Unmodified Ethernet for Industrial Automation

© EtherCAT Technology Group

Unmodified Ethernet for Industrial Automation?

• Benefits of Ethernet for Automation• Ethernet Features – an Overview• Limiting Factors of Ethernet as Fieldbus Replacement

Fieldbus FoundationHigh Speed Ethernet (HSE):

What are the benefits of HSE?

….Use of unmodified Ethernet and standard IP makes HSE systems more

cost-effective than other Ethernet solutions and proprietary networks….

SUE: Standard UnmodifiedEthernet


Benefits of Ethernet for Automation

• Ethernet is in use for Controller/Controller communication since many years, as it saves money to use commodity technologies:Examples:

• CAN (originally developed for automotive applications)

• PC-based Controls

• Windows + Linux

• So Automation benefits from the much larger IT Communication

• Thus low cost hard- and software

• If also on Fieldbus ( I/O, Sensor and Drives) Level: just one communication technology remaining

• Improvement also financed (and driven !) by others


Ethernet Overview: CSMA/CD, TCP/IP & others

• Architecture• Physical Layer: Signal, Cables + Wiring• Media Access Control• Name Resolution• Routing• IP, TCP + UDP

This diagram was hand drawn by Robert M. Metcalfe and photographed by Dave R. Boggs in 1976 to produce a 35mm slide used to present Ethernet

to the National Computer Conference in June of that year.


Ethernet Definition (Wikipedia)

Ethernet is a frame-based computer networking technology for local area networks (LANs).

It defines wiring and signaling for the physical layer, and frame formats and protocols for the media access control (MAC)/data link layer and a common addressing format

Ethernet is standardized as IEEE 802.3.

It has become the most widespread LAN technology in use during the 1990s to the present, and has largely replaced all other LAN standards such as token ring, FDDI, and ARCNET.


7 Application Layercontains a variety of commonly used protocols, such as file transfer, virtual terminal, and email

5 Application Layer: HTTP, FTP, rlogin, Telnet, DHCP,...

6 Presentation Layermanages the syntax and semantics of the information transmitted between two computers

5 Session Layerestablishes and manages sessions, conversions, or dialogues between two computers

4 Transport Layersplits data from the session layer into smaller packets for delivery on the network layer and ensures that the packets arrive correctly at the other end

4 Transport Layer: TCP + UDPHandles communication among programs on a network.

3 Network Layer controls the operation of a packet transmitted from one network to another, such as how to route a packet.

3 Network Layer: IP (Internet Protocol), This layer is used for basic communication, addressing and routing.

2 Data Link Layertransforms a stream of raw bits (0s and 1s) from the physical layer into an error-free data frame (packets) for the network layer

1/2 Medium Access Control (MAC)IEEE 802.3: CSMA/CD (Ethernet), 802.4 Token Bus (ARCnet), 802.5 Token Ring, 802.11 Wireless,

1 Physical Layer transmits signals across a communication medium

Cables, cards and physical aspects: ISO/IEC 11801, parts also in IEEE 802.3

ISO/OSI - Model TCP/IP - Model

ISO/OSI, IEEE 802 and TCP/IP


10GBASE-W W PCS/PMA over undefined PMD 10GBASE-EW W fibre over 1550nm optics10GBASE-LW W fibre over 1310nm optics10GBASE-SW W fibre over 850nm optics10GBASE-KR Backplane Ethernet (802.3ap, 2007)10GBASE-KX4 Backplane Ethernet (802.3ap, 2007)10GBASE-LRM multimode Fibre (802.3aq, 2006)10GBASE-T UTP (802.3an, 2006)40GBASE-SR4 Multimode Fibre, 100m (802.3ba,2010)40GBASE-LR4 Singlemode Fibre, 10km (802.3ba,2010)40GBASE-CR4 Copper Cable Assembly, 10m (802.3ba,2010)40GBASE-KR4 Backplane Ethernet (802.3ba,2010)100GBASE-SR10 Multimode Fibre, 100m (802.3ba,2010)100GBASE-LR4 Singlemode Fibre, 10km (802.3ba,2010)100GBASE-ER4 Singlemode Fibre, 40km (802.3ba,2010)100GBASE-CR10 Copper Cable Assembly, 10m (802.3ba,2010)

Ethernet Transmission Media (IEEE802)

