data-communication-module-4-final.pdf

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Data Communication Module 4 Final
Data Comm. & Networking I! (Negros Oriental State University)
Studocu is not sponsored or endorsed by any college or university
Data Communication Module 4 Final
Data Comm. & Networking I! (Negros Oriental State University)
Downloaded by Delia Penoringan (dpenoringan@mohtiwpampanga.ph.education)
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D A T A
&
II.
III. Fiber Distributed Data Interface and
GigaBit Ethernet
Module 4
Fiber Distributed Data Interface and
Gigabit Ethernet
Introduction
Ethernet is a way of connecting computers together in a local area network
or LAN. It has been the most widely used method of linking computers
together in LANs since the 1990s. The basic idea of its design is that
multiple computers have access to it and can send data at any time. This
is comparatively easy to engineer.
COURSE LEARNING OUTCOMES
At the end the module, the students are expected to introduce the concepts
of Data Communication and networking:
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CONTENTS OF THE MODULE
This module contains the following lessons:
Lesson 1 : Fiber Distributed Data Interface
Lesson 2 : Gigabit Ethernet
DIRECTIONS ON HOW TO USE THE MODULE PROPERLY
In order to benefit profoundly from this module, please be guided by all
the key points presented below.
1. This module contains two (2) lessons. Each lesson is explained
substantively.
Read the explanations thoroughly so that you could understand the lesson
fully.
2. Please use Microsoft Word Long Size for the answer and convert to
PDF. If you want to send your documents online, just send it to our Google
classroom account
Section B: class code: sa5aesv
E-mail: angelieaal1911@gmail.com
3. Feel free to chat, call, text or send an email message to me if you
have questions, reaction, reflections about the content or activities in the
module.
4. The deadline for the submission for this will be posted to our group
chat or google classroom.
LESSON 1
FIBER DISTRIBUTED DATA INTERFACE
Specific Learning Outcomes
At the end of this lesson, you should be able to:
● Understand the uses of FDDI
● Differentiate between different types of FDDI Architecture
● Signify the importance of Architecture of networking
ACTIVATING
Picture Interpretation Activity
Online Collaborative Work Activity
In no more than 3 sentences, give your interpretation in the picture below.
Your interpretation must consider the following questions:
Open your collaborative docs uploaded in the google classroom and
answer the questions online.
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1. What is the central message of
this picture?
Discussion
FDDI is an American National
Standards Institute (ANSI)
standard that defines a dual
Token Ring LAN operating at 100 Mbps over an optical fiber medium. It
is used primarily for corporate and carrier backbones.
Token Ring and FDDI share several characteristics including token passing
and a ring architecture which were explored in the previous section on
Token Ring. Copper Distributed Data Interface (CDDI) is the
implementation of FDDI protocols over STP and UTP cabling. CDDI
transmits over relatively short distances (about 100 meters), providing data
rates of 100 Mbps using a dual-ring architecture to provide redundancy.
While FDDI is fast, reliable, and handles a lot of data well, its major
problem is the use of expensive fiber-optic cable. CDDI addresses this
problem by using UTP or STP. However, notice that the maximum segment
length drops significantly.
FDDI was developed in the mid-1980s to fill the needs of growing high-
speed engineering workstation capacity and network reliability. Today,
FDDI is frequently used as a high-speed backbone technology because of
its support for high bandwidth and greater distances than copper.
FDDI Network Architecture FDDI uses a dual-ring architecture. Traffic on
each ring flows in opposite directions (called counter-rotating). The dual-
rings consist of a primary and a secondary ring. During normal operation,
the primary ring is used for data transmissions, and the secondary ring
remains idle. The primary purpose of the dual rings is to provide superior
reliability and robustness. One of the unique characteristics of FDDI is that
multiple ways exist to connect devices to the ring. FDDI defines three types
of devices: single-attachment station (SAS) such as PCs, dual attachment
station (DAS) such as routers and servers, and a concentrator.
– Dual-ring architecture
– Primary ring for data transmissions
– Secondary ring for reliability and robustness
Components
– Single attachment station (SAS)—PCs
– Dual attachment station (DAS)—Servers
– Concentrator
– FDDI concentrator
– Also called a dual-attached concentrator (DAC)
– Building block of an FDDI network
– Attaches directly to both rings and ensures that any SAS failure or power-down does
not bring down the ring
Summary – LAN technologies include Ethernet, Token Ring, and FDDI
Ethernet Most widely used Good balance between speed, cost, and ease of
installation 10 Mbps to 1000 Mbps Token Ring Primarily used with IBM
networks 4 Mbps to 16 Mbps FDDI Primarily used for corporate backbones
Supports longer distances 100 Mbps.
