Networking vor dem
Internet
Alex Zwahlen, HB9MKU
Bern, 29 Oktober 2014
Zu meiner Person 1/2
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Ausbildung:
1964-68: Lehre Elektronikgerätemechaniker (EGM)
 1968-71: HTL Burgdorf (Elektro - Schwachstrom)
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1972-73 Oy Strömberg AB (ABB) Finland
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1974-94 Digital Equipment Corporation Europe
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Minicomputer real-time applications design
Tele-/Datacomm Tech. Support & Market Analysis
1995-2006 AT&T International
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Corporate Networking
Zu meiner Person 2/2
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1974-78: DEC Datacomm applications support
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1978-1982: DECnet III, X.25
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E-Mail, Videotex, Computer Integrated Telephony
DECnet: ISDN, X.21 integration
1986-1990: DEC: Scientific/Academic Networks
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Packet Switching, Peer-to-Peer, Dynamic routing
1982-1986: DEC: Office Communications
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Message (TTY) switches, IBM 360/370 Front ends
Batch Terminal emulators for IBM/CDC/UNIVAC
First DECnet products (Point-to-Point)
ISO/OSI vs TCP/IP and their integration into DECnet
1990-1994: DEC: Central & Eastern Europe Telecom
1995-2006: AT&T: Global Corporate Networking
Main Topics
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Data Communication Network Topologies
Hierarchical: Batch Terminal, Multiuser On-Line
 Peer-to-peer: Distributed Computing
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Timesharing and Message Switching
History of Packet Switching
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X.25, Videotex, Ethernet
IBM’s SNA and DEC’s DECnet
Protocol Wars: ISO/OSI vs TCP/IP
Science & Academic networks
Early Data Processing
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1884: Punched Cards invented by Hollerith
1911: Hollerith renamed “Computing Tabulating
Recording Corporation (CTRC)”, then
 1924: “International Business Machines (IBM)”
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1964: IBM System/360 introduced
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1974: RJE emulation with Minicomputers
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Remote Job Entry (RJE) via terminal IBM 2780
E.g. DEC to IBM, to Univac, to CDC
File Transfer between heterogeneous systems!
Multi-user on-line computing
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Multiple Users & Terminals on single system
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Timesharing: Full system is shared among users
Program Development, Scientific computing
 Typical Terminals were TTY, later glass-tube VDU
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Point-to-point asynchronous
Transaction processing: limited functions for high
number of users / terminals
Functions as defined by applications, typically against
common database
 Data Entry, Airline Reservation Systems, Banking, Retail
 A typical terminal was IBM 3270
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Multipoint Synchronous (BSC protocol in 1967)
Remote Job Entry Terminals
IBM 2780
RJE Terminal
DEC PDP-11 2780
RJE Emulator
Local Area Connections
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Local: typically same building, often same floor
To connect terminals to computer
Direct wired 4-20mA current loops
 Via Data Switches (e.g. Gangdalf)
 Multipoint/Multidrop serial lines (BSC)
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To interconnect computer systems
Via (parallel-) channel interfaces
 Very Vendor specific, some de-facto standards
 E.g. the IBM/360 channel interface
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Interactive Terminals
TTY
ASR33
IBM
3277
DEC
VT52
Message Switching & SITA
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1837: Electric Telegraph for Railroad
1933: 1st Telex Service in Germany
1948: Store and Forward TWX – Reperforator
1950: SITA opens Manual TTY center in Rome
1966: SITA creates Computer based Store and
Forward Message Center in Franfurt
1969: SITA operates 1st worldwide PS VAN
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PS VAN = Packet Switched Value Added Network
1972: SITA spins off the VAN renamed Equant
1999: France Telecom (ORANGE) buys Equant
Tymeshare & Tymnet
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1964: Tymshare Service Bureau created
1979: Tymnet Value Added Net is spun off
1984: McDD buys Tymnet -> MDNSC
1989: BT buys MDNSC -> BT GNS
1993-98: “Concert” joint venture BT + MCI
1998-2003: break up - 5 years to separate networks!
