ieee and lower level lan protocols
Post on 05-Apr-2018
222 Views
Preview:
TRANSCRIPT
-
8/2/2019 IEEE and Lower Level LAN Protocols
1/62
CHAPTERProtocols and IEEE
Standards
-
8/2/2019 IEEE and Lower Level LAN Protocols
2/62
Chapter Objectives
Discuss different media level protocolsincluding their functioning
The major protocols chosen fordiscussion are as follows:
CSMA/CD, token passing and polling
Discuss the IEEE standards that applyto LANs based on different protocols
-
8/2/2019 IEEE and Lower Level LAN Protocols
3/62
Chapter Modules
LAN Protocol: Carrier Sense MultipleAccess/Collision Detection
(CSMA/CD)
LAN Protocol: Token Passing
LAN Protocol: Polling
IEEE Standards
-
8/2/2019 IEEE and Lower Level LAN Protocols
4/62
END OF CHAPTER
INTRODUCTION
-
8/2/2019 IEEE and Lower Level LAN Protocols
5/62
MODULE
IEEE and Lower Layer LANProtocols
-
8/2/2019 IEEE and Lower Level LAN Protocols
6/62
IEEE Background
Institution of Electrical and ElectronicEngineering (IEEE)
A professional non-profit organization
Project group 802 under IEEE Entrusted with the task of setting standards
relating to physical and logical links of nodes in anetwork
Standard mostly applies to the Physical andData Link layers
Example IEEE 802.3 standard for the Ethernet bus network
-
8/2/2019 IEEE and Lower Level LAN Protocols
7/62
The ISO-OSI Model Recalled
Models the end-to-end communicationprocess
It is a seven-layer model Proposed by International Standard
Organization (ISO)
The model is known as Open Systems
Interconnect (OSI) IEEE sets the standards at the lower levels of
the ISO-OSI model
-
8/2/2019 IEEE and Lower Level LAN Protocols
8/62
ISO-OSI Seven Layer Model
Layer 7 ApplicationLayer 6 PresentationLayer 5 SessionLayer 4 TransportLayer 3 NetworkLayer 2 Data LinkLayer 1 Physical
Source: http://starter.sdsu.edu/remote/demo/osi-tcp.html
Focus of
IEEE 802
http://starter.sdsu.edu/remote/demo/osi-tcp.htmlhttp://starter.sdsu.edu/remote/demo/osi-tcp.htmlhttp://starter.sdsu.edu/remote/demo/osi-tcp.htmlhttp://starter.sdsu.edu/remote/demo/osi-tcp.html -
8/2/2019 IEEE and Lower Level LAN Protocols
9/62
Comparison of ISO-OSI Modeland the DOD (TCP/IP) Model
ApplicationApplicationPresentation
SessionTransport
Host-to-Host
Network InternetData Link
Network AccessPhysical
Source: http://starter.sdsu.edu/remote/demo/osi-tcp.html
http://starter.sdsu.edu/remote/demo/osi-tcp.htmlhttp://starter.sdsu.edu/remote/demo/osi-tcp.htmlhttp://starter.sdsu.edu/remote/demo/osi-tcp.htmlhttp://starter.sdsu.edu/remote/demo/osi-tcp.html -
8/2/2019 IEEE and Lower Level LAN Protocols
10/62
Layer Reference to Protocol
ApplicationApplication FTP, Telnet, SMTP, HTTP,
SNMP ..PresentationSessionTransport Host-to-Host TCP, UDPNetwork Internet IP, ICMPData Link Network
Access Ethernet, Token-Ring ...Physical
Source: http://starter.sdsu.edu/remote/demo/osi-tcp.html
http://starter.sdsu.edu/remote/demo/osi-tcp.htmlhttp://starter.sdsu.edu/remote/demo/osi-tcp.htmlhttp://starter.sdsu.edu/remote/demo/osi-tcp.htmlhttp://starter.sdsu.edu/remote/demo/osi-tcp.html -
8/2/2019 IEEE and Lower Level LAN Protocols
11/62
Network ProtocolsSource: www.networkmagzine.com
-
8/2/2019 IEEE and Lower Level LAN Protocols
12/62
Another Look at Network ProtocolsSource: www.networkmagzine.com
-
8/2/2019 IEEE and Lower Level LAN Protocols
13/62
Network Protocols in the TCP/IPModel
Source: www.networkmagzine.com
http://www.networkmagzine.com/http://www.networkmagzine.com/ -
8/2/2019 IEEE and Lower Level LAN Protocols
14/62
IEEE 802 Focus
OSI Reference
Data Link layer
Physical layer
Areas of applications
Network cards and cables
WAN connectivity etc.
