30/07/14 1 30/07/14 COMPSCI 111/111G - Lecture 05 1

!"#$%&'()$*+',,-()$./'(*!,.)"0*)(1%.(%*,#11.2)(20*3'&-,1*

+4567+8*999*:*999;*!

"#!$#%&'()*+'#!%'!,&-*+*-.!*'/,)+#0!

!"#$%&'%()*#&+,%-+(.$/01&.%*#&+%

–  7<1%#,*3'&*1#(=)(2*.(=*&#$#)>)(2*,#11.2#*'>#&*%?#*8(%#&(#%*

2'31."/0104'%'3'$(*%–  5#11.2#1*.&#*1#(%*.(=*&#$#)>#=*1',#*/,#*".%#&*–  @-1%*")A#*B?<1)$."*"#C#&10*D-%*3.1%#&*–  E'&,.""<*%.A#1*1#$'(=1*

54'$%6107%$"(%#88/(''%09%$"(%/(.&:&(1$%%

COMPSCI 111/111G ! 2!

-+(.$/01&.%*#&+%;()*#&+<%=$#/$(8%>(/3%(#/+3%;+#$(%?@ABC'<%%

F#3'&#*%?#*8(%#&(#%*5-"/B"#*B#'B"#*1?.&#=*%?#*1.,#**,.$?)(#0*('*$',B-%#&1*)(*'G$#*6#'B"#*"#H*,#11.2#1*3'&*'%?#&*-1#&1*

%I<B)$."**9JKL1**'G$#*% http://en.wikipedia.org/wiki/Email!

COMPSCI 111/111G ! 3!

D&/'$%1($70/6%(*#&+%

E#3%F0*+&1'01%– 7#(=*M&1%*#,.)"*,#11.2#*3&',*'(#*$',B-%#&*%'*.('%?#&*'>#&*(#%N'&A*O9JP9Q*

– R1#=*%?#*S*1)2(*3'&*#,.)"*.==&#11#1*

http://openmap.bbn.com/~tomlinso/ray/firstemailframe.html!

COMPSCI 111/111G ! 4!

-*#&+%288/(''%G18(/'$#18&1H%$"(%#88/(''%

localpart@domainname

The local part of the address!Often a username !

The domain name where the mail!server is located!

e.g. andre@cs.auckland.ac.nz

COMPSCI 111/111G ! 5!

I0*:0'&1H%#1%(*#&+%*(''#H(%%I0*:0'(%$"(%*(''#H(%

–  R1#*.(*.BB")$./'(*–  I?-(=#&D)&=*

destination address!

carbon copy!

subject!

message body!

signature!

source address!

COMPSCI 111/111G ! 6!

=(18&1H%#1%(*#&+%*(''#H(%;?<%J/0H/#*%'(18'%$"(%(*#&+%*(''#H(%$0%*#&+%'(/>(/%%

–  R1#1*7),B"#*5.)"*I&.(13#&*6&'%'$'"*O75I6Q*–  R1-.""<*"'$.%#=*.%*<'-&*8(%#&(#%*1#&>)$#*B&'>)=#&*O876Q*

Thunderbird!

Email message!

Computer!

SMTP Mail server (program)!

Computer!

Message sent using SMTP over the Internet!

Email message!

Message stored on SMTP server!

COMPSCI 111/111G ! 7!

=(18&1H%#1%(*#&+%*(''#H(%;K<%=5FJ%'(/>(/%.01$#.$'%$"(%L0*#&1%M#*(%=3'$(*%=(/>(/%%$0%N18%#88/(''%09%*#&+%'(/>(/%

SMTP Mail server program!

Computer! DNS Server!

Name ! ! !IP address!... " " "..."mailhost-vip.auckland.ac.nz 130.216.159.124

" " "..."

COMPSCI 111/111G ! 8!

=(18&1H%#1%(*#&+%*(''#H(%;O<%=5FJ%'(/>(/%'(18'%$"(%(*#&+%*(''#H(%$0%8('P1#P01%*#&+%'(/>(/%%

SMTP Mail server!

Computer! Destination !Mail Server!

Email message!

mail.cs.auckland.ac.nz!

COMPSCI 111/111G ! 9!

