The IEEE 802 is a family of IEEE standards dealing with Local Area Networks and Metropolitan Area Networks. The IEEE 802 family of standards is maintained by the IEEE 802 LAN/MAN Standards Committee (LMSC).
The most widely used standards are for the Bridging and Virtual Bridged LANs (802.1), Ethernet family (802.3), Token Ring (802.5) and Wireless LAN (802.11).
2. Introduction
• The IEEE 802 is a family of IEEE standards dealing with Local Area Networks
and Metropolitan Area Networks. The IEEE 802 family of standards is
maintained by the IEEE 802 LAN/MAN Standards Committee (LMSC).
• The most widely used standards are for the Bridging and Virtual Bridged
LANs (802.1), Ethernet family (802.3), Token Ring (802.5) and Wireless LAN
(802.11). However, in Internetwork Design & LAN/MAN Administration 2
course, we are going to take a comprehensive approach and study the
following eleven IEEE 802 standards:-
3. 1. 802.1 – Bridging and Virtual Bridged LANs
2. 802.3 – Ethernet family
3. 802.5 – Token Ring
4. 802.6 – Fiber Distributed Data Interface (FDDI)
5. 802.11 – Wireless LAN family
6. 802.15 – Wireless PAN (Bluetooth)
7. 802.16 – WiMAX (Worldwide Interoperability for Microwave Access) or
WMAN
8. 802.17 – Resilient Packet Ring
9. 802.20 – Mobile Broadband Wireless Access
10. 802.21 – Media Independent Handover Services
11. 802.22 - Wireless Regional Area Networks
4. IEEE 802.1D (Spanning Tree Protocol or
Common Spanning Tree)
There are several types of spanning-tree protocols that we are going to
discuss, but I will start with the IEEE version 802.1d, which happens to be the
default on all Cisco IOS switches. A history to this is that, long ago, a company
called Digital Equipment Corporation (DEC) created the original version of
Spanning Tree Protocol(STP). The IEEE later created its own version of STP
called 802.1d. Cisco has moved toward another industry standard in its newer
switches called 802.1w (PVST+). One needs to understand both new and old
STP versions.
5. •Spanning Tree Protocol (STP) achieves its primary
objective of preventing network loops on layer 2
network bridges or switches by monitoring the network
to track all links and shut down the redundant ones.
•STP uses the spanning-tree algorithm (STA) to first create
a topology database and then search out and disable
redundant links.
•With STP running, frames will be forwarded on only
premium, STP-chosen links.
•STPs are great for modern networks
6. IEEE 802.1w (Rapid Spanning Tree Protocol)
• Also called (RSTP), this iteration enhanced the BPDU exchange and paved the
way for much faster network convergence, but it still only allows for one
root bridge per network like CST. The bridge resources used with RSTP are
higher than CST’s but less than PVST+.
• PVST+ is the Cisco proprietary enhancement for STP that provides a separate
802.1w spanning- tree instance for each VLAN.
• Rapid PVST+ Cisco’s version of RSTP that also uses PVST+ and provides a
separate instance of 802.1w per VLAN. It gives us really fast convergence
times and optimal traffic flow but predictably requires the most CPU and
memory of all.
7. IEEE 802.1Q
• Created by the IEEE as a standard method of frame tagging, IEEE 802.1q
actually inserts a field into the frame to identify the VLAN. If you are trunking
between a Cisco switched link and a different brand of switch, you have got
to use 802.1q for the trunk to work. We did all these configurations in
Internetworking Design and LAN/MAN Administration 1.
• VLAN 1 is the default native VLAN, and when using 802.1q, all traffic for a
native VLAN is untagged.
• The basic purpose of 802.1q frame-tagging methods is to provide inter-switch
VLAN communication. Remember that any 802.1q frame tagging is removed
if a frame is forwarded out an access link hence tagging is used internally and
across trunk links only!
