08/30/2007
Cisco Certification: Building Your Home Lab, Part II
In the first part of this home lab tutorial, CCNA and CCNP candidates can see that there are a LOT of choices when it comes to what to buy to build your own Cisco practice lab.
Having been there myself, I know it's confusing to decide how many routers or switches to buy, and what I need at the minimum to run labs and get some great hands-on practice. Let's take a look at some lab configurations and some other lab equipment you may need.
A starter practice lab will consist of two Cisco routers and one switch, hopefully a 2950. This is a good way to get started. You will need to make sure that the routers you purchase have Ethernet ports, and at least one serial port. If possible, get routers with BRI ports, so even if you're not configuring ISDN now, you'll be able to in the future. (You will need one additional device to make ISDN work in your lab, and we'll talk about that later in this article.)
You can practice setting IP addresses and testing IP connectivity over the Ethernet interfaces, and you can configure a point-to-point connection between the two serial interfaces. (You must know how to do that before you think of taking the CCNA exams!) Depending on the switch, you can also get some practice putting the Ethernet ports in different VLANs and working with the switch IOS.
This setup does have some limitations. You can't practice trunking or Etherchannels with one switch, and you can't set up a Frame Relay cloud with this configuration. It's a good start, but you should consider getting a few more routers, including one to serve as your Frame Relay switch.
What's a Frame Relay switch? Good question.
The Frame Relay Switch
As you know from your studies, Cisco routers are DTEs by default. The Frame Relay cloud is made up of DCEs.
In a lab environment, you need a device to serve as the Frame Relay cloud. This device will have DCE interfaces, and will actually be performing frame relay switching. But this isn't a switch in our lab - it's a Cisco router.
There are plenty of Cisco routers that make great frame relay switches. Get one of those and a couple of DCE/DTE cables, and you can configure the router as a frame relay switch and have your own working frame relay cloud in your lab!
The Cisco router you choose as your frame relay switch should have at least four serial ports, and if you can get more, great. It's always good to have spare ports.
If you get four Cisco routers, with one as your frame relay switch, you can set up a frame relay cloud and practice your hub-and-spoke frame configurations. Even better, as my labs do in my CCNA Study Guide, you can set up a frame relay cloud and a point-to-point Serial connection. This will help you get real hands-on practice with such features as EIGRP variance.
With that four-router configuration and one switch, you can get some great hands-on experience with many CCNA features that many candidates just read about. If you can add a second 2950 switch, you can practice different spanning-tree configurations, such as changing the root bridge of a given VLAN, working with VLAN Trunking Protocol (VTP), and configuring your own Etherchannel! (You will need some crossover cables to connect your two switches.)
Let's take a look at one more important piece of lab equipment: the ISDN simulator. You can't just take a straight-through cable and connect your BRI interfaces directly. You need a device called an ISDN simulator to act as the phone company in your home network. The newer simulators let you set your own phone numbers and SPIDs; most older ones have a preset phone number and SPID that you must use. Either way, you get truly valuable experience getting hands-on work with ISDN, especially watching PAP and CHAP debugs and understanding the authentication process.
ISDN simulators can set you back a few bucks. I recommend you visit www.ebay.com and search for ISDN simulator. There are generally 20 - 30 used ones on there at any given time. Be careful to purchase one with at least a 30-day guarantee. They are robust devices for the most part, as there is one in my home lab that I've had for three years (when they were really expensive!), and it's never given me a bit of trouble.
There are many online vendors that will sell you a new one, but obviously the price is going to be higher. One company I've had good experiences with is www.vconsole.com. Make sure to shop around, as there are plenty of ISDN simulator manufacturers out there on the web. Vconsole is the only one I've purchased a new unit from, and the 10-port simulator I use in my classes has worked beautifully.
There is another piece of lab equipment that isn't necessary for your lab, but you'll find life is a lot easier with it. And just as the frame relay switch is really a router, so is this device: the access server.
Access servers are devices with an asynchronous port that an octal cable can connect to. What you do is connect your blue console cable (officially referred to as a -rollover cable-) to the console port of your access server. You then take an octal cable, and connect one end of the cable to your Async port. The other end of the cable, as you'd expect from the name, consists of eight smaller RJ-45 connectors. Each one of those goes into the console port of one of your other lab devices, and you configure the access server to allow one-key access to each of the other devices in your practice lab.
The configuration of the access server is a simple one, and I'll have an example of configuring your access server and frame relay switch up later today.
Not everyone can start with a lab this size, so be careful when you buy your first routers. Make sure that they're not just giving you good practice now, but that they allow for future growth of your lab. As you add a frame relay switch, an ISDN simulator, and an access server, you'll get the hands-on experience you need to be successful on the job, acquire the self-confidence and troubleshooting skills needed in the testing room and on the job, and to solve any simulator question on your CCNA and CCNP exams with ease.
