Apple to launch its TV by 2012

Apple to launch its TV by 2012
Apple Inc. is planning to launch its another high profile product and this time its Television.I am going to give you information on Apple TV update. After capturing the Tablet, Computer and Smartphone market ,Apple is now planning to enter the living rooms of the common people with Apple- TV. Apple TV is going to be a slim and thin designed and user friendly in its functioning. Apple is going to launch its TV latest by 2012 according to the sources.

An Apple spokeperson said in an article in The Wall Street Journel :"Apple is working on new technology to deliever video to televisions, and is being discussing whether to launch a TV service"

Apple has been rumored long to be working on a Television, but this time it looks there dream to be come true as they have teamed up with major OEM to sell iOS powered, Apple branded display. Earlier Google was also teamed up with Sony to release its television products but sooner their project gone in vain. But Google is also to be introduce its television series in Europe by 2012.

Its going to be interesting to watch who is going to win a fight when two major firms i.e Apple & Google , when both enters in the world of "Television".For more info on Apple TV updates keep visiting this site.

Integrated Services Digital Network

Integrated Services Digital Network

Integrated Services Digital Network is a system with digitized phone connections, which has pure analog connection. It is the first protocol which describes on a digital communications line. This allows transmission of data, voice, video and graphics at very high speeds over standard communication lines carried by bearer channels (B channels) occupying a bandwidth of 64 kbits per second. A data channel (D channel) handles signaling at 16 kb/s or 64 kb/s depending on the service type. It is not limited to public telephone networks alone. It may be transmitted via networks like telex, packet switched networks, CATV networks, etc.

There are two types of services corresponding with ISDN:
1) Basic Rate Interface Service.
2) Primary Rate Interface Service.

ISDN Basic Rate Interface Service

The ISDN Basic Rate Interface (BRI) service provides two B channels and one D channel. BRI B-channel service works at 64 kbps is used to carry user data. BRI D-channel service works at 16 kbps is used to carry control and signaling information although it also supports user data transmission under certain circumstances. The D-channel signaling protocol contains Layers 1 to 3 of the OSI reference model. International Telecommunication Union-Telecommunications Standards Section (ITU-T) defines the BRI physical layer specification.

ISDN Primary Rate Interface Service

ISDN Primary Rate Interface (PRI) service provides 23 B channels and 1 D channel yielding a total bit rate of 1.544 Mbps. ISDN PRI in different country like Europe, Australia, and other parts of the world provides 30 B channels plus one 64-kbps D channel and a total interface rate up to 2.048 Mbps. ITU-T I.431 defines PRI physical layer specification.

Different services may be called by using different values in the "Bearer Capability" field in the call setup message. One ISDN service is telephony, which can be obtained using full 64 kbps bandwidth but will require the some special processing or bit diddling as ordinary Public service Telephone Network calls.
ISDN Specifications
This section describes the various ISDN specifications for Layer 1, Layer 2, and Layer 3.
Layer 1
ISDN physical layer (Layer 1) frame formats depends upon whether the frame is outbound (from terminal to network) or inbound (from network to terminal). The frames are 48 bits long from which data is represented by 36 bits. The bits of an ISDN frame are used as follows:
1) F: it provides synchronization.
2) L: it adjusts the average bit value
3) E: it ensures contention resolution when several terminals on a passive bus contend for a channel
4) A: it activates devices.
5) S: it is unassigned bit.
6) B1, B2 and D: it handles user data
Multiple ISDN devices can be attached physically to one circuit. In this configuration, collisions occur when two terminals transmit simultaneously. Therefore, ISDN avoids collision by using link contention.

Terminals cannot transmit data to the D channel unless they first detect a specific number of ones corresponding to pre-established priority. If TE detects a bit in the echo channel that is different from D bits then it stop transmitting immediately without wasting time. This technique guarantees that at a time only one terminal can transmit its D message. After successful D-message transmission, the terminal reduces its priority. Terminals cannot increase their priority until all other devices on the same line have had an opportunity to send a D message. Telephone connections have highest priority than all other devices.