8. IEEE 802.1X
• IEEE 802.1X is the standard protocol for port-based network admission
control. It allows hosts and users to be authenticated to the network before
obtaining a connection. As well as providing very effective access control to
wireless and other networks, it is being used increasingly for other aspects of
host security and management.
• IEEE 802.1X, therefore, provides port authorization on a per-user or per-host
basis; support for multiple authentication methods; and separation of the
authenticator from the back-end authentication server, simplifying user
management and policy decision making.
• Besides authentication, perhaps the most useful feature of IEEE 802.1X is
dynamic VLAN assignment, which allows the RADIUS server to assign a
VLAN to a host. Note that dynamic VLAN assignment is not part of the IEEE
802.1X specification, but most vendors have implemented it.
9. IEEE 802.3 Standard (Ethernet)
• Ethernet offers a specific bandwidth between end users. In its most basic
form, Ethernet is a shared medium that becomes both a collision and a
broadcast domain. As the number of users on the shared media increases, so
does the probability that a user is trying to transmit data at any given time.
When one user transmits at about the same time as another, a collision
occurs. In other words, both users cannot transmit data at the same time if
they both are sharing the same network media.
• Ethernet is based on the carrier sense multiple access collision detect
(CSMA/CD) technology, which requires that transmitting stations back off for
a random period of time when a collision occurs. If a station must wait its
turn to transmit, it cannot transmit and receive at the same time. This is called
half duplex operation.
10. Scaling Ethernet
• The original Ethernet standard was based on a bandwidth of 10 Mbps per
network segment. These included 10Base5, 10Base2 and 10Base-T. Over
time, networking technology has evolved to offer higher amounts of
bandwidth. Instead of requiring campuses to invest in a completely new
technology to leverage ever increasing bandwidth, the networking industry
has developed higher-speed generations of Ethernet that are based on
existing Ethernet standards.
12. IEEE 802.5 Standard (Token Ring)
• The token ring network was introduced by IBM in 1984 and later
standardized with protocol IEEE 802.5. It was fairly successful, particularly in
corporate environments, but gradually eclipsed by the later versions of
Ethernet. In IEEE 802.5, the token passing scheme is used in place of Carrier
Sense Multiple Access with Collision Detection (CSMA/CD) on a ring
topology local area network (LAN).
• In this network, a token is circulated around a network. The computer that
has possession of the token has the right to transmit packets for a certain
period of time. If that computer has no packets to transmit then the token
is passed to the next computer. Only one computer at a time can transmit
packets so this helps to avoid collision problems.
14. IEEE 802.6 Standard (FDDI)
• IEEE 802.6 is a standard governed by the ANSI for Metropolitan Area
Networks (MAN). It is an improvement of an older standard (also created by
ANSI) which used the Fiber distributed data interface (FDDI) network
structure. The FDDI-based standard failed due to its expensive
implementation and lack of compatibility with current LAN standards. The
IEEE 802.6 standard uses the Distributed Queue Dual Bus (DQDB) network
form. This form supports 150 Mbit/s transfer rates. It consists of two
unconnected unidirectional buses. DQDB is rated for a maximum of 160 km
before significant signal degradation over fiber optic cable with an optical
wavelength of 1310 nm.
15. • FDDI (Fiber Distributed Data Interface) is a set of ANSI and ISO standards for
data transmission on fiber optic lines in a local area network (LAN) that can
extend in range up to 200 km (124 miles). The FDDI protocol is based on the
token ring protocol. In addition to being large geographically, an FDDI local
area network can support thousands of users. FDDI is frequently used on
the backbone for a wide area network (WAN).
• An FDDI network contains two token rings, one for possible backup in case
the primary ring fails. The primary ring offers up to 100 Mbps capacity. If the
secondary ring is not needed for backup, it can also carry data, extending
capacity to 200 Mbps. The single ring can extend the maximum distance; a
dual ring can extend 100 km (62 miles).
