Wednesday, November 24, 2010
WiMAX
WiMAX is an emerging wireless broadband technology whose download speeds are approximately 10 mbit/s. It is expected to be within the 40 mbit/s range by next year. There is currently only one major WiMAX provider due to the fact that it must be run on it own network: it cannot utilize GSM or CDMA networks as EDGE and EVDO do. However there are plans for widespread WiMax commercial deployment by 2010, and will be marketed as a significantly advanced wireless alternative to Cable and DSL internet services.
Evolution-Data Optimized
EVDO (Evolution-Data Optimized) is significantly faster than EDGE. It transmits data via radio signals, and for this reason is classified as a wireless broadband technology. It is employed in mobile devices around the world via CDMA (Code Division Multiple Access) networks: cellular networks that achieve high data transmission speeds and support a vast number of users
Enhanced Data rates for GSM Evolution)
EDGE (Enhanced Data rates for GSM Evolution) was introduced into the North American via GSM (Global Systems Mobile) networks in 2003 and is now available worldwide. EDGE increases data transmission rates and improves transmission reliability in mobile devices that use it. More importantly, it allows the mobile device to connect to the Internet wirelessly, but its download speed is significantly slower than other mobile wireless technologies. EDGE transmits data at approximately 236.8 kbit/s, which is below the standard for a broadband connection. However, its theoretical maximum speed is 473.6 kbit/s, so it still considered a wireless broadband technology.
Wireless Broadband Mobile
Wireless internet connectivity in cell phones is growing in popularity as well. Cell phones, and other devices featuring windows mobile applications, are now all being designed with advanced wireless technology. This allows them the ability to connect to a wireless broadband internet service, or to the internet via their own cellular phone network. EDGE and EVDO are two of the more popular next-generation mobile system technologies utilized by cellular phone developers.
Wireless Broadband Service
Wireless broadband internet service is growing in popularity for locations outside the home or office as well. When considering broadband, another term you may recognize is wireless internet service. Although often used interchangeably with wireless network, the two do not mean the same thing. Wireless broadband internet service generally refers to a package deal that combines both the wireless technology and broadband service, and to which you can subscribe to. It differs from the wireless network in two ways:
1) it includes both technology and service, whereas having a wireless network necessitates your having to buy both
2) it is generally used in larger locations outside the home or office, such as the downtown area of a city or a college campus.
1) it includes both technology and service, whereas having a wireless network necessitates your having to buy both
2) it is generally used in larger locations outside the home or office, such as the downtown area of a city or a college campus.
Wireless Broadband Network
A term you may recognize in association with wireless broadband internet service includes wireless network. A wireless network is a single broadband internet arrangement established for your home or office. It requires several pieces of equipment that are all one-time cost items: a wireless transceiver, such as a wireless card or antenna, and a wireless router. In addition, you will have to purchase the broadband service, which is a continual expense. You cannot utilize your wireless broadband tools without an ongoing broadband service. Together, the wireless devices and the broadband internet service make up your wireless broadband networ
Latest Development In Broadband
The latest development in broadband internet service is the incorporation of wireless capabilities. Wireless broadband internet service is exactly what the name implies: it is your high speed internet access without cables or wires. The versatility of wireless internet, and its potential for increasing productivity by users, has consumers demanding the service at an increasing rate. They want it in their home, at their office, even at their local coffee shop or bistro. Hence the development of wireless broadband internet service: it is a packaged internet service deal that provides the ability to access the internet wirelessly from any location within the service's coverage area.
What is Wireless Internet Service?
Broadband internet service is a form of high speed internet access. In fact, the name "broadband" has come to be synonymous with high speed internet use in general. Since speed is measured by bit rate, the number of bits processed per unit of time, broadband internet service is defined as being 256 kbit/s (kilobits per second) or faster. Broadband typically downloads at a much faster speed than that, however. As a result, broadband internet service is categorized into two different connection groups: Tier 1 (T1) broadband connections range from 1.544 Mbit/s to 2.048 Mbit/s, and Tier 3 (T3) broadband connections range from 44.736 Mbit/s to 159.2 Gbit/s. With these rates of data transmission, broadband represents an evolution from the original high speed internet service, Integrated Services Digital Network (ISDN), and is by far a significant improvement upon the original internet service, dial-up.
