Chapter 13 Fundamentals of Networking and Network Protocols Copyright 2008 Umakishore Ramachandran and William D Leahy Jr 131 Preliminaries Today a general purpose computer not connected to the net or some net is almost unthinkable ID: 714426
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Slide1
Computer SystemsAn Integrated Approach to Architecture and Operating Systems
Chapter 13Fundamentals of Networking and Network Protocols
©Copyright 2008 Umakishore Ramachandran and William D. Leahy Jr.Slide2
13.1 PreliminariesToday a general purpose computer not connected to the "net" or some net is almost unthinkable.
Connecting to a network requires an I/O device which will use DMASlide3
13.2 Basic Terminologies
Computer connected to a network is called a hostThe connection is made using a device called a Network Interface Card or
NIC
What exactly is the "network" shown in the diagram?
As we shall see it may be one network or a composite of multiple networksSlide4
13.2 Basic Terminologies
What is the Internet? Consider the postal system…Slide5
13.2 Basic Terminologies
Now consider an emailSlide6
13.2 Basic Terminologies
Each cloud represented computers of an Internet Service Provider (ISP)The ISP clouds are not directly connected
Instead they are connected by
routers
, which are special purpose computer for this purpose
How do these routers know where to send information? A universal system of addresses called
Internet Protocol (or IP) Addresses
is part of the answerSlide7
13.2 Basic TerminologiesWe showed connecting using a cable or phone network. Connections may also be made through
Local Area Networks (LAN's)Other hardware deviceshubs/
repeaters
bridges
switches
routersSlide8
13.3 Networking SoftwareNeed to address issues such as
Arbitrary message size and physical limitations of network packetsOut of order delivery of packets
Packet loss
in the network
Bit errors
in transmission
Software is logically in a protocol stack configurationSlide9
13.3 Networking Software
A protocol is the set of rules used to describe all of the hardware and (mostly) software operations used to send messages from Processor A to Processor BA protocol describes the syntax
,
semantics
and
timing
of communication between two devices
Common practice is to attach headers/trailers to the actual payload forming a
packet
or
frame
.Slide10
13.3.1 Need for a LayeredProtocol Stack
Good abstractionSimpler to understand than OGPEasier to design, analyze, implement and test
Design concept is
suites
or
families
What do we mean by layers? Or a layered protocol? Consider the army…Slide11
13.3.1 Need for a LayeredProtocol Stack
General
Colonel
Captain
Sergeant
Private
General
Colonel
Captain
Sergeant
PrivateSlide12
13.3.2 Internet Protocol Stack
Physical
Link
Network
Transport
Application
Layer 1
Layer 2
Layer 3
Layer 4
Layer 5Slide13
13.3.2 Internet Protocol Stack
Application: HTTP, SMTP, FTP, etc. Shield applications using network from network detailsTransport: Breaks message into packets, handles things like out of order packets, may deal with reliabilityNetwork: Responsible for routing, does best effort delivery
Link: Moves the packet using a protocol such as Ethernet, Token Ring, and ATM
Physical: Responsible for physically (electrically, optically, etc.) moving the
bits
of the packet from one node to the next. Slide14
13.3.2 Internet Protocol Stack
Application: HTTP, SMTP, FTP, etc. Shield applications using network from network detailsTransport: Breaks message into packets, handles things like out of order packets, may deal with reliabilityNetwork: Responsible for routing, does best effort delivery
Link: Moves the packet using a protocol such as Ethernet, Token Ring, and ATM
Physical: Responsible for physically (electrically, optically, etc.) moving the
bits
of the packet from one node to the next. Slide15
13.3.2 Internet Protocol Stack
Manufacturers group their protocol software together into a family and give it a nice name…
Novell Corporation
Banyan Systems
Apple Computer
Digital Equipment
IBM
“The Internet Biggie”
Netware
VINES
AppleTalk
DECNET
SNA
TCP/IPSlide16
13.3.2 Internet Protocol Stack
Layer 5: Application-Sends application specific messagesLayer 4: Transport-Sends segmentsLayer 3: Network-Sends packets
Layer 2:
Datalink
-Sends frames
Layer 1: Physical-Sends bitsSlide17
13.3.2 Internet Protocol StackSlide18
13.4 Transport Layer
Assumesend (destination-address, message)
receive (source-address, message)
Functionality of transport layer
Support arbitrary message size at the application level
Support in-order delivery of messages
Shield the application from loss of messages
Shield the application from bit errors in transmission.Slide19
13.4 Transport LayerSlide20
13.4.1 Stop and wait protocols
Simple approachSender sends a packet and waits for a positive acknowledgement, commonly referred to as an ACK. As soon as packet is received, recipient generates and sends an ACK for that packet. ACK should contain information for sender to discern unambiguously packet being acknowledged. Sequence number is unique signature of each packet. Thus, all that needs to be in ACK packet is sequence number of received packet.