Have fun!
Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of over 100 free certification exam tutorials, including Cisco CCNA certification test prep articles. His exclusive Cisco CCNA study guide and Cisco CCNA training is also available!Visit his blog and sign up for Cisco Certification Central, a daily newsletter packed with CCNA, Network+, Security+, A+, and CCNP certification exam practice questions! A free 7-part course, "How To Pass The CCNA", is also available, and you can attend an in-person or online CCNA boot camp with The Bryant Advantage!
Network Liquidators keeps a large amount of new and used Networking and telecom equipment in stock. Visit our blog for more articles and reviews about networking and telecom equipment.
17:19 Posted in Network Hardware | Permalink | Comments (0) | Email this | Tags: Cisco, certifications, frame relay switches, access servers, isdn
08/29/2007
Raid Data Recovery Explained
Raid data recovery is somehow different from all other types of data recovery. Most experts advise not to try to recover the data yourself before sending in the hard drives to a data recovery company. This is because most companies found that most of the times simple users try to recover the files all by themselves, they fail and not only. Their actions will make the recovery process even harder and if the lost information is important, someone will be in big trouble. If it's about raid data recovery better handle it quick to the professionals without touching anything.
You don't have to take chances with the recovery, it's advised to research for a data recovery company that can handle the recovery process for you. Sometimes, it can be expensive for a raid data recovery but usually the price you will have to pay for the recovery is way lower then the price you will have to pay in time and resources to have all your data recreated.
There are procedures that data recovery companies always follow when they have a recovery on the line. These procedures are followed exactly and even expand when it comes to raid data recovery. As a first step in any raid data recovery, experts have to make sure that all drives are working. For Raid 0 as an example, it is a must for all the drives to be 100% functional. When they are not functional, the drives will be taken in the clean room and will be repaired.
When all the drives will function normally, clones of all the drives will be made. During this process, your drive will be placed in a write protect mode to make sure the data will not be altered in any way. The normal recovery process will be performed on the cloned drives, again, for increased safety.
When researching for a data recovery company you will notice some of them will offer a service full guarantee, if they don't get your data back, you don't pay. A phone consultation is something that could help you also. They will also offer you absolute 100% confidentiality on your data.
Even if raid data recovery sometimes can become expensive, most companies will not charge you for an evaluation of a complex raid system. If you need the help of the experts, get it, it's the best way. After getting all your data back, make sure to always backup your information from now on.
Network Liquidators keeps a large amount of new and used Networking and telecom equipment in stock. Visit our blog for more articles and reviews about networking and telecom equipment.
16:14 Posted in Network Hardware | Permalink | Comments (0) | Email this | Tags: Hard Drives, Raid, Data Recovery
08/28/2007
Monitoring Temperature And Humidity Inside The Server Rack
These alarms can be at the rack, or by email, or by SNMP traps, or by all three methods depending on the system. There are several different types of sensor systems from several different manufacturers, available at present. One of them is a compact environmental monitor with one onboard temperature sensor and in addition the ability to support up to 16 remote sensors. The system is very small so you don’t have to change your system. If you receive a problem alert, you are able to identify the rack and power strip having the trouble, and turn off the individual outlet or reboot it.
Another power management and control system available is able to track temperature, humidity, airflow, and water at various locations from 15 to 100 feet away. This system needs only limited rack space and can control individual power receptacles. Another system on the market utilizes two sensor probes in each rack, one in front, one in back, to better measure the environment in the rack. This gives you a thermographic view of the temperature range in the rack and can be displayed in color for all the different racks in the computer center. This information can be used to determine the size and location of any additional A.C. or fans or blowers needed to correct a cooling system. It can also assist in the rearrangement, if necessary, of the rack layout and separation of a cold aisle/hot aisle system or any rack system, or when additional racks are added to a functioning system.
The control of heat generation and temperature in the data center continues to be one of the most critical areas. The monitoring of the environment has gone from the room, to the zone, to inside the individual server rack to give a much more precise picture of what is happening and allow better response to emergency conditions.
Network Liquidators keeps a large amount of New and Used Networking Equipment in stock. Visit our blog for more articles and reviews about networking equipment.
17:15 Posted in Network Hardware | Permalink | Comments (0) | Email this | Tags: Racks, Network Equipment
08/23/2007
Do I Need a Cisco Router?
Do I Need a Cisco Router?
