Summary: TCP and IP were developed by a Department of Defense (DOD) research project to connect a number different networks designed by different vendors into a network of networks (the “Internet”). It was initially successful because it delivered a few basic services that everyone needs (file transfer, electronic mail, remote logon) across a very large number of client and server systems. Several computers in a small department can use TCP/IP (along with other protocols) on a single LAN. The IP component provides routing from the department to the enterprise network, then to regional networks, and finally to the global Internet. On the battlefield a communications network will sustain damage, so the DOD designed TCP/IP to be robust and automatically recover from any node or phone line failure. This design allows the construction of very large networks with less central management. However, because of the automatic recovery, network problems can go undiagnosed and uncorrected for long periods of time.

As with all other communications protocol, TCP/IP is composed of layers:

• IP – is responsible for moving packet of data from node to node. IP forwards each packet based on a four byte destination address (the IP number). The Internet authorities assign ranges of numbers to different organizations. The organizations assign groups of their numbers to departments. IP operates on gateway machines that move data from department to organization to region and then around the world.
  
• TCP – is responsible for verifying the correct delivery of data from client to server. Data can be lost in the intermediate network. TCP adds support to detect errors or lost data and to trigger retransmission until the data is correctly and completely received.
  
• Sockets – is a name given to the package of subroutines that provide access to TCP/IP on most systems.

Network of Lowest Bidders

The Army puts out a bid on a computer and DEC wins the bid. The Air Force puts out a bid and IBM wins. The Navy bid is won by Unisys. Then the President decides to invade Grenada and the armed forces discover that their computers cannot talk to each other. The DOD must build a “network” out of systems each of which, by law, was delivered by the lowest bidder on a single contract.

The Internet Protocol was developed to create a Network of Networks (the “Internet”). Individual machines are first connected to a LAN (Ethernet or Token Ring). TCP/IP shares the LAN with other uses (a Novell file server, Windows for Workgroups peer systems). One device provides the TCP/IP connection between the LAN and the rest of the world.

To insure that all types of systems from all vendors can communicate, TCP/IP is absolutely standardized on the LAN. However, larger networks based on long distances and phone lines are more volatile. In the US, many large corporations would wish to reuse large internal networks based on IBMs SNA. In Europe, the national phone companies traditionally standardize on X.25. However, the sudden explosion of high speed microprocessors, fiber optics, and digital phone systems has created a burst of new options: ISDN, frame relay, FDDI, Asynchronous Transfer Mode (ATM). New technologies arise and become obsolete within a few years. With cable TV and phone companies competing to build the National Information Superhighway, no single standard can govern citywide, nationwide, or worldwide communications.

The original design of TCP/IP as a Network of Networks fits nicely within the current technological uncertainty. TCP/IP data can be sent across a LAN, or it can be carried within an internal corporate SNA network, or it can piggyback on the cable TV service. Furthermore, machines connected to any of these networks can communicate to any other network through gateways supplied by the network vendor.

Addresses

Each technology has its own convention for transmitting messages between two machines within the same network. On a LAN, messages are sent between machines by supplying the six byte unique identifier (the “MAC” address). In an SNA network, every machine has Logical Units with their own network address. DECNET, Appletalk, and Novell IPX all have a scheme for assigning numbers to each local network and to each workstation attached to the network.

On top of these local or vendor specific network addresses, TCP/IP assigns a unique number to every workstation in the world. This “IP number” is a four byte value that, by convention, is expressed by converting each byte into a decimal number (0 to 255) and separating the bytes with a period. For example, the PC Lube and Tune server is 130.132.59.234.

An organization begins by sending electronic mail to Hostmaster@INTERNIC.NET requesting assignment of a network number. It is still possible for almost anyone to get assignment of a number for a small “Class C” network in which the first three bytes identify the network and the last byte identifies the individual computer. The author followed this procedure and was assigned the numbers 192.35.91.* for a network of computers at his house. Larger organizations can get a “Class B” network where the first two bytes identify the network and the last two bytes identify each of up to 64 thousand individual workstations. Yales Class B network is 130.132, so all computers with IP address 130.132.*.* are connected through Yale.