Satellite
The last and slowest broadband service is provided by satellite. Although this is a good replacement for dial-up for those people living in remote rural areas, the installation costs are quite high, but the ongoing monthly charges are competitive to both cable and DSL.
There are many advantages to the DSL and cable broadband service. It provides greater bandwidth than other Internet access forms, and that makes it easier for the computer user to multitask with several applications performing in the background while you surf the web. It is possible for you to surf the web while listening to audio.
The networking of computers in the home is made easier with a broadband connection, by either using wireless or wired modems.
The cost of broadband service is higher annually than the cheaper dial-up version by $100 to $500, but given the advantages and ease of a broadband connection, it is well worth the cost.
A broadband connection allows you to play many popular computer games that rely on a fast Internet connection.
Broadband connection, unlike the old dial-up internet connection, will not engage your phone line when in use. In fact, having a broadband connection makes it possible for you to obtain an Internet phone service so you will no longer need the traditional phone line at all.
Another great benefit of a broadband connection is that you are constantly connected to the Internet. You are quickly able to connect with your work's intranet and email in a matter of seconds.
Many people considering between these broadband Internet service options generally narrow the search to the most popular services which are DSL and cable. A good approach when researching your options would be to ask those in the area you are considering, which service they are using and how it is working for them.
Even though cable broadband Internet service offers a speedy internet connection, this fast speed will not be realized if the connection itself cannot be relied on. For example, the cable connection you receive depends on the shared bandwidth, the number of users on the system at any time, and the latency on the network.
The bandwidth is just one factor that determines the Internet connection's speed. It is a measure of the quantity of data that enters the network over a period of time, and is measured in bps, or bits per second. The greater the data flow, the better the network Internet connection. In broadband connections the supported data rates are generally 300 Kbps and higher, as opposed to the old dial-up maximum of 53Kbps.
Latency is another factor that affects the cable Internet connection's speed. Latency refers to delays incurred in the network data processing. A network is described as low latency if it experiences only small delay times, and high latency if it suffers with long delays. When the latency becomes excessive, data transmission causes a bottleneck that prevents addition data from coming through and this effectively reduces cable's Internet connection bandwidth. So even though the cable bandwidth of your Internet connection is set, its effectiveness can be reduced by bottlenecks of data and a high number of users on the system .
There are many advantages to the DSL and cable broadband service. It provides greater bandwidth than other Internet access forms, and that makes it easier for the computer user to multitask with several applications performing in the background while you surf the web. It is possible for you to surf the web while listening to audio.
The networking of computers in the home is made easier with a broadband connection, by either using wireless or wired modems.
The cost of broadband service is higher annually than the cheaper dial-up version by $100 to $500, but given the advantages and ease of a broadband connection, it is well worth the cost.
A broadband connection allows you to play many popular computer games that rely on a fast Internet connection.
Broadband connection, unlike the old dial-up internet connection, will not engage your phone line when in use. In fact, having a broadband connection makes it possible for you to obtain an Internet phone service so you will no longer need the traditional phone line at all.
Another great benefit of a broadband connection is that you are constantly connected to the Internet. You are quickly able to connect with your work's intranet and email in a matter of seconds.
Many people considering between these broadband Internet service options generally narrow the search to the most popular services which are DSL and cable. A good approach when researching your options would be to ask those in the area you are considering, which service they are using and how it is working for them.
Even though cable broadband Internet service offers a speedy internet connection, this fast speed will not be realized if the connection itself cannot be relied on. For example, the cable connection you receive depends on the shared bandwidth, the number of users on the system at any time, and the latency on the network.