Cisco routers typically maintain the highest price point in the industry, leaving buyers with a quandary when purchasing terminating equipment for their network or T1. There are many choices available when it comes to T1 routers and most are nearly half the price of a comparable Cisco router. Why are Cisco routers such as the 1721 and 2621 comparably more expensive than the competition? Cisco stakes their claim in what they call the Cisco Converged, Intelligent Network, which has four cornerstones: modularity, resilience, adaptivity, and security.
Modularity is most notable in Cisco routers in that the 1721 and 2621 are chassis that accept a wide array of wan interface cards in order to terminate networks of different types. For instance, a T1 would require a T1 DSU interface card while a frame relay network would require a frame interface card, both of which can be installed in the same chassis. Modularity allows Cisco routers to upgrade and change with the needs of the user, saving money in the long term.
Resilience is realized when Cisco gear operates in Cisco infrastructure. A powerful advantage is gained in that the intelligent network is application-aware. This means that the network actively participates with the applications, automatically providing end devices with rights and priorities based on the needs of the device and the application.
Embedded in the Cisco Intelligent Network, the purpose-built Cisco IP Communications applications are also network-aware, meaning that they automatically seek and retrieve the most up-to-date software versions and upgrade themselves. When the network and applications communicate in this highly adaptive way, customers can more quickly deploy communications. This also simplifies management and reduces management costs.
Network intelligence also enhances IP-based security. Integrated security helps Cisco offer an IP network that is the strongest, most secure system available. Cisco security is based not on point products, but rather on multilayer, system-level security that pervades the entire infrastructure, from endpoints such as the IP phones or PCs to the call-processing components to the software and silicon on the router.
Network Liquidators keeps a large amount of Cisco routers, and other Cisco equipment in stock. Visit our blog for more articles and reviews about Cisco networking equipment.
17:34 Posted in Network Hardware | Permalink | Comments (0) | Email this | Tags: Cisco, Routers, 1721
08/21/2007
Nortel Networks Corporation - A Brief History of Your Office Phone System
In offices across the United States and the world, phones drive business. Phone systems enable the vital communication portals that allow cross city, state, and country decisions to be made, whether a simple lunch order or a multi million dollar closure. One corporation that has been involved in this daily business-communication cycle from the infancy of telecommunications has been Nortel Networks Corporation. However, Nortel has not enjoyed a linear, smooth growth; like many companies aged 100 years or more, several transformations, for better or worse, have occurred to shape the giant Nortel Networks Corporation is today.
Nortel began its trek through the world of business in 1895 as Northern Electric, a spin off company of Bell Telephone Company of Canada, incorporated to manufacture business-to-business phones as well as other devices. Northern Electric morphed further into the Northern Electric and Manufacturing Company Limited before the turn of century. With its headquarters and first factories centered in Montreal, Northern Electric continued with phone and other device manufacturing and selling into the early 1900’s, when, in 1914, a merger with Imperial Cable resulted in a new Northern Electric, co-owned by Bell Canada and Western Electric, a U.S. company.
Business continued to grow for Northern Electric after the Western Electric merger until an anti-trust suit was brought against AT&T/Western Electric in 1946, forcing Northern to be sold exclusively to Bell Canada, and in turn forcing Northern Electric to stop producing and distributing products built for Western Electric. Due to this critical financial and logistical set back, Northern began manufacturing and distributing their products, including television sets. In 1964, Bell Canada bought full ownership of Northern Electric and in 1973, took the company public. Within this period of time, two vital decisions were made to advance Northern Electric; first, in 1969, Northern began working on digitizing their telephone systems. Second, steps were taken to enter the U.S. market, including their first U.S. factory opening in Michigan in 1972. These steps resulted in Northern shipping its first digital switching system in 1975.
With a company name change to Northern Telecom Limited, a push to concentrate the company’s emphasis on digital technology, and a merging of parent company Bell Canada Enterprises, Bell Canada and Northern Telecom, and Bell-Northern Research in 1986, business was thriving. In 1995, the company we know today was branded; its 100 year anniversary unveiled the company's streamlined corporate identity, Nortel Networks Corporation.
| Gary Evans is CEO of Hi Line Supply, a Dallas-based telecommunications company with 20 years experience in finding Nortel Norstar, selling Norstar Meridian, and refurbishing Norstar BCM telephone systems. With a company at the forefront of telecommunication equipment, their services reach beyond Texas and the US to their international clients. |
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17:51 Posted in Telecom Equipment | Permalink | Comments (0) | Email this | Tags: Nortel, Phones
Used IT Gear Goes Mainstream
Ask any IT manager what they think about used data networking gear and chances are their eyes will light up. Six years after the Telco bust, the secondary market for IT has grown up and with it companies have grown accustomed to buying used. But with the steep discounts come added risk and buyers are becoming savvy about negotiating the vast, complex market for pre-owned equipment.
