COPE-08 Networks.indd
8
Networks
Uwe R. Zimmer – The Australian National University
Computer Organisation & Program Execution 2021
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 438 of 489 (chapter 8: “Networks” up to page 466)
References for this chapter
[Patterson17]
David A. Patterson & John L. Hennessy
Computer Organization and Design – The Hardware/Software Interface
Chapter 4 “The Processor”,
Chapter 6 “Parallel Processors from Client to Cloud”
ARM edition, Morgan Kaufmann 2017
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 439 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
OSI network reference model
Standardized as the
Open Systems Interconnection (OSI) reference model by the
International Standardization Organization (ISO) in 1977
• 7 layer architecture
• Connection oriented
Hardy implemented anywhere in full …
…but its concepts and terminology are widely used,
when describing existing and designing new protocols …
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 440 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
Application
Presentation
Session
Transport
Network
Data link
Physical
Application
Presentation
Session
Transport
Network
Data link
Physical
Network
Data link
Physical
User data User data
OSI Network Layers
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 441 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
1: Physical Layer
• Service: Transmission of a raw bit stream
over a communication channel
• Functions: Conversion of bits into electrical or optical signals
• Examples: X.21, Ethernet (cable, detectors & amplifi ers)
Application
Presentation
Session
Transport
Network
Data link
Physical
Application
Presentation
Session
Transport
Network
Data link
Physical
Network
Data link
Physical
User data User data
OSI Network Layers
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 442 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
2: Data Link Layer
• Service: Reliable transfer of frames over a link
• Functions: Synchronization, error correction, flow control
• Examples: HDLC (high level data link control protocol),
LAP-B (link access procedure, balanced),
LAP-D (link access procedure, D-channel),
LLC (link level control), …
Application
Presentation
Session
Transport
Network
Data link
Physical
Application
Presentation
Session
Transport
Network
Data link
Physical
Network
Data link
Physical
User data User data
OSI Network Layers
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 443 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
3: Network Layer
• Service: Transfer of packets inside the network
• Functions: Routing, addressing, switching, congestion control
• Examples: IP, X.25
Application
Presentation
Session
Transport
Network
Data link
Physical
Application
Presentation
Session
Transport
Network
Data link
Physical
Network
Data link
Physical
User data User data
OSI Network Layers
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 444 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
4: Transport Layer
• Service: Transfer of data between hosts
• Functions: Connection establishment, management,
termination, flow-control, multiplexing, error detection
• Examples: TCP, UDP, ISO TP0-TP4
Application
Presentation
Session
Transport
Network
Data link
Physical
Application
Presentation
Session
Transport
Network
Data link
Physical
Network
Data link
Physical
User data User data
OSI Network Layers
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 445 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
5: Session Layer
• Service: Coordination of the dialogue between application programs
• Functions: Session establishment, management, termination
• Examples: RPC
Application
Presentation
Session
Transport
Network
Data link
Physical
Application
Presentation
Session
Transport
Network
Data link
Physical
Network
Data link
Physical
User data User data
OSI Network Layers
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 446 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
6: Presentation Layer
• Service: Provision of platform independent coding and encryption
• Functions: Code conversion, encryption, virtual devices
• Examples: ISO code conversion, PGP encryption
Application
Presentation
Session
Transport
Network
Data link
Physical
Application
Presentation
Session
Transport
Network
Data link
Physical
Network
Data link
Physical
User data User data
OSI Network Layers
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 447 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
7: Application Layer
• Service: Network access for application programs
• Functions: Application/OS specific
• Examples: APIs for mail, ftp, ssh, scp, discovery protocols …
Application
Presentation
Session
Transport
Network
Data link
Physical
Application
Presentation
Session
Transport
Network
Data link
Physical
Network
Data link
Physical
User data User data
OSI Network Layers
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 448 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
Application
Presentation
Session
Transport
Network
Data link
Physical
Application
Presentation
Session
Transport
Network
Data link
Physical
IP
Network
Physical
User data User data
OSI
Transport
Application
TCP/IP OSI
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 449 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
Application
Presentation
Session
Transport
Network
Data link
Physical
AppleTalk Filing Protocol (AFP)
Routing Table
Maintenance Prot.
IP
Network
Physical
OSI
Transport
Application
TCP/IP AppleTalk
AT Update Based
Routing Protocol
AT Transaction
Protocol
Name
Binding Prot.
AT Echo
Protocol
AT Data Stream
Protocol
AT Session
Protocol
Zone Info
Protocol
Printer Access
Protocol
Datagram Delivery Protocol (DDP)
AppleTalk Address Resolution Protocol (AARP)
EtherTalk Link
Access Protocol
LocalTalk Link
Access Protocol
TokenTalk Link
Access Protocol
FDDITalk Link
Access Protocol
IEEE 802.3 LocalTalk
Token Ring
IEEE 802.5
FDDI
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 450 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
Application
Presentation
Session
Transport
Network
Data link
Physical
IP
Network
Physical
OSI AppleTalk over IP
EtherTalk Link
Access Protocol
LocalTalk Link
Access Protocol
TokenTalk Link
Access Protocol
FDDITalk Link
Access Protocol
IEEE 802.3 LocalTalk
Token Ring
IEEE 802.5
FDDI
AppleTalk Filing Protocol (AFP)
Routing Table
Maintenance Prot.