The organization then connects to the Internet through one of a dozen regional or specialized network suppliers. The network vendor is given the subscriber network number and adds it to the routing configuration in its own machines and those of the other major network suppliers.

There is no mathematical formula that translates the numbers 192.35.91 or 130.132 into “Yale University” or “New Haven, CT.” The machines that manage large regional networks or the central Internet routers managed by the National Science Foundation can only locate these networks by looking each network number up in a table. There are potentially thousands of Class B networks, and millions of Class C networks, but computer memory costs are low, so the tables are reasonable. Customers that connect to the Internet, even customers as large as IBM, do not need to maintain any information on other networks. They send all external data to the regional carrier to which they subscribe, and the regional carrier maintains the tables and does the appropriate routing.

New Haven is in a border state, split 50-50 between the Yankees and the Red Sox. In this spirit, Yale recently switched its connection from the Middle Atlantic regional network to the New England carrier. When the switch occurred, tables in the other regional areas and in the national spine had to be updated, so that traffic for 130.132 was routed through Boston instead of New Jersey. The large network carriers handle the paperwork and can perform such a switch given sufficient notice. During a conversion period, the university was connected to both networks so that messages could arrive through either path.

Subnets

Although the individual subscribers do not need to tabulate network numbers or provide explicit routing, it is convenient for most Class B networks to be internally managed as a much smaller and simpler version of the larger network organizations. It is common to subdivide the two bytes available for internal assignment into a one byte department number and a one byte workstation ID.

The enterprise network is built using commercially available TCP/IP router boxes. Each router has small tables with 255 entries to translate the one byte department number into selection of a destination Ethernet connected to one of the routers. Messages to the PC Lube and Tune server (130.132.59.234) are sent through the national and New England regional networks based on the 130.132 part of the number. Arriving at Yale, the 59 department ID selects an Ethernet connector in the C& IS building. The 234 selects a particular workstation on that LAN. The Yale network must be updated as new Ethernets and departments are added, but it is not effected by changes outside the university or the movement of machines within the department.

A Uncertain Path

Every time a message arrives at an IP router, it makes an individual decision about where to send it next. There is concept of a session with a preselected path for all traffic. Consider a company with facilities in New York, Los Angeles, Chicago and Atlanta. It could build a network from four phone lines forming a loop (NY to Chicago to LA to Atlanta to NY). A message arriving at the NY router could go to LA via either Chicago or Atlanta. The reply could come back the other way.

How does the router make a decision between routes? There is no correct answer. Traffic could be routed by the “clockwise” algorithm (go NY to Atlanta, LA to Chicago). The routers could alternate, sending one message to Atlanta and the next to Chicago. More sophisticated routing measures traffic patterns and sends data through the least busy link.

If one phone line in this network breaks down, traffic can still reach its destination through a roundabout path. After losing the NY to Chicago line, data can be sent NY to Atlanta to LA to Chicago. This provides continued service though with degraded performance. This kind of recovery is the primary design feature of IP. The loss of the line is immediately detected by the routers in NY and Chicago, but somehow this information must be sent to the other nodes. Otherwise, LA could continue to send NY messages through Chicago, where they arrive at a “dead end.” Each network adopts some Router Protocol which periodically updates the routing tables throughout the network with information about changes in route status.

If the size of the network grows, then the complexity of the routing updates will increase as will the cost of transmitting them. Building a single network that covers the entire US would be unreasonably complicated. Fortunately, the Internet is designed as a Network of Networks. This means that loops and redundancy are built into each regional carrier. The regional network handles its own problems and reroutes messages internally. Its Router Protocol updates the tables in its own routers, but no routing updates need to propagate from a regional carrier to the NSF spine or to the other regions (unless, of course, a subscriber switches permanently from one region to another).