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Reference
Source: https://e-tutes.com/lesson4/fiber-distributed-data-interface-fddi/
https://www.lifewire.com/definition-of-gigabit-ethernet-816338
Learning Activities / Exercises
1. Explain FDDI Network Architecture
FDDI is an American National Standards Institute (ANSI) standard that
defines a dual Token Ring LAN operating at 100 Mbps over an optical
fiber medium. It is used primarily for corporate and carrier backbones.
Token Ring and FDDI share several characteristics including token
passing and a ring architecture which were explored in the previous section
on Token Ring. Copper Distributed Data Interface (CDDI) is the
implementation of FDDI protocols over STP and UTP cabling. CDDI
transmits over relatively short distances (about 100 meters), providing data
rates of 100 Mbps using a dual-ring architecture to provide
redundancy. While FDDI is fast, reliable, and handles a lot of data well,
its major problem is the use of expensive fiber-optic cable. CDDI
addresses this problem by using UTP or STP. However, notice that the
maximum segment length drops significantly.
FDDI uses a dual-ring architecture. Traffic on each ring flows in
opposite directions (called counter-rotating). The dual-rings consist of a
primary and a secondary ring. During normal operation, the primary ring
is used for data transmissions, and the secondary ring remains idle. The
primary purpose of the dual rings is to provide superior reliability and
robustness.
An FDDI concentrator (also called a dual-attachment concentrator
[DAC]) is the building block of an FDDI network. It attaches directly to
both the primary and secondary rings and ensures that the failure or power-
down of any single attachment station (SAS) does not bring down the ring.
This is particularly useful when PCs, or similar devices that are frequently
powered on and off, connect to the ring.
Source: https://e-tutes.com/lesson4/fiber-distributed-data-interface-fddi/
Fiber Distributed Data Interface (FDDI) is a set of ANSI and ISO
standards for transmission of data in local area network (LAN) over fiber
optic cables. It is applicable in large LANs that can extend up to 200
kilometers in diameter.
2. Explain Fiber Distributed Data Interface (FDDI) and Copper
Distributed Data Interface (CDDI) uses
FDDI Network Architecture FDDI uses a dual-ring architecture.
Traffic on each ring flows in opposite directions (called counter-
rotating). The dual-rings consist of a primary and a secondary ring.
During normal operation, the primary ring is used for data
transmissions, and the secondary ring remains idle. The primary
purpose of the dual rings is to provide superior reliability and
robustness. One of the unique characteristics of FDDI is that multiple
ways exist to connect devices to the ring. FDDI defines three types of
devices: single-attachment station (SAS) such as PCs, dual attachment
station (DAS) such as routers and servers, and a concentrator.
FDDI uses optical fiber as the primary transmission medium, but
it also can run over copper cabling. As mentioned earlier, FDDI over
copper is referred to as Copper-Distributed Data Interface (CDDI).
Optical fiber has several advantages over copper media. In particular,
security, reliability, and performance all are enhanced with optical fiber
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media because fiber does not emit electrical signals. A physical medium
that does emit electrical signals (copper) can be tapped and therefore
would permit unauthorized access to the data that is transiting the
medium. In addition, fiber is immune to electrical interference from
radio frequency interference (RFI) and electromagnetic interference
(EMI). Fiber historically has supported much higher bandwidth
(throughput potential) than copper, although recent technological
advances have made copper capable of transmitting at 100 Mbps.
Finally, FDDI allows two kilometers between stations using multi-
mode fiber, and even longer distances using a single mode.
Copper Distributed Data Interface (CDDI) is the implementation
of FDDI protocols over STP and UTP cabling. CDDI transmits over
relatively short distances (about 100 meters), providing data rates of
100 Mbps using a dual-ring architecture to provide redundancy.
Short for Copper Distributed Data Interface, CDDI is officially
called TP-PMD (Twisted-Pair Physical Medium Dependent) and is a data
transmission standard. CDDI uses either STP or UTP copper wire and
based on FDDI (Fiber Distributed Data Interface) which uses fiber optic
lines instead of copper wires.
Copper data distribution interface (CDDI) is an implementation of
fiber distributed data interface (FDDI) networking. CDDI supports
distances of about 100 meters from desktop to concentrator. CDDI is
defined by the ANSI X3T9.5 Committee. The CDDI standard is officially
named the Twisted-Pair Physical Medium Dependent (TP-PMD) standard.