Layer 2
ISDN Layer 2 is signaling protocol called Link Access Procedure D channel (LAPD). LAPD is just like High-Level Data Link Control (HDLC) and Link Access Procedure Balanced (LAPB). As the development of the LAPD acronym indicates, this layer is used across the D channel to check control and signaling information flows. The LAPD frame format is as of HDLC. Like HDLC, LAPD makes use of information, supervisory and unnumbered frames.

Layer 3
ISDN Layer 3 is used for ISDN signaling: ITU-T I.450 and ITU-T I.451. Both these protocols carry end-to-end, circuit-switched and packet-switched connections. A variety of call-establishment, call-termination, information, and miscellaneous messages are described by using SETUP, CONNECT, RELEASE, USER INFORMATION, CANCEL, STATUS, and DISCONNECT. These messages provide same functionality as that of X.25 protocol.

ISDN Channels
ISDN provide three logical digital communication channels which perform the following functions:

B-Channel: it carries user service information including digital data, video, and voice.
D-Channel: it carries signals and data packets between the user and the network.
H-Channel: it performs the same function as B-Channels, but operates at rates exceeding 64 Kbps.

How to Set Up a Server

How to Set Up a Server

Before starting off with solving the query 'how to set up a server', we should know, what is a computer server? The basic purpose of a computer server can be made out from its name. A server is meant to serve the different users in the network. All the resources that the users need to access, are stored in the server and all the users can directly access those resources, without storing anything in their own systems. It is also used for providing security to the system. For example, putting a firewall to the server, to provide facilities like anti spamming and protection against phishing, secures the entire network from the same. With these aspects of the importance of the server in mind, let us try to understand, how to set up a server based network.

Servers are nothing but computers with high configurations. They have large memory capacities and high processor speeds, to handle the request of all the computers connected in the network. Let us try to deal with the set up of different servers, one by one.

How to Set Up a Web Server?
First of all, try to get all the basic requirements of a web server. A web server should have a high speed Internet connection and a large bandwidth. The next important requirement is that you need to choose the right operating system for your server. Linux and Unix are the most appreciated operating systems for a computer server machine. FreeBSD, an open source, Unix based operating system is one of the best options, that you can install in your computer server. The next step after installing the operating system in the web server, is installing an http server. Apache is one of the Hyper Text Transfer Protocol (HTTP) servers, that normally come along with the Free BSD operating system. However, you will need to install it. You can run the Apache server using the 'http' command. But, before doing so, you will have to configure the 'httpd.conf' file in your operating system. Here, you mention the settings for your http server, as well as the name of the website you are going to run. In most of the machines, you will find the 'httpd.conf' file located in the '/usr/local/etc/apache22/'. Now type the IP address of the machine at the web browser. Type http, followed by the IP address. If you can access the web pages stored in your system, that means you have successfully installed the web server and the http server.

How to Set Up a DNS Server?
The next step is to set up a DNS server. DNS is the abbreviation of Domain Name Server. You can learn a few domain name server (DNS) basics first. A domain name server is one that will convert the web address name into the IP address of the machine where the web pages are stored. Suppose if you type the url of buzzle on your machine, your web server will check if the entry of buzzle is there in its database tables, where the web address and the IP addresses of the machines are stored. If it is there, then it will transfer the web address to a web server with a larger database. So much for the importance and working of a DNS server. Now, let's get down to the installation of a DNS server. You will find the file 'namedb.conf' file in the '/etc/namedb' folder in your machine with Free BSD operating system installed. Once, you open the file, make the necessary changes. The file can be easily understood, provided you have some expertise in Unix and Linux based operating systems. All that you need to do is enter the name of the website in that file.