1BASE5 UTP10BASE2 Coax10BASE5 Coax10BROAD36 Coax10BASE-T UTP, duplex mode unknown10BASE-THD UTP, half duplex mode10BASE-TFD UTP, full duplex mode10BASE-FP Passive fiber10BASE-FB Synchronous fiber10BASE-FL Asynchronous fiber100BASE-T2 Two-pair Category 3 UTP100BASE-T4 Four-pair Category 3 UTP 100BASE-TX Two-pair Category 5 UTP100BASE-FX Two-strand Multimode Fibre100BASE-VG Four-Pair Category 3 UTP1000BASE-T Four-pair Category 5 UTP PHY1000BASE-T X Four-pair Category 6 UTP PHY1000BASE-LX Multimode Fibre1000BASE-SX Multimode Fibre or Singlemode Fibre1000BASE-CX X copper over 150-Ohm balanced cable PMD 1000BASE-BX10 Bidirectional single strand Singlemode Fibre1000BASE-LX10 Two-strand Singlemode Fibre1000BASE-PX10 -D Singlemode Fibre, Downstream, 10km1000BASE-PX10 -U Singlemode Fibre, Upstream, 10km1000BASE-PX20 -D Singlemode Fibre, Downstream, 20km1000BASE-PX20 -U Singlemode Fibre, Upstream, 20km1000BASE-KX 1m over Backplane10GBASE-X X PCS/PMA over undefined PMD 10GBASE-LX4 X fibre over 4 lane 1310nm optics10GBASE-CX4 X copper over 8 pair 100-Ohm balanced cable, 15m 10GBASE-R R PCS/PMA over undefined PMD 10GBASE-ER R fibre over 1550nm optics10GBASE-LR R fibre over 1310nm optics10GBASE-SR R fibre over 850nm optics

Large variety of physical layers


Cabling Standards (Copper)

100 MHz 250 MHz 500 MHz 600 MHz 1000 MHz

TIA/EIA568 B.1/2Cat. 5e

ISO/IEC11801:

Class D

CENELECEN50173-1

Class D

TIA/EIA568 B.2-1

Cat. 6

TIA/EIA568 B.2-10

Cat. 6a

ISO/IEC11801:Class E

ISO/IEC11801:

Class EA

CENELECEN50173-1

Class E

CENELECEN50173-1

Class F

ISO/IEC11801:Class F

ISO/IEC11801:

Class FA

TIA/EIA568 B.2Cat. 7

1200 MHz

ISO/IEC11801:

Class G

CENELECEN50173-1

Class G

TIA/EIA568 B.2Cat. 8

IEEE 802.3100BASE-TX1000BASE-T

IEEE 802.310GBASE-T

(100m)

TIA/EIA568 B.2Cat. 7a

IEEE 802.310GBASE-T

(55m)


Tx

Rx

Tx

Rx

Rx

Tx

Rx

Tx

Rx/Tx

Rx/Tx

Rx/Tx

Rx/Tx

Rx/Tx

Rx/Tx

Rx/Tx

Rx/Tx

100BASE-TXtwo pairs:

• one pair sends

• one pair receives

• Encoding: 4B5B – MLT-3Multilevel Transmission Encoding

1000BASE-T four pairs:

• all four pairs send and receive simultaneously

• Encoding: PAM-5 – TCM5-level Pulse Amplitude (PAM-5) with Trellis Coded Modulation (TCM)

Two or Four Pairs?


Start Transmission

Collision Window

undisturbed Transmission Carrier Sense

IEEE 802.3: Media Access Control CSMA/CD

“Carrier-Sense Multiple-Access with Collision-Detection”– The node that wants to send checks if the media is available

“Carrier-Sense”

– All nodes are equal and may send autonomously “Multiple-Access”

– The sender checks after sending if there was a collision “Collision-Detection”

– maximum Ethernet propagation delay: 25,6µs (@10MBit/s)(determined by cable length & repeater delays)


Carrier

Sense

Multiple

Access /

Collision

Detection

Signal Propagation Delay

Node A Node B

A starts sending

Node A Node B

B starts sending

Node A Node B

CollisionNode A Node B

Media Access Control CSMA/CD


Hub

Hub

A

B

• Hubs

• half duplex

• Hub Cascading & Length limited

Ethernet Collision Domain


Switch

Switch

A

B• Switches

• full duplex full duplex communication

Switch sends single cast

communication only to the

destination port

Queues avoid collisions

Switched Ethernet Topology


Most Switches use the “Store and Forward” principle:• Receive entire frame first, check FCS, then forward to destination port. • Advantage: only “healthy” frames are forwarded.• Disadvantage: large and variable forwarding delay

