As the bandwidth demands on campus networks continue to grow and the cost of campus network devices continues to drop, many companies are looking towards switches and virtual LANs (VLANs) to upgrade their network infrastructure. Once the decision is made to move towards a switched network, network managers need not only to understand how VLANs work, but also must have a grasp of issues related to sound VLAN network design.

Through the course of this article, I hope to introduce you to the basics of both a VLAN and a VLAN-based campus switched network. Then we will look at some design issues related to VLANs such as redundancy and load balancing.

VLAN Basics

At its most basic level, a VLAN is analogous to a stack of repeater hubs. It is a broadcast domain. It is a subnet. It is a logical grouping of switch ports into a single entity.

Is it truly possible for a VLAN to be all this? The answer is yes.

VLANs can be made up of any number of ports in the campus switched network. It can be all ports in the network, it can be only one port in the network, and it can be any number of ports in between. This grouping of ports is accomplished by the switches communicating information concerning each VLAN between them. In the Cisco world, the VLAN Trunking Protocol (VTP) accomplishes this communication and makes it the best and fastest connections possible, which also make a VLAN the best router for gaming or anything where the speed of upload and download matters. VTP allows each switch in the network to tell every other switch which VLANs have been programmed into its own database. By this method, each and every switch has a complete listing of the available VLANs that can be assigned to individual switch ports.

With any switch port in the entire campus network able to communicate with any other port as part of a broadcast domain, users are no longer bound by geographical barriers. Users in the same workgroup or corporate function in different buildings no longer need to communicate via routers and other layer 3 devices. For broadcast-driven technologies such as WindowsNT, Novell, and other Network Operating Systems (NOS), this “local” communication ability allows multiple widely scattered user nodes to communicate with a server in a different remote location.

This allows network managers to move their user servers from these remote locations into a central server room, which can be secured, well ventilated, and central to the core of the network. In addition to easing communication between buildings, VLANs also ease communications within the same building. Having multiple user groups on multiple floors no longer requires network managers to maintain multiple repeater hub stacks and multiple router ports per floor regardless of what software is being run such as graphic design platforms.

User data from two PCs on the same VLAN who are connected to two different switches in the network is carried on one physical connection between those two switches. Both the transmitting and receiving switches are able to determine which VLAN any one packet belongs to by using a trunking method called Inter-Switch Link (ISL). ISL is a proprietary Cisco technology where two Cisco switch devices (or a switch and a Cisco router as we will see later) communicate VLAN information to each other.

ISL appends a header onto every frame it sends to the neighboring switch. This header tells the neighbor switch which VLAN this frame belongs to. ISL headers are only attached to data frames between devices. The outgoing trunk port on the source switch attached the header and the incoming trunk port of the destination switch strips the header back off.

VLAN Routing

With all the data flowing through the switches in the same VLAN, how do devices on different VLAN communicate? LAN to LAN communication has traditionally been the role of the router and this same device continues to play the same role in a campus switched network. Remember that each VLAN is a subnet and inter-subnet communication uses Layer 3 of the OSI model. Now, how are routers used in a switched network?

Similar to repeater hubs, each VLAN requires a connection to a router. On a basic level, each VLAN needs one dedicated connection to a router port. This can quickly consume router ports and might cause some networks to purchase more powerful routers and more router ports than they really need. Cisco has devised two alternative options to this problem. The first option is to connect one of the router’s Fast Ethernet ports to one port on the Catalyst switch.

These two devices can then communicate with each other using the same ISL encapsulation that the switches use to communicate. From the routerÕs perspective, the Fast Ethernet port is configured to use sub-interfaces, one for each subnet. The sub-interfaces function exactly as do “real” Ethernet interfaces.

Traffic between VLANs now travels from the switch to the router and back again on the same physical wire. Logically, the data goes to the router with an ISL header of A and is received on one sub-interface. The router then routes the packet to a different sub-interface and sends the packet back to the switch with an ISL header of B (Figure 1).

