Developing transport-independent applications using the Windows Sockets interface

The Windows Sockets Electronic Discussion List

Page 1 of 50

'HYHORSLQJ7UDQVSRUW,QGHSHQGHQW$SSOLFDWLRQV 8VLQJWKH:LQGRZV6RFNHWV,QWHUIDFH &OLFNWRRSHQRUFRS\WKHSURMHFWILOHV 3UHVHQWHGE\'DYLG7UHDGZHOO 'DYLG7UHDGZHOOKDVEHHQDFWLYHLQ0LFURVRIW:LQGRZV6RFNHWVVLQFHLWVLQFHSWLRQDFWLQJDVDFRDXWKRURIWKHVSHFLILFDWLRQDQGGHYHORSLQJWKH :LQGRZV17RSHUDWLQJV\VWHP:LQGRZV6RFNHWVLQWHUIDFH 3RUWLRQVRIWKLVVHVVLRQDUHUHSULQWHGZLWKSHUPLVVLRQIURP3OXJLQWR6HULRXV1HWZRUN3URJUDPPLQJZLWKWKH:LQGRZV6RFNHWV$3,E\- $OODUG.HLWK0RRUHDQG'DYLG7UHDGZHOO0LFURVRIW6\VWHPV-RXUQDO-XO\‹0LOOHU)UHHPDQ,QF

,QWURGXFWLRQ ,QWRGD\ VKHWHURJHQHRXVQHWZRUNVRQHWKLQJLVFOHDUFORVHGSURSULHWDU\VWDQGDUGVDUHXQZHOFRPH$VWKHEXVLQHVVRIQHWZRUNLQJFRPSXWHUV KDVHYROYHGRYHUWKHODVWWZRGHFDGHVKDUGZDUHDQGVRIWZDUHSURYLGHUVKDYHOHDUQHGWKDWFRRSHUDWLRQFDQ\LHOGYHU\UHZDUGLQJUHVXOWV7KH 0LFURVRIWŠ:LQGRZVŠ6RFNHWVHIIRUWUHSUHVHQWVDQH[WUHPHO\XVDEOHRSHQQHWZRUNLQJVWDQGDUGGHYHORSHGE\RYHUFRRSHUDWLQJYHQGRUVLQ WKHQHWZRUNLQJFRPPXQLW\ 7KH:LQGRZV6RFNHWV$3,$SSOLFDWLRQ3URJUDPPLQJ,QWHUIDFH SURYLGHVDSSOLFDWLRQVZLWKDQDEVWUDFWLRQRIWKHQHWZRUNLQJVRIWZDUHEHORZLW 7KHSUHVHQW:LQGRZV6RFNHWVVSHFLILFDWLRQYHUVLRQGHILQHVWKLVDEVWUDFWLRQIRUWKH7&3,3RU,QWHUQHWSURWRFROIDPLO\)RUPDQ\WKH 7&3,3SURWRFROVUHSUHVHQWWKHJUHDWHVWFRPPRQGHQRPLQDWRUEHWZHHQWKHPDQ\GLVWLQFWV\VWHPVWKDWPDNHXSWRGD\ VHQWHUSULVHQHWZRUNV ,QIDFWWKH7&3,3SURWRFROVZHUHGHYHORSHGLQDPDQQHUVLPLODUWRWKH:LQGRZV6RFNHWVVSHFLILFDWLRQRSHQFRRSHUDWLRQEHWZHHQPDQ\ LQWHUHVWHGSDUWLHVZLWKGLIIHUHQWUHTXLUHPHQWV:LQGRZV6RFNHWVGRHVQ WVWRSDW7&3,3KRZHYHU7KHOHYHORIDEVWUDFWLRQLVFRPSOHWHHQRXJK WRVXSSRUWRWKHUSURWRFROIDPLOLHVDVZHOOIRUH[DPSOHWKH;HUR[Š1HWZRUN6\VWHP;16 SURWRFROV'LJLWDO V'(&QHWSURWRFRORU1RYHOOŠ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

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 2 of 50

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ŒDQG&KLFDJRLQFOXGH:LQGRZV6RFNHWVLPSOHPHQWDWLRQVZKLFKDUHFDSDEOHRIVXSSRUWLQJ WUDQVSRUWSURWRFROVLQDGGLWLRQVWR7&3,3VXFKDV,3;63;0DQ\FRUSRUDWHGHYHORSHUVDUHVWDQGDUGL]LQJRQ:LQGRZV6RFNHWVIRU KHWHURJHQHRXVFOLHQWVHUYHUDSSOLFDWLRQGHYHORSPHQWXQGHU0LFURVRIW:LQGRZV :KHWKHU\RX UHGHYHORSLQJFOLHQWVHUYHUSHHUWRSHHURUGLVWULEXWHGQHWZRUNDSSOLFDWLRQV:LQGRZV6RFNHWVUHSUHVHQWVDVWDQGDUG QHWZRUNLQJ$3,IRU0LFURVRIW:LQGRZVZKLFKZLOODOORZ\RXWRGHYHORSIOH[LEOHQHWZRUNLQJDSSOLFDWLRQVIRU7&3,3DQGRWKHUQHWZRUNLQJ SURWRFROV