Sender waits for a period of time called
timeout
. If within this period, it does not hear an ACK, it
re-transmits
the packet. Similarly, the destination may re-transmit the ACK, if it receives the same packet again (an indication to the receiver that his ACK was lost en route) Slide21
13.4.1 Stop and wait protocolsSlide22
13.4.1 Stop and wait protocolsSlide23
13.4.1 Stop and wait protocols
RTT = Round Trip TimeSlide24
13.4.2 Pipelined protocols
(a)
(b)Slide25
13.4.3 Reliable Pipelined ProtocolSlide26
13.4.3 Reliable Pipelined Protocol
Increasing sequence numbers
Active window of
sequence numbers
Packets sent and acknowledged
Packets sent but not yet acknowledged
Packets that are in the active window that can
be sent without waiting for any further ACKs
Packets that cannot yet be sent since they
are outside the active window Slide27
13.4.4 Dealing with transmission errors
Methods are needing to determine if packets are being received correctlyExamplesChecksumsError Correcting Codes (ECC)Slide28
13.4.5 Transport protocols on the Internet
Transport protocol
Features
Pros
Cons
TCP
Connection-oriented; self-regulating; data flow as stream; supports windowing and ACKs
Reliable; messages arrive in order; well-behaved due to self-policing
Complexity in connection setup and tear-down; at a disadvantage when mixed with unregulated flows; no guarantees on delay or transmission rate
UDP
Connection-less; unregulated; message as datagram; no ACKs or windowing
Simplicity; no frills; especially suited for environments with low chance of packet loss and applications tolerant to packet loss;
Unreliable; message may arrive out of order; may contribute to network congestion; no guarantees on delay or transmission rateSlide29
13.4.5 Transport protocols on the Internet
Application
Key requirement
Transport protocol
Web browser
Reliable messaging; in order arrival of messages
TCP
Instant messaging
Reliable messaging; in order arrival of messages
TCP
Voice over IP
Low latency
Usually UDP
Electronic Mail
Reliable messaging
TCP
Electronic file transfer
Reliable messaging; in order delivery
TCP
Video over Internet
Low latency
Usually UDP; may be TCP
File download on P2P networks
Reliable messaging; in order arrival of messages
TCP
Network file service on LAN
Reliable messaging; in order arrival of messages
TCP; or reliable messaging on top of UDP
Remote terminal access
Reliable messaging; in order arrival of messages
TCPSlide30
13.5 Network Layer
Why a separate layer?
Multiple network connections to the host
Multiple hops between source and destination
Route is not static
Transport/network layers interface
Destination address and packet size
Network layer functionality (host)
Routing algorithms
Provide a service model to the transport layer
Pass it up to transport if destination reached
Network layer functionality (Routers)
Routing algorithmsSlide31
13.5.1 Routing AlgorithmsSlide32
13.5.1 Routing Algorithms
Iteration
Count
New node to which least-cost route known
B
Cost
/
route
C
Cost
/
route
D
Cost
/
route
E
Cost
/
route
F
Cost
/
route
Init
A
2/AB
1/AC
4/AD
5/AE
1
A
C
2AB
1/AC
3/ACD
4/ACE
6/ACF
2
AC
B
2/AB
3/ACD
3/ABE
6/ACF
3
ACB
D
3/ACD
3/ABE
5/ADF
4
ACBD
E
3ABE
4/ABEF
5
ACBDE
F
4/ABEF
Slide33
13.5.1 Routing Algorithms
Destination
A
B
C
F
A
5(EA)
3(BA)
4(ECA)
5(EFDCA)
B
7(EAB)
1(EB)
5(ECB)
6(EFDCB
C
6(EAC)
3(EBC)
3(EC)
4(EFDC)
D
8(EACD)
4(EBEFD)
5(ECD)
2(EFD)
F
9(EABEF)
2(EBEF)
7(ECBEF)
1(EF)
DV Table for Node ESlide34
13.5.1 Routing on the Internet
Details of the network layer in a gateway node
Network of networks
Scale, dynamism
Autonomous Systems (AS)
Allows for evolution