The second option is to install a Cisco Route Switch Module (RSM) into one of your Catalyst switches. The RSM installs directly into the Catalyst chassis and attaches to the backplane. It has one virtual interface configured for each VLAN present in the network. Functionally, the RSM operates exactly like the Fast Ethernet ISL connection we just described. The main difference between the two is that the RSM can route between VLANs at Catalyst backplane speeds (1.2 Gbps) as opposed to Fast Ethernet Full Duplex speeds.

Cisco has recently announced a more efficient routing mechanism for use in a switched campus network. The Catalyst Supervisor III switching engine can now be supplemented by a daughter board upgrade called the NetFlow Feature Card (NFFC). The inclusion of this card allows the Catalyst switch and either of the router options discussed above to share layer 3 IP addressing information.

Once the Catalyst starts to learn IP addressing information, it can then replace the router function internally and route packets between two different VLANs on the same chassis. Should your network have only one router at its core (as discussed later in the design section) and multiple remote switches utilizing the NFFC, then routing functions can be spread across all sections of your network. This works to speed up the aggregate flow of data in your network.

Redundancy Options

Redundancy in a campus switched network with Cisco networking devices can be provided in many different ways. One option is to place two Supervisor III switching engines into the same Catalyst 5500 series chassis. One of these modules will function as the master and the other as the slave. Should the master fail for any reason, the slave takes over the operation of the switch. A second redundancy option available is to have two different routers running in your network. These two routers can appear as one router to user PCs by utilization of the Hot Standby Router Protocol (HSRP).

HSRP routers (called primary and standby) communicate between themselves and agree to use both a virtual IP address and MAC address so that user PCs can be statically configured for one default gateway. In this manner, data traffic can be guaranteed to flow through the network because the failure of the primary router causes the standby router to start processing data traffic destined for the virtual address.

One possible resiliency option for switches in a campus network is to have multiple network links between each switch (Figure 2).

From a physical standpoint, these network links should take different paths throughout the campus. On a logical layer, these multiple links can be used to load balance network traffic between the switches by adjusting different settings of the Spanning Tree Protocol (STP).

STP is the method by which switches in a campus network guarantee a loop-free topology. STP was designed to overcome one of the most basic traits of switches. This trait causes all switches to forward each and every broadcast out of all of its ports. STP makes sure that only one broadcast packet is seen on each network link by electing a root of the network. Each switch then traces a least-cost path back to the root. Under normal circumstances, this configuration forces all user traffic along the same set of wires wasting possible network bandwidth.

CiscoÕs STP and VLAN implementation provides for one instance of STP for each VLAN in the network. This feature allows a network manager to assign different roots for each VLAN. Additionally, managers may also decide which physical wires carry traffic for which VLANs. These options allow more bandwidth in the network to be utilized.

Design Issues

By default, all Catalyst switches have every port placed into VLAN 1; that VLAN is the only one running on the switch. This works well for a plug and play situation, but for an operational network (even the smallest) there should be a minimum of 2 VLANs. The default VLAN 1 should be used as a management VLAN. This means that the IP address of each of the switches in your network should be placed into this VLAN. This allows network staff to telnet to the switches without being hampered by or interrupting user data.

In addition, this also allows Simple Network Management Protocol (SNMP) traffic to flow throughout the network with much more ease. You should then create additional VLANs and place user PCs and/or servers into them. This begs the question of how many devices should be in each VLAN.

The answer to the question of VLAN size is best measured by the traffic patterns of each particular network. Factors such as a need to see broadcast traffic, groupings of users, and logical arrangement of network segments all play a part. In general practice, about 150 devices in a VLAN is a good upper limit. Network designers should not over-compensate in the opposite direction and use a large number of smaller VLANs either. Remember that each VLAN keeps a separate version of the spanning tree.

The more VLANs you place on a switch, the higher the load you are placing on the CPU of each and every switch in the network. In a large production environment of 3000-5000 nodes, around 30-35 VLANs is a good upper limit.

When it comes to a physical layout of your switched network, one of the most successful implementations is a hub and spoke design. This allows network staff to place a large switch like a Catalyst 5500 at the center of the network to function as the core switch and to be the STP root for all of the VLANs in the network. This works well due to the fact that each remote switch is now only one data hop away from the root of the spanning tree and two hops away from any other switch in the network.