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 3 of 50

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

:LQGRZV6RFNHWV$UFKLWHFWXUHV +RZDUHWKH:LQGRZV17DQG&KLFDJRRSHUDWLQJV\VWHPVDEOHWRVXSSRUWVHYHUDOWUDQVSRUWSURWRFROVZLWKDVLQJOH$3,VHW"7KHDQVZHUOLHVLQ WKHFDUHIXOO\GHVLJQHGQHWZRUNDUFKLWHFWXUHVRIWKHVHRSHUDWLQJV\VWHPV%HFDXVHDQXQGHUVWDQGLQJRIWKHXQGHUO\LQJQHWZRUNDUFKLWHFWXUHLV DOZD\VKHOSIXODQGIUHTXHQWO\PDQGDWRU\LQGHVLJQLQJDQGLPSOHPHQWLQJIDVWUREXVWQHWZRUNLQJDSSOLFDWLRQVZH OOEULHIO\GHVFULEHKRZ :LQGRZV6RFNHWVILWVLQWRWKHVHRSHUDWLQJV\VWHPV

:LQGRZV6RFNHWVLQ:LQGRZV17 7KHNH\WRWUDQVSRUWLQGHSHQGHQW:LQGRZV6RFNHWVVXSSRUWLQ:LQGRZV17LVDFRPPRQNHUQHOPRGHWUDQVSRUWLQWHUIDFHFDOOHG7UDQVSRUW 'HYLFH,QWHUIDFHRU7',IRUVKRUW$OORIWKHQHWZRUNLQJFRPSRQHQWVRI:LQGRZV17JRWKURXJK7',WRDFFHVVDWUDQVSRUWSURWRFRO VVHUYLFHV

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 4 of 50

7',DEVWUDFWVNH\GLIIHUHQFHVEHWZHHQSURWRFROVVXFKDVWKHIRUPDWRIWUDQVSRUWDGGUHVVHVDQGSURYLGHVFRPPRQHQWU\SRLQWVIRUW\SLFDO WUDQVSRUWIHDWXUHVOLNHVHQGLQJGDWD

1HWZRUNLQJDUFKLWHFWXUHRI:LQGRZV17 $OOWKHNHUQHOPRGHQHWZRUNLQJFRPSRQHQWVRI:LQGRZV17XVHWKH7',LQWHUIDFHWRVSHDNWRWKHWUDQVSRUWOD\HUVEHORZWKHP7KLVXVHRID FRPPRQLQWHUIDFHDOORZVHDV\DGGLWLRQRUUHPRYDORIWUDQVSRUWSURWRFROVVLQFHHDFKWUDQVSRUWSURWRFROLVFRPSOHWHO\VHSDUDWHGIURPWKH OD\HUVZKLFKXVHLWLQIDFWHDFKWUDQVSRUWLVSDFNDJHGDVDVHSDUDWHGULYHUILOH +RZHYHU7',LVQRWWKHRQO\NHUQHOPRGHWUDQVSRUWLQWHUIDFHDYDLODEOHLQ:LQGRZV177KHUHLVDOVRWKH6WUHDPVLQWHUIDFHZKLFKLVEDVHGRQ WKH$7 7Š6956WUHDPVHQYLURQPHQW6WUHDPVLVXVHIXOIRUSRUWLQJH[LVWLQJWUDQVSRUWSURWRFROVWR:LQGRZV17TXLFNO\DQGHDVLO\+RZHYHU LWGRHVLPSRVHDSHUIRUPDQFHRYHUKHDGRQDOOWUDQVDFWLRQVVLQFHWKHUHLVDPDSSLQJOD\HUEHWZHHQWKH7',FDOOVPDGHE\XSSHUOD\HUVDQGWKH LQWHUQDOLQWHUIDFHVXVHGE\6WUHDPV7KH7&3,3DQG,3;63;WUDQVSRUWSURWRFROVVXSSOLHGZLWKWKHRULJLQDOUHOHDVHRI:LQGRZV17H[LVWHGLQ