Gateway node for inter-AS routingSlide35
13.5.1 Hierarchical Routing Algorithms
BGP Border Gateway Protocol
Gateway nodes use
BGP
Nodes within AS use LS or
DVSlide36
13.5.2 Internet Addressing
IP Network
Device
24 bits
8 bits
Telephone Number
Internet Protocol AddressSlide37
13.5.2 Internet AddressingConsider this 32 bit IP Address
(10000000 00111101 00010111 11011000)2Convert each 8-bit octet into a decimal number and separate each with a decimal
128.61.23.216
In this address the first 24 bits are network while the last 8 are the device
128.61.23.216/24Slide38
13.5.2 Internet Addressing
How many IP networks?Slide39
13.5.2 Internet Addressing
How many IP networks?Slide40
13.5.2 Internet Addressing
IP Network
Device
24 bits
8 bits
IP Network
Device
16 bits
16 bits
Device
Device
8 bits
24 bitsSlide41
13.5.3 Network Service Model
Circuit SwitchingSlide42
13.5.3 Network Service Model
MessageSwitchingSlide43
13.5.3 Network Service Model
Packet SwitchingSlide44
13.5.4 Network Layer Summary
Network Terminology
Definition/Use
Circuit switching
A network layer technology used in telephony. Reserves the network resources (link bandwidth in all the links from source to destination) for the duration of the call; no queuing or store-and-forward delays
TDM
Time division multiplexing, a technique for supporting multiple channels on a physical link used in telephony
FDM
Frequency division multiplexing, also a technique for supporting multiple channels on a physical link used in telephony
Packet switching
A network layer technology used in wide area Internet. It supports best effort delivery of packets from source to destination without reserving any network resources en route.
Message switching
Similar to packet switching but at the granularity of the whole message (at the transport level) instead of packets.
Switch/Router
A device that supports the network layer functionality. It may simply be a computer with a number of network interfaces and adequate memory to serve as input and output buffers.
Input buffers
These are buffers associated with each input link to a switch for assembling incoming packets.
Output buffers
These are buffers associated with each outgoing link from a switch if in case the link is busy.
Routing table
This is table that gives the next hop to be used by this switch for an incoming packet based on the destination address. The initial contents of the table as well as periodic updates are a result of routing algorithms in use by the network layer.Slide45
13.5.4 Network Layer Summary
Network Terminology
Definition/Use
Delays
The delays experienced by packets in a packet-switched network
Store and forward
This delay is due to the waiting time for the packet to be fully formed in the input buffer before the switch can act on it.
Queuing
This delay accounts for the waiting time experienced by a packet on either the input or the output buffer before it is finally sent out on an outgoing link.
Packet loss
This is due to the switch having to drop a packet due to either the input or the output buffer being full and is indicative of traffic congestion on specific routes of the network.
Service Model
This is the contract between the network layer and the upper layers of the protocol stack. Both the datagram and virtual circuit models used in packet-switched networks provide best effort delivery of packets.
Virtual Circuit (VC)
This model sets up a virtual circuit between the source and destination so that individual packets may simply use this number instead of the destination address. This also helps to simplify the routing decision a switch has to make on an incoming packet.