 MCI moves customers to TCP/IP
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2000-03: “New Concert” alliance BT + AT&T
2004: BT shuts down last Tymnet supervisor…
History of Packet Switching 1/3
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1958: DARPA created (after Sputnik shock)
1960: SAGE + SABRE: TTY based communications
1961: Sabotage of 3 Microwave Towers in US
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1962: Basic Packet Switching Principles defined
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US West-coast cut off for days
P.Baran (US) objective: reduce vulnerability
D.Davies (UK) objective: share expensive links
Chop data in small blocks, route them individually over
meshed networks to logical addresses
1964: NPL and MIT launched PS experiments
1965: 1st Peer-to-Peer cross-continental WAN
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Arpanet precursor with NCP (Network Control Program)
History of Packet Switching 2/3
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1969: 1st message over Arpanet, a remote login
1969: SITA opens 1st worldwide PS VAN
1971: CYCLADES (F) starts experimental
datagram network (1981 forced to close by FT)
1973: TCP/IP specifications, includes datagram
concepts from CYCLADES (L.Pouzin)
1974: L.Pouzin paper on “Interconnection of
Packet Switched Networks” -> Internet
1975: Arpanet size 99 computers (1980 = 200)
History of Packet Switching 3/3
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1978: Cerf & Kahn publish stable TCP/IP
specification
1981: CSNET (Computer Science Net) created
to avoid conflicts with ARPA.
1981: BITnet created based on IBM’s VNET
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Mainframes, File transfer, E-Mail
1984: EARN = BITnet Europe
1983: Arpanet migrates NCP to TCP/IP.
Splitting TCP and IP was critical to move to Internet
 Internet = Network Interconnecting Networks
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Example: “IP over Avian Carriers” (RFC 1149)
X.25
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X.25 design assumes error prone circuits
Corrects errors in the network
 Mostly used with switched virtual circuits
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1980: Stable X.25 standard, used in Public nets
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US: Compuserve, Tymnet, UK: PSS, F: Transpac, D:
Datex-P, Telenet, etc.
X.25 made Mass-Terminal Nets cost-effective:
Cash-dispenser networks, Point-of-Sales
 Videotex services (D: Btx, F: Minitel)
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Videotex – precursor to WWW
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1983 Bildschirmtext (Telephony Approach)
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1982-2012 Minitel (IT Approach)
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All Data on “Btx-Zentrale” in Ulm (IBM based)
Pages are cached in regional centers
External Databases complex, only large companies could
afford them (e.g. mail-order Quelle)
Btx -> Datex-J (1993) -> T-Online Classic (1995)
Terminal connects to PAD on Transpac (X.25 net)
PAD connects via Transpac to Minitel Servers,
Servers can be any size, ideal for SME
2000: 25Mio Users, 9Mio terminals, €1Billion/year
1982: DEC VAX VTX: Corporate Videotex system
LAN Packet Switching - Ethernet
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1971: ALOHAnet: 1st public demo of Packet
Radio
1980: Ethernet standard available (CSMA/CD),
developed during 1970’s by Xerox, Intel, DEC
1981: 1st Ethernet products by 3-Com
1983: DEC sells Ethernet, IBM announced TR
Status 1983: DECnet vs IBM SNA
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DECnet IV
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Peer-to-Peer
Dynamic Routing (as in
Internet)
LAN’s Ethernet based
64’000 addressable nodes
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IBM SNA
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Terminal – Mainframe
Strictly controlled by
NCP
LAN’s Token Ring
TR
Science & Academic Networks
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1981: CSNET & BITnet created
1983: UNIX (with free TCP/IP) spreads in S&A
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1985: RARE (Réseau Associée pour la Recherche
Européenne) created, promotes ISO/OSI
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USEnet (UNIX), EARN (IBM), HEPnet & SPAN (DEC)
1986: CSNET => NSFNET based on TCP/IP
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Creates UNIX specific networked applications
UUCP mail & file transfer, newsgroups, bulletin boards
Open to all S&A, creating TCP/IP market
1990: European S&A officially supports TCP/IP
1991: NSF lifts restrictions on commercial use
1992: WWW/HTML, 1993 Mosaic browser
Large Distributed Computing Nets
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DECnet
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1987: DEC EASYNET has 25’000 nodes
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1990: HEPnet+SPAN have 20’000 nodes
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Internet has 28’000 hosts
Internet has 300’000 hosts
Gateways
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1983: HEPnet+SPAN to NSFnet/Internet
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Full function
1985 EASYNET-Internet for E-Mail, File x-fer
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Important for Firewall Developments
First Abuses
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1978: 1st Spam mail: DEC to all on ARPANET
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1987: German (KGB) Hacker in sensible US Systems
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Infected IBM systems only
1988: First Internet worm (Morris on UNIX)
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Traced via Tymnet/Telenet and Dial-Up
Wake-up call for better authentication/protection
1987: Christmas worm - BITnet, EARN, VNET
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DEC sends DEC-20/ARPANET sales information
DEC blamed for “Commercial Abuse” of network
Estimated 10% of 60’000 nodes attacked
1989: DECnet worm in HEPnet/SPAN
ISO/Open Systems Interconnect
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1980: First OSI model published
1988-95: Government OSI Profiles (GOSIP)
1990: OSI in European Procurement Handbook and
in US Federal Info Processing Standards (FIPS)
 1990: European Academics formally adopt TCP/IP
 1995: FIPS mandates no longer OSI, instead any
ISO, ITU-T or IETF standards can be used
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Why OSI didn’t succeed?