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 5 of 50

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

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 6 of 50

:LQGRZV6RFNHWVDUFKLWHFWXUHRI:LQGRZV17 ,QDGGLWLRQWRELW:LQGRZV6RFNHWVDSSOLFDWLRQVVXSSRUWHGWKURXJK:62&.'//:LQGRZV17DOVRVXSSRUWVELW:LQGRZV6RFNHWV DSSOLFDWLRQVWKURXJKWKHILOH:,162&.'//7KLVILOHLVFRPSRVHGRIPLQLPDOHQWU\SRLQWVZKLFKFDOOLQWR:LQGRZV17 V:2: :LQGRZVRQ:LQGRZV VXEV\VWHPZKLFKZLGHQVWKHSDUDPHWHUVWRELWVDQGFDOOVLQWR:62&.'//IRUWKHDFWXDOQHWZRUNLQJVXSSRUW 7KXV:,162&.'//DFWVDVDWKXQNLQJOD\HUEHWZHHQELWDSSOLFDWLRQVDQGWKHUHVWRIWKHRSHUDWLQJV\VWHPZKLFKLVDOOELW

:LQGRZV6RFNHWVLQ&KLFDJR 1RWH7KHLQIRUPDWLRQLQWKLVVHFWLRQSHUWDLQVWRWKHQH[WPDMRUUHOHDVHRI:LQGRZVFRGHQDPHG&KLFDJR$OORIWKHLQIRUPDWLRQLQWKLVVHFWLRQ LVSUHOLPLQDU\DQGVXEMHFWWRFKDQJH &KLFDJRDOVRVXSSRUWVPXOWLSOHWUDQVSRUWVXQGHU:LQGRZV6RFNHWVXVLQJWKHVDPHQDPHV:62&.'//DQG:,162&.'//IRUWKHV\VWHP '//VVRWKDWDSSOLFDWLRQELQDU\FRPSDWLELOLW\LVSUHVHUYHG+RZHYHULQWHUQDOO\WKHDUFKLWHFWXUHRI:LQGRZV6RFNHWVLQ&KLFDJRLVVLJQLILFDQWO\ GLIIHUHQWWKDQ:LQGRZV17 VDUFKLWHFWXUH

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 7 of 50

:LQGRZV6RFNHWVDUFKLWHFWXUHRI&KLFDJR 2QHRIWKHNH\GLIIHUHQFHVEHWZHHQWKH&KLFDJRDQG:LQGRZV17:LQGRZV6RFNHWVDUFKLWHFWXUHVLVWKDWWKHUHLVQRWKXQNLQJLQYROYHGIRU ELWDSSOLFDWLRQV7KH:LQGRZV6RFNHWV'//LVFURVVFRPSLOHGLQWRWZRGLIIHUHQWILOHV:62&.'//DQG:,162&.'//(DFKRIWKHVH VSHDNVGLUHFWO\WRWKHXQGHUO\LQJ9['VYLUWXDOGHYLFHGULYHUV ZKLFKSURYLGH:LQGRZV6RFNHWVVXSSRUWWKHUHE\HOLPLQDWLQJDQH[WUDOD\HUIRU ELWDSSOLFDWLRQV

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 8 of 50

1H[W&KLFDJRKDVPXOWLSOHNHUQHOPRGHWUDQVSRUWLQWHUIDFHVLQFOXGLQJERWK7',DQGWKH(&%HYHQWFRQWUROEORFN LQWHUIDFH7KHUHIRUHWKH GULYHUVZKLFKWUDQVODWHEHWZHHQ:LQGRZV6RFNHWVFDOOVDQGWKHWUDQVSRUWGULYHUVDUHGLIIHUHQWIRUHDFKWUDQVSRUW7KH:,162&.9[' SRLQWVWKHXVHUPRGH'//VDWWKHDSSURSULDWHNHUQHOGULYHUWKHQWKH'//VDFFHVV:67&3RU:61:ZKLFKLQWXUQVSHDNWRWKHLU WUDQVSRUWVRYHUHDFKWUDQVSRUW VLQWHUIDFH

7KH6RFNHWV3DUDGLJP 7KH6RFNHWVSDUDGLJPZDVILUVWLQWURGXFHGLQ%HUNHOH\81,;Š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

1HWZRUNE\WH2UGHU 6LQFH:LQGRZV6RFNHWVDSSOLFDWLRQVFDQ WSRVVLEO\EHDZDUHRIZKDWW\SHRIUHPRWHFRPSXWHUV\VWHPWKDWWKH\ZLOOEHGHDOLQJZLWKDSULRULLW LVQHFHVVDU\WRGHILQHDFRPPRQGDWDUHSUHVHQWDWLRQPRGHOIRUYLWDOLQIRUPDWLRQ:LQGRZV6RFNHWVFKRVHWKHELJHQGLDQPRGHOIRUWKH RQWKHZLUHGDWDUHSUHVHQWDWLRQNQRZQDVQHWZRUNE\WHRUGHU