16. The student needs to know how to relate the Token Ring with FDDI (IEEE 802.5 and IEEE 802.6)
17. IEEE 802.11 Standard (Wireless LAN or WI FI)
• The IEEE 802.11 standard describes the wireless area network characteristics. The
IEEE 802.11 can operate in two modes: infrastructure and ad-hoc.
• In the ad hoc mode or infrastructure-less mode, two WLAN stations can
communicate directly with each other whenever they are in the same range
spectrum without the intervention of the access point.
• Each WLAN station can be considered as an access point and a client station at the
same time. However, in the infrastructure mode, the wireless network is
controlled by the access point.
• 802.11 standards specify the use of CSMA/CA (Carrier Sense Multiple Access with
Collision Avoidance) to access a shared medium. Using CSMA/CA, before a station
begins to send data on an 802.11 network, it checks for existing wireless
transmissions. If the source node detects no transmission activity on the network, it
waits a brief, random amount of time, and then sends its transmission.
18. IEEE 802.11a, b, g and n
• The IEEE 802.11 standard is published in four phases. Firstly, it is called 802.11,
which included MAC and three specifications of physical layers (two of them
operating in the 2.4 GHz band, and one using infrared).
• The IEEE 802.11b standard was then published. This operates in the 2.4 GHz
band with the data rate of 5.5 and 11 Mbit/s.
• Afterwards, the IEEE 802.11g standard is specified in the 2.4 GHz band, but
with a data rate of 54 Mbit/s.
• The wireless network based on 802.11b and 802.11g is compatible in the
uplink direction. Thus, a 802.11g wireless card can be connected to the
802.11b network using the data rate of 11 Mbit/s, while the contrary is not
possible.
19. IEEE 802.11a
• Although the 802.11a task group began its standards work before the 802.11b
group, 802.11a was released after 802.11b. The 802.11a standard differs from
802.11b and 802.11g in that it uses multiple frequency bands in the 5-GHz
frequency range and provides a maximum theoretical throughput of 54
Mbps, though its effective throughput falls generally between 11 and 18
Mbps.
• 802.11a’s high throughput is attributable to its use of higher frequencies, its
unique method of encoding data, and more available bandwidth. Perhaps
most significant is that the 5-GHz band is not as congested as the 2.4-GHz
band.
• Thus, 802.11a signals are less likely to suffer interference from microwave
ovens, cordless phones, motors, and other (incompatible) wireless LAN
signals.
20. IEEE 802.11b
• In 1999, the IEEE released 802.11b, also known as “Wi-Fi,” for Wireless
Fidelity. 802.11b uses DSSS (direct sequence spread spectrum) signaling.
• 802.11b uses the 2.4–2.4835-GHz frequency range (also called the 2.4-GHz
band) and separates it into 14 overlapping 22-MHz channels.
• 802.11b provides a theoretical maximum of 11-Mbps throughput; actual
throughput is typically around 5 Mbps.
• To ensure this throughput, wireless nodes must stay within 100 meters (or
approximately 330 feet) of an access point or each other, in the case of an
ad-hoc network.
• Among all the 802.11 standards, 802.11b was the first to take hold and
remains the most popular. It is also the least expensive of all the 802.11
WLAN technologies.
21. IEEE 802.11g
• IEEE’s 802.11g WLAN standard is designed to be just as affordable as
802.11b while increasing its maximum capacity from 11 Mbps to a maximum
theoretical throughput of 54 Mbps through different encoding techniques.
• The effective throughput of 802.11g ranges generally from 20 to 25 Mbps.
An 802.11g antenna has a geographic range of 100 meters (or
approximately 330 feet).
• 802.11g, like 802.11b, uses the 2.4-GHz frequency band. In addition to its
high throughput, 802.11g benefits from being compatible with 802.11b
networks.
22. • Thus, if a network administrator installed 802.11b access points on
her LAN last year, this year she could add 802.11g access points,
and the laptops could roam between the ranges of the 802.11b and
802.11g access points without an interruption in service.