To provide redundancy options for the network core switch, a second Catalyst 5500 series switch can be placed at the core. For added redundancy, the second switch should at a minimum be connected to a separate power circuit. The second switch can also be placed in a different room on the floor or on an entirely different floor altogether. Each closet switch would then have two data connections outbound from it to the core, one for each core switch (Figure 3).

Communications between the two core switches should be accomplished via ISL trunking and Fast EtherChannel (FEC).

FEC is a method where two different physical links between two network devices are combined logically together to ÒdoubleÓ the bandwidth. This comes into play with two core switches in the following manner. Under normal circumstances, one of the two wires would not be used for data traffic due to STP preventing bridging loops by blocking one of the ports. When FEC molds the two lines onto one, STP sees this wire as one unit and all data traffic now flows over both physical lines between the switches.

For those networks that require redundancy options at the user PC level, network designers can place two PCs on each desk and place each of these PCs in a different VLAN. One such environment might be a securities trading company whose brokers need mission critical information every moment of the day. A database front-end can be placed on servers in each and every VLAN. Each of the servers would be fed its information from a common back-end server and/or mainframe. One benefit of this configuration is that the client/server information is a UDP broadcast every 2-5 seconds, and placing servers in every VLAN reduces the broadcast traffic across the network as a whole. Now, these multiple PCs can ensure the end-userÕs access to mission critical information in the event of a failure in any one VLAN.

Summary

VLANs are a technology that is rapidly changing the way in which networks are built. It is important that designers know the basic capabilities of VLANs and factors that play into their operation. Building on these blocks will allow network staff to configure a highly redundant, stable, and powerful network.

Over the years, the simple doorbell has changed and is becoming increasingly high tech. There are many modern doorbells that integrate seamlessly into smart homes. If you are thinking of upgrading your doorbell, you will need to know how they have changed and how they are becoming more high tech.

The Traditional Doorbell

The traditional doorbell has not actually changed since the Victorian era. The only change that has come about is the way in which the doorbell was rung. When the doorbell was first introduced, visitors would pull on a cord or metal chain which would then ring the doorbell. Over time, this evolved into a button which activated the buzzer.

The traditional doorbell is still used in the majority of homes. They are easy to install and can be bought from any home store. However, there are newer doorbells which might suit your needs more than the traditional one.

The Audio Doorbell

The first big upgrade to the doorbell was to integrate it with audio. This was generally used for apartment blocks and other high-rise buildings. Audio increased the security of the doorbell system by allowing people to communicate with visitors before they were let into the building.

Audio doorbells are something that many people have in their homes via intercom systems. This is ideal if you have a long driveway with a gate that you need to remotely open for visitors. Most people will not benefit from intercom systems if visitors are able to walk up to their front door.

The Video Doorbell

While the introduction of audio for the intercom system was a step forward, it was not the last. The addition of video to the doorbell system was the next step that was taken. There are a number of different ways that this has been done and it is important to know what they are.

The first was to use a separate CCTV camera to provide the video aspect of the system while an audio doorbell was used for communication with visitors. This system was not the best because of the separate installations required. Additionally, it was often difficult to have the video and audio feed in the same location.

The second way that this system was implemented was through the use of a combined audio and video system. These systems consist of a doorbell with audio capabilities and an integrated camera. This provides an easy to use system where the video and audio are relayed to a single point. For more, see some video doorbell reviews and their specifications here. These systems are more popular with people than the CCTV and audio doorbell setup.

The Introduction Of The Smart Doorbell

For many years, the audio and video intercom system was the peak of doorbell technology. However, with the recent leaps made in technology, doorbells have become more high tech. They have moved from the stationary systems that we used to know to a smart system that integrates with the rest of the smart home.

The smart doorbell is a relatively new technology and has not yet become a mainstay. There are a few systems on the market that you can look at if you want to create a smart home. These doorbells will work in a similar manner to the video and audio doorbells. However, the primary difference is that they can be accessed via a smartphone.

Each doorbell system will have an app that you download which allows you to access the video and audio for the system. There are also some smart doorbell systems which can be integrated with smart locks. This allows you to unlock the door for your visitors remotely which can be very helpful. Smart doorbells allow you to access your intercom system from anywhere in your home or even when you are outside of the house.

Of course, it is important to note that these systems are still relatively expensive. They will generally cost a few hundred and the model that you need will vary depending on the doorbell you are replacing.

Over the years, doorbells have become more high-tech in line with the changes in general technology. The traditional doorbell has not changed since the Victorian ear, but you are able to get modern doorbells that have video and audio capabilities. Smart doorbells are also now available which allow you to access their video and audio feed from your phone.

Are you considering the prospect of purchasing a 3D printer? If you are it likely means that you are involved in an industry or activity which makes use of such a piece of equipment.

Why are 3D printers so effective and should you invest in one? Let’s take a look at these questions in a little more detail.

Why Are 3D Printers So Effective?

Quicker Time To Market

When you use 3D printing you can develop ideas at a much quicker rate. In fact, you can create a 3D print of a concept on the same day you came up with it in some instances. This is a great bonus for companies who need to always stay a step ahead of the competition as it cuts the time to market significantly.

It Can Be A Less Expensive Option

We all know that production runs and prototyping injection mold tools can take up a huge amount of your business finances. Using 3D printing means that you can create parts or tools through additive manufacturing. Rates for this type of manufacturing are a lot lower than those for the traditional counterpart.

Cut Down On The Risk Factor

In the world of business, it is almost always necessary to take some level of risks. However, trying to cut down the risk factor as much as possible can really benefit your business. With the help of the best mid range 3d printer, you can verify your design before you move to the expensive step of making it. Having a printed prototype can certainly give you room to make necessary changes and confidence to take your concept to the next level. After all, making changes on a 3D prototype isn’t going to set you back much, but making alterations to a test model sure is going to be less easy on your bank balance.

Clear Impression Of Your Concept

Have you ever tried to describe an incredible concept that you have only to be met with a host of blank expressions on faces of the people you are addressing? This is because it is often very challenging to give your concept justice when you are only using words or sketches to explain yourself. When you are able to show a 3D print of your concept you leave no room for doubt or confusion as to the idea that you are putting forward.

Great For Tradeshows

Often, we want to test the market first before we commit ourselves to the concept we have in mind. Using 3D prints at events such as trade shows gives you the opportunity to show potential investors and buyers exactly what you have in mind. In fact, you may find that potential buyers are able to add useful feedback at this point in the process so that your finished product embraces all of the valuable opinions and likes of the people who will be buying it.

Should You Purchase A 3D Printer?

It is very clear that 3D printers come with a host of benefits. In fact, we have only described a few of them above, there are many more. However, just because these printers come with a wide choice of benefits, does it mean that you should purchase one? Actually, that depends on a number of factors.

Your Use

If you already have a good business and feel that a 3D printer would truly add to your success, it is certainly worthy of your consideration. This means that you know you have enough uses for the equipment to make the investment worthwhile. However, if you do not yet know how often you would use such a piece of equipment and feel that it may only be used on an occasional basis it may be better to consider the hire of such equipment rather than an outright purchase.

Your Budget

It is also important to take your budget into consideration. While a 3D printer may be of much benefit to your business, if it is going to be a massive expense which is outside your budget it may be of more harm than good to you.

Indeed, 3D printers offer many benefits to the companies who use them. If you are thinking about making such a purchase we hope that the details we have provided above will be useful in your decision.

If you are wondering what the time clock app is, it is one of the most productive applications that you can ever use. Of course, this is dependent on whether or not you are its intended user. So, exactly what does a time clock app do?

It is the replacement of yesterday’s Bundy clock. If you know anything about Bundy clocks, you would know that employees had their own cards and then punched it on the clock when they go in and out of work. It made it easier for the payroll officer to compute salaries.

But with the time clock app, the life of payroll officers is about to become much, much easier. This is because everything is automated. Employees can either log onto an app or the website and then indicate that they are at work. They use the same software to log out from work. It’s that simple. But if you know anything about payroll, being able to track your employees hours is very critical for business.