Contrary to popular thinking, availability often trumps price as the critical factor for buying used. While manufactures like Cisco and Foundry Networks commonly stick customers with two and three-week lead times, virtually any piece of equipment can be sourced from the gray market in 24 hours. Of course the discount for used, which ranges from 50-90 percent off list pricing has proved to be the real elixir; coaxing even the most conservative buyers to board the gravy train. According to industry estimates, 70 percent of companies have experience buying second-hand gear today. What is tricky about the secondary market is finding good gear and buyers have learned a lot about how to protect themselves.
Estimates of the counterfeit and stolen goods trade for data networking equipment run as high as $40 billion, a figure deserving of some scrutiny having been published by the Alliance For Gray Market and Counterfeit Abatement (AGMA) a consortium formed in September 2001 by leading IT manufacturers including Cisco and HP. Whatever the number is, it’s big. And as online market places such as eBay have exploded so has the level of fraud.
Search for used Foundry Networks on Google or eBay and the results are myriad. Hundreds of resellers, predominately in the US, offer used switches, routers, load balancers and firewalls with varying configurations and terms of sale. With eBay’s built-in seller rating system whereby for each transaction, the buyer and seller are allowed to rate each other by leaving feedback, buyers are encouraged to select only the vendors who have a high positive feedback rating (90% and up) and a history of many such transactions.
Buyers have learned that eBay also is a haven for counterfeiters, primarily from China who list new Cisco auctions at irresistible prices. To the untrained eye, these products appear identical to the real thing and in some cases will operate like normal. The trouble comes when the end-user tries to purchase support, known as SMARTnet from Cisco only to learn that the serial number is invalid or doesn’t exist. By that time the seller has his money and has likely changed his identity online. For the customer, equipment failure is imminent and a refund is merely a pipe dream.
A quick Google search for “used Foundry switches” will garner 1,600,000 results comprising mostly news and other product information together with links to resellers who specialize in the sale of such gear. While most online users will focus on the organic links, companies with paid advertisements on the right side of a Google results page are considered credible sources as well.
Buyer Beware. Things to consider before buying used:
· Run a D&B (Dun and Bradstreet) on the company – D& B hosts a database of over 64M businesses worldwide. Through their Data Universal Numbering System (DUNS) you can access useful information on a company such as names and contact information for their principals, company credit rating, and pertinent financial information. By verifying with D&B, you can be assured that a company is in good standing and is conducting business with fair-practice in mind.
· Validate all serial numbers – Serial numbers unique identifiers that are assigned to every hardware unit. By checking a components serial number, you can verify its authenticity and ensure the unit is not stolen.
· Verify Warranty terms in writing – As with any big-ticket purchase, it is always important to clearly understand the terms of purchase. Many companies offer a limited warranty that may cover parts, but not labor. With any used product, something that functions perfectly today, may encounter problems down the road. Make sure you understand what condition the unit is in, and whose responsibility the potential repair costs are. Be aware that there are many companies that offer total repair cost warranties to end-users.
· Never pay cash – This should be common knowledge, but cash purchases are not as secure as other forms of payment. Credit cards, wire transfers, and checks all provide a record to a company and bank account. This will provide you with a paper trail to a specific person or business should there be any disputes or legal issues that come up.
Picking up the phone and calling a brick and mortar business is always the safest way of purchasing equipment but it doesn’t guarantee a buyer will not be defrauded. There are hundreds of trusted resellers in North America with a range of scale and expertise. Most firms will accept credit cards, wire transfers, and Paypal. A quick scan of a website will provide some peace of mind but buyers today understand that the more information they can glean on a vendor, the better they will sleep at night.
| About Author: Peter Gilberd has a collective 10 years experience in IT sales. He is currently the president of Townsend Assets Group (TAG), a leading reseller of pre-owned data networking equipment. With more than 2500 customers in 23 countries, TAG helps customers acquire, manage and remarket their technology. For more information go to Townsend Assets.
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16:09 Posted in Network Hardware | Permalink | Comments (0) | Email this | Tags: Foundry Networks
08/16/2007
Hubs, Switches And Routers - What's The Difference?
The backbone of a computer network uses 3 types of devices to interconnect computers -- hubs, switches and routers. Each is important and serves a different role in facilitating communication between networked computers. From the outside these devices may look similar -- small, metal boxes with multiple connectors or ports where ethernet cables are attached (routers may also expose other types of connectors). The terms 'hub', 'switch', and 'router' are often used interchangeably and misused -- in fact, the devices are quite different. Hubs are used to simply interconnect individual computers. Switches do the same (but more efficiently). However, routers interconnect different networks (as opposed to individual machines).
