1. Email, VoIP and Wired and Wireless Networks
By Sam Heighes

2. Definitions
Store and forward is a telecommunications technique in which information is sent to an intermediate station where it is kept and sent at a later time to the final destination or to another intermediate station.
An address book or a name and address book (NAB) is a book or a database used for storing entries called contacts.
An attachment is a file that you want to include with your message. You can add many attachments to an message.
Carbon copy (Cc) – enter it here if the needs to be seen by this person but is not addressed to them.
Blind carbon copy (Bcc) – enter it here to prevent other recipients knowing you’ve sent it to this person.

3. Print screen of an email message

4. Advantages of s
It’s quick and easy to use. An typically arrives seconds after it’s sent.
Unlike letters, a single can be sent to multiple people at no extra cost.
s can have text, images, audio and video in them.
Files can be sent with an , as attachments.
s can be forwarded. This is when you send an you’ve received on to someone else.
All providers work together. Regardless of provider, if you have a person’s address you can send them an .
It doesn’t cost to send an . The costs are covered by your internet service provider (ISP) or by advertisements.

5. Disadvantages of email
Because it’s so quick, it’s easy to send an you might later regret, or to send one to the wrong person entirely.
s can be misunderstood. A rushed may be interpreted as rude by the recipient. Emoticons can help but are best avoided in formal or professional s.
overload - because it’s so easy to send an it’s possible to receive lots of s every day, sometimes far too many to deal with.
Spam and junk mail – s you haven’t asked for and don’t want. A good spam filter will stop most of these from reaching your inbox but sometimes mail that isn’t junk may slip into your junk mail unnoticed. It is always worth checking your junk mail if an you are expecting doesn’t arrive.
Attachments may contain viruses that can damage your computer.
There is no way of knowing if a recipient received an unless a read receipt is used. A read receipt is sent to the sender when the recipient opens the .
It’s rare to receive an instant response to an as they may be treated as less urgent than a phone call.

6. Simple Mail Transfer Protocol (SMTP)
Simple Mail Transfer Protocol (SMTP) is an Internet standard for electronic mail ( ) transmission. First defined by RFC 821 in 1982, it was last updated in with the Extended SMTP additions by RFC which is the protocol in widespread use today.
SMTP by default uses TCP port 25. The protocol for mail submission is the same, but using port 587, and SMTP connections secured by SSL, known as SMTPS, default to port 465.
While electronic mail servers and other mail transfer agents use SMTP to send and receive mail messages, user-level client mail applications typically use SMTP only for sending messages to a mail server for relaying. For receiving messages, client applications usually use either the POP3 or the IMAP.
While proprietary systems (such as Microsoft Exchange and Lotus Notes/Domino) and webmail systems (such as Hotmail, Gmail and Yahoo! Mail) use their own non-standard protocols to access mail box accounts on their own mail servers, all use SMTP when sending or receiving from outside their own systems.

7. Post Office Protocol
In computing, the Post Office Protocol (POP) is an application-layer Internet standard protocol used by local clients to retrieve e- mail from a remote server over a TCP/IP connection. POP has been developed through several versions, with version 3 (POP3) being the current standard.
Virtually all modern clients and servers support POP3, and it along with IMAP (Internet Message Access Protocol) are the two most prevalent Internet standard protocols for retrieval, with many webmail service providers such as Google Mail, Microsoft Mail and Yahoo! Mail also providing support for either IMAP or POP3 to allow mail to be downloaded.

