EnterPrise Networking Orientation
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Transcript of EnterPrise Networking Orientation
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aveen Patel
Introduction toEnterprise Networking
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Course Objective
To understand both the What and the Why of
networks in general and the Enterprise Model
specifically.
Note: This course is not specific to Engineers majors. It is
intended for a wide audience with little or no prior experience
with the Networks, or Internet in general.
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This course will develop fundamental concepts, protocols &
architecturesof Broadband and Enterprise Networking.
Broadband networking driven by the imminent convergenceof
telephony (voice), Internet (data), cable (video), and wireless
networks.
Fundamental ideas in telephone, networking, cable systems,
wireless
Convergence architectures: B-ISDN, ATM, Frame Relay,
Internet
Course Description Highlights
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Issues:
High-speed switching & router-design,
Quality of service (QoS) building blocks and architectures
Traffic engineering (MPLS, ATM, frame-relay),
Fiber optical communications,
Optical networking concepts,
Protection/restoration/survivability,
Optical link layers (SONET, WDM)
Course Description Highlights
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LANs/MANs/Last-Mile:
Gigabit Ethernet,
802.11a/b and community/hot-spot networks
Cable-modem, DSL principles and economics
Free-space-optical networkMultihop/3G wireless data, smart antennas, OFDM
The course will involve substantial reading and a term project to help student
synthesize the variety of concepts and appreciate the broad techno-economic
challenges.
Course Description Highlights
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Pre-requisites
Our assumptions about you:
Computer networks background.
Internet experience.
Access to a computer.Knowledge of Networking Devices
Basic Network Terms
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Answers to FAQ's
Lot of paper readings in the class (due every homework) + research case study(writing skills)
Informal quizzes given occasionally to complement homeworks. These are notgraded.
All homeworks due at the beginning of the class indicated on the coursecalendar
Up to one late submission: no penalty
Beyond that 20% penalty: only if submitted before solutions are posted (max oneweek grace period)
All quizzes are open-book and extremely time limited.
Quizzes consist of design qns, numerical, and short answer questions.
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Grading
Homework 25%
Term Project 15%
Exams 60%
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Whats an Enterprise Networking?
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OverviewConnectivity:
direct (pt-pt, N-users),
indirect (switched, inter-networked)
Telephony, Internet, Cable Networks: Basic Concepts
Concepts: Topologies, Framing, Multiplexing,Flow/Error Control, Reliability, Multiple-access,
Circuit/Packet-switching, Addressing/routing,Congestion control
Data link/MAC layer: SLIP, PPP, LAN technologies
Interconnection Devices
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Transporting Electrical Signals
Common types of transmission media
Wire pair
Coaxial cable
Fiber optic cable
Radio
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Problems?
Security!
Its much easier to protect centralized
resources than when they are distributed.Network itself as the target..
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Before the Internet
Postal network.
Delivers different types of objects (letters, packages, etc.) world-wide.
Relatively high delay but relatively cheap.
Sender and receiver identified by their postal address (name, number,
street, city, etc.).Telephone network.
Engineered to deliver real-time voice.
Also world-wide.
Low delay but more expensive.
Users identified buy telephone number.
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Telephone Network: What is It?
Specialized to carry voice traffic
Aggregates like T1, SONET OC-N can also carry data
Also carries
Telemetry, video, fax, modem calls
Internally, uses digitalsamples
Switches and switch controllers arespecial purpose computers
Pieces:
1. End systems
2. Transmission3. Switching
4. Signaling
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Telephone Network: What is It?
Single basic service: two-wayvoice
low end-to-end delay
guarantee that an accepted call will run to completion
Endpoints connected by a circuit, like an electrical circuit
Signals flow both ways (ful l duplex)
Associated with reservedbandwidth and buffer resources
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Telephone Network Design
Fully connected core
simple routing
telephone numberis a hint about how to routea call
But not for 800/888/700/900 numbers: these are pointers to a directory thattranslates them into regular numbers
hierarchically allocatedtelephone number space
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Telephone Network Design
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Evolution of Communications Networks
POTS network is not designed for other forms of
communications (audio, video, and data).
About 30 years ago, a second communications network was
created with the goal of providing a better transportmechanism for data.
In this class, we will study the technology underpinning data
networks.
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aveen Patel
Whats a network?
Merriam-Webster Dictionary:
|A fabric or structure of cords or wires that cross at regular
intervals
A system of computers, terminals and databases connected by
communication lines
A computer network is defined as the interconnection of 2 or
more independent computers.
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Why network?
Before networks:
One large computer (mainframe) used for all processing in
businesses, universities, etc.Smaller, cheaper computers
Personal computers or workstations on desktops.
Interconnecting many smaller computers is advantageous! Why?
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Why network?
Resource sharing!
Hardware: printers, disks, terminals, etc.
Software: text processors, compilers, etc.