Network Hub:
Compared to switches and routers, hubs are the least expensive, simplest device on the network. All data that enters one port of the hub is sent out all the other ports. Hence, all computers connected to the same hub see each other's network communications. The hub doesn't pay any attention to the transmitted data, it simply passes it along to its other ports. A hub's value lies in the fact it is inexpensive and offers a quick and easy way to connect computers in a small network.
Network Switch:
The job of a switch is similar to a hub's -- but it does it more efficiently. Each packet of data (ethernet frame) that is transmitted on the network has a source and destination MAC address. A switch has the ability to remember the address of each computer attached to its ports and will act as a traffic cop -- only passing transmitted data to the destination machine and not all the others. This can have a significant positive affect on network performance because it eliminates unnecessary transmissions and frees-up network bandwidth. A switch can be thought of as the central component of a single network. It is used to interconnect devices on the network and to deliver layer 2 (OSI model) frames. A switch differs from a hub in that it does not retransmit frames to all other devices -- rather, a switch makes a direct link between the transmitting and receiving devices.
Network Router:
Compared to switches, routers are slow and relatively expensive. A router is an intelligent device that interconnects two or more networks for the purpose of delivering layer 3 (OSI model) packets. Since there may be more than one possible path, a router takes into account multiple criteria when determining which path to send the data packets. The fact that switches and routers operate at different layers of the OSI model indicates they rely on different information (contained in the frames or packets) to send data from a source to a destination.
An important difference between switched and routed networks is switched networks do not block broadcasts. As a result, switches can be overwhelmed by broadcast storms. Routers block LAN broadcasts, so a broadcast storm only affects the broadcast domain from which it originated. Since routers block broadcasts, they also provide a higher level of security than switches.
Analogy
Here's an analogy to help explain the difference between a router and switch -- a corporation's mail room. When an employee sends a letter it may (a) be delivered to its final destination by the company's internal mail delivery system or, (b) taken to the local Post Office (if the recipient resides outside the company). A switch represents the corporation's mail room, and a router the local Post Office.
A switch does not look inside the mail or examine the type of mail being delivered. The only logic behind a switch is a table of MAC addresses (one for each computer on the network) and which port a destination MAC is connected. That is, the switch stores a table of company employees and their office numbers and is responsible for delivering internal mail directly to employees. So, if mail arrives at the switch that is destined for an employee then a switch knows how to deliver it. A router, on the other hand, is responsible for delivering mail destined for individuals outside the company. In addition, routers can look inside the mail and delivery rules can be applied based on the mail's contents. This feature allows routers to play an important role in network security.
How a Switch Operates:
Switches are essentially multi-port bridges. They were designed to reduce the size of collision domains. In addition to faster CPUs and memory, two other technological advances made switches possible -- Content Addressable Memory (CAM) and application-specific integrated circuits (ASIC). CAM is memory that works backward compared to conventional memory -- that is, given a data value the memory returns the associated address. This allows a switch to directly find the port associated with a MAC address (the data value). An ASIC is a device that can be programmed to perform functions at logic speeds in hardware. The use of CAM and ASIC technologies greatly reduced the delays caused by software processing and enabled a switch to keep pace with the demands of high data rates in Ethernet networks.
Switches can operate in one of three modes -- store-and-forward, cut-through and fragment-free. The trade-offs are performance versus reliability. In store-and-forward switching the switch reads the entire frame and checks for errors. In cut-through switching the switch reads the beginning of the frame up through the destination MAC address. In fragment-free switching the first 64 bytes of a frame are read -- enough to determine whether or not it is a collision fragment (which account for the majority of frame errors).
The Layer 2 switch builds its forwarding table using MAC addresses. When a host has data for a non-local IP address, it sends the frame to the closest router (also known as its default gateway). The host uses the MAC address of the router as the destination MAC address.
How a Router Operates:
Just as a switch keeps a table of known MAC addresses, a router keeps a table of IP addresses known as a routing table. An important function of a router is to maintain these tables and make sure other routers are notified of changes in the network topology. This function is performed using routing protocols to communicate with other routers. When packets arrive at a router's interface it applies various criteria and protocols to determine the best path on which to transmit the packet to its next destination.
A router can be programmed to apply sophisticated rules based on the contents of the data packets that it sees. For example, routers can be programmed to act as hardware firewalls, can implement network address translation (NAT) and provide DHCP services to the network.
Because of their built-in intelligence, routers are generally considered the most complex devices on a network. In addition to directing packet traffic, routers can be configured to monitor network traffic, adapt to changes in the network that they detect dynamically, and protect networks by filtering packets and determining which packets will be blocked or allowed through.