Undiagnosed Problems

IBM designs its SNA networks to be centrally managed. If any error occurs, it is reported to the network authorities. By design, any error is a problem that should be corrected or repaired. IP networks, however, were designed to be robust. In battlefield conditions, the loss of a node or line is a normal circumstance. Casualties can be sorted out later on, but the network must stay up. So IP networks are robust. They automatically (and silently) reconfigure themselves when something goes wrong. If there is enough redundancy built into the system, then communication is maintained.

In 1975 when SNA was designed, such redundancy would be prohibitively expensive, or it might have been argued that only the Defense Department could afford it. Today, however, simple routers cost no more than a PC. However, the TCP/IP design that, “Errors are normal and can be largely ignored,” produces problems of its own.

Data traffic is frequently organized around “hubs,” much like airline traffic. One could imagine an IP router in Atlanta routing messages for smaller cities throughout the Southeast. The problem is that data arrives without a reservation. Airline companies experience the problem around major events, like the Super Bowl. Just before the game, everyone wants to fly into the city. After the game, everyone wants to fly out. Imbalance occurs on the network when something new gets advertised. Adam Curry announced the server at “mtv.com” and his regional carrier was swamped with traffic the next day. The problem is that messages come in from the entire world over high speed lines, but they go out to mtv.com over what was then a slow speed phone line.

Occasionally a snow storm cancels flights and airports fill up with stranded passengers. Many go off to hotels in town. When data arrives at a congested router, there is no place to send the overflow. Excess packets are simply discarded. It becomes the responsibility of the sender to retry the data a few seconds later and to persist until it finally gets through. This recovery is provided by the TCP component of the Internet protocol.

TCP was designed to recover from node or line failures where the network propagates routing table changes to all router nodes. Since the update takes some time, TCP is slow to initiate recovery. The TCP algorithms are not tuned to optimally handle packet loss due to traffic congestion. Instead, the traditional Internet response to traffic problems has been to increase the speed of lines and equipment in order to say ahead of growth in demand.

TCP treats the data as a stream of bytes. It logically assigns a sequence number to each byte. The TCP packet has a header that says, in effect, “This packet starts with byte 379642 and contains 200 bytes of data.” The receiver can detect missing or incorrectly sequenced packets. TCP acknowledges data that has been received and retransmits data that has been lost. The TCP design means that error recovery is done end-to-end between the Client and Server machine. There is no formal standard for tracking problems in the middle of the network, though each network has adopted some ad hoc tools.

If you live in Gmail, but don’t always have a broadband connection available, today should be a happy day for you. Google is rolling out a new system for letting Gmail users access their accounts offline. Google will cache your messages on your system using Google Gears. You’ll be able to open your browser to Gmail.com, see your inbox, read and label messages and even write replies without a Net connection. Your messages will send once your system reconnects to the Web.

The system is beta (of course) and accessible through Gmail Labs. But it won’t be immediately available to everyone – Google is parsing out access as it experiments with the new feature. I don’t have access to the new feature yet, so I’ve still got lots of questions. But Google’s post makes it sound like the experience will be almost indistinguishable from using Gmail normally.

“Gmail uses Gears to download a local cache of your mail. As long as youre connected to the network, that cache is synchronized with Gmails servers. When you lose your connection, Gmail automatically switches to offline mode, and uses the data stored on your computers hard drive instead of the information sent across the network. You can read messages, star and label them, and do all of the things youre used to doing while reading your webmail online. Any messages you send while offline will be placed in your outbox and automatically sent the next time Gmail detects a connection,” Gmail Engineer Andy Palay wrote.

There will also be a “flaky connection mode” that’s supposed to give you the best of both worlds. It’ll assume that you’re disconnected and use the local cache to store your data, but whenever your connection is working, it’ll sync with Google’s servers in the background.

This all sounds pretty good, but here are my questions:

How much will Gmail cache?

How extensively can you search?

Will you work the same way in Gmail whether you’re offline or online?