=(18&1H%#1%(*#&+%*(''#H(%;Q<%G'(/%.0++(.$'%*#&+%9/0*%*#&+%'(/>(/%%

–  T)U#&#(%*B&'%'$'"1*3'&*$'""#$/(2*,.)"**–  646V*O6'1%*4G$#*6&'%'$'"*VQ*–  85W6*O8(%#&(#%*5#11.2#*W$$#11*6&'%'$'"Q*

Thunderbird!

Email message!

Computer!

Mail Server!

Computer!

Message received using POP3 or IMAP protocol!

Email message!

Message stored on mail server!

COMPSCI 111/111G ! 10!

JRJO%>(/'4'%%S52J%JRJO%%1(2&$32(!4&'/!5'6%!78*2!5&'%'*'.!9:*

–  !,.)"*)1*='N("'.=#=*3&',*1#&>#&*%'*"'$."*$',B-%#&*.(=*=#"#%#=*3&',*%?#*1#&>#&*.H#&*='N("'.=*

–  E'*8(%#&(#%*$'((#$/'(*(#$#11.&<*%'*&#.=*%?#*='N("'.=#=*,#11.2#1*–  83*"'$."*$',B-%#&*)1*#&.1#=0*%?#*,#11.2#1*.&#*"'1%*

S52J%%%1;#%2&#2%!<-$.!"**266!5&'%'*'.:%–  !,.)"*)1*A#B%*'(*1#&>#&*–  !,.)"*$")#(%*X-1%*1?'N1*N?.%*,#11.2#1*.&#*'(*%?#*1#&>#&*.(=*='N("'.=1*%?#,*'(*=#,.(=*O('%*=#"#/(2*%?#,QY*6'11)D"#*%'*='N("'.=*'("<*B.&/.""<0*#Y2Y*'("<*%?#*1-DX#$%*")(#Y*

–  !,.)"*$.(*-1-.""<*'("<*D#*&#.=*N?#(*$'((#$%#=*%'*%?#*8(%#&(#%**–  #,.)"*$")#(%1*$.(*D#*1#%*%'*,.)(%.)(*.*"'$."*$'B<*3'&*'Z)(#*–  ;''=*%'*.$$#11*#,.)"*,#11.2#1*3&',*=)U#&#(%*,.$?)(#1*

COMPSCI 111/111G ! 11!

T*#&+%

•  [#D*)(%#&3.$#*3'&*#,.)"*O1),)".&*%'*?'%,.)"0*<.?''\Q*•  7%.&%#=*#.&"<*]LLL1*•  ^]_*,)"")'(*.$/>#*-1#&1*OK:]L9]Q*•  7'B?)1/$.%#=*1#.&$?*3.$)")/#10*D'%?*3'&*$'(%#(%*.(=*$'(%.$%1Y*I?)1*,.A#1*3'"=#&1:,.)(%.)()(2*$'(%.$%1**-((#$#11.&<*

•  +'(>#&1./'(*>)#N*•  +?.%0*?.(2'-%*.==#=*".%#&*•  6&'D"#,1*3'&*-1#&`*B?)1?)(20*%.&2#%#=*.=10*%&)#1*%'*2#%*<'-*='*'%?#&*%?)(21*O#Y2Y*-1#*2''2"#aQ*

COMPSCI 111/111G ! 12!

J/&>#.3%#18%(*#&+%5(''#H('%:#''%$"/04H"%*#13%*#."&1('%

–  +.(*D#*&#.=*D<*'%?#&1*N?)"#*)(*%&.(1)%***5(''#H('%#/(%'$0/(8%01%$"(%8('P1#P01%*#&+%'(/>(/%

–  +.(*D#*.$$#11#=*D<*%?#*.=,)()1%&.%'&*'3*%?#*1<1%#,*– 5)1=)&#$%#=*#,.)"*,)2?%*D#*.-%',./$.""<*1#(=*%'*.=,)()1%&.%'&*

–  F.$A-B*$'B)#1*,)2?%*D#*,.=#*.-%',./$.""<*D#*%?#*,.)"*1#&>#&*U(H#+&$3%

–  8""#2."*%'*&#.=*B?<1)$.""<*B'1%#=*,.)"*Ob#=#&."*$&),#*)(*%?#*R7WQ*–  6#&3#$%"<*"#2."*%'*&#.=*#,.)"*,#11.2#1*– 5.(<*,.X'&*$',B.()#1*)(*R7W*$?#$A*#,B"'<##1*#,.)"*O]_c*d*P_c*=#B#(=)(2*'(*%?#*1-&>#<Q*

COMPSCI 111/111G ! 13!