It is also referred to as the Twisted-Pair Distributed Data Interface (TP-
DDI), consistent with the term Fiber-Distributed Data Interface (FDDI).
CDDI is consistent with the physical and media-access control layers
defined by the ANSI standard.
CDDI uses cabling, which is unshielded twisted pair cables (UTP)
made of copper. CDDI also uses the same protocols and constructs as
FDDI, but uses copper wire as the medium.
3. FDDI is an Example of which topology?
Yes, FDDI’s primary fault-tolerant feature is the dual ring. If a station on
the dual ring fails or is powered down, or if the cable is damaged, the dual
ring is automatically wrapped (doubled back onto itself) into a single ring.
When the ring is wrapped, the dual-ring topology becomes a single-ring
topology. Data continues to be transmitted on the FDDI ring without
performance impact during the wrap condition.
Fiber Distributed Data Interface (FDDI) is usually implemented as a dual
token-passing ring within a ring topology (for campus networks) or star
topology (within a building). The dual ring consists of a primary and
secondary ring. The primary ring carries data. The counter-rotating
secondary ring can carry data in the opposite direction, but is more
commonly reserved as a backup in case the primary ring goes down. This
provides FDDI with the degree of fault tolerance necessary for network
backbones. In the event of a failure on the primary ring, FDDI
automatically reconfigures itself to use the secondary ring as shown in the
illustration. Faults can be located and repaired using a fault isolation
technique called beaconing. However, the secondary ring can also be
configured for carrying data, extending the maximum potential bandwidth
to 200 Mbps.
Fiber Distributed Data Interface (FDDI) is a set of ANSI and ISO
standards for transmission of data in local area network (LAN) over fiber
optic cables. It is applicable in large LANs that can extend up to 200
kilometers in diameter.
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4. What are the main Characteristics of the FDDI?
FDDI share several characteristics including token passing and a ring
architecture which were explored in the previous section on Token Ring.
One of the unique characteristics of FDDI is that multiple ways exist to
connect devices to the ring. FDDI defines three types of devices: single-
attachment station (SAS) such as PCs, dual attachment station (DAS) such
as routers and servers, and a concentrator.
An analysis is made of the impact of various design decisions on the
error detection capability of the fiber distributed data interface (FDDI), a
100-Mb/s fiber-optic LAN standard being developed by the American
National Standards Institute (ANSI). In particular, the frame error rate,
token loss rate, and undetected error rate are quantified. Several
characteristics of the 32-b frame check sequence (FCS) polynomial, which
is also used in IEEE 802 LAN protocols, are discussed. The standard uses
a nonreturn to zero invert on ones (NRZI) signal encoding and a 4-b to 5-
b (4b/5b) symbol encoding in the physical layer. Due to the combination
of NRZI and 4b/5b encoding, many noise events are detected by code (or
symbol) violations. A large percentage of errors are detected by FCS
violations. The errors that escape these three violations remain undetected.
The probability of undetected errors due to creation of false starting
delimiters, false ending delimiters, or merging of two frames is analyzed.
It is shown that every noise event results in two code bit errors, which in
turn may result in up to four data bit errors. The FCS can detect up to two
noise events. Creation of a false starting delimiter or ending delimiter on a
symbol boundary also requires two noise events. This assumes enhanced
frame validity criteria. The author justifies the enhancements by
quantifying their effect. < >
5. What are the limitations that prevent the growth of FDDI?
CDDI transmits over relatively short distances (about 100 meters),
providing data rates of 100 Mbps using a dual-ring architecture to provide
redundancy. While FDDI is fast, reliable, and handles a lot of data well,
its major problem is the use of expensive fiber-optic cable. CDDI
addresses this problem by using UTP or STP. However, notice that the
maximum segment length drops significantly.
FDDI uses a dual-ring architecture. Traffic on each ring flows in opposite
directions (called counter-rotating). The dual-rings consist of a primary
and a secondary ring. During normal operation, the primary ring is used
for data transmissions, and the secondary ring remains idle. The primary
purpose of the dual rings is to provide superior reliability and robustness.
Assignment # 8:
1. Why is the fiber Channel spelled as “Fibre”?
There is no difference in meaning between fiber and fibre. Fiber is the
preferred spelling in American English, and fibre is preferred in all the
other main varieties of English.