The bandwidth is just one factor that determines the Internet connection's speed. It is a measure of the quantity of data that enters the network over a period of time, and is measured in bps, or bits per second. The greater the data flow, the better the network Internet connection. In broadband connections the supported data rates are generally 300 Kbps and higher, as opposed to the old dial-up maximum of 53Kbps.
Latency is another factor that affects the cable Internet connection's speed. Latency refers to delays incurred in the network data processing. A network is described as low latency if it experiences only small delay times, and high latency if it suffers with long delays. When the latency becomes excessive, data transmission causes a bottleneck that prevents addition data from coming through and this effectively reduces cable's Internet connection bandwidth. So even though the cable bandwidth of your Internet connection is set, its effectiveness can be reduced by bottlenecks of data and a high number of users on the system .
Fiber-Optic
The newest broadband service is fiber-optic, which is the fastest Internet connection thus far. However, this type of Internet service is still in its infancy as its service areas are quite limited and because the laying down of the fiber-optic cable takes a while to complete. Wherever it is available, the cost not only competes with that of DSL and cable, but it provides a much faster connection than both of those services.
Cable
The broadband cable connection is provided by the local cable TV provider. Here the cable Internet connection speed varies with the number of users on the service at a specific point in time. Given a specific geographical area, users of the broadband cable service share the connection bandwidth which slows the speed the more users are on the system. This will occur at the peak times for example late in the evenings after the work day is over when many people will be accessing the Internet. Somewhat misleadingly, often the cable company would estimate connection speeds that are based on the thinking that you are using the service. But that is clearly not the case.
DSL
The DSL (or Digital Subscriber Line) internet service makes its connection by utilizing unused telephone wires that cause no interruption to your telephone service. The speed you experience with a DSL connection varies with your distance from the switching station. Your speed will be slower the further away you are and faster the closer you are to the switching station and this may be a deciding factor when you attempt to select between a DSL line and a cable connection.
What is Broadband?
Broadband Internet service truly is the most used form of Internet access because of its high access speeds; it is offered in four different forms, DSL (or Digital Subscriber Line), also fiber-optic, cable, and satellite. The old dial-up connection is the only non-broadband internet service available, and even though it is cheaper, most Internet users are moving towards the faster broadband Internet connection.
Internet Speed Test
Check the speed of your dialup, cable, DSL, or wireless internet by using our flash Internet Speed Test. Upload speed, download speed, and ping latency are all checked. Just click the "Begin Test" button below. Once the test is complete your results will be listed below the test.
SPEED TEST FROM HERE
SPEED TEST FROM HERE
Headers Provide Routing Information
Besides the most common identifications (from, to, date, subject), email headers also provide information on the route an email takes as it is transferred from one computer to another. As mentioned earlier, mail transfer agents (MTA) facilitate email transfers. When an email is sent from one computer to another it travels through a MTA. Each time an email is sent or forwarded by the MTA, it is stamped with a date, time and recipient. This is why some emails, if they have had several destinations, may have several RECEIVED headers: there have been multiple recipients since the origination of the email. In a way it is much like the same way the post office would route a letter: every time the letter passes through a post office on its route, or if it is forwarded on, it will receive a stamp. In this case the stamp is an email header.
When viewed in their entirety, these multiple recipient headers will look like this in an email:
Received: from tom.bath.dc.uk ([138.38.32.21] ident=yalrla9a1j69szla2ydr)
by steve.wrath.dc.uk with esmtp (Exim 3.36 #2)id 19OjC3-00064B-00
for example_to@imaps.bath.dc.uk; Sat, 07 Jun 2005 20:17:35 +0100
Received: from write.example.com ([205.206.231.26])
by tom.wrath.dc.uk with esmtp id 19OjBy-0001lb-3V
for example_to@bath.ac.uk; Sat, 07 Jun 2005 20:17:30 +0100
Received: from master.example.com (lists.example.com [205.206.231.19])
by write.example.com (Postfix) with QMQP
id F11418F2C1; Sat, 7 Jun 2005 12:34:34 -0600 (MDT)
In the example shown above, there are three Received: stamps. Reading from the bottom upwards, you can see who sent the message first, next and last, and you can see when it was done. This is because every MTA that processed the email message added a Received: line to the email's header. These Received: lines provide information on where the message originated and what stops it made (what computers) before reaching its final destination. As the example shows, these Received: lines provide the email and IP address of each sender and recipient. They also provide the date and time of each transfer. The lines also indicate if the email address was part of an email list. It is all this information that is valued by computer programmers and IT department associates when making efforts to track and stop SPAM email message. And it is this information that arguable makes headers the most important part of an email.
