10325476 (8(+9;: #%e#f(+6gh#'>jik9l47>m4en47&o#%...

Post on 08-Mar-2021

0 Views

Category:

Documents

0 Downloads

Preview:

Click to see full reader

TRANSCRIPT

� �����������

� ����������� ��� ������� ������

� �"!$#"%'&)(+*-,/.10325476�(8(+9;: <=#"%'>@?347.A!$# BDC#"%E#F(+6�GH#'>JIK9L47>M4EN"47&O#"% P

Q ����R�S �8�T��8��� UV��WVX��

Y[Z \^]"_a`J]bZ�cedgfh`Jiajk]"_ml�nbop_q_rfs_t\Hfvu wf/`Jxgj�\gfs_-yzjkd{i|nbo`Jiqo}ZH_~u ]L_�_~]"j�Z �Ao��n"f���� ������� \�wf/`rf�l/`J];j�Z \D��f�i�i�f�d{i�_�y�o}i|n���wf�u f/`�`rf�d{i�_~d{]��^]"f \��Md{Zgf

i�f/`Jiqo}ZH_~u ]L_�_~]"j�Z��� ������� ��� �}�5����¡p�A¢������ \�wf/`rf�l/`J];j�Z f/`ml�j�i�i�f�l/`J];j�Z \D��f�i�i�f�d{i�_�yAo5i

n"f£iewf�l�f�yH`rf�d^is�¤ ��g¡p����¡}¥¦� § �^¡ �5�g¡5��¨D§��5© ¥ª�p�¥¦� §�� \�wf/`rf�l/`J]"j�Z \��3f�i�iaf�d^i�_�yAo}i-n;f

iewf�l�f�yH`rf�d^i«_~d{]��^]"f \��Md{ZHfvi�f/`Jiqo}ZH_~u ]L_�_~];jkZ���opl�¬­d{]�`�`rf�u f�Zk`�_=®`rf�u y¯j�i�]L_°o�`rf�d^i�_|f/`±Z�d{u wf�i�j`°o�`J];jkZH_|\gfs_²`°iqo}u fs_=��³�i�j`rjel�j�n;fs_\^d `�´­yzf¶µ¸·-¹ º1» ¼z½�¾�¿ À�½�ÁàĸÅ/Æ=¼DÅ�ÇT½-ĸÅaÈ�ÅÉÀ�½+ÊÉ�

Ë n�f°ÌÍ]L_a`~fv\gf�d�Ì `ôHy¯fs_±\Hf[yÍiajp`~jel�j�n"fs_t\gf¸nb]bo}]L_rj�Z µ¸·|¹ �Î �ÏyÍi�j`rj�l�j�n"fs_ Å=ÐDÑ�¾�Ò^Å�Ó Å�½tÀ�½Ã½�Å�РÔ�Ó/Å º8_�`rj�y�Õ�o5Z{\�ÕªÖmo}]�`/Ê× �ÏyÍi�j`rj�l�j�n"fs_ ÂK¾�Ð�½�ÁªÐD¼DÅ�Çvº$l�jkZk`J]bZ�dHj�dH_|µ¸·|¹ j�d yÍ];y¯f�n']bZHf�\

µ[·|¹vÊ

� �"!$#"%'&)(+*-,/.10325476�(8(+9;: <=#"%'>@?347.A!$# BDC#"%E#F(+6�GH#'>JIK9L47>M4EN"47&O#"% Ø

� � Ùe���Ú�{Û��X8� �VÜ ÝVÜßÞ

à fál�j�Zk`Ji=âj�n"fv\^d ã�deÌ op_q_Jd^iaf¶¬�dgf£n���wf�u f/`�`rf�d{i²ZD��f�Zk��jk];f[yAop_yÍnbd­_m¬­dgf¸n"f£iewf�l�f�yH`rf�d{iäZgfáy�d^]"_q_rf¸i�f�l�f/��j�]'iK�å æ wf/`Jxgj�\gf¸o}i�isâf/`çf/`èoT`q`rf�Zk`rf º�ÇT½�¾�Èêé~À�РÔ�éaëmÀeÁì½�ÊÉ�í`Jiqo}ZH_~u ]L_�_~];jkZ\D�îd^Zgfï`°iqo}u f ðo nbo ñ�j�]L_ïo���f�l¸ol�¬­d^]F`�`rf�u f�Zk`±]bZ^\{]��^]'\{dHf�n8�

å æ wf/`Jxgj�\gf[\gfs_|ñ+f�Z�âf/`Ji�fs_m\D�òo}Zk`J]"l�];y�o�`J];jkZ º�Ç�ó'ÁÃÔ�Á$ÐÍô ëäÁªÐ ÔH¾�ëÈ�Ó°¾�½�¾ÂK¾eóîÊ/�R`Jiqo}Z­_Ju ]L_q_J]"j�Z l�j�Zk`Jd^Z�dgf[\gfï`Jiqo}u fs_Ïõ�d­_r¬�d��7ðo d{ZHfn']'u ]F`rf \^d Zgjku ��i�f[\gfï`°iqo}u fs_�ZHj�Z�Õ�ol�¬­d^]F`�`gwf�fs_=�à �òol�¬�d{]�`q`rf�u f�Z�`mfs_a`±]'Z{\^]F�g]b\^dgf�n�j�d l�d{u d{nbo�`J]Fñ��

� �"!$#"%'&)(+*-,/.10325476�(8(+9;: <=#"%'>@?347.A!$# BDC#"%E#F(+6�GH#'>JIK9L47>M4EN"47&O#"% ö

÷ ������íÙe��X8��� ø ù ú ûTügý

émetteur récepteur

tem

ps

ACK

trame1

ACK

trame2

trame2

NAK

þ iqo}u fhf�i�i�j�Z�wf�f���ol�¬­d^]F`�`rf�u f�Zk`�yzj}_~]�`°]Fñÿf/`tZ�wfKceo�`J]Lñ

� �"!$#"%'&)(+*-,/.10325476�(8(+9;: <=#"%'>@?347.A!$# BDC#"%E#F(+6�GH#'>JIK9L47>M4EN"47&O#"% �

÷ ������íÙe��X8��� ø ù ú û���ý

émetteur récepteur

ACK

trame1

trame2

trame2

ACK

tem

poris

ateu

rte

mpo

risat

eur

tem

poris

ateu

r

tem

ps

þ iqo}u fhy¯f�iq\^dgf��Ï`~f�u yzj�i�]L_°oT`~f�d^i

� �"!$#"%'&)(+*-,/.10325476�(8(+9;: <=#"%'>@?347.A!$# BDC#"%E#F(+6�GH#'>JIK9L47>M4EN"47&O#"% �

÷ ������íÙe��X8��� ø ù ú û���ý

émetteur récepteur

ACK

trame1

tem

poris

ateu

r

trame1

ACK

tem

poris

ateu

r

tem

ps

émetteur récepteur

ACK

tem

poris

ateu

r

ACK

tem

poris

ateu

rte

mpo

risat

eur

ACK

trame(1)

trame(1)

trame(2)

trame(1) acceptée

trame(1) ignorée

trame(2) acceptée

µhl�¬�d{]�`�`~f�u f�Zk`my¯f�i�\{d�®^\^dgyÍnb]"l=o�`J];jkZ��Z�d^u wf�i�j`°o�`J];j�Z \gfs_-`Jiqo}u fs_

� �"!$#"%'&)(+*-,/.10325476�(8(+9;: <=#"%'>@?347.A!$# BDC#"%E#F(+6�GH#'>JIK9L47>M4EN"47&O#"% �

÷ ������íÙe��X8��� ø ù ú û� Ïý

tem

ps

tem

poris

ateu

r

émetteur récepteur

tem

poris

ateu

r

trame(1)

trame(1)te

mpo

risat

eur

émetteur récepteur

tem

poris

ateu

r

trame(1)

trame(1)

tem

poris

ateu

r

ACK

ACK interprété

comme acquittement

pour trame(2)

n’est pas remarquée

tem

poris

ateu

rtrame(2)trame(2)

ACK(1)

plus tard

ACK(1)ACK

la perte de la trame(2)

trame(1) acceptée

trame(1) ignorée

trame(2) sera renvoyée

trame(1) ignorée

trame(1) acceptée

þ f�u y¯j�i�]"_Jo�`rf�d{i�f°Ì^yÍ]bi�fá`Ji�j�y `âj`=�Z�d^u wf�i�j`°o�`J];j�Z \gfs_topl�¬­d{]�`�`rf�u f�Zk`�_

� �"!$#"%'&)(+*-,/.10325476�(8(+9;: <=#"%'>@?347.A!$# BDC#"%E#F(+6�GH#'>JIK9L47>M4EN"47&O#"% �

÷ ��� �íÙe��X���� ø ù ú �g�������H �e� ���T� �H���� �

� ��� ��� ��

tem

ps

émetteur récepteur

ACK(3)

ACK(2)

ACK(1)

trame(1)

trame(2)

trame(3)

�äfs_�yÍi�j`rj�l�j�n"fs_�_rjkZk`v¼�ÐDÁ Ô�ÁªÓÉÅ/ ½�Áþ�ÐDÐßÅ=ó;Ççf/`tZHf[y¯f�i�u f/`�`~f�Z�`¬�d��îd^ZgfáyAo}d��^i�f¸d�`J]bn']L_°o�`J]"j�Z \Hfvnbo l=opyAol�]�`^wf¸\{d l=o5ZÍo}n��

� �"!$#"%'&)(+*-,/.10325476�(8(+9;: <=#"%'>@?347.A!$# BDC#"%E#F(+6�GH#'>JIK9L47>M4EN"47&O#"% �

Q ���R�S ���������� Ùe���Ú�5�$�íÜR�

à �Ãwf�u f/`�`~f�d^i«yzf�d�`mf�Zk��j=´�f�i-\Hfs_-`Ji�o5u fs_-_Jo}Z­_to�`�`rf�Z{\{i�fn��òol�¬�d{]�`�`~f�u f�Zk` º+È�Á;È�Å=óbÁ$ÐDÁªÐÍôÊÉ�V³Ïj�d^i|d�`°]'n']"_�f�içf�Zgl�j�i�f\{o���o}Zk`°o c�f[nbo l=opyAol�]�`^wf¸\{d l=o5ZÍo}n�®gj�Z yAo _�_�f ðo d^Z u j­\Hf�Í]b\^]bi�f�l/`J];jkZ{Zgf�nDj�ðd n"fs_èol�¬­d^]F`�`rf�u f�Zk`�_ç_�j�Zk`±o�õ�j�d�`^wfs_ ðo \Hfs_`Jiqo}u fs_|f�Zk��j=´«wf�fs_ç\Ío}Z­_mn��òo}d�`Jiafv\{]'i�f�l/`°]"j�Z º+ÈêÁ ôô�Ò�È�ÀHÂ���Á$ÐÍôÊ/��¯fs_rjk]bZ \gfï`°o}u y¯j�ZH_|yzjkd{i|n"fs_|`Jiqo}u fs_mZHj�Z�Õ�ol�¬�d{]�`q`gwf�fs_��

N+1

N+2

N

temps

N N N

N+1 N+1

N+1

N+1 N+1 N+1 N+1

N+2

N+2

N+2 N+2 N+2

N N N N N

N+3

N+3

N+3 N+3 N+3

N+4

N+3

N+2

N+4

N+4

N+4 N+4

N+5

N+5

N+5

T(N) T(N+1) T(N+2) T(N+3) T(N+4) T(N+5)

T(N) T(N+1) T(N+2) T(N+3) T(N+4) T(N+5)

ACK(N+1)ACK(N) ACK(N+2) ACK(N+3) ACK(N+4)

récepteur

émetteur

tam

pons

tam

pons

� �"!$#"%'&)(+*-,/.10325476�(8(+9;: <=#"%'>@?347.A!$# BDC#"%E#F(+6�GH#'>JIK9L47>M4EN"47&O#"% �

� �g�mÛ�e�p�� ��� ���Ú��$Ù­�¦�V���5�����

à o `Jiqo}ZH_~u ]L_�_~]"j�Z l�j�Zk`J]'Z�dgfáyzf�i�u f/`mn���wf�u f/`�`rf�d{iä\gf`Jiqo}ZH_~u f/`�`Ji�fhy�n'dH_~];f�d^i�_ç`Jiqo}u fs_-_°o}Z­_±o���jk]biçi�f��l�d n"f�d{i�_ol�¬�d{]�`�`~f�u f�Zk`�_=� Ë n�ñ¦o}d�`tn']bu ]�`rf�i�n;fvZgj�u �Íi�fá\gfï`°iqo}u fs_ZHj�Z�Õ�ol�¬­d^]F`�`gwf�fs_�y¯j�d{i-\gfs_±iqo}]L_rjkZH_t\gfál=oy�ol�]F`gwf[\gfï`Ji�o5]F`rf�u f�Zk`f/`±\gfï`Éo5]bn'n;f \Hf[u wf�u j�]'iaf º+`°o}u y¯j�Z­_ÉÊ�l/xgf��£n;fvi�wf�l�f�y­`~f�d^i«f/`n���wf�u f/`�`rf�d{iK� �­� §ß¡5� ��"!8� �«¢ #ä¢%$ �à o u wf/`Jxgj�\gfá\Hfs_|ñ�f�ZDâf/`°i�fs_�\��òo5Zk`J];l�]"yAo�`J]"j�Z Z�wf�l�fs_�_~]�`~fn��î]'Zk`Ji�j­\{dHl/`J];j�Z \gf¸Z�d^u wf�iaj5_�\Hf¶_Hwf�¬­dHf�Zgl�fáyzj�d^i|n"fs_|`Ji�o5u fs_o}]'ZH_~]�¬­dD�îd{ZHfh`°o}]'n'n;f \Hf¶ñ+f�Z�âf/`Ji�f¸u o=ÌÍ]'u o}n"f[y¯j�d^içn8�Ãwf�u f/`�`~f�d^i«f/`n"f£iewf�l�f�yH`rf�d{iK�

§ÿ¢�© ����5� ��� � ��'&ÿ¢���§V�����)(+*�, Î , × ,.-/-0-1,3254 ®^Z76�8:9<;>=@?�A fs_a`ZHj�i�u o}n"f�u f�Zk`=� 2 6 ×.B C Î �

¡5¨D¥D!E!8� © ¨F$�¥�© ¨G!¦� ��� !ª¨ H���§I��^¡5�� ��� !KJ ���© �g¡ ¡p�A¢��g�ML�N

¡5¨D¥D!E!8� © ¨F$�¥�© ¨G!¦� ��� !ª¨ H���§I��^¡5�� �«¢ � ������7O�¡p�A¢��g�PLKQ

� �"!$#"%'&)(+*-,/.10325476�(8(+9;: <=#"%'>@?347.A!$# BDC#"%E#F(+6�GH#'>JIK9L47>M4EN"47&O#"% R$P

� �g�m����� ��� X �K��gS �e�=� �g�

N+2 N+3 N+4 N+5 N+6 N+7N+1N

envoyées et acquittéesenvoyées, ne pas

encore acquittées

ne pas encore envoyées, mais

peuvent être envoyées

ne peuvent pas encore

être envoyées

taille de la fenêtre

temps

N+8

� �g�mÛ�e�p�� ��Ü  ��HÙe�H�ÿ� �HÜ�

temps

N+2 N+3 N+4 N+5 N+6 N+7N+1N N+8

numéros de séquence présentement acceptés

� �"!$#"%'&)(+*-,/.10325476�(8(+9;: <=#"%'>@?347.A!$# BDC#"%E#F(+6�GH#'>JIK9L47>M4EN"47&O#"% RSR

T ÞR�gS ��X8�U ÷ ������íÙe��X8� V~��X8� ù ú

Émetteur

Récepteur

7

6 1

5W

2

0

4X

3Y

7

6 1

5W

2

0

4X

3Y

7

6 1

5W

2

0

4X

3Y

7

6 1

5W

2Z

0

4 3Y

7

6 1

5W

2

0

4X

3Y

7

6 1

5W

2

0

4X

3Y

7

6 1

5W

2

0

4X

3Y

7

6 1

5W

2Z

0

4 3Y

(a) (b) (c) (d)

[]\_^.`a^b\dc^fehgi^/jdkmln\Sehoqpbosr_ltehoquv\<j_^.ewltosxsxq^zy/l|{v^}p~j_^}��\��_�G�^bg�uv��j_^0���^}���E^b\_p}^zpbu�j��^}�����_g]���Eoqe|�]��lS�oq\_oqeio�lnxq^b��^b\Se|��������ltr_gb�^}�]x�km^}\S{vuvoq^/jE^/xsl�r_gi^}��o��^bg�^�ehghlt��^t����p|��ltr_gb�^}�]xsl�g��^}pb^brDehosun\�j_^0xsl�rEgi^b��o��^}gi^eighln��^n���aj���lnr_gb�^b�]x�l�g��^bpb^}rEehoquv\�j_��rEgi^b��os^}g�lnp}���Eoqeiei^b��^b\Se|�

� �"!$#"%'&)(+*-,/.10325476�(8(+9;: <=#"%'>@?347.A!$# BDC#"%E#F(+6�GH#'>JIK9L47>M4EN"47&O#"% R+Ø

� ���Ú�{Û��X8� ���L�HT �gÜ�<U ù �g�������� �ÿ��gX��HÙ��5�n  ûTügý

temps

N N N

N+1 N+1

N+1

N+2

N+2

N N+2 N+2

N+3

N+3

N+4

N+4

T(N) T(N+1) T(N+2) T(N+3) T(N+4)

T(N) T(N+2) T(N+3) T(N+4)

ACK(N) ACK(N+2) ACK(N+3) ACK(N+4)

tam

ponsN+1

N+1

N+1

N+2

N+3

N+4

T(N+1)

N+3

N+2

N+3

N+4

N+3

N+4

N+1

T(N+1)

perdueTrame(N+1)

T(N+5)

récepteur

émetteur

tam

pons

N+5N+2

T(N+5)

ACK(N+1)

�|x{o¬­dHft`°iqo}u fèfs_a`�ol�¬­d^]F`�`gwf�fá]bZ^\{]��^]'\{dgf�n'n"f�u f�Zk`=�¢¡�Z l=op_|\��îd^Zf�i�i�f�d{iK®�n ov`Jiqo}u f±fs_a`çiaf/`Jiqo}Z­_Ju ]L_�f ºªi�f/`°iqo}Z­_Ju ]"_q_J]"j�Z ]bu y�n'];l�]�`rfTÊ/�à fs_mZ�d{u wf�i�j}_|\gf¶_gwf�¬�dgf�ZHl�f wf/�g]F`rf�Zk`±n;fs_t\^dgy�n']"l=o�`J];j�Z­_=�

� �"!$#"%'&)(+*-,/.10325476�(8(+9;: <=#"%'>@?347.A!$# BDC#"%E#F(+6�GH#'>JIK9L47>M4EN"47&O#"% R�ö

� ���Ú�{Û��X8� ���L�HT �gÜ�<U ù �g�������� �ÿ��gX��HÙ��5�n  û���ý

temps

N N N

N+1 N+1

N+2

N N+2 N+3

N+3

T(N) T(N+1) T(N+2) T(N+3)

T(N) T(N+2) T(N+3)

ACK(N) ACK(N+2) ACK(N+3)

récepteur

émetteur

tam

pons

N+1

N+3

N+2

N+1

N N+2

N+3

N

N

T(N)

T(N)

ACK(N)

T(N+1)