If you search for it online, you will see that there are many brands of time clock apps out there. The question is, which one do you choose?

If you are like most businessman, you are most likely budget-conscious and are wondering or even worried how much such an app would cost you. Well, you would be glad to know that there are apps that cost only five dollars per month per user.

So if you only have five employees, it’ll only cost you $25 per month. Aside from being able to track the time of your salaried employees, you can also track the work hours of your hourly workers. But this is not all.

If they are working on a project, you can use the app to track the progress of that particular project. Index Time Clock is simple and it’s straightforward app. But most users appreciate the app because it makes life much more easier than if they were to do manual log in and out.

Out on the applications marketplace, you will find many brands of time clock software. What you want to do is decide which one is actually worth your time. You can easily know this just by checking out the storage things and customer reviews.

No matter what you do, only use an app that has an average star rating of at least four stars based on many, many ratings. An app that has an average star rating of 4.6 stars is much better then a five star rating based on 10 ten ratings if it is based on 100 ratings.

Of course, you don’t want to base your decision on the ratings alone. Make sure that you try out different software before making a decision. The trial period for time clock apps differ from one another. And so, it will definitely help if you try out at least three before settling for one. It’s not rocket science, but you have to make your experience the guide.

Whether you are new to the business world or have been running your own company for some time, you may have come across the term ‘vanity numbers’ and wondered whether this system could be something that could be of benefit to you and your business needs. Let’s take a closer look at what vanity numbers are and how you can get one.

What Are Vanity Numbers?

This is a local telephone number which is toll-free. The subscriber requests a number which uses a certain sequence of numbers which is easy for people to remember. That is why you will often see numbers advertised by takeaway services, taxi companies, and other businesses, ending in repeat digits. The numeric sequence is eye-catching and easy for people to quickly remember. That is why vanity numbers are often viewed as an excellent marketing resource for many businesses.

In fact, before we look at how you can get a vanity number for your business, let’s take a quick look at the main advantages that this service will offer you.

The Main Advantages Of Having A Vanity Number

You may come across other benefits to having vanity numbers, however below we have listed the main ones in our opinion:

– Customers and potential clients are able to make contact with you without facing a charge for the call.

– Your give your business a more professional appearance which can attract more clients and instill confidence that they should choose you for their needs.

– You are able to give your business a national presence.

How Do I Get A Vanity Number For My Business?

If you like the sound of all the benefits that having a vanity number can bring to your business you are likely keen to get yourself one as quickly and easily as possible. What process do you need to follow?

You Need To Find A Vanity Number Provider

First and foremost you need to find a vanity number provider. This step can take a little more time and effort than you may initially have thought. As you research vanity number providers relevant to your area you may find that there are many to choose from. Take the time to analyze each option and decide which one offers the best service for you and your needs.

Choose Your Number Wisely

It’s easy to get carried away when thinking about what vanity number you want for your business, but make sure you take the time to identify what would work best. Take into account the nature of your business, any numbers which are relevant to your line of work and how the numbers would be dialed on a keypad. If you think you have identified a great number try putting the digits into the keypad on your phone to see how it feels.

In addition, don’t forget that vanity numbers are very popular so there is every chance that the first number you come up with may already be taken. Try to have a number of options available so that you have a backup plan if need be.

It’s also a good idea to involve others at this stage of the process. What may sound like a great and memorable number to you may not be met with the same enthusiasm by other people. Try out your ideas with a variety of people and see which one seems to come up tops. If need be, you may need to go back to the drawing board and think up a whole new idea for your number.

The Role Of The Vanity Number Provider

As well as providing you with a number which you feel would be beneficial to your business, the vanity number provider will then have the responsibility of forwarding your calls to your regular phone number.

Certainly, vanity numbers can be a great marketing tool for your business, whether you are a sole trader, a large company or fit somewhere in the middle. We hope that the details we have outlined above have not only helped you to understand what vanity numbers are, but will also help you to find one that is just right for you.

You really have to love technology today and all the ways it can be implemented. And the amount of new gadgets coming out everyday is mind blowing.

I was looking around Amazon today and was stunned by some of the gadgets that I personally would never have thought of to make them “high-tech”.