When viewed in their entirety, these multiple recipient headers will look like this in an email:
Received: from tom.bath.dc.uk ([138.38.32.21] ident=yalrla9a1j69szla2ydr)
by steve.wrath.dc.uk with esmtp (Exim 3.36 #2)id 19OjC3-00064B-00
for example_to@imaps.bath.dc.uk; Sat, 07 Jun 2005 20:17:35 +0100
Received: from write.example.com ([205.206.231.26])
by tom.wrath.dc.uk with esmtp id 19OjBy-0001lb-3V
for example_to@bath.ac.uk; Sat, 07 Jun 2005 20:17:30 +0100
Received: from master.example.com (lists.example.com [205.206.231.19])
by write.example.com (Postfix) with QMQP
id F11418F2C1; Sat, 7 Jun 2005 12:34:34 -0600 (MDT)
In the example shown above, there are three Received: stamps. Reading from the bottom upwards, you can see who sent the message first, next and last, and you can see when it was done. This is because every MTA that processed the email message added a Received: line to the email's header. These Received: lines provide information on where the message originated and what stops it made (what computers) before reaching its final destination. As the example shows, these Received: lines provide the email and IP address of each sender and recipient. They also provide the date and time of each transfer. The lines also indicate if the email address was part of an email list. It is all this information that is valued by computer programmers and IT department associates when making efforts to track and stop SPAM email message. And it is this information that arguable makes headers the most important part of an email.
Header Characteristics
A single email header has some important characteristics, including perhaps the most important part of an email - this is the KEY:VALUE pairs contained in the header. Looking at the above, you can tell some of the KEY:VALUE pairs used. Here is a breakdown of the most commonly used and viewed headers, and their values:
From: sender's name and email address (IP address here also, but hidden)
To: recipient's name and email address
Date: sent date/time of the email
Subject: whatever text the sender entered in the Subject heading before sending
From: sender's name and email address (IP address here also, but hidden)
To: recipient's name and email address
Date: sent date/time of the email
Subject: whatever text the sender entered in the Subject heading before sending
Header
In an e-mail, the body (content text) is always preceded by header lines that identify particular routing information of the message, including the sender, recipient, date and subject. Some headers are mandatory, such as the FROM, TO and DATE headers. Others are optional, but very commonly used, such as SUBJECT and CC. Other headers include the sending time stamps and the receiving time stamps of all mail transfer agents that have received and sent the message. In other words, any time a message is transferred from one user to another (i.e. when it is sent or forwarded), the message is date/time stamped by a mail transfer agent (MTA) - a computer program or software agent that facilitates the transfer of email message from one computer to another. This date/time stamp, like FROM, TO, and SUBJECT, becomes one of the many headers that precede the body of an email.
To really understand what an email header is, you must see one. Here is an example of a full email header*:
Return-Path:
X-SpamCatcher-Score: 1 [X]
Received: from [136.167.40.119] (HELO dc.edu)
by fe3.dc.edu (CommuniGate Pro SMTP 4.1.8)
with ESMTP-TLS id 61258719 for example_to@mail.dc.edu; Mon, 23 Aug 2004 11:40:10 -0400
Message-ID: <4129F3CA.2020509@dc.edu>
Date: Mon, 23 Aug 2005 11:40:36 -0400
From: Taylor Evans
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.0.1) Gecko/20020823 Netscape/7.0
X-Accept-Language: en-us, en
MIME-Version: 1.0
To: Jon Smith
Subject: Business Development Meeting
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
* email headers should always be read from bottom to top.