(ca. 10…125 µs, depending on frame length –the buffer delay comes on top)

Only very few Switches make use of the “Cut-Through” principle:• Frames are forwarded shortly after receiving the destination address.• Advantage: shorter delay (ca. 5…7 µs) • Disadvantage: corrupted frames are forwarded as well

FCSPadDATALENSADASFDPreamble

“Store and Forward” vs. “Cut-Through”



• The Length Byte has two meanings: if it is >0x5DC then it describes the type of the “payload” (Ethertype, e.g. IP 0x0800 or ARP 0x0806 or EtherCAT 0x88A4)

• If the data length is <46 Byte, Padding Bytes are introduced to achieve a minimum length of 46 Bytes (for collision detection)

Frame Check Sequence (CRC)


Padding Field

7 1 6 6 2 46-1500 0-46 4 Byte

Data „Payload“LengthSender Address

Destination Address

Start Frame Delimiter „10101011“

Preamble “1010101010.....” used for Bit Synchronisation

Ethernet Packet


“Medium Access Control Address” (MAC-ID) has to be unique• Two Fields of 3 Bytes:

– 1. OUI (Organizationally Unique Identifier)– 2. Serial Number

• The OUI is assignedby the IEEE Standards Department (USA)

• e.g. Beckhoff OUI : 0x00 01 05http://standards.ieee.org/develop/regauth/oui/public.html

Ethernet MAC-ID

Result fromhttp://standards.ieee.org/cgi-bin/ouisearch


Ethernet-Header(MAC-ID) Ethernet

IP-Header(IP-Address) Internet Protocol (IP)

TCP-Header(IP-Port) TCP

08-0

0

PR

OT

(DNS/DHCP/HTTP/FTP)

HostName

AddressResolution

Host NameResolution

„CX_001387“

00 01 05 00 13 87

169.254.254.88

21 (FTP), 80 (HTTP)

Addressing: MAC-ID, IP Address, Host Name

• Structure allows one to exchange protocol layers


?DNS Server

1. Entry in Cache of the DNS Server?

2. if not: ask next “superior” DNS Server

3. “authorative Server” distributes data to all others

authorativeDNS Server

• Changes may take time to propagate through the system(all caches have to be updated)

Host Name Resolution: Domain Name Service Working Principle


TCP Address: Port Number

IPAddress

EthernetAddress: MAC-ID

MAC-ID ?

If no entry in ARP Cache

Send ARP Request (Broadcast)with IP Address and MAC ID

FF FF FF FF FF FF

Communication starts

Node answers with MAC-IDand both MAC-ID and IP-Address

These are entered in ARP Cache

ARP: Address Resolution Protocol


version Hdr Len Service Type Total Length16bit Identification Flags 13bit Fragment Offset

8bit Time to Live 8bit Protocol 16bit Header Checksum32bit Source IP address

32bit Destination IP addressOptions (if any), padding

IP Datagram Data (up to 65535 Bytes)

IP Header and Data CRC0800DASA

20 B

ytes

Ethernet

• Datagram with 20 Byte Header• Unsecured Data Transport from a source address to a destination address• Header: Address, Header-Checksum, Protocol Information, Time to Live,

Fragmentation Information etc.• Supports Routing between Networks• IP-Address: Network- and Host Address• IP-Address resolution via

ARP 0x0806

Internet Protocol (IP)


Problem: Shortage of IP Addresses

IPv4: 32bits = 232= 4,294,967,296 nodes maximum, out of which only 3.706.650.624 can be used (Rest: Class D+E + Special Usage)

Source: Internet World Stats – www.internetworldstats.com/stats.htm

Estimated Internet Users worldwide:

2,267,233,742(Dec 31, 2011)


• On February 3, 2011, the Internet Assigned Numbers Authority (IANA) allocated the last 5 blocks of IPv4 addresses to the 5 Regional Internet Registries (RIR)

• On April 19, 2011, APNIC (Asia Pacific), ran out of addresses.

• Raúl Echeberría, Chairman of the Number Resource Organization (NRO),the official representative of the five RIRs: “This is an historic day in the history of the Internet, and one we have been anticipating for quite some time. The future of the Internet is in IPv6. All Internet stakeholders must now take definitive action to deploy IPv6.”

