© university of new hampshire interoperability laboratory auto-negotiationauto-negotiation this is...

© UNIVERSITY of NEW HAMPSHIRE INTEROPERABILITY LABORATORY

Auto-NegotiationAuto-Negotiation

This is good stuff folks.

By Matthew Hersh

UNIVERSITY of NEW HAMPSHIRE

INTEROPERABILITY LABORATORY

Auto-Negotiation(It’s the way to go)

Presentation Goals:Presentation Goals:Presentation Goals:Presentation Goals:

•To portray the concept of Auto-Negotiation (ANEG)

•To exhibit how devices choose the appropriate link speed and duplex.

•To compare copper and fiber Auto-Negotiation methods.

•To portray the concept of Auto-Negotiation (ANEG)

•To exhibit how devices choose the appropriate link speed and duplex.

•To compare copper and fiber Auto-Negotiation methods.




Auto-NegotiationAuto-NegotiationAuto-NegotiationAuto-Negotiation

•What is ANEG?

Some devices support more than one speed, i.e. 10BASE-T and 100BASE-TX. A device that supports multiple speeds and/or duplex’s needs a mechanism to decide what speed and duplex to link at. ANEG is that mechanism.

•What is ANEG?

Some devices support more than one speed, i.e. 10BASE-T and 100BASE-TX. A device that supports multiple speeds and/or duplex’s needs a mechanism to decide what speed and duplex to link at. ANEG is that mechanism.




The two islandsThe two islandsThe two islandsThe two islands

•Lets look at an example.– Two men are stranded on two different islands.

Each one is very lonely and wants to talk to someone.

– So one day the first man “James” carves a note into a piece of bark and throws it into the ocean.

– To his great surprise and excitement many days later a piece of bark floats onto his beach, but when he picks it up, the note he finds is in a different language.

•Lets look at an example.– Two men are stranded on two different islands.

Each one is very lonely and wants to talk to someone.

– So one day the first man “James” carves a note into a piece of bark and throws it into the ocean.

– To his great surprise and excitement many days later a piece of bark floats onto his beach, but when he picks it up, the note he finds is in a different language.





– James isn’t about to give up, so he sits down and tries to figure out a way to communicate, first he decides they need to speak the same language, but he doesn’t know what language(s) his friend speaks.

– While he is thinking a second piece of bark floats onto the beach. He looks at it and finds that is identical to the first one, so he still can’t read it, but he realizes that the man he is talking to is very smart.

– By throwing more than one piece of bark with the same note, it increased that chance that he would receive it

– James isn’t about to give up, so he sits down and tries to figure out a way to communicate, first he decides they need to speak the same language, but he doesn’t know what language(s) his friend speaks.

– While he is thinking a second piece of bark floats onto the beach. He looks at it and finds that is identical to the first one, so he still can’t read it, but he realizes that the man he is talking to is very smart.

– By throwing more than one piece of bark with the same note, it increased that chance that he would receive it





– So now James starts to carve a new note. He writes down each of the languages he can speak, and if he speaks it fluently or not. Then he copies it many times and throws them into the ocean.

– Days later, he starts to get pieces of bark back. His friend had gotten the idea, and all of these pieces of bark listed the languages his friend could speak.

– So he circled a language they could both speak fluently and threw them back into the ocean.

– So now James starts to carve a new note. He writes down each of the languages he can speak, and if he speaks it fluently or not. Then he copies it many times and throws them into the ocean.

– Days later, he starts to get pieces of bark back. His friend had gotten the idea, and all of these pieces of bark listed the languages his friend could speak.

– So he circled a language they could both speak fluently and threw them back into the ocean.





– The next piece of bark he received was a hello note from his new friend “Chris” in a language that he could read, and from then on they were great pen pals.

– The next piece of bark he received was a hello note from his new friend “Chris” in a language that he could read, and from then on they were great pen pals.




TransmissionsTransmissionsTransmissionsTransmissions

•A device will always be sending stuff, even when not connected to another device.– If the device only supports one speed/duplex

combo, then the device will be transmitting link signaling according with that speed (Does not support ANEG – Legacy device).

– If the device supports more than one speed (or duplex), then the device will be transmitting FLPs (Does Support ANEG).