Both spellings are many centuries old, and neither spelling was clearly
prevalent on either side of the Atlantic until the second half of the 18th
century. This was a period in which many British educators began to
consider it proper for English words of French and Latin origin to take their
more French and Latin forms rather than their more Anglicized
forms. Fibre is the French spelling of the word from which the English
word is derived, so it was promoted as the standard spelling despite its
being unphonetic. The belief that French and Latin should hold sway over
English never had much traction in the post-independence United States,
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and while Americans also favored the French spelling through the 19th
century, the more phonetic fiber steadily gained ground through that
century until becoming the preferred form around 1910.
LESSON 2
GIGABIT ETHERNET
Specific Learning Outcomes
At the end of this lesson, you should be able to:
● Understand the how Ethernet work
● Differentiate the different connection type
● Signify the importance of Ethernet
What Is Gigabit Ethernet?
Gigabit Ethernet is part of the Ethernet family of computer networking
and communication standards. The Gigabit Ethernet standard supports
a theoretical maximum data rate of one gigabit per second (1,000
Mbps).
How Does Gigabit Ethernet Work?
It was once believed that achieving gigabit speeds with Ethernet would
require the use of fiber optic cables or other special network cable
technology. Fortunately, those are only necessary for long distances.
For most purposes, Gigabit Ethernet works well using a regular
Ethernet cable (specifically, the CAT5e and CAT6 cabling standards).
These cable types follow the 1000BASE-T cabling standard (also called
IEEE 802.3ab).
How Fast Is Gigabit Ethernet in Practice?
Because of factors like network protocol overhead and re-transmissions
due to collisions or other transient failures, devices cannot actually transfer
useful message data at the full 1 Gbps rate. Under normal conditions, the
effective data transfer might reach 900 Mbps, but the average connection
speed varies based on many factors.
For example, disk drives can limit the performance of a Gigabit Ethernet
connection on PCs. There's also the factor of bandwidth limiting the
connection. Even if a whole home network can get download speeds of 1
Gbps, two simultaneous connections immediately halve the available
bandwidth for both devices. The same is true for any number of concurrent
devices.
Some home routers with Gigabit Ethernet ports might have CPUs that
are unable to handle the load needed to support incoming or outgoing
data processing at the full rates of the network connection. The more
client devices and concurrent sources of network traffic, the harder it
will be for a router processor to support maximum speed transfers over
any connection.
How to Tell if a Network Supports Gigabit Ethernet
Network devices provide the same RJ-45 connection type whether their
Ethernet ports support 10/100 (Fast) or 10/100/1000 (Gigabit)
connections. Ethernet cables are often stamped with information about
the standards they support, but they do not indicate whether the network
is actually configured to run at that rate.
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Learning Activities / Exercises
1. Explain Gigabit Ethernet.
Gigabit Ethernet (GbE or 1 GigE) is the term applied to
transmitting Ethernet frames at a rate of a gigabit per second (1 billion bits
per second). The most popular variant 1000BASE-T is defined by
the IEEE 802.3ab standard. It came into use in 1999, and has
replaced Fast Ethernet in wired local networks due to its considerable
speed improvement over Fast Ethernet, as well as its use of cables and
equipment that are widely available, economical, and similar to previous
standards.
Gigabit Ethernet is part of the Ethernet family of computer
networking and communication standards. The Gigabit Ethernet standard
supports a theoretical maximum data rate of one gigabit per second (1,000
Mbps).
2. How does gigabit Ethernet work?
It was once believed that achieving gigabit speeds with Ethernet
would require the use of fiber optic cables or other special network
cable technology. Fortunately, those are only necessary for long distances.
For most purposes, Gigabit Ethernet works well using a regular Ethernet
cable (specifically, the CAT5e and CAT6 cabling standards). These cable
types follow the 1000BASE-T cabling standard (also called IEEE
802.3ab).
3. Are there any restrictions on how Ethernet is cabled?
A single shared cable can serve as the basis for a complete Ethernet
network, which is what we discussed above. However, there are practical
limits to the size of our Ethernet network in this case. A primary concern
is the length of the shared cable.
Electrical signals propagate along a cable very quickly, but they weaken
as they travel, and electrical interference from neighboring devices
(fluorescent lights, for example) can scramble the signal. A network cable
must be short enough that devices at opposite ends can receive each other's
signals clearly and with minimal delay. This places a distance limitation
on the maximum separation between two devices (called the network
diameter) on an Ethernet network. Additionally, since in CSMA/CD only
a single device can transmit at a given time, there are practical limits to the
number of devices that can coexist in a single network. Attach too many
devices to one shared segment and contention for the medium will
increase. Every device may have to wait an inordinately long time before
getting a chance to transmit.