IPv4 Address Exhaustion now in final stage

Feb 3, 2011


The solution: IPv6 with 3.4 x 1038 Addresses!

IPv6: 128bits = 2128=

340,282,366,920,938,463,463,374,607,431,768,211,456 nodes maximum

– or approximately 4.8 x 1028 for every person alive

– or approximately 4.5 x 1015 for each observable star in the known universe

Next Header16bit Payload Length

Source IP address, Bits 96..127Source IP address, Bits 64..95Source IP address, Bits 32..63Source IP address, Bits 0..31

Destination IP address, Bits 96..127Destination IP address, Bits 64..95Destination IP address, Bits 32..63Destination IP address, Bits 0..31

Hop LimitVersion Traffic Class Flow Label

IPv6 Header

40 B

ytes

However: slow adoption rate of this new internet protocol generation(March 28, 2012: only 0,48%* of the Google users has IPv6)

* Source: www.google.com/intl/en/ipv6/statistics/


• Private IP Addresses, non routable: 10.0.0.0 to 10.255.255.255172.16.0.0 to 172.31.255.255192.168.0.0 to 192.186.255.255

IP-Device172.16.20.3 172.16.17.103

172.16.20.2

172.16.20.1

172.16.17.102

172.16.17.101

Router

172.16.1.1 180.1.1.1

Example: local Network Class B

IP-Device

IP-Device

IP-Device

IP-Device

IP-Device

The intermediate solution: Private Addresses

• but: IP Masquerading (NAT), Proxy,… (communication from local network to internet only)


Classless Inter-Domain Routing

1. within Subnet: Address resolution with ARP

2. if IP Address outside Subnet: send Data with Destination IP Adresse and Gateway-MAC-ID

3. Private Networks (non routable IP Addresses) cannot be reached fromoutside (IP-Masquerading)

168.12.41.52

Gateway

10.13.102.1

10.13.2.2 194.175.173.88

IP Routing: functionality


168.12.41.52

Gateway

10.13.102.1

10.13.2.2 194.175.173.88

A

-Wants to FTP with 194.175.173.88

-FTP control: well known port 21 (TCP)

FTP

from port 21

toport 21

TCP

IP Address: 10.13.2.2

Subnet Mask: 255.255.0.0

Gateway 10.13.102.1

Ethernet MAC ID 00-01-01-02-03-04

A

IP Routing: Example


168.12.41.52

Gateway

10.13.102.1

10.13.2.2 194.175.173.88

A



Gateway 10.13.102.1

Ethernet MAC ID 00-01-01-02-03-04

-TCP passes TCP Datagram to IP

from 10.13.2.2

to194.175.173.88

IP

A

IP Routing: Example


168.12.41.52

Gateway

10.13.102.1

10.13.2.2 194.175.173.88

A



Gateway 10.13.102.1

Ethernet MAC ID 00-01-01-02-03-04

-IP compares IP Addresses according to subnet mask

A

Subnet mask 255.255.0.0 11111111 11111111 00000000 00000000

own IP Addr. 10.13.2.2 00001010 00001101 00000010 00000010

Destination 194.175.173.88 11000010 10101111 10101101 01011000

-result: Net ID parts differ,therefore different net, data has to be forwarded to gateway

IP Routing: Example


168.12.41.52

Gateway

10.13.102.1

10.13.2.2 194.175.173.88

A



Gateway 10.13.102.1

Ethernet MAC ID 00-01-01-02-03-04

-What is the MAC ID of the Gateway?

-Node A sends ARP request

-broadcast with “what is the MAC ID of IP Address 10.13.102.1?

-Gateway answers with ARP response:

-I am 10.13.102.1 and my MAC ID is ….

-Node A enters this MAC ID in ARP cache

A

IP Routing: Example


168.12.41.52

Gateway

10.13.102.1

10.13.2.2 194.175.173.88

A



Gateway 10.13.102.1

Ethernet MAC ID 00-01-01-02-03-04

-ARP cache of Node A (cmd: arp –a)

A

Internet Address Physical address Type

10.13.102.1 00-a0-f9-02-d0-70 dynamic

10.13.2.3 00-05-01-0a-03-02 dynamic

IP Routing: Example


168.12.41.52

Gateway

10.13.102.1

10.13.2.2 194.175.173.88

A



Gateway 10.13.102.1

Ethernet MAC ID 00-01-01-02-03-04

-Ethernet driver packs the IP datagram in an Ethernet packet and sends it to the gateway