Is Gears up to the challenge? Google launched this system for creating offline access to Web apps nearly two years ago. For a long time, the only apps that used it were Google Reader and to do list Remember the Milk — an indication that developing for and implementing Gears wasn’t quite as simple as Google would have you believe. In fact, bringing Gmail offline was an obvious use of Gears that has taken 21 months to come to fruition.

(Google also says its readying an offline version of Google Calendar, also presumably using Gears, though the company didnt specifically say that. Offline Calendar will initially be available only for users of Google Apps Standard Edition and theres no firm release date.)

Is Gears ready now? We’ll see soon. I’ll check back in once I get a chance to play with Gmail offline. And let me know what questions you have. I’ll do my best to answer them. In the meantime, you can watch this relatively lame video from your friends at Google.

SysTweak also has a system optimization software specifically designed for optimizing Windows Vista. With Advanced Vista Optimizer, you can personalize your Vista experience by customizing appearance and tweaking the system for the best possible performance. For optimal Vista operation, consider Advanced Vista Optimizer by SysTweak. 

With the latest update of its virtual exploration app, Google now lets virtual tourists dive into the ocean, zoom over to Mars, and even travel back in time. The company unveiled Google Earth 5.0 at a recent launch event, which included appearances by Jimmy Buffet and former VP Al Gore, who presented some chilling climate-change imagery that really showed off the ever-growing power of Googles great tool.

Google Earth still lags behind Microsofts LiveSearch Maps when it comes to local search capabilities. I had no problem searching for exact locations with Google Earth, but LiveSearch Maps did a better job of finding locations by keywords, such as a persons name, business, or landmark. I also think that LiveSearchs Virtual Earth 3D provides better 3D renderings of cities than Google Earths comparable 3D Buildings layer. However, Google Earth provides far deeper, richer environments to explore. Its just more fun to use, and the latest version of Googles offering only propels it further ahead of the competition.

Google Earth maps both the ocean surface and the seafloor. Navigation works in much the same way as it does when youre exploring on land, but when you zoom close enough on a body of water youre hovering over, you dip under the surface. At that point, you see a topographical view of the underwater terrain. I found that the interesting areas to explore underwater tended to be coastal areas. In the deeper ocean, I often found myself staring into an endless expanse of blue water. For a really exciting test dive, zoom over to the deepest point in the ocean, the Mariana Trench. You can find the trench off the coast of Guam. If you have the Borders and Labels layer checked, you see the entire length of the trench surrounded by a white border. Or you can simply plug in its latitude and longitude coordinates (11.35,142.2) into Google Earths Fly to field.

Note that your computer needs a fairly robust graphics system to take full advantage of the ocean view. I had no trouble when I used a desktop from the PCMag.com Labs with an ATI Radeon x300 graphics card. But my underwater excursion didnt go as well—and sometimes not at all—when I was piloting the older machine in my cube or my three-year-old MacBook at home.

Google Earth 5.0 offers 21 new layers dedicated to ocean exploration. So, for example, click on Explore the Ocean and you can view articles, images, and video for specific regions. The National Geographics layer lets you put your knowledge to the test by taking a geography quiz. Other layers include Jacques Cousteau, which takes you on a video tour of areas the famous explorer covered, and the cool Animal Tracking, which combines Google Earths ocean exploration with a new touring feature. The amalgam lets you swim along with tagged, satellite-tracked sea animals on their underwater journey. Clicking on an icon of a great white shark off the coast of California let me view the predators movements from its watery perspective as it cruised the Pacific.

The touring feature lets you record and narrate your actions in Google Earth, then save them as a KML file so that you can share your multimedia journey with others. Recording a tour is simple: Click on a small camera icon on the top toolbar, and youll get a control bar from which you can record (as well as play and, of course, stop playing or recording).

DSL (Digital Subscriber Line) is a high-speed Internet service that competes with cable Internet to provide online access to local customers. DSL operates over standard copper telephone lines like dial-up service, but is many times faster than dial-up. In addition to being faster than dial-up, DSL does not tie up the phone line, coexisting with telephone service so that one can surf the Net and use the phone at the same time.