=:#*%#18%=.#*%!"#$%&'%':#*,%

–  W=>#&/1)(2*#,.)"10*(.,#=*.H#&*$.((#=*,#.%*******>).**.(*'"=***5'(%<*6<%?'(*7A#%$?***–  R(1'")$)%#=0*D-"A*#,.)"*O,#11.2#*1#(=*%'*%?'-1.(=1*'3*B#'B"#Q**–  7B.,,)(2*)1*)""#2."0*D-%*#(3'&$#,#(%*)1*=)G$-"%*–  WD'-%*9LL*D)"")'(*1B.,*#,.)"*,#11.2#1*B#&*=.<*O]L9VQ*– 5.(<*#,.)"*$")#(%1*B&'>)=#*1B.,*M"%#&1*

=.#*%>&#%(*#&+,%–  !,.)"1*B&',)1)(2*,'(#<0*3&##*2.=2#%10*B&)e#1***–  f'.g#1`*,.=#d-B*1%'&)#10*.1A)(2*<'-*%'*3'&N.&=*,.)"10*B.<*,'(#<Y***

–  6?)1?)(2`*.$h-)&#*1#(1)/>#*)(3'&,./'(*D<*,.1h-#&.=)(2*.1*.*%&-1%N'&%?<*#(/%<*O#Y2Y*.1*<'-&*D.(A0*'&*<'-&*,.)"*B&'>)=#&Q*

COMPSCI 111/111G ! 14!

F"(%':#*%'6($."%%%

COMPSCI 111/111G ! 15!

S1'$#1$%*(''#H&1H%;S5<%=31."/0104'%'3'$(*%09%.0**41&.#P01%

–  i)1%*'3*$'(%.$%1*–  T)1B".<1*$'(%.$%1*%?.%*.&#*$-&&#(%"<*'(")(#*–  5#11.2#1*.&#*1#(%*),,#=).%#"<*)(*&#."*/,#*

COMPSCI 111/111G ! 16!

I"#$%'3'$(*%;?<%

=$#/$%4:%$"(%."#$%.+&(1$V%%7#%*%?#*1%.%-1*%'*j'(")(#j*%

Client!(me)! Client!

Server!

Client tells the server "that you are online, gives"

server list of contacts" Server stores: "your IP address, list of your contacts"

COMPSCI 111/111G ! 17!

I"#$%'3'$(*%;K<%

=(/>(/%/(':018'%

Client!(me)! Client!

Server!

Server sends IP addresses"of all your contacts that are"

currently online"

Server sends your IP address"to anyone that lists you as"

a contact"

COMPSCI 111/111G ! 18!

I"#$%'3'$(*%;O<%I+&(1$'%.#1%."#$%$0%(#."%0$"(/%7&$"04$%$"(%'(/>(/%

Client! Client!

Server!

COMPSCI 111/111G ! 19!

I0**01%."#$%'3'$(*'%I"#$%=3'$(*'%

–  8+k*O3&',**9JJKQ*–  57E*–  l.?''*–  ;''2"#*+?.%*.(=**f.(2'-%*–  7A<B#*,#11.2#1*

%2::+&.#P01'%4'(8%#'%.+&(1$'%

–  5.(<*–  7',#*$")#(%1*.""'N*-1#&*%'*$'((#$%*%'*,-"/B"#*$?.%*1<1%#,1*–  5)&.(=.*–  [?.%1WBB**O$'(%'&/'(*'3*mm[?.%n1*-BopQ*

I"#$%/00*'%–  W(<'(#*)(*%?#*1.,#*q&'',p*$.(*1##*%?#*1.,#*$?.%*

COMPSCI 111/111G ! 20!

L#1H(/'%213%(+(.$/01&.%.0**41&.#P01%

–  l'-*$.(('%*#.1)"<*A('N*N?'*.*B#&1'(*)1*–  6#'B"#*,)1&#B&#1#(%*%?#,1#">#1*

Who they say they are! Who they really are!