Data.
Robustness.
Fault tolerance through redundancy.
Load balancing.
Processing and data can be distributed over the network.
Location independence.Users can access their files, etc. from anywhere in the network.
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Transmission
Definition
Electrical transfer of a signal, message, or other form of
intelligence from one location to another
Co-exists withswitchingas being one of the two major disciplines oftelecommunication
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Connectivity...
Building Blocks
links: coax cable, optical fiber...
nodes: general-purpose workstations...
Directconnectivity:
point-to-point
multiple access
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Connectivity (Continued)
Indirect Connectivity
switched networks
=> switches
inter-networks
=> routers
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What is Connectivity ?
Direct or indirect accessto every other node in the
network
Connectivityis what you get instead of a direct physical
linkKey Tradeoff: Performance characteristics worse!
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Connectivity
Internet:
Best-effort
(no performance guarantees)
Packet-by-packet
A pt-pt link:Always-connected
Fixed bandwidth
Fixed delay
Zero-jitter
A hi
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Architecture
Digital Divide
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Digital DivideThe Flip-side of the Knowledge Era
Our objective is freedom from distance. We aredetermined to link all the villages of India not only
with good roads but also with good telecom and
internet services
------ Prime Minister of India15th Au ust 2001
Haves Have-Nots
Knows Know -Nots
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BITS for All
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Last Mile Technology Solutions : 802.11(b)
NIC-Centre
New AdministrativeBuilding
(
Mantralaya
(
500 Meters
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Informal Quiz: Prerequisites
T F (True or False)
Datalink refers to the 3rd layer in the ISO/OSI reference model
If peak rate = 10 Mbps, Avg rate = 2 Mbps and Service rate = 4 Mbps,multiplexing gain = 2.
An even parity bit value for the 8-bit string 01101010 is 0.
Packet forwarding is a control-plane function and routing is a data-plane
function. Bridges and switches in Ethernet allow separation of collision domains, and
reduce the degree of sharing of the physical media.
Finding path from one node to another in a large network is a transport layerfunction.
It is impossible to send 3000 bits/second through a wire which has a bandwidth
of 1000 Hz. Randomness (in service and arrival) is what causes queuing at buffers.
Littles law which relates expected queuing delay E(T) and expected # in thesystem E(n) is applicable only to M/M/1 queues.
Littles law also holds for instantaneous(as opposed to average) queuing delayand instantaneous number in the system
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aveen Patel
Informal Quiz (Continued)
Bit stuffing is used so that framing characters do not occur in the framepayload.
CRC is based upon the idea that it is highly unlikely for an uncorrupted packetto be perfectly divisible by the CRC polynomial.
Random access MAC protocols tend to perform very well at low loads in termsof channel multiplexing; but suffer from high delay at high loads.
Taking turns or token-based protocols like token-ring offer a best of bothpartitioning and random access worlds.
For long delay paths, on-off flow control is better than window flow control.
Ethernet uses a CSMA/CD access method.
The packets sent in a connection-oriented network are called datagrams.
The distance-vector protocol involves checking neighbors distance vectorsand updating its own distance vector.
Address structure is required to recognize whether the destination is one-hopor multiple-hops away.
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aveen Patel
Informal Quiz: Solutions
T F (True or False)
Datalink refers to the 3rd layer in the ISO/OSI reference model
If peak rate = 10 Mbps, Avg rate = 2 Mbps and Service rate = 4 Mbps,multiplexing gain = 2.
An even parity bit value for the 8-bit string 01101010 is 0.
Packet forwarding is a control-plane function and routing is a data-plane function.
Bridges and switches in Ethernet allow separation of collision domains, andreduce the degree of sharing of the physical media.
Finding path from one node to another in a large network is a transport layerfunction.
It is impossible to send 3000 bits/second through a wire which has a bandwidth of1000 Hz.
Randomness (in service and arrival) is what causes queuing at buffers. Littles law which relates expected queuing delay E(T) and expected # in the
system E(n) is applicable only to M/M/1 queues.
Littles law also holds for instantaneous(as opposed to average) queuing delayand instantaneous number in the system
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Informal Quiz Solutions
Bit stuffing is used so that framing characters do not occur in the framepayload.
CRC is based upon the idea that it is highly unlikely for an uncorrupted packetto be perfectly divisible by the CRC polynomial.
Random access MAC protocols tend to perform very well at low loads in termsof channel multiplexing; but suffer from high delay at high loads.
Taking turns or token-based protocols like token-ring offer a best of bothpartitioning and random access worlds.
For long delay paths, on-off flow control is better than window flow control.
Ethernet uses a CSMA/CD access method.
The packets sent in a connection-oriented network are called datagrams.
The distance-vector protocol involves checking neighbors distance vectors andupdating its own distance vector.
Address structure is required to recognize whether the destination is one-hop ormultiple-hops away.