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Page 1: VWeW*Tq!TeW* ie*y]qyze]!Wqi!N V i!V]

VW eW*Tq!TeW* _ie*y]qyze ]!Wqi!NV__i!V]< Gyq< e�_Ny]yq ]!Wpe7qy!W

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{j$�t� 7 �Ys� s�� $t �Y� t��bB�, s� I$R{���� �$8� >� qY�I$R{���� �$8� $t���%sj > $R I�ht�I sR �Y� �$8� $t���%sjt��I�I �B ��{�$%� sjj A$�R BP s }s{,��� N�� + � ��}��R�t��Y� 8$t$8Z8 %sjZ� BP �Y� �BZtIT��$}T�$8� I�jsk w}�B}sT�s�$Bt I�jsk }jZR }�B{�RR$t� �$8� $t �BZ���R AZ� �-{jZI$t��Y� JZ�Z$t� I�jskD� �Y�t �Y� tZ8A�� BP }s{,��R �Ys� b$jjA� $t �Y� t��bB�, $t �Y� PZ�Z�� �$8� > L + � $R �$%�t Ak

z � >> L + � H ) z � >>H L� � ���3

� ��` � >> L iH�

� � ���3

� ��r � >> L iH wdD

bY��� ` � >3H ; \(, di ��}��R�t�R �Y� �s�� BP }s{,��R �Ys� s����JZ�R��I Ak �Y� {j$�t�� stI r � >3H ; \(, di ��}��R�t�R �Y��s�� BP }s{,��R �Ys� s�� {B8$t� P�B8 �Y� t��bB�,� qY����8 � � � ���

� ��� ` � >> L iH ��}��R�t�R �Y� tZ8A�� BP }s{,��R�Ys� b$jj A� ��JZ�R��I stI � � � ���

� ��� r � >>L iH ��}��R�t�R �Y�tZ8A�� BP }s{,��R �Ys� b$jj A� ��{�$%�I IZ�$t� �Y� PZ�Z���$8� $t���%sj >>� > L + � � dH� <��� + � YsR �Y� �Bj� BP �Y�{Bt��Bj YB�$9Bt %sjZ� PB� �Y� {Bt��Bj jsb�N�� p � � >3H ��}��R�t� �Y� �BZtIT��$}T�$8� I�jsk BAR��%�I Ak�Y� {j$�t� 7� Vt �R�$8s�� BP + � {st A� BA�s$t�I Ak ZR$t�x � >>H ) E7z p � � >iH b$�Y ( � i � > bY��� > I�tB��R �Y�{Z���t� �$8� $tR�st� s� �Y� {j$�t��

1�1 qY� {Bt��Bj jsbqB BA�s$t �Y� {Bt��Bj jsb �Y� PBjjBb$t� sRRZ8}�$Bt s��8sI�U qY� {Bt��Bj YB�$9Bt %sjZ� $R �JZsj �B x � >>H� qY�{Bt��Bj R$�tsj $R sRRZ8�I �B A� {BtR�st� B%�� �Y� {Bt��BjYB�$9Bt stI b$jj A� �JZsj �B ` � >>H� qY� ���8� � � ���

� ��� r � >0L>H $R s}}�B-$8s��I Ak x � >>Hr � >>H� stI z � >>L+ � H $R �JZsj �Bx � >>H r � � � >>H� bY��� r � � � ��}��R�t�R �Y� ��P���t{� R$�tsjPB� �Y� }s{,�� �s�� �B BA�s$t AstIb$I�Y Ps$�TRYs��� G$�Y�Y� sAB%� sRRZ8}�$Bt �Y� {Bt��Bj jsb $R �$%�t Ak

` � � >>H ) �z � >>Hx � >>H L r � � >>H L r � � � � � >>H w1D

WB�� YBb�%�� �Ys� �Y� R$�tsj r � � � $R tB� ,tBbt Ak �Y�{Bt��Bjj�� stI $� $R tB� }�B%$I�I Ak �Y� t��bB�, �-}j${$�jk�

