.

Giving people unsolicited access to your network could reduce connection speed, cause you to exceed data caps, or allow hordes of criminals to use your network for nefarious purposes, said the ICO.

Welcoming the move, D-Link's Chris Davies pointed out that there was no excuse for being caught out.

"There is no doubt that in the past setting up security on wireless networks could be tricky," said Chris. "But this is no longer the case with most wireless products.

"Security can be set up wiin a couple of minutes with no prior technical knowledge required. We've also been working with ISPs to help them ship products to consumers with security pre-configured."

Let's just hope the ICO doesn't start fining home users for data breaches. Or maybe that would be the kick in the butt some of them need?
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