22:25 Posted in Network Hardware | Permalink | Comments (0) | Email this | Tags: Routers, Switches
VoIP And Local Telephone Companies
With VoIP technology entering the mainstream, it brings the possibilities or huge profits for the companies that provide the service. The current promise of cost savings is driving more and more residential and business users to investigate this technology. But the local telephone companies are not going to give up customers without a fight.
There is a current mandate by the US federal government that all VoIP providers offer E911 service. The initial blocking of this information was with the public switched telephone network maintained by the major telephone companies
The next stumbling block is ‘naked DSL’ or DSL access without local phone service. This service is rare, but without it a residence would not be able to use VoIP as their primary phone service mechanism. You see, DSL is running over your existing phone line provided by your local telephone company. Drop your local phone service and you’ll probably drop your broadband DSL access as well. (Cable broadband access is a viable solution here and the increased cost in cable access should be offset by the reduction on your monthly phone bill)
These are just two fronts in the battle over VoIP. Should companies be compensated for the infrastructures they build? Should E911 service be ‘free’ and offered as a public service? What about the existing phone service run into our homes? Who pays for those lines to be laid and hooked into the public switched telephone network?
There really are no easy answers to the questions above. The phone companies are not about to give up customers without a fight. They have years and billions of dollars spent in building one of the most reliable communications networks ‘currently’ known to us.
Is VoIP the next step in the evolving communications industry? How will this play out with phone companies offering internet and TV services and cable providers offering phone and internet service? The line is being blurred and yet the technology pushes forward.
I don’t have the answers, only questions. I know how I’d like to see it all play out, but alas, there is no Nirvana and no, it would seem we all cannot get along. Not when there’s literally billions of dollars at stake. There will be winners and losers as this war rages on, but it is my hope that we, the end users, will, in the end, be better for it. After all, we’ve been down this path many times before and it’s turned out ok.
Remember the advent of the PC and where we’ve gone since then? Remember the first bulky cellular phones vs. what’s available today? Yes, TV’s, radios, computers, phones the list goes on. Technology advances will continue to push us into new directions. I’m sure that in the end, VoIP will be as commonplace as the home computer.
We can leverage this technology today in a cost effective manner. Like any technology how you implement VoIP will make the difference. Whether you’re a residential or business user, there can be an immediate benefit. Check with your communications broker to find out if your existing phone needs can be met cost effectively with VoIP.
About the Author:
FullService Broadband Provider offers free, unbiased information on broadband and communications technology. Our free service is made possible through Try Right Technology, Inc. Article by Michael Weaver.
21:13 Posted in Telecom Equipment | Permalink | Comments (0) | Email this | Tags: VoIP
Why I like Google
Google Maps
This has to be one of the best online mapping programs out there. I've been using online map programs for years, and this is, by far the easiest online mapping program to use. Not only can you view a traditional street map, but you can see a satellite view, or even a hybrid view of a map overlay on the satellite image. As well as driving routes to destinations of your choosing, it will also show you addresses and phone numbers of restaurants and businesses that you're searching for. It also has traffic overlays for most major cities, so you can plan your route around heavy traffic before you even leave your house.
Google maps are extremely interactive; you can pan by simply dragging the map. Zooming is just as easy; simply roll your scroll wheel up or down to change the level of zoom. Of course, there are buttons on the left of the map that you can use to perform these functions if you prefer. Personalizing the map is just as easy, simply click on My Maps, and you're given a plethora of easy to use options. You can add place markers, draw lines and shapes as well as make notes. Even if you don't like the directions that Google has given you, one can simply click and drag the highlighted route to a road that you want to use. You can also add multiple points and get directions from A - B - C - D. I honestly think you can plan an entire road trip with nothing else but Google Maps.
Google also recently added a new feature called Street View, which actually gives you a streets eye view of the road you're looking at. Yes, you heard me right; they have a fleet of Chevy Cobalts whose sole purpose is to drive around all day taking street level pictures. I can't imagine how difficult it must be to take a picture of every street in the US, but Google has taken on the task in living up to their motto of "to organize the world's information and make it accessible to our users". In the street mode, you can pan zoom, and even navigate forward or backward on the street.
Google Maps is also available on your mobile phone, so if even if you don't have access to a computer, you will still be able to access Google maps just as long as you subscribe to a data plan through you’re service provider.
Google Video
Google Video has completely changed the way people watch video on the internet. It also has created a new type of blogging, the video blog. Instead of typing out a blog post, people now use their web cams to record their blog posts and upload them to Google video to be published. Google video has opened a doorway for an amazing new way to communicate with people around the world. To show your cool video to a friend, you had to invite them over to your house and plug your camera into your TV. Now, you simply copy the video from your camera, and upload it to Google. Now even friends that live thousands of miles away can see you get some mad air on your skateboard.