1�n yI�t�$h{s�$Bt BP �Y� stIb$I�Y 3s$�T7Ys��yt B�I�� �B $I�t�$Pk �Y� AstIb$I�Y Ps$�TRYs�� %sjZ� s }�BAT$t� 8�{Yst$R8 8ZR� A� ZR�I �Ys� ��$�R �B ��s{, �Y� �%BTjZ�$Bt BP �Y� AstIb$I�Y Ps$�TRYs�� R$�tsj� qY� R$8}j�R�s}}�Bs{Y �B �Y� }�BAj�8 $R �B ZR� s �s8} R$�tsj �Ys�$t{��sR�R s� {BtR�st� �s�� Zt�$j s R$�tsj $R �$%�t Ak �Y�t��bB�, BP $t{$}$�t� {Bt��R�$Bt� N�� |r � � � >3H ��}��R�t� �Y���s{,$t� R$�tsj� �Y�t �Y� �%BjZ�$Bt BP �Y� R$�tsj $R I�ht�IAk

|r � � � >>H ) |r � � � >> � dH L dn p � � >>Hr � � >>H wnD

b$�Y |r � � � >(H ) ( stI r � � >(H ) d3(� �Y� {BtR�st� nbsR {YBR�t RB �Ys� |r � � � >>H ) d sP��� s �$8� $t���%sj BP�Y��� �BZtIT��$}T�$8�� Vt Z}}�� ABZtI BP d $R $8}BR�I $t|r � � � >>H�

Control 2004, University of Bath, UK, September 2004 ID-082

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qY� %sjZ�R BP |r � � � >3H stI r � � >3H s�� sI`ZR��I B%�� �$8�I�}�tI$t� Bt �Y� $tPB�8s�$Bt �Ys� $R }�B%$I�I Ak �Y� t��TbB�, bY${Y $R {s��$�I Ak �Y� e]W A$�R $t �Y� y_ Y�sI��Is�s��s8�GY�t �Y� {Bt��Bjj�� I���{�R s� s �$%�t �$8� j� �Ys� �Y�4Bb $R {sZR$t� $t{$}$�t� {Bt��R�$Bt stI w|r � � � >j � dH k` � D� bY��� ` � $R �Y� $tR�st�st�BZR �s�� %sjZ� �Ys� $R{s��$�I Ak �Y� }s{,�� $t �Y� h�jI !}�$BtR� �Y�t |r � � � >j �dH ) ` � bwd L ` � D � stI r � � >jH ) w` � ` � Dbwd L ` � DqY� %sjZ� ` � bwd L ` � D ��}��R�t�R �Y� "8s-$8Z8" �s���Ys� b$jj s%B$I �Y� 4Bb �B Ys%� �bB }s{,��R s� �Y� Rs8��$8� $t s AZ&�� BP s �BZ���� stI w` � ` � Dbwd L ` � D�$%�R �Y� �s�� s� bY${Y |r � � � >3H b$jj $t{��sR� $t B�I�� �Ys�|r � � � >3H ) ` � sP��� �Y��� �BZtIT��$}T�$8��

1�; p�t��s�$t� }s{,��RqB ��t��s�� }s{,��R P�B8 �Y� {Bt��Bj R$�tsj w}s{,���s��D` � >>H� �Y� PBjjBb$t� s}}�Bs{Y $R ZR�I� V }s{,�� $R��JZ�R��I Ak �Y� {j$�t� bY�t �Y� %s�$sAj� � � >>H sRRZ8�R�Y� %sjZ� d s{{B�I$t� b$�Y

� � >>H )F ( $P ` � � >> � dH L ` � � >>H c d3(

d3( $P ` � � >> � dH L ` � � >>H � d3( w;D

stI ` � � >>H $R BA�s$t�I P�B8 �Y� 4Bb �s�� {Bt��Bj R$�tsj` � >>H Ak �̀ � >>H ) ` � � >> � dH L ` � >>H� � � >>H

1�x W��bB�, BZ�}Z� }s{,�� �s�� R$�tsj_s{,��R s��$%� P�B8 �Y� t��bB�,� Bt� sP��� �Y� B�Y��� qBAZ$jI �Y� R$�tsj r � >>H s �$8�� $R ZR�I �B {BZt� �Y� tZ8A��BP �$8� RjB�R A��b��t �B {BtR�{Z�$%� }s{,��R 0X>>H� GY�ts }s{,�� s��$%�R �Y� $tR�st�st�BZR wBZ�}Z�D 4Bb �s�� $RI�ht�I Ak r � � � � >>H ) db0X>>H stI �Y� �$8�� $R ��R�s���IP�B8 9��B �B A��$t {BZt�$t� PB� �Y� t�-� }s{,��� qY�R$�tsj r � >>H $R BA�s$t�I Ak �Y� PBjjBb$t� hj����

r � >>H ) wd� dx � >>H Dr � >> � dH L d

x � >>Hr � � � � >>H wxD

n 7$8Zjs�$Bt i�RZj�Ryt �Y$R R�{�$Bt R$8Zjs�$Bt ��RZj�R b$�Y �Y� {Bt��Bj sj�BT�$�Y8 s�� RYBbt�

n�d W��bB�, 8BI�jqY� t��bB�, 8BI�j $R RYBbt $t h��d� V I$R{���� �$8� R$8ZTjs�B� bsR ZR�I b$�Y s R$8Zjs�$Bt R��} �JZsj �B �Y� IZ�s�$BtBP s }s{,��� yt �Y$R R$8Zjs�$Bt s {j$�t� R�tI s }s{,�� �B��{�$%� s }s{,�� P�B8 �Y� R��%��� qY� �BZtIT��$} I�jskR� $tI$R{���� �$8� Zt$�R� IZ� �B }�B}s�s�$Bt BAR��%�I Ak {j$�t�7 wp0Lg � D s��U p0Lg � ) 1;� p0Lg � ) 1E� p0Lg � ) 1(�p0Lg � ) d1� p0Lg � ) dd�

Control flow

Data flow

Network Model

C - Client

S - Server

R -Router

R1

S1

C2S2

S3

R2

R4

C4

C3R3

S4

S5

C1

C5

L12

L23

L34

L - Link

3$�Z�� dU W��bB�, 8BI�j stI 7��%${� 8BI�j�

0 100 200 300 400 500 600 700 8000

1

2Packets in queue of router 1

[pac

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0 100 200 300 400 500 600 700 8000

2

4

6Packets in queue of router 2

[pac

kets

]

0 100 200 300 400 500 600 700 8000

5

10 Packets in queue 2 of router 3

[pac

kets

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t [discrete time]

3$�Z�� 1U WZ8A�� BP }s{,��R bs$�$t� $t JZ�Z� BP �BZ���id stI �Y� s{�$%� 4BbR $t �BZ��� id�

n�1 7$8Zjs�$Bt i�RZj�R]B8}Z��� R$8Zjs�$BtR b��� IBt� bY��� {j$�t�R ]d� ]1� ]n�];� ]x R�tI �Y�$� h�R� }s{,�� �B R��%��R 7d� 71� 7n� 7;�7x ��R}�{�$%�jk s� I$R{���� �$8� $tR�st�R 0 � ) d� 0 � ) 1x(�0 � ) dx(� 0 � ) d stI 0 � ) �x� qY� h�R� }s{,�� $R ZR�I �BBA�s$t st �R�$8s�� BP �Y� h�R� �BZtIT��$}T�$8� %sjZ�� sP�����{�$%$t� �Y� h�R� }s{,�� �Y� {Bt��Bjj�� A��$tR B}��s�$t��3$�Z�� 1 RYBbR �Y� tZ8A�� BP }s{,��R bs$�$t� $t JZ�Z�R BP�BZ���R id� i1 stI in� *Z�$t� �Y� �$8� $t���%sj >(� dx(HBt� YsR �bB I�{BZ}j�I RZATt��bB�,R� ]d\7d $R I�{BZ}j�IP�B8 ];\7; stI ]x\7x� AZ� ];\7; stI ]x\7x {B8}��� PB�AstIb$I�Y $t �Y� U � � j$t,� ]j$�t� ]d {st ��� s 4Bb �s�� Z}�B d3(� ]j$�t� ]; ���R �Y� $t$�$sj %sjZ� BP d3(� AZ� bY�t ]xA��$tR ��JZ�R�$t� }s{,��R� AB�Y ]; stI ]x s}}�Bs{Y �Y�(3x %sjZ�� qY$R {st A� %��$h�I $t h�Z��R n� x stI �� WB���Ys� �Y� �s��R s� bY${Y �Y� 4BbR �s��R $t{��sR� I�}�tI BP�Y� �BZtIT��$}T�$8� %sjZ�R� 3$��n RYBbR �Y� }s{,�� �s��BP {j$�t� ]d stI tZ8A�� BP }s{,��R $t �Y� t��bB�, BP �Y�4Bb BP {j$�t� ]d� 3$�Z�� ; RYBbR �Y� �BZtIT��$} I�jskBAR��%�I P�B8 {j$�t� ]d stI $�R 8s-$8Z8 stI 8$t$8Z8%sjZ�R� stI }s{,��R ��JZ�R��I stI ��{�$%�I Ak {j$�t� ]d�

Control 2004, University of Bath, UK, September 2004 ID-082

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0 100 200 300 400 500 600 700 8000

0.2

0.4

0.6

0.8

1Packet Rate of Client 1 and Probing Reference Signal

[pac

ket r

ate]

0 100 200 300 400 500 600 700 8000

5

10

15

20

25Number of packets in the network of <Client 1 , Server 1>

[pac

ket]

t [discrete time]