COMPSCI 111/111G ! 21!

2W#."*(1$'%D&+(%$"#$%&'%#W#."(8%$0%#%*(''#H(%

–  R1-.""<*1#(%*>).*#,.)"*–  E'%*1#$-&#*–  D#C#&*1#(=*.*")(A*%'*%?#*M"#*%?.(*%?#*M"#*)%1#"3*O,-$?*1,.""#&0*,'&#*")A#"<*%'*.&&)>#Q*!Y2Y**-1#*=&'BD'g0*2''2"#*=&)>#*

%2W#."*(1$'%*#3%.01$#&1%8#1H(/04'%N+('%

–  7B<N.&#0*,."N.&#0*>)&-1#1*–  6.&/$-".&"<*=.(2#&'-1`**#g#$-%.D"#*.C.$?,#(%1*OY#g#0*Y$',Q*

–  4%?#&*1##,)(2"<*?.&,"#11*M"#*%<B#1*,.<*."1'*$'(%.)(*#g#$-%.D"#*$'=#*

–  E#>#&*'B#(*.(*.C.$?,#(%*<'-*$.(('%*%&-1%*

COMPSCI 111/111G ! 22!

D0/4*'%5(''#H(%X0#/8%

–  W1<($?&'('-1*$',,-()$./'(*–  T)1$-11)'(*2&'-B*–  4(")(#*$',,-()/#1*–  IR5J=IS%???%=K%I%KB?Q*

508(/#$0/%–  W=,)()1%&.%'&*N)%?*.D)")%<*%'*#=)%0*******=#"#%#0*,'>#*,#11.2#1*

%F"/(#8%

–  W(*'(")(#*$'(>#&1./'(*–  5#11.2#*N)%?*&#B")#1**

*

G=-M-F%O1%.&%#=*9JrLQ%–  f-2#*1<1%#,*'3*B-D")$*3'&-,1*–  4>#&*_L0LLL*(#N12&'-B1*

COMPSCI 111/111G ! 23!

YT008%*#11(/'Z%01%$"(%S1$(/1($%M(P[4(W(%;-P[4(W(%01%$"(%M($<%

–  f'N*%'*D#?.>#*B'")%#"<*–  f'N*%'*.>')=*B)s.""1*–  R(=#&1%.(=)(2*$-"%-&."*('&,10*-(=#&1%.(=)(2*'(")(#*$',,-()/#1*

=0*(%E(#8&1H%–  ?CB`::NNNY9L9#,.)"#/h-#C#/B1Y$',:*–  ?CB`::NNNY3.h1Y'&2:&3$1:&3$9r__Y?%,"*–  ?CB`::NNNY."D)'(Y$',:(#/h-#C#:**

COMPSCI 111/111G ! 24!

http://en.wikipedia.org/wiki/Netiquette!

=4**#/3%-*#&+%.#1%X(%4'(8%$0%'(18%*(''#H('%$0%(*#&+%#88/(''('%

–  W1<($?&'('-1*$',,-()$./'(*–  R1-.""<*('%*1#$-&#0*)Y#Y*$.(*D#*&#.=*D<*'%?#&*B#'B"#*–  +.(*D#*,)-1#=*3'&*1B.,*.(=*1$.,*–  R1#=*%'*1#(=*M"#1*.1*.C.$?,#(%1*–  +.(*D#*,)1-1#=*%'*=)1%&)D-%#*1B<N.&#0*,."N.&#0*>)&-1#1*

S1'$#1$%*(''#H&1H%–  7<($?&'('-1*$',,-()$./'(*–  R1-.""<*."1'*('%*>#&<*1#$-&#*–  R1#=*%'*1##*)3*3&)#(=1*.&#*'(")(#*–  ;''=*%'*$?.%*N)%?*'%?#&*B#'B"#*–  +?.%*&'',1*.""'N*%'*$?.%*N)%?*,.(<*B#'B"#*.%*%?#*1.,#*/,#*

D0/4*'%–  q!"#$%&'()$*=)1$-11)'(*2&'-Bp0*-1-.""<*,'=#&.%#=0*–  *".&2#&*.(=*,'&#*1%.D"#*%?.(*$?.%*&'',1*

%COMPSCI 111/111G ! 25!