Different subgroups under 802 thatfocus on different activities of the LAN
-
8/2/2019 IEEE and Lower Level LAN Protocols
15/62
IEEE 802 Subgroups and theirResponsibilities
802.1
Internetworking
802.2
Logical Link Control (LLC)
802.3
CSMA/CD
802.4
Token Bus LANContinued
-
8/2/2019 IEEE and Lower Level LAN Protocols
16/62
IEEE 802 Subgroups and theirResponsibilities (Cont.)
802.5
Token Ring LAN
802.6
Metropolitan Area Network
802.7
Broadband Technical Advisory Group
802.8
Fiber-Optic Technical Advisory GroupContinued
-
8/2/2019 IEEE and Lower Level LAN Protocols
17/62
IEEE 802 Subgroups and theirResponsibilities (Cont.)
802.9
Integrated Voice/Data Networks
802.10
Network Security
802.11
Wireless Networks
802.12
Demand Priority Access LANs
Ex: 100BaseVG-An LAN
-
8/2/2019 IEEE and Lower Level LAN Protocols
18/62
Ethernet Protocol Standards
10 Mbps IEEE 802.3
100 Mbps IEEE 802.3u
1 Gbps IEEE 802.3ab
Uses all 4 pairs of the RJ-45 cable(www.techfest.com/networking/lan/ethernet1.htm )
10 Gbps
IEEE 820.3ae
http://www.techfest.com/networking/lan/ethernet1.htmhttp://www.techfest.com/networking/lan/ethernet1.htmhttp://www.techfest.com/networking/lan/ethernet1.htmhttp://www.techfest.com/networking/lan/ethernet1.htm -
8/2/2019 IEEE and Lower Level LAN Protocols
19/62
Wireless LAN Protocols
802.11 1-2 Mbps, 2.4 GHz, FHSS and DSSS
IEEE 802.11a 54 Mbps, 5 GHz, Orthogonal Frequency DivisionMultiplexing
IEEE 802.11b 11 Mbps, 2.4 GHz, DSSS
IEEE 802.11g 20+ Mbps, 2.4 GHZ 108 Mbps, 2.4 GHz (Extreme G)
-
8/2/2019 IEEE and Lower Level LAN Protocols
20/62
Newer Wireless Protocol
IEEE 802.11n
-
8/2/2019 IEEE and Lower Level LAN Protocols
21/62
A Perspective of IEEE 802 Standardsin Network Communication
LogicalLink
Control(LLC)
MediaAccessControl(MAC)
802.2
802.3
802.4802.5802.12
802.1 appliesto both.