Datagram
This model does not need any call setup or tear down. Each packet is independent of the others and the switch provides a best effort service model to deliver it to the ultimate destination using information in its routing table.Slide46
13.6 Link Layer and Local Area Networks
Innovations in the link layer in the 70's led to making the internet a household termLink layer is responsible for acquiring physical medium for transmission, and sending packet over the physical medium to destination host.Broad Classification
Random Access: Example-Ethernet
Taking Turns: Example-Token Ring
Portion of protocol that deals with gaining access to physical medium is called the
Media Access and Control
(MAC) layerSlide47
13.6.1 Ethernet
Listen for Carrier
Transmit
Message
Abort
Transmission
Need to
Transmit
Medium
Idle
Collision
Detected
Transmission
Complete
No collision
Medium
Not IdleSlide48
Terminologies
Base band signalingManchester encodingCSMA
/CD
CSMA
/CA
Hidden terminal problem
RTS
/CTS
xBASEy
Watch
Triumph of the Nerds (PBS show)
Joe
Cindy
Bala Slide49
13.6.1 Manchester Encoding
0 1 1 0 0 1 0 1 1 Slide50
13.6.1 Ethernet
Hidden Terminal ProblemSlide51
13.6.2 Token RingSlide52
Comparison
Link Layer Protocol
Features
Pros
Cons
Ethernet
Member of random access protocol family; opportunistic broadcast using CSMA/CD; exponential backoff on collision
Simple to manage; works well in light load
Too many collisions under high load
Token ring
Member of taking turns protocol family; Token needed to transmit
Fair access to all competing stations; works well under heavy load
Unnecessary latency for token acquisition under light loadSlide53
13.6.3 Other link layer protocols
FDDI: Fiber Distributed Data InterfaceFiber optics basedHigh bandwidth backbone used to connect LAN'sATM: Asynchronous Transfer Mode
Guarantees quality of service using link reservation and admission control to avoid congestion
Connection oriented and can have transport layer implemented on top of it
Used in MAN's and WAN's
PPP: Point to Point
Used by dial-up connections
WidespeadSlide54
13.6.3 Other link layer protocols
Ethernet is really not just one protocol. As obsolescence approaches a new version is introduced and typically comes out on top FDDI was upstaged by Gigabit EthernetATM is likely to be upstaged by 10-Gigabit EthernetSlide55
13.7 Relationship between the three layers
Both TCP and IP include error checkingThey don't have to be used togetherMost layers are in software but the link layer is often implemented in hardwareSlide56
13.8 Data structures for packet transmission
/* Packet Header Data Structure */
struct
header_t
{
int
destination_address
; /* destination address */
int
source_address
; /* source address */
int
num_packets
; /* total number of */
/* packets in message */
int
sequence_number
; /* sequence number of */
/* this packet */
int
packet_size
; /* size of data */
/* contained in the */
/* packet */
int
checksum; /* for integrity check of */
/* this packet */
};Slide57
13.8 Data structures for packet transmission
/* Packet Data Structure */
struct
packet_t
{
struct
header_t
header; /* packet header */
char *data; /* pointer to the memory */
/* buffer containing the data */
/* of size
packet_size
*/
};Slide58
13.9 Message transmission time
P1
Protocol
stack
Network
P2
Protocol
stack
S
R
T
w
msg
pkt1
pkt2
pktn
…
T
fSlide59
13.9 Message transmission time
Sender
Overhead
Time on
the wire
Time of
Flight
Receiver
OverheadSlide60
13.10 Protocol Layering
Layering is a structuring tool for combating complexity of protocol stack Allows partitioning total responsibility for message transmission and reception among various layers. Modularity allows integration of a new module at a particular layer with minimal changes to the other layers.
It might appear that a potential downside to layering might be a performance penalty, as the message has to traverse several layers.
Judicious definition of interfaces between layers avoids such inefficiencies.Slide61
13.10.1 OSI Model
Presentation layer subsumes user directed input/output functionalities that are common across different applications.Session layer maintains process-to-process communication details and provides a higher-level abstraction between an application and the transport layer (e.g. Unix socket).
Application
Presentation
Transport
Network
Data Link
Physical
Session
7
6
5
4
3
2
1Slide62
13.10.2 Practical issues with layering
Application
Presentation
Transport
Network
Data Link
Physical
Session
7
6
5
4
3
2
1
Physical
Ethernet Card
IP
TCP
Telnet, FTP, etc.