A

from 01-01-01-02-03-04

to00-a0-f9-02-d0-70

Ethernet

IP Routing: Example


168.12.41.52

Gateway

10.13.102.1

194.175.173.88

A

B

10.13.2.2

internal IP Address: 10.13.102.1Subnet Mask: 255.255.0.0Ethernet MAC ID 00-a0-f9-02-d0-70externalIP Address 168.12.41.52Subnet Mask: 255.255.0.0Gateway 168.12.78.234Ethernet MAC ID 00-03-47-4A-1A-FF

-Gateway unpacks IP datagram from Ethernet frame

B

from 10.13.2.1

to194.175.173.88

IP

IP Routing: Example


168.12.41.52

Gateway

10.13.102.1

194.175.173.88

A

B


- Replaces local IP Address by its own external IP Address (NAT, IP Masquerading)

B

from 10.13.2.1 168.12.41.52

to194.175.173.88

IP

10.13.2.2

IP Routing: Example


168.12.41.52

Gateway

10.13.102.1

194.175.173.88

A

B


- compares IP addresses according to subnet mask

- decides to forward the datagram to next gateway

- finds MAC-ID of next gateway (ARP)

- packs datagram in Ethernet frame with MAC-ID of next gateway

-sends it to the gateway and so on…

B

10.13.2.2

IP Routing: Example


168.12.41.52

Gateway

10.13.102.1

10.13.2.2 194.175.173.88

IP Routing: Example



16bit source port number

TCP data (theoretically up to 65495 Bytes,

typically restricted by the implementation)

TCP Header and DataIP-HDR (Protokoll=06)

20 B

ytes

16bit destination port number

16bit TCP checksum 16bit urgent pointer


IP

32bit sequence number32bit acknowledgement number

16bit window sizeHDR LEN flags(reserved)

• Connection oriented data transport, carried in IP data• Point to point between exactly two host ports

• Reliable: Transfers are acknowledged, Order of sequential packets maintained• Data transferred as a stream of bytes• Good for protocols needing to move streams of data

• - HTTP, FTP, SMTP• Only works with unicast

IP addresses• No broadcast

or multicast

Ethernet – Transmission Control Protocol (TCP)


• Establish: Three way handshake between two hostsHost 1 sends SYN (synchronize) to host 2Host 2 sends ACK to host 1 along with its own SYN Host 1 sends ACK to host 2

• Terminate: Four way handshakeHost 1 sends FIN (final) to host 2Host 2 send ACK to host 1Host 2 (in a separate message) sends FIN to host 1Host 1 sends ACK to host 2

it takes some time to establish/terminate a connection!

Ethernet: TCP Handshaking

Host 1 Host 2

Host 1 Host 2

SYN

ACK, SYN

ACK

FIN

FIN

ACK

ACK


16bit source port number

UDP data (theoretically up to 65507 Bytes,

typically restricted by the implementation)

UDP Header and DataIP-HDR (Protokoll=17)

8 B

ytes 16bit destination port number

16bit UDP length 16bit UDP checksum


IP

• Simple datagram-oriented data transport, carried in IP data• Non-guaranteed delivery of data

Packets may be delivered out of order or may not be delivered at all!• Less overhead than TCP• Needed for broadcast and multicast applications• Suitable for request / response type protocols (polling)

SNMPTFTPDHCP / BOOTP

Ethernet User Datagram Protocol (UDP)


Feature TCP UDP

End to End Control Yes No

Time Montitoring of Connection Yes No

Flow Control (via Network) Yes No

Sequence Control Yes No

Error Detection Yes Optional

Fixing of Errors Yes No

Adressing of higher Layers Yes Yes

Header Size 20-60 Bytes 8 Byte

Performance Slow Faster

Loading of System resources Higher Lower

Comparison TCP - UDP


Network Layer Protocols

• ARP, Address Resolution Protocol.• DRARP, Dynamic RARP. • InARP, Inverse Address Resolution Protocol. • IP, Internet Protocol.• IPv6, Internet Protocol version 6. • MPLS, Multi-Protocol Label Switching. • RARP, Reverse Address Resolution Protocol.

found in RFC 826 (ARP):

„The world is a jungle in general, and the networking game contributes many animals.