ACK(N+1)

perdu

T(N+4)

tam

pons

£¤)¥�¦¤�§�¤�¨ª©«¤]¬­¥¯®5¦¤�©«¤]¥�° ±}²ª¤ ³´ µ � ´ ±}®ª¤ ®­¬ §�¶+²+©«¤]²<¬ ®­¬ © ´ ° ¨·¶�² ¸3±©«¶�¬¹©�¤�¸ µ ¤�¸º©3¥ ´ ° ¤�¸»¶�²+© ¦¤�©�¦¤¼¥d¤�½§]¬�¤�¸P§�¶�¥�¥K¤�§�©«¤]° ¤]²�©¿¾K¬ª¸�À@¬ � ³´° ´ ±}²+©«¤]² ´ ²+©P¤�©�¥d¤�§�¶�²�² ´]Á  © ´zµ ¶�¥Ã¸ µb´ ®­¬ª¨ µ ±Ä§ ´ ©Å±w¶�² �

Æ.ÇwÈ�ÉwÊfËÍÌnκÏ�Ð�Ñ�Ò~ÓÕÔEÌSÌnÖÄ× Ø�ÉwÊfÙ�Ú�ÓÕÐFÈ�É.ÛGÜÉwÊÝÉiÌnÔtÞªÉfÙ3ß�ÖhÓÕÙàÓÝáwÓÕËsÉwÊ âbã

ä å>æèç/é7êå>ëvì í�îwì@éïé]ìªðñé¹ò ó ì]ô�ì�ç õ¿öì�ëvìª÷�ç~ønù

temps

N N N

N+1 N+1

N+1

N+2

N+2

N

N+3

T(N) T(N+1) T(N+2) T(N+3) T(N+4)

T(N) T(N+2) T(N+3) T(N+4)

ACK(N) NAK(N+1)

N+1

N+2

N+3

N+4

T(N+1)

T(N+1)

perdueTrame(N+1)

N+1

N+3

N+4

N+2

N+4

N+1

N+2

N+3

N+5

N+5

T(N+5)

T(N+5)

N+2 N+2

N+3

N+2

N+3

N+4

N+2

N+3

N+4

N+1

N+5

ACK(N+4)

émetteur

récepteur

tam

pons

tam

pons

ú»û ´ À@¬ª¤ ´ §�À<¬­±�©�©�¤]° ¤]²+©M¤�¸K©M§]¬�° ¬ µ}´ ©3±hü�ýÿþ��������� ´ §�À@¬­±�©�©«¤©«¶�¬¹©�¤�¸ µ ¤�¸º©3¥ ´ ° ¤�¸ ¾�¬@¸«À<¬ � ´ ¬ ²<¬­° ¦¤]¥d¶ � �7ú»û ´ À<¬�¤�'þ�� ¤�¸K©´ ¸ ¸�¶¹§]±�¦¤ ´ � ¤�§ ¬­² ©«¤]° ¨ ¶�¥�±h¸ ´ ©«¤]¬�¥¯¨ ¶�¬­¥º¨ ¤]¥�° ¤�©�©3¥K¤ ¸ ´¥d¤�©3¥ ´ ²ª¸�° ±h¸�¸�±Ä¶+² ¤]² § ´ ¸�®�¤¼¨ ¤]¥�©«¤ �

Æ.ÇwÈ�ÉwÊfËÍÌnκÏ�Ð�Ñ�Ò~ÓÕÔEÌSÌnÖÄ× Ø�ÉwÊfÙ�Ú�ÓÕÐFÈ�É.ÛGÜÉwÊÝÉiÌnÔtÞªÉfÙ3ß�ÖhÓÕÙàÓÝáwÓÕËsÉwÊ â �

ä å>æèç/é­êå>ëSì í�îhìªéïé�ì�ð1é<ò � å������ ÷������ �����

temps

N N N

N+1 N+1

N+1

N+2

N+2

N

N+3

T(N) T(N+1) T(N+2) T(N+3) T(N+4)

T(N) T(N+2) T(N+3) T(N+4)

ACK(N)

N+1

N+2

N+3

N+4

T(N+1)

N+1

N+2

N+3

N+4 N+4

N+1

N+2

N+3

T(N+1)

N-1 N+1

perdue

NAK(N+1)

trame(N+1)

T(N+2)

T(N+2)

ACK(N)