1
2
3
4
5Slide63
13.11 Networking HardwareHub/RepeaterSlide64
13.11 Networking Hardware
More HubsSlide65
13.11 Networking HardwareBridge
HUB
HUB
BRIDGE
1
2
3
4
Collision domain
Collision domain Slide66
13.11 Networking HardwareSwitchSlide67
13.11 Networking HardwareVLAN
Switch
1
2
3
4
Switch
5
6
7
8Slide68
13.11 Networking HardwareNIC
MAC address
Message
Header
Payload Slide69
13.11 Networking HardwareRouter
IP address of the destination
Message
MAC address of router
Payload for the router
Payload for destination node Slide70
13.11 Networking Hardware
Name of Component
Definition/Function
Host
A computer on the network; this is interchangeably referred to as
node
and
station
in computer networking parlance
NIC
Network Interface Card; interfaces a computer to the LAN; corresponds to layer 2 (data link) of the OSI model
Port
End-point on a repeater/hub/switch for connecting a computer; corresponds to layer 1 (physical) of the OSI model
Collision domain
Term used to signify the set of computers that can interfere with one another destructively during message transmission
Repeater
Boosts the signal strength on an incoming port and faithfully reproduces the bit stream on an outgoing port; used in LANs and WANs; corresponds to layer 1 (physical) of the OSI modelSlide71
13.11 Networking Hardware
Name of Component
Definition/Function
Hub
Connects computers together to form a single collision domain, serving as a multi-port repeater; corresponds to layer 1 (physical) of the OSI model
Bridge
Connects independent collision domains, isolating them from one another; typically 2-4 ports; uses MAC addresses to direct the message on an incoming port to an outgoing port; corresponds to layer 1 (physical) of the OSI model
Switch
Similar functionality to a bridge but supports several ports (typically 4-32); provides expanded capabilities for dynamically configuring and grouping computers connected to the switch fabric into VLANs; corresponds to layer 1 (physical) of the OSI model
Router
Essentially a switch but has expanded capabilities to route a message from the LAN to the Internet; corresponds to layer 3 (network) of the OSI model
VLAN
Virtual LAN; capabilities in modern switches allow grouping computers that are physically distributed and connected to different switches to form a LAN; VLANs make higher level network services such as broadcast and multicast in Internet subnets feasible independent of the physical location of the computers; corresponds to layer 1 (physical) of the OSI modelSlide72
13.12 Network Programming
P1
P2
Socket Slide73
13.12.1 Unix Sockets
Socket: create an endpoint of communicationBind: bind a socket to a name or an address
Listen
: listen for incoming connections on the socket
Accept
: accept an incoming connection request on a socket
Connect
: send a connection request to a name (or address) associated with a remote socket
Recv
: receive incoming data on a socket from a remote peer
Send
: send data to a remote peer via a socket Slide74
13.13 Network Services and Higher Level Protocols
P1
P2
foo (args)
foo (args)
return
RPC
Host 1
Host 2 Slide75
13.13 Network Services and Higher Level Protocols
User
fopen
NFS client
RPC layer at client
RPC layer at server
NFS server
Unix file system
Unix file system
Network Slide76
13.15 Historical Perspective
From Telephony to Computer NetworkingEvolution of the InternetPC and the arrival of LAN
Evolution of LANSlide77
13.15.1 From Telephony to Computer Networking
1875 Telephone invented…analog system1960 Telephone infrastructure goes digitalSlide78
13.15.1 From Telephony to Computer Networking
1940's Mainframe computers developed1960's TransitionBatch-oriented card-input/output
CRT I/O and timesharingSlide79
13.15.1 From Telephony to Computer NetworkingSlide80
13.15.1 From Telephony to Computer Networking
EXTRA!!!!!
1960 AT&T
INTRODUCES
DATAPHONE
First Commercial
Modem!Slide81
13.15.1 From Telephony to Computer Networking
1968/9 Carterphone decision allowed devices which were beneficial and not harmful to the network to be connected to the Public Switched Telephone Network (PSTN).
Paved the way for computers to communicate using the telephone switching infrastructure.Slide82
13.15.2 Evolution of the Internet
1965 DoD DARPA plans first computer network1969 ARPANET connects 4 computers using packet switched networkStanford Research Institute, UCLA, UC Santa Barbara, and the University of Utah
Networking luminary Leonard
Kleinrock
, is credited with successfully sending the first network “message” from UCLA to Stanford.Slide83
13.15.2 Evolution of the Internet
“Router” in the network was called Interface Message Processor (IMP), built by a company called BBN (which stands for Bolt, Beranak
, and Newman Inc.).
IMP system architecture required a careful balance of the hardware and software that would allow it to be used as a store-and-forward packet switch among these computers.
IMP's used modems and leased telephone lines to connect to one another.
1971 The ARPANET grows to 23 hosts connecting universities and government research centers around the country. Slide84
13.15.2 Evolution of the Internet
1973 Robert Metcalfe and David Boggs invent the Ethernet networking system at the Xerox Palo Alto Research Center.Slide85
13.15.2 Evolution of the Internet1973 The ARPANET goes internationalSlide86
13.15.2 Evolution of the Internet
1975 Internet operations transferred to the Defense Communications Agency 1978 Hayes Microcomputer Products releases the first mass-market modem, transmitting at 300 bps (0.3K).1980 John
Shoch
at Xerox creates the first “worm” program, with the capacity to travel through networks.