And I’m talking some pretty low tech stuff here. Super simple things.

Just to give you an example, how about the meat thermometer…

Yup, the simple “no-tech” meat thermometer has now become a high tech gadget! For me a meat themometer looked something like the picture on the right. You know, the “boring” kind that your mom used. Heck, even your grandmother. That’s what I’ve been using as well.

But no more! I ended up buying one of the digital instant read ones. Which I definitely like the idea of it being an “instant” read. So now I’m part of the 21st century. Or sort of…

If you really want to be a high-tech cook, then there is even a wireless temp reader remote digital thermometer. And get this, it can connect to your phone using an app!

So now you can be outside by the pool or whatever and the little app on your phone will tell you when your dinner reaches a certain temperature or whatever you need. They even have Bluetooth ones! Crazy!

But that’s not all…

How about a digital spoon scale? Yeah, a cross between a regular teaspoon and an actual scale! So now you can measure exactly how much something weighs in your teaspoon.

I don’t know why? Maybe you can measure the amount of sugar you put in your coffee each day to get that perfect cup?

And I saw things like door locks that are super tech rich.

Ones that read your fingerprint so you don’t need a key or anything. My only problem with that is, what happens if the finger print reader breaks, or gets too dirty or something? How would you get into your house?

One cool gadget that I really did like, being in New York with our winters, is the remote car starter in consumer reports. I LOVE the idea of starting my car from inside my warm house rather than freezing while I’m waiting for it to warm up.

Times sure have changed when I grew up from when a Pager was high tech. Yet I do love the ingenuity of some of the gadgets I ran across. And I can’t wait to see more of what comes out.

What about you? Have you seen some cool gadgets that have been beefed up with some tech? Share them in the comments and let us know!

If you want to engage in internet business world, then you probably need a website where buyers can view your products or services you offered. However, because internet marketing has been rapidly growing for quite some time now, you need something that will compel your targeted viewers to pay a visit to your site. We cannot avoid competitions today.

Video marketing has become a must have skill for today’s internet marketer and you must learn effective video marketing tips to increase sales of your products and services.

Websites like YouTube has inspired and successfully contributed to the growth of video marketing. Video marketers are driving huge traffic to their sites by uploading substantial number of videos on this website. To ensure that your probable customers are not snatched away by your competitors, you cannot ignore placing your videos at such website.

One of the most formidable places where you can get thousands, or even millions, of viewers is Youtube. Tons of internet marketers have been uploading their videos in Youtube since it generates and drives traffic to their website.

Customers will select whatever is available to them first, therefore ensure employing marketing tools in a way that they select your link so that you can use it to your advantage.

With more than 87 million of unique visitors across the globe every day, no doubt you can reach them wherever they are. 26% of the viewers mostly come from search engines like Google or Yahoo. So, you must put on the right niches that best describes your video in order not to lose your goal traffic. The truth is, when a person searches on a certain video, they will probably approach the first link he sees, or move along the second one, if it did not satisfy him.

The first thing you should know about video marketing is to determine your prospect. Choose a niche that fits your company as well as your website. Your sole purpose why you build such videos is to direct them to your website to increase your traffic and to persuade them about your products or services.

Secondly, make a video that is concise and purposeful. Don’t fluff around as it may detract customers. Make a precise video that focuses on your key selling points. If you are still not as proficient using and creating videos as you’d like, then use a good service like video production Calgary to create them for you. Customers are not interested in viewing long or dull videos. Prudence and the success of your website lies in devising a video that is crisp, and conveys the message to your prospective customers in a short period of time.

Keep the message short, concise and informative. Brevity and focus is a strong factor that may lead them to view your website and press them to check out the stuffs you offer.

People are more attracted to videos that have personal touch. Either make a video by yourself or make use of slides to produce a video, but be passionate and fervent about your video. Remember, people are not attracted to dry impersonal words; rather they are swayed away by feelings. Attract viewers to your services by engrossing them in your impartial video.

Lastly, post your video to the top listed video-posting sites like YouTube, as it has the maximum audience for all types of videos. With these tips in your arsenal you can easily reach the zenith of the marketing world.