3$�Z�� nU _s{,�� �s�� BP {j$�t� ]d stI tZ8A�� BP }s{,��R$t �Y� t��bB�, BP �Y� 4Bb {j$�t� ]d\R��%�� 7d�

0 100 200 300 400 500 600 700 8000

10

20

30Round-trip delay, minimum values from Client 1

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cret

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0 100 200 300 400 500 600 700 8000

0.5

1Packets Requested by Client 1

[pac

ket]

0 100 200 300 400 500 600 700 8000

0.5

1 Packets Received by Client 1

[pac

ket]

t [discrete time]

3$�Z�� ;U iBZtIT��$} I�jsk� 8$t$8Z8 %sjZ�R BAR��%�IP�B8 {j$�t� ]d� }s{,��R ��JZ�R��I stI ��{�$%�I Ak {j$�t�]d�

3$��x RYBbR �Y� }s{,�� �s�� BP {j$�t� ]; stI tZ8A�� BP}s{,��R $t �Y� t��bB�, BP �Y� 4Bb BP {j$�t� ];� 3$�Z�� ERYBbR �Y� �BZtIT��$} I�jsk BAR��%�I P�B8 {j$�t� ]; stI$�R 8s-$8Z8 stI 8$t$8Z8 %sjZ�R� stI }s{,��R ��JZ�R��IstI ��{�$%�I Ak {j$�t� ];� 3$��� RYBbR �Y� }s{,�� �s��BP {j$�t� ]x stI tZ8A�� BP }s{,��R $t �Y� t��bB�, BP �Y�4Bb BP {j$�t� ]x� 3$�Z�� M RYBbR �Y� �BZtIT��$} I�jskBAR��%�I P�B8 {j$�t� ]x stI $�R 8s-$8Z8 stI 8$t$8Z8%sjZ�R� stI }s{,��R ��JZ�R��I stI ��{�$%�I Ak {j$�t� ]x�GY�t {j$�t� ]n A��$tR ��JZ�R�$t� }s{,��R $� $8}BR�R s��R��${�$Bt Bt �Y� s%s$jsAj� AstIb$I�Y Bt {j$�t�R� ]d {st��� Z} �B (�EE� ]; stI ]x {st ��� Z} �B (3nn �s{Y� qY�R$8Zjs�$Bt ��RZj�R PB� ]n stI ]1 s�� RYBbt $t h��R dd� d1��� d(� VP��� �$8� > ) 1x( bY�t sjj {j$�t�R s�� ��JZ�R�$t�}s{,��R� �Y� {Bt��R��I j$t, U � � $8}BR�R s ��R��${�$Bt Bt]1�]n�];�]x BP (�1x� ]d $R sjRB s&�{��I Ak ]1 AZ� $� {st��� Z} �B (�x� A�{sZR� �Y� 4Bb P�B8 ]d 8ZR� RYs�� �Y�j$t, U � � b$�Y 4BbR P�B8 ]1 stI ]n� 3�B8 �Y� ��RZj�R Bt�{st R�� �Ys� �Y� 4Bb �s�� BP �s{Y {j$�t� $R t�s� BP �Y� sAB%�

0 100 200 300 400 500 600 700 8000

0.2

0.4

0.6

0.8

1Packet Rate of Client 4 and Probing Reference Signal

[pac

ket r

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0 100 200 300 400 500 600 700 8000

5

10

15Number of packets in the network of <Client 4, Server 4>

[pac

ket]

t [discrete time]

3$�Z�� xU _s{,�� �s�� BP {j$�t� ]; stI tZ8A�� BP }s{,��R$t �Y� t��bB�, BP �Y� 4Bb {j$�t� ];\R��%�� 7;�

0 100 200 300 400 500 600 700 8000

10

20Round-trip delay, minimum values from Client 4

[dis

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0 100 200 300 400 500 600 700 8000

0.5

1Packets Requested by Client 4

[pac

ket]

0 100 200 300 400 500 600 700 8000

0.5

1 Packets Received by Client 4

[pac

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t [discrete time]

3$�Z�� EU iBZtIT��$} I�jsk� 8$t$8Z8 %sjZ�R BAR��%�IP�B8 {j$�t� ];� }s{,��R ��JZ�R��I stI ��{�$%�I Ak {j$�t�];�

%sjZ�R� 3�B8 �Y� R$8Zjs�$Bt ��RZj�R Bt� {st BAR��%� �Ys��Y� tZ8A�� BP }s{,��R bs$�$t� $t JZ�Z�R $R ABZtI�I �B sjBb�� %sjZ�� stI �Y� AstIb$I�Y s}}�B-$8s��R �Y� %sjZ�RBP Ps$� RYs��� qY� 8�st %sjZ� BP }s{,��R $t id $R d }s{,���$t �BZ��� i1 $R d�x }s{,�� stI $t �BZ��� in �Y� 8�st %sjZ�BP }s{,��R $R n� *Z� �B $t{$}$�t� {Bt��R�$Bt �Y� �BZtIT��$}I�jsk $R tB� {BtR�st� B%�� �$8�� 3jBbR b$�Y jBb�� %sjZ�RBP }�B}s�s�$Bt I�jsk sR ]; stI ]x Ys%� Y$�Y�� I$&���t{�RA��b��t �Y� 8$t$8Z8 stI 8s-$8Z8 �BZtIT��$} I�jskR�qY$R Ys}}�tR A�{sZR� 4BbR b$�Y jBb�� 8$t$8Z8 �BZtIT��$} I�jsk %sjZ�R� IZ� �B }�B}s�s�$Bt� Ys%� �Y� ��tI�t{k�B Ys%� Y$�Y�� 4Bb �s�� %sjZ�R� bY${Y s�� }�tsj$9�I Ak�BZ���R b$�Y $t{$}$�t� {Bt��R�$Bt� bY�t {B8}��$t� b$�Y4BbR b$�Y Y$�Y�� �BZtIT��$} �$8� bY${Y Ys%� jBb�� 4Bb�s��R %sjZ�R�

n�n ]B8}s�$RBt b$�Y q]_ }�B�B{BjqY� q]_ {Bt��R�$Bt {Bt��Bj $R $8}j�8�t��I Ak Ys%$t��bB B}��s�$Btsj 8BI�RU �Y� �-}Bt�t�$sj $t{��sR�� stI �Y�

Control 2004, University of Bath, UK, September 2004 ID-082

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0 100 200 300 400 500 600 700 8000

0.2

0.4

0.6

0.8

1Packet Rate of Client 5 and Probing Reference Signal

[pac

ket r

ate]

0 100 200 300 400 500 600 700 8000

2

4

6

8Number of packets in the network of <Client 5, Server 5>

[pac

ket]

t [discrete time]

3$�Z�� �U _s{,�� �s�� BP {j$�t� ]x stI tZ8A�� BP }s{,��R$t �Y� t��bB�, BP �Y� 4Bb {j$�t� ]x\R��%�� 7x�

0 100 200 300 400 500 600 700 8000

10

20Round-trip delay, minimum values from Client 5

[dis

cret

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0 100 200 300 400 500 600 700 8000

0.5

1Packets Requested by Client 5

[pac

ket]

0 100 200 300 400 500 600 700 8000

0.5

1 Packets Received by Client 4

[pac

ket]

t [discrete time]

3$�Z�� MU iBZtIT��$} I�jsk� 8$t$8Z8 %sjZ�R BAR��%�IP�B8 {j$�t� ]x� }s{,��R ��JZ�R��I stI ��{�$%�I Ak {j$�t�]x�

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0 100 200 300 400 500 600 700 8000

0.2

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0 100 200 300 400 500 600 700 8000

2

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t [discrete time]

3$�Z�� �U _s{,�� �s�� BP {j$�t� ]n stI tZ8A�� BP }s{,��R$t �Y� t��bB�, BP �Y� 4Bb {j$�t� ]n\R��%�� 7n�

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10

20

30Round-trip delay, minimum values from Client 3

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1Packets Requested by Client 3

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1 Packets Received by Client 3

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t [discrete time]

3$�Z�� d(U iBZtIT��$} I�jsk� 8$t$8Z8 %sjZ�R BAR��%�IP�B8 {j$�t� ]n� }s{,��R ��JZ�R��I stI ��{�$%�I Ak {j$�t�]n�

0 100 200 300 400 500 600 700 8000

0.2

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1Packet Rate of Client 2 and Probing Reference Signal

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0 100 200 300 400 500 600 700 8000

5

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15Number of packets in the network of <Client 2 , Server 2>

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t [discrete time]

3$�Z�� ddU _s{,�� �s�� BP {j$�t� ]1 stI tZ8A�� BP }s{,��R$t �Y� t��bB�, BP �Y� 4Bb {j$�t� ]1\R��%�� 71�

Control 2004, University of Bath, UK, September 2004 ID-082

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0 100 200 300 400 500 600 700 8000

20

40Round-trip delay, minimum values from Client 2

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Control 2004, University of Bath, UK, September 2004 ID-082