At nearly every layer of a network architecture there are several potential protocols that could be used.“


Transport Layer Protocols

• AH, IP Authentication Header. • AX.25. • CBT, Core Based Trees. • DVMRP, Distance Vector Multicast Routing Protocol. • EGP, Exterior Gateway Protocol. • ESP, Encapsulating Security Payload. • GGP, Gateway to Gateway Protocol. • GRE, Generic Routing Encapsulation. • HMP, Host Monitoring Protocol. • ICMP, Internet Control Message Protocol. • ICMPv6, Internet Control Message Protocol for IPv6. • IDPR, Inter-Domain Policy Routing Protocol. • IFMP, Ipsilon Flow Management Protocol. • IGAP, IGMP for user Authentication Protocol. • IGMP, Internet Group Management Protocol. • IGRP, Interior Gateway Routing Protocol. • IP in IP Encapsulation. • IPPCP, IP Payload Compression Protocol. • IRTP, Internet Reliable Transaction Protocol. • ISO-IP. • L2TP, Level 2 Tunneling Protocol. • Minimal Encapsulation Protocol. • MLD, Multicast Listener Discovery. • Mobility Header

• MOSPF, Multicast Open Shortest Path First.• MTP, Multicast Transport Protocol. • NARP, NBMA Address Resolution Protocol. • NETBLT, Network Block Transfer. • NVP, Network Voice Protocol. • OSPF, Open Shortest Path First Routing Protocol. • PGM, Pragmatic General Multicast. • PIM, Protocol Independent Multicast. • PTP, Performance Transparency Protocol. • RDP, Reliable Data Protocol. • RSVP, Resource ReSerVation Protocol. • SCTP, Stream Control Transmission Protocol. • SEND, SEcure Neighbor Discovery. • SDRP, Source Demand Routing Protocol. • SKIP, Simple Key management for Internet Protocol. • ST, Internet Stream Protocol. • TCP, Transmission Control Protocol.• TMux, Transport Multiplexing Protocol. • TP/IX. • UDP, User Datagram Protocol.• UDP-Lite, Lightweight User Datagram Protocol. • VMTP, Versatile Message Transaction Protocol. • VRRP, Virtual Router Redundancy Protocol.


Application Layer Protocols (I)

• ACAP, Application Configuration Access Protocol. • AgentX. • AODV, Ad hoc On-Demand Distance Vector. • APEX, Application Exchange Core. • ATMP, Ascend Tunnel Management Protocol. • AURP, AppleTalk Update-based Routing Protocol. • Authentication Server Protocol. • BFTP, Background File Transfer Program. • BGP, Border Gateway Protocol. • BOOTP, Bootstrap Protocol. • CFDP, Coherent File Distribution Protocol. • Chargen, Character Generator Protocol. • CLDAP, Connection-less Lightweight X.500 Directory

Access Protocol. • COPS, Common Open Policy Service. • CRANE, Common Reliable Accounting for Network

Element. • Daytime, Daytime Protocol. • DCAP, Data Link Switching Client Access Protocol. • DHCP, Dynamic Host Configuration Protocol.• DHCPv6, Dynamic Host Configuration Protocol for IPv6. • DIAMETER. • DICT, Dictionary Server Protocol.

• Discard, Discard Protocol. • DIXIE. • DMSP, Distributed Mail Service Protocol. • DNS, Domain Name System.• DRAP, Data Link Switching Remote Access Protocol. • DTCP, Dynamic Tunnel Configuration Protocol. • Echo. • EMSD, Efficient Mail Submission and Delivery. • EPP, Extensible Provisioning Protocol. • ESRO, Efficient Short Remote Operations. • ETFTP, Enhanced Trivial File Transfer Protocol. • Finger. • FTP, File Transfer Protocol.• GDOI, Group Domain of Interpretation. • Gopher. • HOSTNAME. • HSRP, Hot Standby Router Protocol. • HTTP, HyperText Transfer Protocol.• ICAP, Internet Content Adaptation Protocol. • ICP, Internet Cache Protocol. • iFCP, Internet Fibre Channel Protocol. • IKE, Internet Key Exchange. • IMAP, Interactive Mail Access Protocol.