AT Update Based Routing
Protocol
AT Transaction
Protocol
Name Binding
Protocol
AT Echo
Protocol
AT Data Stream Protocol AT Session Protocol Zone Info Protocol Printer Access Protocol
Datagram Delivery Protocol (DDP)
AppleTalk Address Resolution Protocol (AARP)
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 451 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
Serial Peripheral Interface (SPI)
Used by gazillions of devices … and
it’s not even a formal standard!
Speed only limited by what
both sides can survive.
Usually push-pull drivers,
i.e. fast and reliable, yet not friendly to wrong
wiring/programming.
1.8” COLOR TFT LCD display from Adafruit SanDisk marketing photo
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 452 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
Serial Peripheral Interface (SPI)
Full Duplex, 4-wire, fl exible clock rate
Receive shift register
Transmit shift register
Clock generator
Receive shift register
Transmit shift register
MISO MISO
MOSI MOSI
SCK SCK
NSS CS
Slave selector
Master Slave
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 453 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
Serial Peripheral Interface (SPI)
MISO
MOSI
SCK
CS
time
Set
Sample
Set Set Set Set Set Set Set
Sample Sample Sample Sample Sample Sample Sample
Receive shift register
Transmit shift register
Clock generator
Receive shift register
Transmit shift register
MISO MISO
MOSI MOSI
SCK SCK
NSS CS
Slave selector
Master Slave
Clock phase and
polarity need to
be agreed upon
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 454 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards (SPI)
Serial Peripheral Interface (SPI)
Receive shift register
Transmit shift register
Clock generator
Receive shift register
Transmit shift register
MISO MISO
MOSI MOSI
SCK SCK
NSS CS
Slave selector
Master Slave
from STM32L4x6 advanced ARM®-based 32-bit MCUs reference manual: Figure 420 on page 1291
1 shift register?
FIFOs?
Data connected to
an internal bus?
CRC?
DMA?
Speed?
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 455 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards (SPI)
Receive shift register
Transmit shift register
Clock generator
Receive shift register
Transmit shift register
MISO MISO
MOSI MOSI
SCK SCK
NSS CS
Slave selector
Master Slave
Receive shift register
Transmit shift register
Clock generator
Receive shift register
Transmit shift register
MISO MISO
MOSI MOSI
SCK SCK
S1 CS
Slave selector
Master Slave 1
Receive shift register
Transmit shift register
Slave 2
Receive shift register
Transmit shift register
Slave 3
MISO
MOSI
SCK
CS
MISO
MOSI
SCK
CS
S2
S3
Full duplex with 1
out of x slaves
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 456 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards (SPI)
Receive shift register
Transmit shift register
Clock generator
Receive shift register
Transmit shift register
MISO MISO
MOSI MOSI
SCK SCK
NSS CS
Slave selector
Master Slave
Receive shift register
Transmit shift register
Clock generator
Receive shift register
Transmit shift register
MOSI MOSI
SCK SCK
S1 CS
Slave selector
Master Slave 1
Receive shift register
Transmit shift register
Slave 2
Receive shift register
Transmit shift register
Slave 3
MOSI
SCK
CS
MOSI
SCK
CS
S2
S3
Concurrent simplex
with y out of x slaves
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 457 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards (SPI)
Receive shift register
Transmit shift register
Clock generator
Receive shift register
Transmit shift register
MISO MISO
MOSI MOSI
SCK SCK
NSS CS
Slave selector
Master Slave
Receive shift register
Transmit shift register
Clock generator
Receive shift register
Transmit shift register
MISO MISO
MOSI MOSI
SCK SCK
NSS CS
Slave selector
Master Slave 1
Receive shift register
Transmit shift register
Slave 2
Receive shift register
Transmit shift register
Slave 3
MISO
MOSI
SCK
CS
MISO
MOSI
SCK
CS
Concurrent
daisy chaining
with all slaves
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 458 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
Ethernet / IEEE 802.3
Local area network (LAN) developed by Xerox in the 70’s
• 10 Mbps specification 1.0 by DEC, Intel, & Xerox in 1980.
• First standard as IEEE 802.3 in 1983 (10 Mbps over thick co-ax cables).
• currently 1 Gbps (802.3ab) copper cable ports used in most desktops and laptops.
• currently standards up to 100 Gbps (IEEE 802.3ba 2010).
• more than 85 % of current LAN lines worldwide
(according to the International Data Corporation (IDC)).