émetteur

récepteur

N+2 N+3 N+4

tam

pons

tam

pons

trames ignoréesú»û ´ À@¬ª¤ ´ §�À<¬­±�©�©�¤]° ¤]²+©M¤�¸K©M§]¬�° ¬ µ}´ ©3±hü�ýÿþ��������� ´ §�À@¬­±�©�©«¤©«¶�¬¹©�¤�¸ µ ¤�¸º©3¥ ´ ° ¤�¸ ¾�¬@¸«À<¬�� ´ ¬ ²<¬­° ¦¤]¥d¶ � � £ � ´ §�À<¬­±�©�©�¤]° ¤]²+©²5¦¤"! ´ ©3±hü�7þ�������#$�� ®ª¤]° ´ ²­®ª¤ µb´ ¥d¤�©Å¥ ´ ²@¸3° ±w¸ ¸3±w¶�² ³´ ¨ ´ ¥�©3±f¥P®�¤µ}´ ©3¥ ´ ° ¤&%'�(��#)$�� �ÿú»û ´ À@¬ª¤*�7þ�� ¤�¸�© ´ ¸ ¸«¶�§]±�¦¤ ´ � ¤�§ ¬�²©«¤]° ¨ ¶�¥�±w¸ ´ ©«¤]¬­¥ ¨·¶+¬­¥¯¨ ¤]¥�° ¤�©�©3¥K¤ ¸ ´ ¥K¤�©3¥ ´ ²@¸3° ±h¸ ¸3±w¶�² ¤]² § ´ ¸�®ª¤¨ ¤]¥ ©�¤ � µb´ ©3¥ ´ ° ¤&� ��+ µ ²��-, ´ ¨ ´ ¸�®ª¤ ®�¬�¨ µ ±w§ ´ ©3±Ä¶�² ´ � ¤�§ §�¤¨7¥K¶0©�¶�§�¶ µ ¤ �

Æ.ÇwÈ�ÉwÊfËÍÌnκÏ�Ð�Ñ�Ò~ÓÕÔEÌSÌnÖÄ× Ø�ÉwÊfÙ�Ú�ÓÕÐFÈ�É.ÛGÜÉwÊÝÉiÌnÔtÞªÉfÙ3ß�ÖhÓÕÙàÓÝáwÓÕËsÉwÊ â/.

ä å>æèç/é­êå>ëSì í�îhìªéïé�ì�ð1é<ò � å������ ÷������ ��0��

N+3

N+4

N+5

temps

N N N

N+1 N+1

N+2

N

T(N) T(N+1) T(N+2) T(N+3) T(N+5)

T(N) T(N+2) T(N+3)

ACK(N) ACK(N+2) ACK(N+3)

tam

pons

N+3

N+2

N+1

N

T(N+1)

ACK(N+1)

N+3

N+2

N

N+1

N+4

N+4

N+5

T(N+4) T(N+5)

N+1 N+2 N+3 N+4 N+5

T(N+4)

ACK(N+4)

perdu perdu

tam

pons

récepteur

émetteur

1 ±G®�¤�¸ ´ §�À<¬­±�©�©�¤]° ¤]²+©�¸»¸�¶�²+©P¨·¤]¥�®­¬@¸32 µ}´ ©Å¥ ´ ° ¤¼þ4��� ¸3¬�± � ´ ²+©«¤´ §�À<¬­±�©�©�¤ ´ ¬ª¸ ¸�± µ ¤�¸»©3¥ ´ ° ¤�¸º¨'¥�¦¤�§ ¦¤]®�¤]²+©«¤�¸ �

Æ.ÇwÈ�ÉwÊfËÍÌnκÏ�Ð�Ñ�Ò~ÓÕÔEÌSÌnÖÄ× Ø�ÉwÊfÙ�Ú�ÓÕÐFÈ�É.ÛGÜÉwÊÝÉiÌnÔtÞªÉfÙ3ß�ÖhÓÕÙàÓÝáwÓÕËsÉwÊ â65

7 é8� æÿõ:9 øSõ�õ0øSå>æ ÷�å>æèç~ø�æ ð%ì ��0��

;=<4>@?BA@CD<FEG;H<3IJ<�K L M<4N <POQKRCTSVU £W� ¶�¥�®­¥d¤)®�¤ µb´ ©3¥ ´ ²ª¸�° ±h¸�¸�±Ä¶+² ²�� ¤�¸K©¨ ´ ¸�²5¦¤�§�¤�¸ ¸ ´ ±}¥d¤]° ¤]²�©º§�¶�²ª¸�¤]¥ � ¦¤ � ú ¤�©�©«¤ ° ¦¤�© û ¶@®ª¤¼¤�¸K©¬¹©3± µ ±w¸ª¦¤�¤�2ª¸3± µ ¤�¸»©3¥ ´ ° ¤�¸M¥d¤�¨'¥�¦¤�¸�¤]²+©«¤]²+©P®�¤�¸�° ¤�¸�¸ ´ !�¤�¸±f²­®¢¦¤�¨·¤]²�® ´ ²+©�¸�2@¶³¬ ¸�± µ ¤ ¥¹¦¤�§�¤�¨@©«¤]¬­¥5¤�¸�©P§ ´ ¨ ´:X'µ ¤ ®�¤¥d¤�Y ´ ¸ ¸«¤]° X7µ ¤]¥ µ ¤�¸»©3¥ ´ ° ¤�¸P® ´ ²ª¸ µ � ¶�¥�®�¥K¤ ¶�¥�±Z!�±}² ´zµ �\[ ¤�¸!�¥ ´ ²­®ª¸ © ´ ° ¨ ¶�²ª¸P¸�� ´ � ³¤]¥K¤]²�© ´~µ ¶�¥Ã¸�²¢¦¤�§�¤�¸�¸ ´ ±f¥K¤ �

] AF^`_bacOedf^`g U £ ´ ¸ª¦¤�À@¬ª¤]²�§�¤ ¶�¥�±Z!�±}² ´zµ ®ª¤�¸º© ´ ° ¨ ¶�²ª¸»¤�¸�©º©«¶�¬.¾Ã¶�¬­¥Ã¸§�¶+²ª¸�¤]¥ � ¦¤�¤ � £ ´ © ´ ± µ}µ ¤ ®�¤�¸¯© ´ ° ¨·¶+²ª¸M®�¬ § Á¶/©�¦¤)¥�¦¤�§�¤�¨ª©«¤]¬�¥5¤�¸K©° ±}²�±}° ±h¸�¦¤�¤ �ñú ¤�¨ ¤]²­® ´ ²+©32 µ �à¬<©3± µ ±h¸ ´ ©3±w¶�² ®�¤ µ}´ § ´ ¨ ´ §]±�©�¦¤)®­¬§ ´ ² ´zµ ¤�¸K©�° ¶�±}²@¸ ¤ih § ´ §�¤¼À@¬�� ´ � ¤�§ µ}´ ° ¦¤�© û ¶<®�¤¥d¤]² � ¶�±Ä¤�j/¥K¤Ã¾Ã¤�© ¸ª¦¤ µ ¤�§�©3±iü �

Æ.ÇwÈ�ÉwÊfËÍÌnκÏ�Ð�Ñ�Ò~ÓÕÔEÌSÌnÖÄ× Ø�ÉwÊfÙ�Ú�ÓÕÐFÈ�É.ÛGÜÉwÊÝÉiÌnÔtÞªÉfÙ3ß�ÖhÓÕÙàÓÝáwÓÕËsÉwÊ âlk

m ç/øDë�øvõ=�'ç~øvå>æ í1ì ù�ì�æMêì�ç/é�ì<õ í în� æèç~ø�÷@øDob�'ç/øSå>æ

£ �à¬<©3± µ ±h¸ ´ ©Å±w¶�² ®ª¤ ün¤]² Á¤�©3¥d¤�¸M®�� ´ ²+©3±w§]±Ä¨ ´ ©3±Ä¶+² ¨ ¶�¬­¥ µ ¤�¸M¨7¥d¶/©«¶¹§�¶ µ ¤�¸´ � ¤�§ ¬�²�¤I©Å¥ ´ ²@¸3° ±w¸ ¸3±w¶�² §�¶�²�©Å±f²<¬ª¤ ®ª¶�±i© ¥K¤�¸�¨ ¤�§�©�¤]¥ µ ¤�¸§�¶�²�®­±�©3±Ä¶�²@¸ ¸3¬�± � ´ ²+©«¤�¸�ýp ¬�² ©«¤]° ¨·¶+¥ ±h¸ ´ ©«¤]¬­¥»±f²­®�± � ±}®�¬�¤ µ ¨·¶�¬�¥¯§ û ´ À@¬�¤I©3¥ ´ ° ¤²ª¶�²QY ´ §�À<¬­±�© ©�¦¤�¤

p © ´ ± µfµ ¤�¸ ®�¤ ün¤]² Á¤�©3¥K¤�¸P¤�© ²<¬�° ¦¤]¥K¶~¸P®ª¤¼¸ª¦¤�À@¬ª¤]²�§�¤�ý;H<3IJ<�K L M<PND<POQKRC/S�q�rtsvu rxw 2zy u {:r|s] AF^`_baFO}df^`g q4r|svu rxw 2zy u r|s~ �

Émetteur

Récepteur

0 1 2 3 4 5 6 7�

0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 �

0 1 2 3 4 5 6 7

0 1 2 3 4 5 6 7�

0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 �

0 1 2 3 4 5 6 7

(a) (b)�

(c)�

(d)�

���������3�/��������n����������� �"�����Z���������l�z���6������� �����¢¡ ���:£�¤�¥)£§¦"¥W¨T©ª�-«¬�­� ®6¯�°�����²±³��� ¡l� ���J�n�����}¯/����n��®´�����l��µ6�=¨��¯Z� ¶e���n©��¢¡ ���D��µ·±�¸�n��¯��H� �n¹/�´�����T����n��©t���¢�­�����������Z���l�z���´���Z��� ���3�¢¡l�n�H£�¤�¥£§¦`¥»º6©ª��µ�����®6¯�°�n���¼±½�n� ¡l�l���H�������¯/������n®´�Z���l��µ6�:º}��¯Z� ¶e���n©��¢¡�� � �3µ¾±�¸���Z¯��=� �n¹/�´�����T����n��¿

Æ.ÇwÈ�ÉwÊfËÍÌnκÏ�Ð�Ñ�Ò~ÓÕÔEÌSÌnÖÄ× Ø�ÉwÊfÙ�Ú�ÓÕÐFÈ�É.ÛGÜÉwÊÝÉiÌnÔtÞªÉfÙ3ß�ÖhÓÕÙàÓÝáwÓÕËsÉwÊ â À

