Network protocols and standards
Task 2 (P2)
TCP/IP (Transmission Control Protocol/ Internet Protocol)
TCP/IP is several communication protocols used to connect
hosts on the internet. It uses several protocols, including TCP and IP. Web
browsers use TCP when they connect to servers on the internet. It is also used
to deliver email and transfer files to different locations.
AppleTalk
AppleTalk is a relatively cheap local-area network
architecture built into Apple Macintosh computers and laser printers. AppleTalk
supports Apple’s local talk cabling system, as well as Ethernet.it will connect
Mac computers and printers if they are all equipped with AppleTalk hardware and
software.[1]
UDP (User Datagram Protocol)
UDP is a transport layer protocol that uses the IP network
layer protocol. It provides a datagram service to an IP host. UDP is an
unreliable service that provides no guarantees for delivery and no security
from duplication.[2]
802.11
802.11 And 802.11x is a family of wireless technologies that
have been developed by the IEEE. 802.11 is an over the air (OTA) interface that
is between a wireless client e.g. a smartphone and a base station. It can also
be used between two wireless clients. E.g. an iPhone can be tethered with an
iPad to provide Wi-Fi between the two. There are quite a few different
specifications in the 802.11 family.
802.11 applies to
wireless Local Access Networks and will provide a 1-2 mbps speed the 2.4GHz
frequency.
802.11a is an
extension to 802.11 that applies to wireless Local Access Networks and provides
up to 54-Mbps on the 5GHz frequency.
802.11b is an
extension that can provide 11Mbps speeds on the 2.4GHz frequency.
802.11g applies
to wireless LANs and used for wireless data transmission over short distances
at up 54 Mbps in the 2.4GHz frequency.
802.11n is a
wireless technology that can include multiple-input multiple-output (MIMO). The
second transmitter and receiver antennas allow increased data through increased
range. The real speed of this is 100Mbit/s.
802.11ac can
deliver data speeds of up to 433Mbps per spatial stream or 1.3Gbps in a three
antenna design. This operates on the 5GHz frequency.
Infrared
Infrared in mobile phones uses infrared waves to send data
from one mobile phone to another. Infrared works to different to other wireless
sending media because both phones have to be in very close proximity and in
line of each other. Both sensors must be facing each other in order for the
infrared to work.
3G
3G is an abbreviation of third generation of mobile
telecommunications technology. 3G is based on a set of standards used for
mobile devices and mobile telecommunications that comply with the International
Mobile Telecommunications-2000 specification by the International
Telecommunication Union. 3G is used for a wide range of services, such as
telephony, mobile internet access, fixed wireless internet access, video chats
and mobile TV.
3G can provide mobile data at a transfer rate of at least
200kbit/s.
4G
4G is short for fourth generation of mobile communications
technology. It is a faster and more adapted version of 3G. 4G provides
ultra-broadband internet access as well as the normal voice and SMS services.
4G users can often get speeds beyond 100Mbps which can support high quality
video streaming. There were pre-4G technologies available by network operators
but it would often fall short of 100Mbps
802.2
802.2 divides the data link between sub layers in the OSI
model. It defines Logical Link Control, which is the upper portion of the OSI
model. The 802.2 sub layer adds some control information to the message that
has been created by the upper layer.
802.3
802.3 is the standard which Ethernet operates by. It is the
standard for CSMA/CD. CSMA/CD is what Ethernet uses to control access to the
network cable. The original 802.3 standard is 10Mbps.
FDDI
FDDI is a set of ANSI protocols for sending data over fibre
optic cabling. FDDI networks are token passing networks and support data rates
of up to 100 Mbps. FDDI networks are commonly used with WANs
802.5
The token is a frame that is designed to travel to each node
around the ring. When it doesn’t have any data attached to it, a node on the
network can modify the frame. Each node on the network checks the token as it
passes through to see if the data is connected to that node.
Bluetooth
Bluetooth is a wireless technology for exchanging data over
a short distance. The Bluetooth chip is mainly used in computers, mobile
devices and digital cameras. Bluetooth uses a special radio frequency to
transmit data. It is very secure and can connect up to eight devices at any one
time.
Factors affecting range and speed of wireless technologies
Electronic Interference
Wireless networks commonly use the 2.4GHz frequency wave to
send and receive data. When there are other nearby devices such as mobiles and
tablets emit this frequency, they will interfere with the networks signal. Once
the interference stops the network returns to optimal speeds.
Physical Obstacles
Physical obstacles can cause interference for wireless
signals. When the data is being sent through the signals through large
obstacles, degradation occurs because the object absorbs the signals and
scatters it. Thicker objects such as thick walls absorb a larger portion of the
signals.
Bandwidth Use
Network traffic can affect the performance of other devices
attached to the network. Bandwidth determines the maximum data rate that can be
transferred over a network.
Domain Name System (DNS)
A DNS protocol maps text names to IP addresses
automatically. Before DNS was created, computers used simple text file
maintained by the network information centre that mapped names to IP addresses.
By having DNS, when searching for webpages all you would have to remember is www.apple.com instead of an IP address like
216.27.22.162.
Dynamic Host Configuration Protocol (DHCP)
A DHCP protocol assigns dynamic IP addressed to devices on a
network. With dynamic addressing, a device can have a different IP address
every time it connects to the network.
HyperText Transfer Protocol (HTTP)
HTTP is the underlying used by the World Wide Web. It
defines how messages are formatted and transmitted and what actions web
browsers should take in response to various commands. E.g. when you enter a
websites URL into your web browser, this sends a HTTP command to the web server
directing it to fetch the web page.
File Transfer Protocol (FTP)
The FTP protocol exchanges files over the internet. It works
in the same way as HTTP. FTP uses the internet’s TCP/IP protocols to enable
data transfer.
Simple Mail Transfer Protocol (SMTP)
SMTP is a protocol for sending e-mail messages between web
servers. A lot of e-mail systems that send mail over the internet use SMTP to
send messages from one server to another. These messages can then be retrieved
by using an e-mail client that supports either POP or IMAP.
Post Office Protocol (POP)
The POP protocol is used to retrieve e-mail from a mail
server. On most e-mail applications, you can use POP to retrieve e-mails or
IMAP. POP3 can be used to send messages to another mail server without the use
of SMTP.