•A device will always be sending stuff, even when not connected to another device.– If the device only supports one speed/duplex

combo, then the device will be transmitting link signaling according with that speed (Does not support ANEG – Legacy device).

– If the device supports more than one speed (or duplex), then the device will be transmitting FLPs (Does Support ANEG).




Copper ANEG (NLPs)Copper ANEG (NLPs)Copper ANEG (NLPs)Copper ANEG (NLPs)

• This is a 10BASE-T LTP (link test pulse)

• It exactly matches an NLP (normal link pulse) sent by an Auto-Negotiating device

• This is a 10BASE-T LTP (link test pulse)

• It exactly matches an NLP (normal link pulse) sent by an Auto-Negotiating device




Copper ANEG (FLPs)Copper ANEG (FLPs)Copper ANEG (FLPs)Copper ANEG (FLPs)

•What is an FLP?– An FLP is a Fast Link Pulse. It is a 16-bit code

word that is transmitted through a burst of electronic pulses.

– An FLP has 17 “clock” pulses(NLPs).– If there is a pulse between two clock pulses,

then that pulse is considered a “data” pulse.– Since there are 17 clock pulses, there are 16

possible data pulses, which is how the FLP is a 16 bit code word.

•What is an FLP?– An FLP is a Fast Link Pulse. It is a 16-bit code

word that is transmitted through a burst of electronic pulses.

– An FLP has 17 “clock” pulses(NLPs).– If there is a pulse between two clock pulses,

then that pulse is considered a “data” pulse.– Since there are 17 clock pulses, there are 16

possible data pulses, which is how the FLP is a 16 bit code word.




Copper ANEG (FLPs)Copper ANEG (FLPs)Copper ANEG (FLPs)Copper ANEG (FLPs)

•Since FLPs are 16-bit code words, that means that there are 16 bits that can be either one or zero.

•Each bit represents a capability that the DUT can or cannot support.

•Since FLPs are 16-bit code words, that means that there are 16 bits that can be either one or zero.

•Each bit represents a capability that the DUT can or cannot support.




Copper ANEG – Base PageCopper ANEG – Base PageCopper ANEG – Base PageCopper ANEG – Base Page

• All Auto-Negotiating devices transmit a Base Page to determine link partner capabilities. The Base Page is a series of transmitted FLPs that are identical.

• The Base Page is broken down as follows:– Bits 0-4, Selector Field Combination – defines what technology is being

used.– Bits 5-11, Technology Ability Field – defines what capabilities are

supported by the DUT. 10BASE-T full and half duplex, 100BASE-TX full and half duplex, 100BASE-T4, PAUSE, and ASM_DIR PAUSE are all possibilities that a device can advertise in the Technology Ability Field of its Base Page.

– Bit 12 – Recently defined as “Extended Next Pages” bit, intended for use with 10GBase-T.

– Bit 13 – Remote Fault Bit– Bit 14 – Acknowledge Bit– Bit 15 – Next Page Bit

• All Auto-Negotiating devices transmit a Base Page to determine link partner capabilities. The Base Page is a series of transmitted FLPs that are identical.

• The Base Page is broken down as follows:– Bits 0-4, Selector Field Combination – defines what technology is being

used.– Bits 5-11, Technology Ability Field – defines what capabilities are

supported by the DUT. 10BASE-T full and half duplex, 100BASE-TX full and half duplex, 100BASE-T4, PAUSE, and ASM_DIR PAUSE are all possibilities that a device can advertise in the Technology Ability Field of its Base Page.

– Bit 12 – Recently defined as “Extended Next Pages” bit, intended for use with 10GBase-T.

– Bit 13 – Remote Fault Bit– Bit 14 – Acknowledge Bit– Bit 15 – Next Page Bit




Copper ANEG – Base PageCopper ANEG – Base PageCopper ANEG – Base PageCopper ANEG – Base Page

•A device will set any of the bits in the Base Page that the device actually supports. If a device wants to indicate 1000BASE-T capabilities, the next page bit must be set because 1000BASE-T links can only be established through a Next Page Exchange.

•There are two types of Next Pages: Message Page and Unformatted Page.

•A device will set any of the bits in the Base Page that the device actually supports. If a device wants to indicate 1000BASE-T capabilities, the next page bit must be set because 1000BASE-T links can only be established through a Next Page Exchange.

•There are two types of Next Pages: Message Page and Unformatted Page.




Copper ANEG - Next PagesCopper ANEG - Next PagesCopper ANEG - Next PagesCopper ANEG - Next Pages

•A device will support a Next Page Exchange usually if it has additional information that it wants to transmit (i.e. 1000BASE-T capabilities).

•If the device wants to indicate 1000BASE-T capabilities, the first Next Page it will send is a Message Page.

•A device will support a Next Page Exchange usually if it has additional information that it wants to transmit (i.e. 1000BASE-T capabilities).

•If the device wants to indicate 1000BASE-T capabilities, the first Next Page it will send is a Message Page.




Next Pages – Message PageNext Pages – Message PageNext Pages – Message PageNext Pages – Message Page

• A device can indicate a Next Page to be a Message Page by setting the Message Page bit (bit 13).

• The Message Page will contain a code number. This code number corresponds to the reason for going through a Next Page Exchange.

• A message code 8, for example, indicates that the device wants to attempt a 1000BASE-T link and that two Unformatted Next Pages are following.

• A message code 1 indicates that it is Null Message Page, and no more information needs to be transmitted.

• A device can indicate a Next Page to be a Message Page by setting the Message Page bit (bit 13).

• The Message Page will contain a code number. This code number corresponds to the reason for going through a Next Page Exchange.

• A message code 8, for example, indicates that the device wants to attempt a 1000BASE-T link and that two Unformatted Next Pages are following.

• A message code 1 indicates that it is Null Message Page, and no more information needs to be transmitted.




Next Pages – Unformatted PageNext Pages – Unformatted PageNext Pages – Unformatted PageNext Pages – Unformatted Page

• Contains 11 bits of information• Contents of these pages can be defined by

previous message pages.• When a message code 8 had already been sent,

the first Unformatted Page following the message page would contain the 1000BASE-T capabilities. This also includes Master/Slave bits.

• The second Unformatted Page in a 1000BASE-T Next Page Exchange contains a seed value which is the last resort to resolve a Master and Slave.

• Contains 11 bits of information• Contents of these pages can be defined by

previous message pages.• When a message code 8 had already been sent,

the first Unformatted Page following the message page would contain the 1000BASE-T capabilities. This also includes Master/Slave bits.

• The second Unformatted Page in a 1000BASE-T Next Page Exchange contains a seed value which is the last resort to resolve a Master and Slave.




““Bitwise” look at pagesBitwise” look at pages““Bitwise” look at pagesBitwise” look at pages

•This is a bit by bit look at the three types of pages

•As you can see each is the same 16 bits long, but have slightly different configurations

•Blue indicates the Base Page, and Yellow indicates Next Pages

•This is a bit by bit look at the three types of pages

•As you can see each is the same 16 bits long, but have slightly different configurations

•Blue indicates the Base Page, and Yellow indicates Next Pages

Page Type Bit 0 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 Bit 8 Bit 9 Bit 10 Bit 11 Bit 12 Bit 13 Bit 14 Bit 15

Base10BASE-T

Half Duplex

10BASE-T Full

Duplex

100BASE-TX Half Duplex

100BASE-TX Full Duplex

100BASE-T4 PAUSEAsynchronous

PAUSENot

DefinedRemote

FaultAcknowledge

Next Page

Message Toggle Ack2Message

PageAcknowledge

Next Page

Unformatted Toggle Ack2Message

PageAcknowledge

Next Page

Selector Field bits (0 - 4)

Message Code bits (0 - 10)

Data bits (0 - 10)




Fiber Auto - NegotiationFiber Auto - NegotiationFiber Auto - NegotiationFiber Auto - Negotiation

•1000BASE-SX and 1000BASE-LX devices also determine a link using ANEG.

•These technologies use fiber, so ANEG is different than it is for copper, however the concepts are the same.

•1000BASE-SX and 1000BASE-LX devices also determine a link using ANEG.

•These technologies use fiber, so ANEG is different than it is for copper, however the concepts are the same.




/C/ Ordered Sets/C/ Ordered Sets/C/ Ordered Sets/C/ Ordered Sets

• Fiber ANEG still uses 16-bit code words.• It also has a Base Page, but instead of using FLPs, it

uses /C/ ordered sets.• ANEG coordinates with the PCS to decide what to

send.• If ANEG is restarted, ANEG temporarily takes control

of the PCS.• While the device is ANEGing, ANEG tells the PCS

what to transmit within the /C/ ordered set.• When a link is established, the PCS takes control

and transmits /I/ ordered sets and/or packets.

• Fiber ANEG still uses 16-bit code words.• It also has a Base Page, but instead of using FLPs, it

uses /C/ ordered sets.• ANEG coordinates with the PCS to decide what to

send.• If ANEG is restarted, ANEG temporarily takes control

of the PCS.• While the device is ANEGing, ANEG tells the PCS

what to transmit within the /C/ ordered set.• When a link is established, the PCS takes control

and transmits /I/ ordered sets and/or packets.




/C/ Ordered Sets/C/ Ordered Sets/C/ Ordered Sets/C/ Ordered Sets

•/C/ ordered sets contain the following abilities:

– 1000BASE-X full and half duplex

– PAUSE settings

– Remote Fault

– Next Page

•/C/ ordered sets contain the following abilities:

– 1000BASE-X full and half duplex

– PAUSE settings

– Remote Fault

– Next Page




Fiber ANEG – Next PageFiber ANEG – Next PageFiber ANEG – Next PageFiber ANEG – Next Page

•Devices can call for a Next Page Exchange, however, it is not required and rarely implemented.

•Devices can call for a Next Page Exchange, however, it is not required and rarely implemented.




““Bitwise” look at the PageBitwise” look at the Page““Bitwise” look at the PageBitwise” look at the Page

•This is a bit by bit look at the Base Page for Fiber ANEG.

•This is a bit by bit look at the Base Page for Fiber ANEG.




Copper ANEG vs. Fiber ANEGCopper ANEG vs. Fiber ANEGCopper ANEG vs. Fiber ANEGCopper ANEG vs. Fiber ANEG

• The major issue between copper and fiber ANEG is where each is located in OSI stack. – For copper, ANEG is located below the PMA. This means that

the ANEG process can occur before signaling is transmitted

– For fiber, ANEG is located in the PCS. This means that two devices must transmit signaling before ANEG can be done

• What this means is that copper ANEG can be used for multiple speeds that use difference signaling techniques, while fiber ANEG can only be used for 1000BASE-X devices.

• The major issue between copper and fiber ANEG is where each is located in OSI stack. – For copper, ANEG is located below the PMA. This means that

the ANEG process can occur before signaling is transmitted

– For fiber, ANEG is located in the PCS. This means that two devices must transmit signaling before ANEG can be done

• What this means is that copper ANEG can be used for multiple speeds that use difference signaling techniques, while fiber ANEG can only be used for 1000BASE-X devices.




OSI locationOSI locationOSI locationOSI location

AUTONEG

PMA

PCS

RECONCILIATION

LLC - LOGICAL LINK CONTROL

LANCSMA/CDLAYERS

HIGHER LAYERS

MEDIUM

MII

MDI

PHY

100BASE-T4100BASE-T2

PMD

PMA

PCS

RECONCILIATION


LANCSMA/CDLAYERS

HIGHER LAYERS

MEDIUM

MII

MDI

PHY

100BASE-FX

AUTONEG

PMD

PMA

PCS

RECONCILIATION


LANCSMA/CDLAYERS

HIGHER LAYERS

MEDIUM

MII

MDI

PHY

100BASE-TX

100Mb/s

MAC -- MEDIA ACCESS CONTROLCLAUSE 4

MAC CONTROL (OPTIONAL)CLAUSE 31





CLAUSE 22

CLAUSE 24

CLAUSE 25

CLAUSE 28

CLAUSE 22

CLAUSE 24

CLAUSE 26

CLAUSE 22

T4=CLAUSE 23T2=CLAUSE 32

CLAUSE 28

APPLICATION

PRESENTATION

SESSION

TRANSPORT

NETWORK

DATA LINK

PHYSICAL

OSIREFERENCE

MODELLAYERS




OSI LocationOSI LocationOSI LocationOSI Location

AUTONEG

PMA

PCS

RECONCILIATION


LANCSMA/CDLAYERS

HIGHER LAYERS

MEDIUM

GMII

MDI

PHY

1000BASE-T

PMD

PMA

PCS

RECONCILIATION


LANCSMA/CDLAYERS

HIGHER LAYERS

MEDIUM

GMII

MDI

PHY

1000BASE-SX1000BASE-LX1000BASE-CX

AUTONEG

1000Mb/s





APPLICATION

PRESENTATION

SESSION

TRANSPORT

NETWORK

DATA LINK

PHYSICAL

OSIREFERENCE

MODELLAYERS

CLAUSE 35

CLAUSE 40

CLAUSE 28

CLAUSE 35

PCS,PMA =CLAUSE 36ANEG=CLAUSE 37

SX,LX=CLAUSE 38CX=CLAUSE 39




Priority ResolutionPriority ResolutionPriority ResolutionPriority Resolution

• When two devices are connected, before they actually establish a link, they send information back and forth to determine what each device supports.

• There is an order of speed/duplex combinations in which every device should follow. This is called Priority Resolution.

• Once all information is transmitted, a link should be established according to the Priority Resolution.

• When two devices are connected, before they actually establish a link, they send information back and forth to determine what each device supports.

• There is an order of speed/duplex combinations in which every device should follow. This is called Priority Resolution.

• Once all information is transmitted, a link should be established according to the Priority Resolution.




Copper Priority ResolutionCopper Priority ResolutionCopper Priority ResolutionCopper Priority Resolution

1. 1000BASE-T full duplex2. 1000BASE-T3. 100BASE-T2 full duplex4. 100BASE-TX full duplex5. 100BASE-T26. 100BASE-T47. 100BASE-TX8. 10BASE-T full duplex9. 10BASE-T

1. 1000BASE-T full duplex2. 1000BASE-T3. 100BASE-T2 full duplex4. 100BASE-TX full duplex5. 100BASE-T26. 100BASE-T47. 100BASE-TX8. 10BASE-T full duplex9. 10BASE-T




Fiber Priority ResolutionFiber Priority ResolutionFiber Priority ResolutionFiber Priority Resolution

1. 1000BASE-X full duplex

2. 1000BASE-X half duplex

• 1000BASE-X refers to either 1000BASE-SX or 1000BASE-

LX.




Priority ResolutionPriority ResolutionPriority ResolutionPriority Resolution

•Auto-Negotiating devices that are connected should establish the Highest Common Denominator(HCD) link in accordance with the Priority Resolution.




Parallel DetectionParallel DetectionParallel DetectionParallel Detection

•Legacy devices only support one speed, and only half duplex at that speed. If an Auto-Negotiating device is connected to a Legacy device, the ANEG device needs a method to detect the type of signaling being received.

•The link established will be a half duplex link.

•This method is called parallel detection.

•Legacy devices only support one speed, and only half duplex at that speed. If an Auto-Negotiating device is connected to a Legacy device, the ANEG device needs a method to detect the type of signaling being received.

•The link established will be a half duplex link.

•This method is called parallel detection.




Parallel DetectionParallel DetectionParallel DetectionParallel Detection

• Some devices can be configured to transmit only one speed. If the other device connected is ANEGing, that device will have to parallel detect to the appropriate speed in order to establish a link.

• However, in this case, the ANEGing device should always establish a half duplex link, but the manually configured device could be set to full duplex, in which case the link established will be full duplex on one end and half duplex on the other.

• Some devices can be configured to transmit only one speed. If the other device connected is ANEGing, that device will have to parallel detect to the appropriate speed in order to establish a link.

• However, in this case, the ANEGing device should always establish a half duplex link, but the manually configured device could be set to full duplex, in which case the link established will be full duplex on one end and half duplex on the other.




SoftwareSoftwareSoftwareSoftware

•Much software created by former and current students.

•Software all written in Labview, a picture oriented programming language.

•Two main parts to the code: receive, and transmit.

•Much software created by former and current students.

•Software all written in Labview, a picture oriented programming language.

•Two main parts to the code: receive, and transmit.




Receive SoftwareReceive SoftwareReceive SoftwareReceive Software




Transmit SoftwareTransmit SoftwareTransmit SoftwareTransmit Software

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