Á Â Ã ä

£¤¼¨'¥d¶/©«¶�§�¶ µ ¤ Ä [ £ ú Å Ä ±�! û £¤ � ¤ µ [ ´ © ´ £>±f²ÇÆ ú ¶�²+©3¥d¶ µ¢È¬¹©Å± µ ±w¸�¤p ®ª¤�¸»ü ´ ²­±w¶�²ª¸ Å�É $Ç$�$�$�$�$ É È ¤�©�®ª¤�¸ X ±�©�¸ ®�¤I©3¥ ´ ²ª¸�¨ ´ ¥d¤]²�§�¤p Ê Y X ±i© ²¹¬­° ¦¤]¥d¶ ®ª¤¼¸ª¦¤�À@¬�¤]²ª§�¤ ¤�© ¬­²ª¤ ün¤]² Á¤�©3¥d¤ ®�� ´ ²+©3±Ä§]±w¨ ´ ©3±w¶�²Å ´ � ¤�§ ¬�²�¤I© ´ ± µfµ ¤»¾K¬ª¸�À@¬��Õ³´ Ë�Èp §�¶+²+©3¥ Á¶ µ ¤)®���¤]¥ ¥d¤]¬�¥d¸ ´ � ¤�§ úvÌ»úÍ ´ §�À<¬­±�© ©«¤]° ¤]²�©«¸ ²5¦¤"! ´ ©3±iün¸Å6ÎvÏÑÐ È 2ª¤�© ¬­² ° ¦¤�§ ´ ²­±h¸3° ¤¼®ª¤ ¥d¤Ã¾Ã¤�© ¸ª¦¤ µ ¤�§�©3±iü �

1 1 1

7E

fanion

Protocole HDLC

0

1

1

0

1

séquence P/F prochain

P/F

P/F

prochaintype

modificationtype

trame information

trame supervision

trame non-numérée

3 1 31bits

2 ou 4 1

checksumfanion

7Emessage

variable >=0

adresse contrôle

Æ.ÇwÈ�ÉwÊfËÍÌnκÏ�Ð�Ñ�Ò~ÓÕÔEÌSÌnÖÄ× Ø�ÉwÊfÙ�Ú�ÓÕÐFÈ�É.ÛGÜÉwÊÝÉiÌnÔtÞªÉfÙ3ß�ÖhÓÕÙàÓÝáwÓÕËsÉwÊ Ò´Ó

Ô ÃÖÕ­× ì�ç × × ×

ØÚÙ'Û�Ü 1ÞÝ�ß|ànáRâäãfà ² Ý +¬å æ�ß·çHè(çQé­ç}âêÝ ý Ý ² �eçëàìÝîí�Ý`ï'æPá Àzð Ýiètïñ+òåÝ ² é3áHæóï ð â(ôÝ`ïõíÇá ² ïöí�Ý ðø÷ ü á ² àêç ² ïñí ��ð�² çQéiè(Ýiè Å � É È �

Ü Ü Ü å)ç}à ² è Y è(ç Y å)ç}à ² èõæ�ß·çHè(çQé­ç}âêÝ ý æ�Ý�ß|ù ÝièÖâ ��ð èúà�ânàZïúá8èúàìç ² í�Ýæ�â ð ïúàêÝ ð ß¾ïõæ�ßxç:è�çøé­ç}âêÝ`ï Å�+¬å 2 +¬åüû 2�ý æÇæ�Ý�âìþWáRâ Æ42 Ýiè(é�� È 2 é­ç ² èúß ÁçëâìÝí � Ý�ßªß·Ý ð ß¾ï 2 é­ç ²Þÿ�!øð ß|á X âêÝ �á âná é­ç ð é�û�ÝÑßQôÝ`ïtÝ3á ð�2 é­ç ² èúß Áç}âêÝÑÝiè! Ý`ïªèúàêç ² í ð é3á ² áRâÚÅTânà !�² Ý È 2 ïtÝ�ù X âná X âêÝ �á Ä [*ã ú¶�

1 1 1 1 ou 2variable

2 ou 4 1

7E

adressefanion

FF

contrôle

03protocole message checksum

fanion

7E

Protocole PPPå�åbå ð èúà�ânàZïtÝ í�Ý ðø÷ æ�ß·çHè(çQé­ç}âêÝ`ï à ² è(Ý�ß ² Ý`ï �Ù�� Ü ãfà ²�� � ç ² èVß·ç}âäå ß·çHè(çQé­ç}â�� ôÝièVá�ânàZï|ï(Ý�ù Ý ² èöí�Ýîâ�à�� ² Ý �

á ð è���Ý ² èúàêé3á8èúàìç ²� � Ü � Ýiè���ç}ß � � ç��ëèúß·ç}âäå ßxç:è�çøé­ç}â��óé­ç�� ÿ � ð ß|á8èúàêç�� í�Ý â�á é­ç ð é���Ý

ßøôÝ`ïtÝ3á ð

���������! #"%$'&)(+*-,/.102"3"%465 78���!9;:-.1(<����=?>���@�A"%0CBD�!9�E�4�.19F.@G�.1 H��� I�J

top related