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 9 of 50

7KH:LQGRZV6RFNHWVLQWHUIDFHRIIHUV$3,VWRDSSOLFDWLRQSURJUDPPHUVWRGRWKHQHFHVVDU\FRQYHUVLRQEHWZHHQWKHORFDOV\VWHP UHSUHVHQWDWLRQRUKRVWE\WHRUGHU DQGQHWZRUNE\WHRUGHU7KHUHLVQRKDUPLQXVLQJWKHVHURXWLQHVRQV\VWHPVZKLFKVWRUHGDWDLQ ELJHQGLDQQDWLYHO\LQIDFWLW VHQFRXUDJHG%\UHOLJLRXVO\XVLQJWKHE\WHRUGHULQJ$3,V\RXUFRGHFDQEHXVHGRQV\VWHPVZLWKGLIIHUHQW LQWHUQDOUHSUHVHQWDWLRQVZLWKRXWLQKHULWLQJE\WHRUGHULQJSUREOHPVWKHUHE\PDNLQJ\RXUFRGHPRUHSRUWDEOH

$*XLGHG7RXURIWKH:LQGRZV6RFNHWV$3, $OWKRXJKWKH:LQGRZV6RFNHWVVSHFLILFDWLRQGHILQHVDOORIWKH:LQGRZV6RFNHWVIXQFWLRQVDQGVWUXFWXUHVWKLVJXLGHGWRXURIWKH$3,ZLOOJLYH \RXDEDVLFXQGHUVWDQGLQJRIWKHEXLOGLQJEORFNVRID:LQGRZV6RFNHWVDSSOLFDWLRQ)ROORZLQJWKHZDONWKURXJKZHZLOOGLVFXVVWKHXVHRI :LQGRZV6RFNHWVE\WKH:RUP+ROHVDPSOHDSSOLFDWLRQ

7KH%DVLF6WUXFWXUHV $OWKRXJKWKH:LQGRZV6RFNHWVVSHFLILFDWLRQFRQWDLQVDERXWDGR]HQGLIIHUHQWVWUXFWXUHVDSSOLFDWLRQGHYHORSHUVZLOOTXLFNO\EHFRPHIDPLOLDU ZLWKDIHZWKDWDUHUHTXLUHGE\QHDUO\DOO:LQGRZV6RFNHWVDSSOLFDWLRQV

struct sockaddr { u_short sa_family; char sa_data[14]; }; struct sockaddr_in { short sin_family; u_short sin_port; struct in_addr sin_addr; char sin_zero[8]; }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

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List struct

hostent { char FAR * char FAR * FAR * short short char FAR * FAR *

Page 10 of 50

h_name; h_aliases; h_addrtype; h_length; h_addr_list;

}; 7KHKRVWHQWVWUXFWXUHLVJHQHUDOO\XVHGE\WKH:LQGRZV6RFNHWVGDWDEDVHURXWLQHVWRUHWXUQKRVWRUV\VWHPLQIRUPDWLRQDERXWDVSHFLILHG V\VWHPRQWKHQHWZRUN7KHKRVWVWUXFWXUHFRQWDLQVWKHSULPDU\QDPHIRUDV\VWHPLQFOXGLQJRSWLRQDODOLDVHVIRUWKHSULPDU\QDPH $GGLWLRQDOO\LWFRQWDLQVDOLVWRIDGGUHVVHV IRUWKHVSHFLILHGV\VWHP7KLVLQIRUPDWLRQLVJHQHUDOO\VRXJKWIRUWKHUHPRWHV\VWHPWRZKLFKDQ DSSOLFDWLRQLVFRQQHFWLQJXVLQJWKH:LQGRZV6RFNHWVGDWDEDVHURXWLQHVGHVFULEHGODWHU

struct

protoent { char FAR * char FAR * FAR * short

p_name; p_aliases; p_proto;

servent { char FAR * char FAR * FAR * short char FAR *

s_name; s_aliases; s_port; s_proto;