-
8/2/2019 IEEE and Lower Level LAN Protocols
22/62
END OF MODULE
-
8/2/2019 IEEE and Lower Level LAN Protocols
23/62
MODULE
LAN Lower Layer Protocol:
IEEE 802.3 Carrier Sense MultipleAccess/ Collision Detection
(CSMA/CD)
-
8/2/2019 IEEE and Lower Level LAN Protocols
24/62
An Overview of CSMA/CD
CSMA/CD has two components asmentioned
First is the Carrier Sense MultipleAccess (CSMA) component
Second is the Collision Detection (CD)
component
-
8/2/2019 IEEE and Lower Level LAN Protocols
25/62
CSMA Component ofCSMA/CD
CSMA (Carrier Sense Multiple Access)
Check the bus for traffic
If the bus is free, then transmit
If it is busy, wait for a random period oftime before attempting to transmit again
-
8/2/2019 IEEE and Lower Level LAN Protocols
26/62
CD Component of CSMA/CD
Two stations may check the data bussimultaneously
Both may find the line free and engage in the
transmission of data Both transmission will collide
CD component will detect this collision Inform the workstations of the collision
Each station will wait for a random period oftime before attempting to transmit again
-
8/2/2019 IEEE and Lower Level LAN Protocols
27/62
CSMA/CD Usage
Used extensively in bus LANs
-
8/2/2019 IEEE and Lower Level LAN Protocols
28/62
CSMA/CD Standards
Highly standardized protocol
Different protocol standards fordifferent speeds of communication
10 Mbps Ethernet standard
IEEE 802.3
-
8/2/2019 IEEE and Lower Level LAN Protocols
29/62
IEEE 802.3
10G bps Ethernet IEEE 802.3z
1G bps Ethernet IEEE 802.3ab
100M bps Ethernet
IEEE 802.3u 10M bps Ethernet
IEEE 802.3
-
8/2/2019 IEEE and Lower Level LAN Protocols
30/62
END OF MODULE
-
8/2/2019 IEEE and Lower Level LAN Protocols
31/62
MODULE
LAN Lower Layer Protocol:
IEEE 802.4 Token Bus Protocol
-
8/2/2019 IEEE and Lower Level LAN Protocols
32/62
Token Bus
Server
Client Client Client
Token
A token is distributed to each client in turn.
-
8/2/2019 IEEE and Lower Level LAN Protocols
33/62
Token Bus Data Pickup
A token is sent from one node to theother
The client wanting to transmit grabs anempty token
Data is attached
Token leaves for the next node and itstravel on the bus until it reaches theaddress to which the data is destined
Cont.
-
8/2/2019 IEEE and Lower Level LAN Protocols
34/62
Token Bus Data Delivery
Token delivers the data to the addressee
Acknowledgement is returned to the sender
Token is passed to the next node The process continues
If there is an error in delivering the
information, a request for retransmissionattached to the token and it is sent to thesender
T k B S d d d
-
8/2/2019 IEEE and Lower Level LAN Protocols
35/62
Token Bus Standard andApplications
IEEE 802.4
It can be used in both broadband andbaseband transmission
-
8/2/2019 IEEE and Lower Level LAN Protocols
36/62
END OF MODULE
-
8/2/2019 IEEE and Lower Level LAN Protocols
37/62
MODULE
LAN Lower Layer Protocol:
IEEE 802.5 Token Passing Protocol
-
8/2/2019 IEEE and Lower Level LAN Protocols
38/62
Token Passing Protocol inOperation
D
A
B
C
Circulating
Token
Server Workstation
Workstation
No collisions
-
8/2/2019 IEEE and Lower Level LAN Protocols
39/62
Comparison with CSMA/CD
Absence of collision
Offers a systematic method of
transmitting information In theory, it is superior to CSMA/CD
More sophisticated to implement
Protocols used in the newer and mostpopular networks are, however, basedon CSMA/CD
-
8/2/2019 IEEE and Lower Level LAN Protocols
40/62
The Token
Token
Data packet that could carry data
Circulates around the ring
Offers an opportunity for each workstationand server to transmit data
-
8/2/2019 IEEE and Lower Level LAN Protocols
41/62
The Transmitting Workstation
Waits for a free token in order to be able toattach the data to be transmitted to the token
On finding a free token, attach the following:
Senders address Receivers address
Data block to be transmitted
Error checking details
etc.