DSL service requires a DSL modem, which connects to the telephone wall jack and computer. The device acts as a modulator, translating the computer’s digital signals into voltage sent across the telephone lines to a central hub known as a Digital Subscriber Line Access Multiplier (DSLAM, or dee-slam). In lay terms the DSLAM acts as a switchboard for local DSL clients, routing requests and responses between each client’s computer address and the Internet.

Voice calls and DSL can coexist on copper lines because each service utilizes its own frequency band. You might think of bands like lanes of a freeway. Voice signals are sent in a relatively low band, while Internet signals occupy a much higher band. To keep the voice band clear of bleeding signal noise, a small filter is commonly installed on all telephone lines in the house, blocking the higher frequencies.

The DSL “service lane” is split for two-way traffic, or downstream and upstream signals. When you click on a link, you are requesting something from the Internet, initiating upstream traffic. The returned webpage arrives as downstream traffic. Since requests only require small bits of data, the upstream lane can be fairly narrow (low bandwidth), but the downstream lane must be much wider (high bandwidth) to send webpages, multimedia, graphics, files and programs. Thus, standard DSL is called Asynchronous DSL or ADSL, because the download speed is much faster than the upload speed.

Businesses, however, might require sending large files, data and programs between non-local networked offices, in which case a different flavor of DSL might be preferred. Synchronous DSL or SDSL offers the same high speed for both downloading and uploading. Hard core geeks might also like SDSL for exchanging files, games and other multimedia. The drawback is that it is more expensive than standard DSL.

With today’s ubiquitous use of cell phone service, millions of people have foregone landline service all together. In this case a service known as “naked DSL” might be offered in your area, which provides DSL service without telephone service.

In many areas, fiber optic cable service (FiOS) is replacing standard telephone lines. FiOS provides much greater bandwidth than copper lines with the ability to offer true high-speed Internet that is many times faster than DSL or standard cable service. Though availability differs between regions, FiOS services typically offer bundled options for television, digital telephone and Internet.

Among the various DSL packages, plans are based on speed, with slower speeds costing less than plans that offer higher speeds. Bottom-tier DSL might be as little as $12 US Dollars (USD) per month, and is still many times faster than dial-up. Mid-range plans might run closer to $20 USD, and $30 USD can typically buy top tier plans. Your distance to the nearest DSLAM will determine in large part the actual speeds you achieve. The closer to the DSLAM the better, as signal degrades with distance causing latency issues. If you are at the outskirts of the service area, you might not see the full speed of your subscribed plan.

A DSL modem is commonly included with service as a “leased” item to be returned at the end of the contract, but this is typically a standard modem without router or wireless capability. If you desire wirelessly sharing your Internet connection with another computer in the home or office, you’ll likely require an upgrade. In some cases, the cost of this upgrade in the DSL contract is equal to buying a wireless router with built-in modem yourself. Read the fine print; if you’ll have to return the device at the end of the contract period, you might want to opt to supply your own equipment.

---

Search engine placement or top ranking or internet marketing is most easily understood as getting your web site to come up high in search engine listings for key phrases relative to your product or business. We have proven examples that show web traffic before and after our search engine placements and the results are incredible. Search engine placement efforts have increased traffic on some of our clients web sites by 20 times! An industry statistic is that 46% of your traffic will come from search engines.
Does Search Engine Marketing, top ranking Really Work?
The simple answer is YES, but the best results are obtained from web sites that were designed with search engine placement, top ranking in mind.  Unfortunately most web site developers pay little, or no attention to how a search engine would index the web site. Even worse, is that some web site layouts prevent the search engines from indexing the site at all.  Certain elements must be written into the HTML code of a web page that range from the meta tags within the page header, right down to the way the text is written into the page. We say “page” instead of “site” because search engines index web “pages” not web sites. Most of the time we consult with our client to re-write the text within their pages, and we do the rest. We dont trick the search engines, we simply make your web pages relevant to what your potential clients would look for. And YES it really works! 