Application Layer Protocols (II)

• IPFIX, IP Flow Information Export. • IPP, Internet Printing Protocol. • IRC, Internet Relay Chat. • ISAKMP, Internet Security Association and Key

Management Protocol. • iSCSI. • IUA, ISDN Q.921-User Adaptation. • Kerberos. • Kermit. • L2F, Layer 2 Forwarding. • L2TP, Level 2 Tunneling Protocol. • LDAP, Lightweight Directory Access Protocol. • LDP, Label Distribution Protocol. • LDP, Loader Debugger Protocol. • LFAP, Light-weight Flow Admission Protocol. • LMTP, Local Mail Transfer Protocol. • LPR. • MADCAP, Multicast Address Dynamic Client

Allocation Protocol. • MASC, Multicast Address-Set Claim. • MATIP, Mapping of Airline Traffic over Internet

Protocol. • Mbus, Message Bus. • MGCP, Multimedia Gateway Control Protocol.

• Mobile IP. • MPP, Message Posting Protocol. • MSDP, Multicast Source Discovery Protocol. • MTP, Mail Transfer Protocol. • MTQP, Message Tracking Query Protocol. • MUPDATE, Malbox Update. • NAS, Netnews Administration System. • NFILE. • NFS, Network File System. • NNTP, Network News Transfer Protocol. • NTP, Network Time Protocol. • ODETTE-FTP, ODETTE File Transfer Protocol. • OLSR, Optimized Link State Routing. • Ph. • Photuris. • POP, Post Office Protocol. • Portmapper. • PPTP, Point to Point Tunneling Protocol. • PWDGEN, Password Generator Protocol. • Quote, Quote of the Day Protocol. • RADIUS, Remote Authentication Dial-In User

Service. • RAP, Internet Route Access Protocol. • RIP, Routing Information Protocol.


Application Layer Protocols (III)

• RIPng. • Rlogin. • RLP, Resource Location Protocol. • RMCP, Remote Mail Checking Protocol. • RSIP, Realm Specific IP. • RTCP, RTP Control Protocol. • RTP, Real-Time Transport Protocol. • RTSP, Real Time Streaming Protocol. • RWhois, Referral Whois Protocol. • SACRED, Securely Available Credentials. • Send, Message Send Protocol. • SFTP, Simple File Transfer Protocol. • SGMP, Simple Gateway Monitoring Protocol. • SIFT/UFT, Sender-Initiated/Unsolicited File Transfer. • SIP, Session Initiation Protocol. • SLP, Service Location Protocol. • SMTP, Simple Mail Transfer Protocol. • SMUX.• SNMP, Simple Network Management Protocol.• SNPP, Simple Network Paging Protocol. • SNTP, Simple Network Time Protocol. • SOCKS. • SRTCP, Secure RTCP. • SRTP, Secure Real-time Transport Protocol.

• SSP, Switch-to-Switch Protocol. • STATSRV, Statistics Server. • STUN, Simple Traversal of UDP Through NAT. • SUA, Signalling Connection Control Part User

Adaptation Layer. • Syslog. • SYSTAT. • TACACS. • TBRPF, Topology Broadcast based on Reverse-Path

Forwarding. • Telnet. • TFTP, Trivial File Transfer Protocol. • Time, Time Protocol. • TRIP, Telephone Routing over IP. • TSP, Time Stamp Protocol. • TUNNEL. • UMSP, Unified Memory Space Protocol. • UUCP. • VEMMI, VErsatile MultiMedia Interface. • WebDAV, Web Distributed Authoring and Versioning. • Whois. • Whois++. • Z39.50.


Ethernet Introduction: Summary

• Ethernet is the technology described in the IEEE 802.3 standards

• The term „Ethernet“ is mistakingly used for a suite of network technologies: Ethernet, IP, TCP, UDP, FTP, HTTP and more, which are also referred to as the „Internet Technologies“

• Stacking of protocol layers – and thus tunneling of protocols – is a key feature of the Internet Technologies.

• Ethernet is used on a large variety of physical layers.

• Switching topologies have replaced collision domains – CSMA/CD is legacy technology, hubs are outdated.

• TCP/IP is a powerful protocol implemented in rather complex software stacks.


Unmodified Ethernet for Industrial Automation?

• What looks like a good idea in the first place seems to be pretty complex

• Achieving Real Time Performance with unmodified Ethernet seems to require a lot of IT know how and looks challenging

• Even those that claimed to make use of unmodified Ethernet throughout now use FPGAs instead of standard MACs

• Further details can be found in the Industrial Ethernet comparison available for download here:www.ethercat.org/pdf/english/Industrial_Ethernet_Technologies.pdf

Documents

Unmodified Ethernet for Industrial Automation