Carrier Sense Multiple Access with Collision Detection (CSMA/CD)
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 459 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
Ethernet / IEEE 802.3
OSI relation: PHY, MAC, MAC-client
Application
Presentation
Session
Transport
Network
Data link
Physical
Application
Presentation
Session
Transport
Network
Data link
Physical
Network
Data link
Physical
User data User data
OSI Network Layers
OSI
reference
model
Application
Presentation
Session
Transport
Network
Data link
Physical
IEEE 802.3
reference
model
MAC-client
Media Access (MAC)
Physical (PHY)
Upper-layer
protocols
IEEE 802-specific
IEEE 802.3-specific
Media-specific
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 460 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
Ethernet / IEEE 802.3
OSI relation: PHY, MAC, MAC-client
Application
Presentation
Session
Transport
Network
Data link
Physical
Application
Presentation
Session
Transport
Network
Data link
Physical
Network
Data link
Physical
User data User data
OSI Network Layers
802.3 MAC
Physical medium-
independent layer
MAC Client
MII
Physical medium-
dependent layers
MDI
802.3 MAC
Physical medium-
independent layer
MAC Client
MII
Physical medium-
dependent layers
MDI
PHY
Link media,
signal encoding, and
transmission rate
Transmission rate
MII = Medium-independent interface
MDI = Medium-dependent interface – the link connector
Link
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 461 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
Ethernet / IEEE 802.11
Wireless local area network (WLAN) developed in the 90’s
• First standard as IEEE 802.11 in 1997 (1-2 Mbps over 2.4 GHz).
• Typical usage at 54 Mbps over 2.4 GHz carrier at 20 MHz bandwidth.
• Current standards up to 780 Mbps (802.11ac) over 5 GHz carrier at 160 MHz bandwidth.
• Future standards are designed for up to 100 Gbps over 60 GHz carrier.
• Direct relation to IEEE 802.3 and similar OSI layer association.
Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA)
Direct-Sequence Spread Spectrum (DSSS)
Networks
© 2021 Uwe R. Zimmer, The Australian National University page 462 of 489 (chapter 8: “Networks” up to page 466)
Network protocols & standards
Bluetooth
Wireless local area network (WLAN) developed in the 90’s with different features than 802.11:
• Lower power consumption.
• Shorter ranges.
• Lower data rates (typically < 1 Mbps). • Ad-hoc networking (no infrastructure required). Combinations of 802.11 and Bluetooth OSI layers are possible to achieve the required features set. Networks © 2021 Uwe R. Zimmer, The Australian National University page 463 of 489 (chapter 8: “Networks” up to page 466) Network protocols & standards Token Ring / IEEE 802.5 / Fibre Distributed Data Interface (FDDI) • “Token Ring “ developed by IBM in the 70’s • IEEE 802.5 standard is modelled after the IBM Token Ring architecture (specifi cations are slightly different, but basically compatible) • IBM Token Ring requests are star topology as well as twisted pair cables, while IEEE 802.5 is unspecified in topology and medium • Fibre Distributed Data Interface combines a token ring architecture with a dual-ring, fi bre-optical, physical network. Unlike CSMA/CD, Token ring is deterministic (with respect to its timing behaviour) FDDI is deterministic and failure resistant None of the above is currently used in performance oriented applications. Networks © 2021 Uwe R. Zimmer, The Australian National University page 464 of 489 (chapter 8: “Networks” up to page 466) Network protocols & standards Fibre Channel • Developed in the late 80’s. • ANSI standard since 1994. • Current standards allow for 16 Gbps per link. • Allows for three different topologies: Point-to-point: 2 addresses Arbitrated loop (similar to token ring): 127 addresses deterministic, real-time capable Switched fabric: 224 addresses, many topologies and concurrent data links possible • Defi nes OSI equivalent layers up to the session level. Mostly used in storage arrays, but applicable to super-computers and high integrity systems as well. Networks © 2021 Uwe R. Zimmer, The Australian National University page 465 of 489 (chapter 8: “Networks” up to page 466) Network protocols & standards Fibre Channel Mapping of Fibre Channel to OSI layers: Application Presentation Session Transport Network Data link Physical Application Presentation Session Transport Network Data link Physical IP Physical User data User data OSI TCP/IP OSI IP Physical Application FC/IP FC-0 Application FibreChannel FC-4 FC-4 FC-3 FC-2 FC-3 FC-2 FC-1 TransportTransport NetworkNetwork Application FC-3 Common service FC-4 Protocol mapping FC-2 Network FC-0 Physical FC-1 Data link Networks © 2021 Uwe R. Zimmer, The Australian National University page 466 of 489 (chapter 8: “Networks” up to page 466) Networks • Network layer models • Open Systems Interconnection (OSI) reference model • Practical network standards • Serial Peripheral Interface (SPI) • Ethernet / IEEE 802.3 (CSMA/CD) • Tokenring / IEEE 802.5 / FDDI • Wireless networks / IEEE 802.11 (CSMA/CA, DSSS) • Fibre Channel Summary