• According to a Forrester Research Media Field Study, getting a loyal audience in the first place is best done by Search Engine Placement. 
• According to a GVU Users Survey, 84.8% of Internet users use Search Engines to find Web sites. 

Top Ways Websites are Discovered 

• Banner ads: 1%
• Targetted email: 1.2%
• TV spots: 1.4%
• “by accident”: 2.1%
• Magazine ads: 4.4%
• Word-of-mouth: 20%
• Random Surfing: 20%

Search Engine: 46%

Search Engine placement, top ranking is very much alive and kicking. But lets take this a step further. Lets see the quality of prospects coming to your website through search engines as opposed to other advertising mediums. 
Every time your potential customers use the search engines, they qualify themselves as hot prospects by conducting searches on keywords that are directly related to your product or service. Their choice of keyword is proof that they have a genuine interest in what you offer. These people spend their valuable time exploring the search engines for your type of product or willing to do business with you. At the very least, theyre seriously considering it! 
But merely getting your Website “indexed” or listed in the search engines is not enough. In order to get any significant traffic from the search engines, your Website must be within the top 30 search results (preferably the top 20). Very rarely will anyone look beyond the first 30 results returned from a search. This makes perfect since because the most relevant sites are always listed at the top. So if your prospect doesnt find what they want within the first 20 to 30 listings, theyll simply do a new search. 

Microsoft has dropped two strong hints in the past two days that the next version of its Windows operating system will arrive in 2009, shaving up to a year off previous expectations. It could also be a signal that Microsoft intends to cut its losses with Windows Vista, which has been poorly received or shunned by customers, especially large companies.

Microsoft has long said it wants to release Windows 7 (formerly known as Windows Vienna) about three years after Vista, which was released to manufacturing in November 2006 but not officially launched until January 2007. Given Microsofts recent track record – Vista arrived more than five years after XP — most outsiders had pegged sometime in 2010 as a safe bet for Windows 7s arrival.

Microsoft Chairman Bill Gates answered a question at a business meeting in Miami about Windows Vista by saying “Sometime in the next year or so we will have a new version.”

And during its announcement yesterday that it would extend the availability of Windows XP Home for low-cost laptops, Microsoft said it would retire the operating system only after June 30, 2010, or one year after the release of Windows 7, whichever comes later.

The Symptoms you get

When you launch MSN Messenger and try to logon, you get error message 80048820.  A wild guess, your system time, or system date needs adjusting.

Possible Cause of Code 80048820

There are a variety of causes of this error:

1) Incorrect Proxy Setting for Internet Explorer.

2) softpub.dll may have become unregistered.

3) Your system clock may be showing an incorrect time -  or date! (Wrong time is the most likely cause of 80048820).

4) Firewall problems. Particularly with Netgear.

After I posted about on “How to get SmartBRO Canopy IP Address” some people asked on how they can increase their Smartbro speed connection (smartbro is only available in the Philippines). Well here is a guide on how you can increase your internet browsing speed.

This guide worked for me when Im still a Smartbro subscriber (I switch now to PLDT MyDSL) and this settings also worked on some of my friends who uses Smartbro.

I posted this guide to help you increase your browsing speed but I cant give you the assurance that this guide will work for you but 90% of the people that uses this proxy settings worked for them and have seen the difference.

For Internet Explorer:

► Go to Tools
► Options
► Connections
► Lan settings
► Use Proxy Server

For Mozilla FireFox:

► Go to Tools
► Option
► Advance
► Network
► Settings
► Use Manual Proxy Configuration

For Address, use any of the following:

proxy.meridian.ph
proxy.smartwifi.com.ph
proxy.smartbro.net

or

203.84.191.215
121.1.3.194
121.1.3.200

for all the address use the port 8080

Note: This Proxy is for SmartBro Users Only.