1981
Ungermann
-Bass ships the first commercial Ethernet network interface card.Slide87
13.15.2 Evolution of the Internet
1981 ARPANET has 213 hosts. A new host is added approximately once every 20 days. 1982 The term 'Internet' is used for the first time. 1983 TCP/IP becomes the universal language of the Internet. Developed by Vinton Cerf and Robert Kahn
1984 CISCO founded
Early 80's Unix and IBM OS included TCP/IPSlide88
13.15.2 Evolution of the Internet
Late 90's Internet becomes household termNeeded PCNeeded "Killer app" i.e. WWW & browsersSlide89
13.15.3 PC and the arrival of LAN
1971 Intel introduces the first microprocessor - the Intel 4004.1971 The Kenbak-1, the first microcomputer, is introduced in Scientific American, selling a total of 40 units in 2 years.
Used 130 IC's with a 256 byte memory and 8-bit words, processed 1000 instructions per second, and cost $750.Slide90
13.15.3 PC and the arrival of LAN1972 Intel launches the 8-bit 8008 - the first microprocessor which could handle both upper and lowercase characters.
1972 Xerox develops the Xerox Alto - the first computer to use a Graphic User Interface.
The
Alto
consists of four major parts: the graphics
display
, the
keyboard
, the graphics
mouse
, and the disk s
torage/processor
box. Each
Alto
is housed in a beautifully formed, textured beige metal cabinet that hints at its $32,000 price tag (1979US money). With the exception of the disk storage/processor box, everything is designed to sit on a desk or tabletopSlide91
13.15.3 PC and the arrival of LAN
1973 Robert Metcalfe and David Boggs invent the Ethernet networking system at the Xerox Palo Alto Research Center.Slide92
13.15.3 PC and the arrival of LAN
1974 Intel introduces the 8080 microprocessor5 times faster than the 8008. And the heart of the future Altair 8800.
1975 MITS markets the Altair 8800 - the first mass-market microcomputer, launching the Personal Computer Revolution.
1975 Bill Gates and Paul Allen form the Microsoft company to create software for the new Altair 8800.Slide93
13.15.3 PC and the arrival of LAN
1976 Apple Computer is formed by Steve Jobs, Steve Wozniak, and Ron Wayne, and launches the Apple Computer.1977 Tandy Radio Shack ships its first personal computer - the TRS-80. It sells over 10,000 units, tripling expectations.1977 Apple Computer launches the Apple II, which sets new standards for sophisticated personal computer systems.Slide94
13.15.3 PC and the arrival of LAN
1978 The C programming language is completed at AT&T Bell Laboratories, offering a new level of programming.1978 Apple and Tandy ship PCs with 5.25" floppy disks, replacing cassette tape as the standard storage medium for PCs.1978 Hayes Microcomputer Products releases the first mass-market modem, transmitting at 300 bps (0.3K).Slide95
13.15.3 PC and the arrival of LAN
1978 Intel ships the Intel 8086 microprocessor, with 29,000 transistors, and running at 4.77 megahertz.1979 Personal Software creates VisiCalc for the Apple II, the first electronic spreadsheet program, selling over 100,000 copies.1979 Intel develops the 8088 microprocessor, which would later become the heart of the IBM PC.Slide96
13.15.3 PC and the arrival of LAN
1979 Motorola develops the Motorola 68000 microprocessor, offering a new level of processing power.1979 Robert Metcalf founded 3COM1980 Seagate Technology introduces the first microcomputer hard disk, capable of holding 5 megabytes of data.
1980 Philips introduces the first optical laser disk, with many times the storage capacity of floppy or hard disks.Slide97
13.15.3 PC and the arrival of LAN
1980 Xerox creates Smalltalk - the first object-oriented programming language.1981 Ungermann-Bass ships the first commercial Ethernet network interface card
.
1981 Xerox introduces the Xerox Star 8010, the first commercial Graphic User Interface computer, for $16,000-$17,000.Slide98
13.15.3 PC and the arrival of LAN
1981 Microsoft supplies IBM with PC-DOS (which it would also sell as MS-DOS), the OS that would power the IBM PC.1981 IBM brings to market the IBM PC, immediately establishing a new standard for the world of personal computers.Slide99
13.15.4 Evolution of LAN
Thicknet
Coaxial cable/Vampire taps
10base5 (10
Mbits
/sec, baseband, 500 meters)
1979-1985Slide100
13.15.4 Evolution of LAN
Thinnet
Coaxial cable/BNC connectors
10base2 (10
Mbits
/sec, baseband, 200 meters)
1985-1993Slide101
13.15.4 Evolution of LANFast Ethernet
Move "ethernet" into the box100baseT (T for twisted pair)RJ45 Connectors