• 802.11g’s compatibility with the more established 802.11b has
caused many network managers to choose it over 802.11a, despite
802.11a’s comparative advantages.
23. IEEE 802.11n
• In January 2004, IEEE announced that it would constitute a new working
group (TGn) 802.11 for developing a new amendment to the IEEE 802.11
standard for wireless network.
• They estimated that the data rate would attain 540 Mbit/s. This is done by
adding MIMO and channel-bonding/40 MHz operation to the PHY layer,
and frame aggregation to the MAC layer. MIMO uses multiple transmitter
and receiver antennas to improve system performance.
• MIMO is a technology which uses multiple antennas to coherently resolve
more information than possible using a single antenna. Two important
benefits are provided by 802.11n: antenna diversity and spatial
multiplexing.
NB. Know Comparison of the IEEE 802.3 (Ethernet) MAC protocol (CSMA/CD)
to IEEE 802.11 (Wireless LAN) MAC protocol (CSMA/CA)
24. IEEE 802.15 Standard (Bluetooth or WPAN)
• The 802.15 Wireless Personal Area Network (WPAN) efforts focus on the
development of consensus standards for Personal Area Networks or short
distance wireless networks.
• These WPANs address wireless networking of portable and mobile
computing devices such as PCs,
• Personal Digital Assistants (PDAs), peripherals, cell phones, pagers and
consumer electronics, allowing these devices to communicate and
interoperate with one another in a small range.
• The Bluetooth standard specified in IEEE 802.15 provides a wireless network
technology for rather small cells and is typically used to create wireless
personal area networks.
• Most of the phones we use in our midst support Bluetooth connection.
25. IEEE 802.16 Standard (WiMAX or WMAN)
• In 2001, IEEE standardized a new wireless technology under its 802.16 (wireless
MAN) committee.
• The first version of this standard specified signals operating between 10 GHz and
66 GHz and required antennas with a line-of-sight path between them.
• Since 2001, IEEE has released additional versions of the 802.16 standard.
• WiMAX is capable of providing much greater throughput than the 802.11 access
methods—up to 70 Mbps. Its range is also much greater, at 50 kilometers (or
approximately 30 miles).
• WiMAX is more expensive than existing options; its subscriber wireless stations
cost approximately.
• However, service providers view WiMAX as an excellent high-speed Internet
access option for rural users who are not served by broadband cable or DSL
connections.
26. IEEE 802.17 Resilient Packet Ring (RPR)
• Resilient Packet Ring (RPR) is a new technology being standardized in the
IEEE (802.17 Workgroup). The objective is to enable a true alternative to
SONET transport for packet networks, providing carriers with resiliency, fast
protection and restoration, and performance monitoring comparable to
those of SONET networks.
• In reality RPR is complementary to both SONET and Ethernet. Both SONET
and Ethernet are excellent Layer 1 technologies. Whereas SONET was
designed as a Layer 1 technology, Ethernet has evolved into one.
• Through its various incarnations, Ethernet has transformed from the
CSMA/CD shared media network architecture to a full duplex, point-to-point
switched network architecture.
27. IEEE 802.20 Mobile Broadband Wireless
Access (MBWA)
• IEEE 802.20 or MBWA enables worldwide deployment of affordable,
ubiquitous, always-on and interoperable multi-vendor MBWA networks that
meet the needs of business and residential end-user markets. It specifies
physical and MAC layers of an air interface for interoperable MBWA
systems, operating in licensed bands below 3.5 GHz, optimized for Ip data
transport, with peak data rates per user in excess of 1 Mbps. It supports
various vehicular mobility classes up to 250 km/h in a MAN environment
and targets spectral efficiencies, sustained user data rates and numbers of
active users that are all significantly higher than those achieved by existing
mobile systems.
28. Research on
• IEEE 802.21Media Independent Handover (MIH) and
• IEEE 802.22Wireless Regional Area Networks (WRAN)