8. Internet Message Protocol
The Internet Message Access Protocol (commonly known as IMAP) is an Application Layer Internet protocol that allows an client to access on a remote mail server. The current version, IMAP version 4 revision 1 (IMAP4rev1), is defined by RFC An IMAP server typically listens on well-known port 143. IMAP over SSL (IMAPS) is assigned well-known port number 993.
IMAP supports both on-line and off-line modes of operation. clients using IMAP generally leave messages on the server until the user explicitly deletes them. This and other characteristics of IMAP operation allow multiple clients to manage the same mailbox. Most clients support IMAP in addition to Post Office Protocol (POP) to retrieve messages; however, fewer services support IMAP.[1] IMAP offers access to the mail storage. Clients may store local copies of the messages, but these are considered to be a temporary cache.[2]
Incoming messages are sent to an server that stores messages in the recipient's box. The user retrieves the messages with an client that uses one of a number of retrieval protocols. Some clients and servers preferentially use vendor-specific, proprietary protocols, but most support SMTP for sending and POP and IMAP for retrieving , allowing interoperability with other servers and clients. For example, Microsoft's Outlook client uses MAPI, a Microsoft proprietary protocol to communicate with a Microsoft Exchange Server. IBM's Notes client works in a similar fashion when communicating with a Domino server. All of these products also support POP, IMAP, and outgoing SMTP. Support for the Internet standard protocols[citation needed] allows many clients such as Pegasus Mail or Mozilla Thunderbird to access these servers, and allows the clients to be used with other servers.

9. History of
Ray Tomlinson is credited with inventing in Like many of the Internet inventors, Tomlinson worked for Bolt Beranek and Newman as an ARPANET contractor. He picked symbol from the computer keyboard to denote sending messages from one computer to another. So then, for anyone using Internet standards, it was simply a matter of nominating Internet pioneer Jon Postel, who we will hear more of later, was one of the first users of the new system, and is credited with describing it as a "nice hack". It certainly was, and it has lasted to this day.

10. VoIP acronym VOIP Voice over Internet Protocol
VOIP Voice over Internet Packet
VOIP Video Over IP (Internet Protocol) Plugin (software)

11. Definition of VoIP
voice messaging technology: a technology that enables voice messages to be sent via the Internet, often simultaneously with data in text or other forms.

12. Software required of Codec
Codecs are utilities that are required to read a digital media file's streams. In order to properly stream a digital media file, a user's computer must be equipped with all the necessary codecs. For instance, it is possible that a digital media file cannot be streamed through a media player although its format is supported by the application. It is also possible that a user can stream a digital media file's audio, but not its video (or vice versa). When this occurs, users should analyze the digital media file with codec information software. In addition to indicating which codecs are required to stream a digital media file, codec information software can also be used to obtain the necessary utilities.

13. Internet Packets
VoIP endpoints usually have to wait for completion of transmission of previous packets, before new data may be sent. Although it is possible to pre-empt (abort) a less important packet in mid- transmission, this is not commonly done, especially on high-speed links where transmission times are short even for maximum-sized packets. An alternative to pre-emption on slower links, such as dialup and digital subscriber line (DSL), is to reduce the maximum transmission time by reducing the maximum transmission unit. But every packet must contain protocol headers, so this increases relative header overhead on every link traversed, not just the bottleneck (usually Internet access) link.

14. Hardware need for a VoIP call
Above all else, VoIP is basically a clever "reinvention of the wheel." In this article, we'll explore the principles behind VoIP, its applications and the potential of this emerging technology, which will more than likely one day replace the traditional phone system entirely.
The interesting thing about VoIP is that there is not just one way to place a call. There are three different "flavors" of VoIP service in common use today

15. Type
UTP/STP
Coaxial
Fibre Optic
Infrared
Microwave
Satellite (high frequency to 50 GHz range, radio signals)
Details
Maximum Data Transfer Rate
100 Mbps
14 Tera bits per second
115 Kbit/s
1 Gbit/s
Maximum Range
160km
120m
1cm
6,000km
Benefits
Quick
Cheap
Limitations
Expensive
Low Bandwidth
Example of how it is used
Telephone Exchange
Bluetooth

16. Advantages and Disadvantages of Wireless Network
Easily integrated into existing wired-Ethernet networks.
Access and accessibility improved.
Backwards compatible as standards improve.
Speed of installation.
Cost Savings.
Disadvantages of Wi-Fi.
Transmission speeds can fluctuate.
Conflict of ‘standards’.
Security

17. LAN and WAN
LAN- A local area network (LAN) is a computer network that user interconnects computers in a limited area such as a home, school, computer laboratory, or office building using network media.
WAN- A wide area network (WAN) is a network that covers a broad area (i.e., any telecommunications network that links across metropolitan, regional, or national boundaries) using private or public network transports.