Fortunately, most of this information is hidden inside the email with only the most relevant or mandatory headers appearing to the user. Those headers that we most often see and recognize are bolded in the above example.
To really understand what an email header is, you must see one. Here is an example of a full email header*:
Return-Path:
X-SpamCatcher-Score: 1 [X]
Received: from [136.167.40.119] (HELO dc.edu)
by fe3.dc.edu (CommuniGate Pro SMTP 4.1.8)
with ESMTP-TLS id 61258719 for example_to@mail.dc.edu; Mon, 23 Aug 2004 11:40:10 -0400
Message-ID: <4129F3CA.2020509@dc.edu>
Date: Mon, 23 Aug 2005 11:40:36 -0400
From: Taylor Evans
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.0.1) Gecko/20020823 Netscape/7.0
X-Accept-Language: en-us, en
MIME-Version: 1.0
To: Jon Smith
Subject: Business Development Meeting
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
* email headers should always be read from bottom to top.
Fortunately, most of this information is hidden inside the email with only the most relevant or mandatory headers appearing to the user. Those headers that we most often see and recognize are bolded in the above example.
Trace Email Address Source
This tool attempts to locate the source IP address of an email based on the email headers (Where did the email come from). Just copy and paste the full headers of the email you've received into the box below and press submit. When the page reloads scroll down to the bottom for the email header analysis and results. We're in the process of compiling a set of instructions to obtain email headers from a variety of popular webmail services and email applications. In the mean time if you have questions please post them in the Email Tracing Forum.
CAUTION: This E-Mail header analysis tool assumes all mail servers and clients in the transmission path are trustworthy. It does not attempt to detect forged e-mail headers. Forged headers are common in spam and other malicious e-mail, therefore this tool cannot be relied upon to accurately identify the source of such messages.
CAUTION: This E-Mail header analysis tool assumes all mail servers and clients in the transmission path are trustworthy. It does not attempt to detect forged e-mail headers. Forged headers are common in spam and other malicious e-mail, therefore this tool cannot be relied upon to accurately identify the source of such messages.
What is an IP address?
Every device connected to the public Internet is assigned a unique number known as an Internet Protocol (IP) address. IP addresses consist of four numbers separated by periods (also called a 'dotted-quad') and look something like 127.0.0.1.
Since these numbers are usually assigned to internet service providers within region-based blocks, an IP address can often be used to identify the region or country from which a computer is connecting to the Internet. An IP address can sometimes be used to show the user's general location.
Because the numbers may be tedious to deal with, an IP address may also be assigned to a Host name, which is sometimes easier to remember. Hostnames may be looked up to find IP addresses, and vice-versa. At one time ISPs issued one IP address to each user. These are called static IP addresses. Because there is a limited number of IP addresses and with increased usage of the internet ISPs now issue IP addresses in a dynamic fashion out of a pool of IP addresses (Using DHCP). These are referred to as dynamic IP addresses. This also limits the ability of the user to host websites, mail servers, ftp servers, etc. In addition to users connecting to the internet, with virtual hosting, a single machine can act like multiple machines (with multiple domain names and IP addresses).
Since these numbers are usually assigned to internet service providers within region-based blocks, an IP address can often be used to identify the region or country from which a computer is connecting to the Internet. An IP address can sometimes be used to show the user's general location.
Because the numbers may be tedious to deal with, an IP address may also be assigned to a Host name, which is sometimes easier to remember. Hostnames may be looked up to find IP addresses, and vice-versa. At one time ISPs issued one IP address to each user. These are called static IP addresses. Because there is a limited number of IP addresses and with increased usage of the internet ISPs now issue IP addresses in a dynamic fashion out of a pool of IP addresses (Using DHCP). These are referred to as dynamic IP addresses. This also limits the ability of the user to host websites, mail servers, ftp servers, etc. In addition to users connecting to the internet, with virtual hosting, a single machine can act like multiple machines (with multiple domain names and IP addresses).
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