OSI too late, complicated, expensive, unproven
 Euro Academic’s “supported” OSI mainly to get €
 EDP suppliers “not really” supporting a 3rd stack
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Frame Relay, ATM
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FR designed during 1980’s for low error links
1990 Gang of 4: Cisco, DEC, NT, Stratacom
created FR Forum. Standards accepted in 1991
 Removed lots of X.25 error correcting overhead
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DTE’s have to detect + correct errors, 56Kbps–45Mbps
 QoS by Service Providers
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1993-98 Plusnet AG (CH + D)
ATM – Broadband ISDN
Low jitter, fixed 53 byte cells,
 34-155Mbps
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International Network Alliances
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Motivation: Single Point of Contact for
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Unisource (1991-99)
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KPN (NL), Televerket (S), Swisscom (CH), Telefonica (E)
AT&T (USA) in 1994 (AT&T – Unisource)
Concert (1993-2003)
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FR/ATM ports & PVCs, Access, On-Premise Routers
1993-98: British Telecom & MCI (USA)
2000-03: British Telecom & AT&T (USA)
GlobalOne (1996 - 2000)
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Deutsche Telekom, France Telecom, Sprint (USA)
Ended in 2000 when FT acquired Equant
International Corporate
Networks
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BMW 2000
Domestic sites networked by Deutsche Telekom
 Other countries by AT&T
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Siemens 2003
IT Network outsourced to AT&T and Telekom
 Telekom: D, Eastern Europe, Italy, Nordic
 AT&T: Rest of Europe & Worldwide
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2003+: VPN over Internet, ADSL access
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No QoS, but cheap!
Cost-Example: Transatlantic Cable
Name:
Capaciy
Cable
Repeater
Total #
Voice-ch.
Cost/Voicech. SFr/mo
SFr / min
(8h/day)
1956: TAT-1
144kHz 48vc
later doubled
Dual coax CanadaScotland
Vacuum tube
unidirectional
96
150’000
10.42
1963: TAT-3
138vc
Coax US-England
Vacuum tube
bidirectional
138
105’000
7.25
1970: TAT5
845vc
Coax US-France
Germanium
transistor
845
17’000
1.18
1974:
1840vc
Coax CanadaEngland
Silicon transistor
1840
7’800
0.54
1976: TAT-6
2 Cables à
4200vc/cable
Coax US-France
Silicon transistor
4200
3’500
0.24
1983: TAT-7
2 x 4200vc
Coax US-England
Silicon transistor
4200
3’500
0.24
1988: TAT-8
2 Pairs à 280
Mbps / 4000vc
Optical 1.3um SM
Regenerative
O-E-O
8000
1’800
0.13
1991: TAT-9
3 Pairs à
560Mbps/pair
Optical
Regenerative
O-E-O
24’000
600
0.04
1994:
2.5 GBps
Optical
Regenerative
O-E-O
36’000
400
0.03
TAT-12/13
2 Pairs à 5Gbps,
later tripled
Optical 1.55um (2
addl wl later)
Optical amplifier
144’000
100
0.0069
2001: TAT-14
4 Pairs à
160Gbps
Optical (16 wl à
10Gbps)
Optical amplifier
10’000’000
1.44
0.0001
2000-03: TGN
8 Pair7680Gbps
Optical
Optical amplifier
100’000’000
0.14
0.0000
CANTAT-2
CANTAT-3
1995: