PGM: experminents with the IF toolset Marc Boyer LIAFA - Univ. - - PowerPoint PPT Presentation

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PGM: experminents with the IF toolset Marc Boyer LIAFA - Univ. - - PowerPoint PPT Presentation

PGM: experminents with the IF toolset Marc Boyer LIAFA - Univ. Paris 7 - France PGM: experminents with the IF toolset p.1/21 The protocol PGM: experminents with the IF toolset p.2/21 PGM PGM = Pragmatic General Multicast Pragmatic =


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SLIDE 1

PGM: experminents with the IF toolset

Marc Boyer LIAFA - Univ. Paris 7 - France

PGM: experminents with the IF toolset – p.1/21

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SLIDE 2

The protocol

PGM: experminents with the IF toolset – p.2/21

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SLIDE 3

PGM

PGM = Pragmatic General Multicast Pragmatic = basic reliability, no membership Multicast = diffusion trough a tree NAK-oriented

PGM: experminents with the IF toolset – p.3/21

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SLIDE 4

Ideal behavior

Sender Node Receiver Application ODATA(1) ODATA(1) ODATA(1) ODATA(2) ODATA(3) ODATA(4) ODATA(2) ODATA(3) ODATA(4) ODATA(2) ODATA(3) ODATA(4)

PGM: experminents with the IF toolset – p.4/21

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SLIDE 5

How lost are recovered

Sender Node Receiver Application ODATA(1) ODATA(1) ODATA(1) ODATA(2) ODATA(3) ODATA(3) NAK(2) 2 3 NAK(2) NCF(2) ODATA(3) ODATA(2) NCF(2) RDATA(2) RDATA(2)

PGM: experminents with the IF toolset – p.5/21

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SLIDE 6

If the NAK is “too late”

1 1 2 3 3 2 4 3 4 Sender Node Receiver Application ODATA(1) ODATA(1) ODATA(3) ODATA(3) ODATA(2) ODATA(1) 1 2 2 3 2 3 4 3 4 5 ODATA(4) ODATA(5) 2 5

???

PGM: experminents with the IF toolset – p.6/21

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SLIDE 7

Loss unrecoverable

1 1 2 3 3 2 4 3 4 Sender Node Receiver Application ODATA(1) 1 2 2 3 2 3 4 3 4 5 2 5 ODATA(1,1) ODATA(2,1) ODATA(3,1) ODATA(4,2) ODATA(1,1) ODATA(3,1) ODATA(5,3) LOSS(2) ODATA(3) ODATA(4) ODATA(5)

+ SPM messages

PGM: experminents with the IF toolset – p.7/21

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SLIDE 8

First experiment: untimed model

PGM: experminents with the IF toolset – p.8/21

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SLIDE 9

Basic property

Are all messages delivered or declared as lost ? topology S-N-R FIFO channels

  • nly ODATA can be lost

SPM rate linked to the advance of the window

PGM: experminents with the IF toolset – p.9/21

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SLIDE 10

Last window

The last window can be “frozen”

Sender Node Receiver Application ODATA(1) 7 8 9 6 7 8 5 6 7 4 5 6 ODATA(6,4) ODATA(6,4) ODATA(7,5) ODATA(8,6) ODATA(9,7) ODATA(8,6) 7 8 7 8 9 Waiting...

add of a “closing SPM”

PGM: experminents with the IF toolset – p.10/21

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SLIDE 11

Closing SPM

Sender Node Receiver Application ODATA(1) 7 8 9 6 7 8 5 6 7 4 5 6 ODATA(6,4) ODATA(6,4) ODATA(7,5) ODATA(8,6) ODATA(9,7) ODATA(8,6) 7 8 7 8 9 SPM(9,10) LOSS(7) ODATA(8) ODATA(9)

PGM: experminents with the IF toolset – p.11/21

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SLIDE 12

Topology reduction

Can we remove the nodes? Are both systems equivalent?

Sender Node Receiver

  • Receiver

Sender

PGM: experminents with the IF toolset – p.12/21

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SLIDE 13

Equivalence point of view

as a black box from the sender point of view from the receiver point of view

Receiver Sender Receiver Sender Sender Receiver PGM: experminents with the IF toolset – p.13/21

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SLIDE 14

Equivalence Result

No equivalence for the receiver... Tuning the hiding relation: hiding the NCF hiding all but NCF and NAK

PGM: experminents with the IF toolset – p.14/21

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SLIDE 15

Second experiment: timed model

PGM: experminents with the IF toolset – p.15/21

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SLIDE 16

The model

topology S-N-R FIFO channels with delays

  • nly ODATA can be lost

SPM rate linked to the advance of the window

Sender Node Receiver

PGM: experminents with the IF toolset – p.16/21

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SLIDE 17

Recovering a loss

ODATA/SPM NAK RTT

Did the NAK arrives “in time”?

PGM: experminents with the IF toolset – p.17/21

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SLIDE 18

Duration

✂☎✄ ✆ ✝ ✞ ✟✡✠ ☛ ☞ ✌ ✍ ✌ ✎ ☛ ☞ ✌ ✍ ✌

LOSS_MAX

PROD_RATE

✝ ✞ ✟ ✑ ✁ ✒ ✓ ✆✕✔ ✠

Window Size

Mess seq. num.

AMB_RATE

✗ ✏

PROD_RATE Note:

☛ ☞ ✌ ✍ ✌

false for the last messages (

✁ ✒ ✓ ✆

LOSS_MAX

Window Size

)

PGM: experminents with the IF toolset – p.18/21

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SLIDE 19

Lifetime of messages in transmit window

nothing specified in the RFC a sender can drop each message once send

  • ur model:

try to keep the max. numb. of packets constant rate fom producer

✂ ✆

Window Size

✖ ✄ ✎ ✏

PROD_RATE

PGM: experminents with the IF toolset – p.19/21

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SLIDE 20

Experiments

Recovering all losses, except first and last window:

Window Size

✄✆☎ ✝

LOSS_MAX

AMB_RATE

✟ ✠ ✡ ☛ ☛

PROD_RATE (1)

see ProdRateVsLosses.pdf see WindowVsLosses.pdf see AmbRateVsLosses.pdf

PGM: experminents with the IF toolset – p.20/21

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SLIDE 21

Conclusion

work under progress trying to generate the relation with TReX

PGM: experminents with the IF toolset – p.21/21