As well as personal videos, you can find many clips from TV shows and movies on Google Video. Although some companies have asked Google to remove videos due to copyright violations, most have not. So there is a good chance you can still see your favorite clip of your favorite show. Just don't expect to watch the whole episode.
Google Video has also spawned a new kind of viral marketing. Many companies have created funny clips and purposely post them to Google Video in hopes that people will spread the news of that video around to their friends. While similar to TV commercials, these videos are free to publish, and instead of forcing consumers to watch the commercial, it does the opposite. It seeks to entice the consumer to search out their video for entertainment. For example, the movie Snakes on a Plane was a success at the box office, mostly due to its occult like following on the internet.
Google Docs and Spreadsheets
Have you ever been away from your home computer wanting to work on a homework assignment, job project, or even get an idea for the novel you're writing? I can't tell you how many times this has happened to me. Google Docs and Spreadsheets is an entirely different approach to word processing. Instead of a stand alone application like Microsoft Word, Docs and Spreadsheets simply uses your favorite internet browser. You simply log into your Google account, and open the Docs and Spreadsheets program, that's it. And the best part is it's free. So not only do you have a great program available to you where ever you have an internet connection, it allows you to save your documents online. No more lugging a thumb drive around with you. Just save it on Google and access it from anywhere in the world. And for those of you with privacy concerns, don't worry. Google's not in the habit of just handing over your personal information like most companies are. In fact, they even stood up to the Department of Justice when they requested something simple, such as search terms, imagine how they will fight to keep your personal documents safe.
You might be saying, "But I like Word, and I've used other free applications and still go back to Word, what makes this better?" I felt the same way when I heard about Docs and Spreadsheets. But, I decided to give it a try. The interface is very simple and easy to learn. Nothing really stood out at first, until I wanted to work on something I had left at the office. Now, I had to VPN into my work network, then remote desktop to my computer to get to the document. That's when it hit me, "This is just a pain." From that point on, I started using Docs and Spreadsheets and never turned back.
Oh yea, and no more syncing. Since your documents are in one location, you don't have to worry about constantly syncing them, or worry about overwriting a newer copy.
Google Desktop
Bring the power of the Google search to your desktop. This is a fantastic search program, not only do you have the power of the Google search engine right on your desktop, but it has a nice sidebar feature that allows for gadgets. Some of which include an RSS feed monitor, local weather forecast, calendar, clock, and many more to choose from. Once it indexes your hard drive, search results appear within seconds.
Google Calendar
Google Calendar is an interactive calendar, which allows you to save appointments, meetings and more. It does everything that the Calendar in Microsoft Outlook does, but stores the information on Google's servers as apposed to your local PC. Again, like Docs and Spreadsheets, this allows you to access your appointments from anywhere in the world with an internet connection. Also, with Google Calendar you can send appointment reminders to your phone.
The interface is extremely simple, like all of Google's products. There are tabs on the top of the page that allows you to change the view from single day, to week, to month. It also has a view that will give you the agenda for all the upcoming events. It's also easy to import your Outlook or iCal calendar schedule into the Google Calendar. Simply click the add button, and select import.
Google Calendar also allows you to have several calendars, and so it's possible to have a public calendar that's viewable by others, and of course a private calendar which is only visible to you. You also can add your friends or coworkers public calendar to so scheduling meetings can be done without having to try and find a date that you are both available. Just simply look at their calendar, and find a suitable date for the appointment.
Ken Hendrickson works for Network Liquidators which specializes in selling new and used network and telecom equipment; including Cisco, Foundry Networks, Nortel Networks, Extreme Networks, Avaya Telecom, Plantronics, GN Netcom and more.
16:04 Posted in Web | Permalink | Comments (0) | Email this | Tags: Google
08/15/2007
Cisco Certification: Building Your Home Lab, Part II
In the first part of this home lab tutorial, CCNA and CCNP candidates can see that there are a LOT of choices when it comes to what to buy to build your own Cisco practice lab.
Having been there myself, I know it's confusing to decide how many routers or switches to buy, and what I need at the minimum to run labs and get some great hands-on practice. Let's take a look at some lab configurations and some other lab equipment you may need.
A starter practice lab will consist of two Cisco routers and one switch, hopefully a 2950. This is a good way to get started. You will need to make sure that the routers you purchase have Ethernet ports, and at least one serial port. If possible, get routers with BRI ports, so even if you're not configuring ISDN now, you'll be able to in the future. (You will need one additional device to make ISDN work in your lab, and we'll talk about that later in this article.)