How to Set Up an FTP Server?
For uploading files into your computer server, what you will need is an FTP server. FTP stands for File Transfer Protocol. FTP can be used in any network that uses TCP/IP model. You can get a lot of FTP servers, if you browse over the Internet. For example, File Zilla software can be used for setting up an FTP server on any machine running on Windows. In FreeBSD you will find FTP servers, with the names, 'ftpd' or 'in.ftpd' in the '/sbin' or '/usr/sbin' directory. It is a single executable file. Once, it is installed, the FTP server will allow all the users added into your systems, to upload, download and access files. These users have to simply type in their user names and passwords on the remote machines.

How to Set Up a File Server?
Setting up a file server in FreeBSD is not a very tedious task. You just need to download the Samba server setup. Setting up a file server in your network will allow the machines with Windows operating system logged into your network, to access the resources on the server. You need to install samba in the '/usr/ports/net/samba' folder. You can use the command make install to install it, once you are in that folder. Then you will have to make the necessary changes in the configuration files in the '/usr/local/etc/smb.conf' file. For initializing samba at the boot time, you just need to change the line 'samba_enable:=NO' to 'samba_enable:=YES' in the file 'rc.conf' located in the '/etc' folder.

By following the simple procedures mentioned above, you can simply learn how to set up a server network. However, it is better that before dealing with the configuration files, you ask a person with expertise in Linux, to proceed with modifying the files.

Commonly Used Ports

Commonly Used Ports

What are TCP and UDP Ports?
Protocol is a set of instructions that are to be followed. Likewise, there are certain instructions that are to be followed in communication of data over internet. These set of instructions are called protocols used in the internet services. Basically, there are two types of protocols used over the internet, viz., TCP and UDP. TCP stands for transmission control protocol and UDP stands for user datagram protocol. Now, you must be wondering, why are these protocols required in simple communication over the Internet! The answer to this question is that the communication must be safe, quick and reliable. In TCP, the data transfer from one computer to another is done directly. To be more precise, the two devices intended to start a conversation connect to each other and start transferring data. These two computers or devices remain connected throughout the period of transfer and get disconnected after the transfer of data is completed. On the other hand in UDP, the data is converted into data packets and are sent over the internet. There is no direct connection between the two devices intended to communicate. The UDP transfer of data does not guarantee a reliable transfer of data. The communication in UDP is slower as compared to the TCP.

Every computer and device on the internet has its own IP address. This IP address is unique to every computer and device. When some information is sent on the internet, the IP address acts as an address of each of the device. The data is sent with the IP address of the receiver device or computer and the data is accepted with the help of TCP or UDP ports. When information is sent over the internet, the IP address and the port of the receiver device are the additional information sent. These ports are called TCP/IP ports. There are certain commonly used ports over the internet. The IANA (Internet Assigned Numbers Authority) has registered all the TCP/IP port numbers. To know more about the TCP/IP port numbers, read TCP/IP ports table explained. Here we are going to discuss some of the commonly used computer networking ports. Read more on TCP/IP model.

Commonly Used Port Numbers
Here is a commonly used ports list, which includes all the commonly used ports for transferring information over the internet.

Keywords     Protocols Used     Port Number     Description
tcpmux     TCP, UDP     1     TCP port service multiplexer
echo     TCP, UDP     7     Echo
discard     TCP, UDP     9     Discard
msp     TCP, UDP     18     Message Send Protocol
ftp     TCP, UDP     21     File transfer protocol
ssh     TCP, UDP     22     Remote login protocol
telnet     TCP, UDP     23     Telnet
smtp     TCP, UDP     25     Simple Mail Transfer Protocol
domian     TCP, UDP     53     Domain Name Sever (read more on domain name server basics)
www     TCP, UDP     80     World Wide Web or also known as HTTP
rtelnet     TCP, UDP     107     Remote Telnet Services
pop 2     TCP, UDP     109     Post Office Protocol 2
pop 3     TCP, UDP     110     Post Office Protocol 3
sftp     TCP, UDP     115     Simple File Transfer Protocol
snmp     TCP, UDP     161     Simple Network Management Protocol
bgp     TCP, UDP     179     Border Gateway Protocol