-
8/2/2019 IEEE and Lower Level LAN Protocols
42/62
At the Receiving End
Data is received and checked for errors
Outcomes at the receiving end
Data received without errors
Date received with errors
-
8/2/2019 IEEE and Lower Level LAN Protocols
43/62
Error-free Delivery of Data
An acknowledgment is attached to thetoken
Acknowledgment is passed to thesender
Token is set free for other nodes to
transmit information At this time, the next workstation on
the ring will receive an opportunity
-
8/2/2019 IEEE and Lower Level LAN Protocols
44/62
Correcting Errors in Delivery
A request for retransmission is attachedto the token
Token carries the message forretransmission to the sender
The data is thus retransmitted
-
8/2/2019 IEEE and Lower Level LAN Protocols
45/62
Token Regeneration
The token is regenerated at regularintervals to sustain the timing of
circulation of the token
-
8/2/2019 IEEE and Lower Level LAN Protocols
46/62
Usage of Token Passing
Used extensively in ring LANs Especially in the IBM token-ring LAN
A version of this protocol is also usedon certain types of bus LANs Token-bus networks
Used in large fiber-optics backbones Used for the construction of very large
networks
-
8/2/2019 IEEE and Lower Level LAN Protocols
47/62
Usage in Practice
Used in backbones
Uses in a number of IBM shops
Overall, the usage of Ethernet surpassesthe usage of Token-Ring networks thatare based on the Token-Passing
protocol
-
8/2/2019 IEEE and Lower Level LAN Protocols
48/62
Token Passing Standards
IEEE 802.5
For the token-ring LANs
IEEE 802.4 For the token-bus LANs
A FDDI protocol is used on large fiber-
optic ring backbones
-
8/2/2019 IEEE and Lower Level LAN Protocols
49/62
END OF MODULE
-
8/2/2019 IEEE and Lower Level LAN Protocols
50/62
MODULE
WAN Protocol: Token Passing onFDDI
-
8/2/2019 IEEE and Lower Level LAN Protocols
51/62
ANSI X3T9.5 Protocol
This wide are network protocol isstandardized by ANSI
Works similar to Token PassingProtocol
Used in FDDI and CDDI backbone
networks Usually implemented in dual-ringformat for fault tolerance
R li bili C R i
-
8/2/2019 IEEE and Lower Level LAN Protocols
52/62
Reliability: Counter RotatingRing
By-pass
the defective
segment ofthe cable
-
8/2/2019 IEEE and Lower Level LAN Protocols
53/62
END OF MODULE
-
8/2/2019 IEEE and Lower Level LAN Protocols
54/62
MODULE
LAN Lower Layer Protocol:
Polling
-
8/2/2019 IEEE and Lower Level LAN Protocols
55/62
Polling in Operation
Server
WS A WS B W S C
WS : Work Station
Poll
Data Delivery
Acknowledgement orRequest for
retransmission
-
8/2/2019 IEEE and Lower Level LAN Protocols
56/62
Polling and Delivery of Data
Server polls each workstation
A workstation responds by sending adata packet
Data packet is delivered to the addressfound in the packet
-
8/2/2019 IEEE and Lower Level LAN Protocols
57/62
At the Receiving End
If there are no errors : Acknowledgment is returned to the sender
The server then continues with the pollingprocess
If there are errors: A request for retransmission is conveyed to
the sender The entire transmission process is then
repeated
-
8/2/2019 IEEE and Lower Level LAN Protocols
58/62
The Usage of the Polling Protocol
Mainly used in multi-user micro-computer
Based on the physical and logical startopologies
Example
A multi-user microcomputer running theUnix operating systems
Diffi lti i I l ti
-
8/2/2019 IEEE and Lower Level LAN Protocols
59/62
Difficulties in ImplementingPolling in LANs
It is difficult to implement the pollingprotocols in large networks withmultiple segments
Multiple servers in different segmentsmay have problems in polling all the
workstations
-
8/2/2019 IEEE and Lower Level LAN Protocols
60/62
Polling Implementations
True multi-user systems such as a Unixbased multi-user system
-
8/2/2019 IEEE and Lower Level LAN Protocols
61/62
END OF MODULE
-
8/2/2019 IEEE and Lower Level LAN Protocols
62/62
END OF MODULEEND OF CHAPTER
top related