You can practice setting IP addresses and testing IP connectivity over the Ethernet interfaces, and you can configure a point-to-point connection between the two serial interfaces. (You must know how to do that before you think of taking the CCNA exams!) Depending on the switch, you can also get some practice putting the Ethernet ports in different VLANs and working with the switch IOS.
This setup does have some limitations. You can't practice trunking or Etherchannels with one switch, and you can't set up a Frame Relay cloud with this configuration. It's a good start, but you should consider getting a few more routers, including one to serve as your Frame Relay switch.
What's a Frame Relay switch? Good question.
The Frame Relay Switch
As you know from your studies, Cisco routers are DTEs by default. The Frame Relay cloud is made up of DCEs.
In a lab environment, you need a device to serve as the Frame Relay cloud. This device will have DCE interfaces, and will actually be performing frame relay switching. But this isn't a switch in our lab - it's a Cisco router.
There are plenty of Cisco routers that make great frame relay switches. Get one of those and a couple of DCE/DTE cables, and you can configure the router as a frame relay switch and have your own working frame relay cloud in your lab!
The Cisco router you choose as your frame relay switch should have at least four serial ports, and if you can get more, great. It's always good to have spare ports.
If you get four Cisco routers, with one as your frame relay switch, you can set up a frame relay cloud and practice your hub-and-spoke frame configurations. Even better, as my labs do in my CCNA Study Guide, you can set up a frame relay cloud and a point-to-point Serial connection. This will help you get real hands-on practice with such features as EIGRP variance.
With that four-router configuration and one switch, you can get some great hands-on experience with many CCNA features that many candidates just read about. If you can add a second 2950 switch, you can practice different spanning-tree configurations, such as changing the root bridge of a given VLAN, working with VLAN Trunking Protocol (VTP), and configuring your own Etherchannel! (You will need some crossover cables to connect your two switches.)
Let's take a look at one more important piece of lab equipment: the ISDN simulator. You can't just take a straight-through cable and connect your BRI interfaces directly. You need a device called an ISDN simulator to act as the phone company in your home network. The newer simulators let you set your own phone numbers and SPIDs; most older ones have a preset phone number and SPID that you must use. Either way, you get truly valuable experience getting hands-on work with ISDN, especially watching PAP and CHAP debugs and understanding the authentication process.
ISDN simulators can set you back a few bucks. I recommend you visit www.ebay.com and search for ISDN simulator. There are generally 20 - 30 used ones on there at any given time. Be careful to purchase one with at least a 30-day guarantee. They are robust devices for the most part, as there is one in my home lab that I've had for three years (when they were really expensive!), and it's never given me a bit of trouble.
There are many online vendors that will sell you a new one, but obviously the price is going to be higher. One company I've had good experiences with is www.vconsole.com. Make sure to shop around, as there are plenty of ISDN simulator manufacturers out there on the web. Vconsole is the only one I've purchased a new unit from, and the 10-port simulator I use in my classes has worked beautifully.
There is another piece of lab equipment that isn't necessary for your lab, but you'll find life is a lot easier with it. And just as the frame relay switch is really a router, so is this device: the access server.
Access servers are devices with an asynchronous port that an octal cable can connect to. What you do is connect your blue console cable (officially referred to as a -rollover cable-�) to the console port of your access server. You then take an octal cable, and connect one end of the cable to your Async port. The other end of the cable, as you'd expect from the name, consists of eight smaller RJ-45 connectors. Each one of those goes into the console port of one of your other lab devices, and you configure the access server to allow one-key access to each of the other devices in your practice lab.
The configuration of the access server is a simple one, and I'll have an example of configuring your access server and frame relay switch up later today.
Not everyone can start with a lab this size, so be careful when you buy your first routers. Make sure that they're not just giving you good practice now, but that they allow for future growth of your lab. As you add a frame relay switch, an ISDN simulator, and an access server, you'll get the hands-on experience you need to be successful on the job, acquire the self-confidence and troubleshooting skills needed in the testing room and on the job, and to solve any simulator question on your CCNA and CCNP exams with ease.
Have fun!
| Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of over 100 free certification exam tutorials, including Cisco CCNA certification test prep articles. His exclusive Cisco CCNA study guide and Cisco CCNA training is also available! Visit his blog and sign up for Cisco Certification Central, a daily newsletter packed with CCNA, Network+, Security+, A+, and CCNP certification exam practice questions! A free 7-part course, "How To Pass The CCNA", is also available, and you can attend an in-person or online CCNA boot camp with The Bryant |
18:10 Permalink | Comments (0) | Email this | Tags: Cisco, Router, Certification