Engineers have developed a number of network devices that alleviate these
difficulties. Many of these devices are not specific to Ethernet, but play
roles in other network technologies as well.
4. What is a multicast, Unicast and Broadcast?
Multicast is a type of communication where multicast traffic addressed for
a group of devices on the network. IP multicast traffic are sent to a group
and only members of that group receive and/or process the Multicast
traffic.
Devices which are interested in a particular Multicast traffic must join to
that Multicast group to receive the traffic. IP Multicast Groups are
identified by Multicast IP Addresses (IPv4 Class D Addresses)
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In Multicast, the sender transmit only one copy of data and it is delivered
and/or processed to many devices (Not as delivered and processed by all
devices as in Broadcast) who are interested in that traffic.
Example: Multicast Windows Deployment Services (WDS) OS
deployment traffic, IP TV etc.
Multicast is a communication method and data delivery scheme in which
a single source sends the same data to multiple receivers simultaneously.
It is similar to broadcasting but more secure because it has an added bonus
of receiver discretion, where the data is received by specific users or hosts.
The multicast process involves a single sender and multiple receivers.
versus systems that are designed to be connection-dependent, like a client-
server system. User datagram protocol (UDP) is the most common
protocol used with multicasting.
Email is the best example of multicast, where a user can choose to send
mail to many different addresses, rather than a complete contact list.
Another example is the one-to-many multicasting of a streaming video
toward many users from a single server. Another good example is Internet
protocol (IP) multicasting, where network nodes, like switches and routers,
handle data packet replication through multicast groups.
Multicast can be one-to-many or many-to-many
distribution. Multicast should not be confused with physical layer point-
to-multipoint communication. Group communication may either be
application layer multicast or network assisted multicast, where the latter
makes it possible for the source to efficiently send to the group in a single
transmission.
Unicast is communication between a single sender and a single receiver
over a network. The term exists in contradistinction.
Unicast is a type of communication where data is sent from one computer
to another computer.
In Unicast type of communication, there is only one sender, and one
receiver.
Example:
1) Browsing a website. (Webserver is the sender and your computer is the
receiver.)
2) Downloading a file from a FTP Server. (FTP Server is the sender and
your computer is the receiver.)
Broadcast is a type of communication where data is sent from one
computer once and a copy of that data will be forwarded to all the devices.
In Broadcast, there is only one sender and the data is sent only once. But
the Broadcast data is delivered to all connected devices.
Switches by design will forward the broadcast traffic and Routers by
design will drop the broadcast traffic. In other words, Routers will not
allow a broadcast from one LAN to cross the Router and reach another
Network Segment. The primary function of a Router is to divide a
big Broadcast domain to Multiple smaller Broadcast domain.
5. What does UTP, STP cabling mean?
Unshielded twisted pair (UTP) is a ubiquitous type of copper
cabling used in telephone wiring and local area networks.
unshielded twisted pair, a popular type of cable that consists of two
unshielded wires twisted around each other. Due to its low cost, UTP
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cabling is used extensively for local-area networks (LANs) and telephone
connections. UTP cabling does not offer as high bandwidth or as good
protection from interference as coaxial or fiber optic cables, but it is less
expensive and easier to work with.
STP Cabling is twisted-pair cabling with additional shielding to
reduce crosstalk and other forms of electromagnetic interference (EMI).
Shielded twisted-pair (STP) cabling is more expensive than unshielded
twisted-pair (UTP) cabling. It has an impedance of 150 ohms, has a
maximum length of 90 meters, and is used primarily in networking
environments with a high amount of EMI due to motors, air conditioners,
power lines, or other noisy electrical components. STP cabling is the
default type of cabling for IBM Token Ring networks.
Assignment # 9:
1. What do the LEDs indicate?
LED stands for "light emitting diode." A diode is an electrical component
with two terminals which conduct the electricity only in one direction.
With an electrical current, the diode emits a bright light around the small
bulb. Typically, diodes have been used in many technologies such as
radios, televisions and computers as an electrical component for
conduction.
Connecting a diode to an electrical current excites the electrons within
the diode, making them release photons, which we see as light. The color
of the light is a direct result of the energy gap in the semiconductor of the
diode. This means that LEDs produce a spectrum of colors easily and
brightly while using very little electricity to do so.
Good Luck!!!
“Live a good life. More smiling, less worrying. More
compassion, less judgment. More blessed, less stress. More
love, less hate.”
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