}; struct

}; 7KHSURWRHQWDQGVHUYHQWVWUXFWXUHVDUHDOVRILOOHGE\WKH:LQGRZV6RFNHWVGDWDEDVHURXWLQHV7KHVHVWUXFWXUHVFRQWDLQLQIRUPDWLRQDERXWD SDUWLFXODUSURWRFRO7&3RU8'3 RUVHUYLFHILQJHURUWHOQHWIRUH[DPSOH UHVSHFWLYHO\$ORQJZLWKWKHSULPDU\QDPHDQGDQDUUD\RIDOLDVHV IRUWKHSURWRFRORUVHUYLFHWKHVHVWUXFWXUHVDOVRFRQWDLQWKHLUFRUUHVSRQGLQJELW,'VQHFHVVDU\WREXLOGDYDOLG7&3,3HQGSRLQWDGGUHVV

typedef struct WSAData { WORD WORD char char unsigned short unsigned short char FAR * } WSADATA;

wVersion; wHighVersion; szDescription[WSADESCRIPTION_LEN+1]; szSystemStatus[WSASYS_STATUS_LEN+1]; iMaxSockets; iMaxUdpDg; lpVendorInfo;

)LQDOO\WKH:6$'DWDVWUXFWXUHLVILOOHGLQE\D:LQGRZV6RFNHWV'//ZKHQDQDSSOLFDWLRQFDOOVWKH:6$6WDUWXS $3,$ORQJZLWK:LQGRZV

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 11 of 50

6RFNHWVYHUVLRQLQIRUPDWLRQWKHVWUXFWXUHDOVRFRQWDLQVYHQGRUVSHFLILFLQIRUPDWLRQVXFKDVWKHPD[LPXPQXPEHURIVRFNHWVDYDLODEOHDQG WKHPD[LPXPGDWDJUDPVL]H7KHV]'HVFULSWLRQDQGV]6\VWHP6WDWXVPHPEHUVFDQEHXVHGE\DQLPSOHPHQWDWLRQWRLGHQWLI\LWVHOIDQGWKH FXUUHQWVWDWXVRIWKH'//)RUH[DPSOHDQLPSOHPHQWDWLRQPD\UHWXUQWKHWH[W-RH V6KDUH:DUH:LQGRZV6RFNHWVLPSOHPHQWDWLRQY LQV]'HVFULSWLRQ7KHVSHFLILFDWLRQRIWKHOS9HQGRU,QIRPHPEHULVFRPSOHWHO\XSWRDQLPSOHPHQWRUDQGLVQRWGHILQHGLQWKH :LQGRZV6RFNHWVVSHFLILFDWLRQ

6HWWLQJ8SDQG&OHDQLQJ8Ss_port; 7KHH[DPSOHXVHVJHWVHUYE\QDPH WRUHVROYHWKHSRUWQXPEHURIWKH)73VHUYLFHRYHU7&37KHSRUW,'LVXVHGWRFRQVWUXFWWKHVRFNDGGUBLQ VWUXFWXUHHQGSRLQWDGGUHVV IRUIXWXUHXVHE\WKHDSSOLFDWLRQ$VZHPHQWLRQHGEHIRUHWKHDGGUHVVIDPLO\IRU7&3,3LVDOZD\VDVVLJQHGDV

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 15 of 50

$)B,1(7:HXVHWKH,1$''5B$1s_port;

/* Allow the server to accept connections

/* over any inte

/* Bind remote server’s address and port */ if (bind(srv_sock,(LPSOCKADDR)&srv_addr,sizeof(srv_addr))==SOCKET_ERROR){ sprintf(buf,"Windows Sockets error %d: Couldn’t bind socket.", WSAGetLastError());

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 25 of 50

MessageBox (hWnd,buf,"Windows Sockets Error",MB_OK); shutdown_app(); } /* Client-server network interaction takes place here */ &OLHQWVLGHFRQQHFWLRQOHVV

/* Static IP address for remote server for example. In reality, this would be specified as a hostname or IP address by the user */ #define

SERVER

"131.107.1.121"

struct sockaddr_in srv_addr,cli_addr; LPSERVENT srv_info; LPHOSTENT host_info; SOCKET cli_sock; . . /* Create client-side datagram socket */ cli_sock=socket(PF_INET,SOCK_DGRAM); if (cli_sock==INVALID_SOCKET){ sprintf(buf,"Windows Sockets error %d: Couldn’t create socket.", WSAGetLastError()); MessageBox (hWnd,buf,"Windows Sockets Error",MB_OK); shutdown_app(); } cli_addr.sin_family=AF_INET; cli_addr.sin_addr.s_addr=INADDR_ANY; cli_addr.sin_port=0; /* no specific local port req’d */ /* Bind local socket */ if (bind(cli_sock,(LPSOCKADDR)&cli_addr,sizeof(cli_addr))==SOCKET_ERROR){ sprintf(buf,"Windows Sockets error %d: Couldn’t bind socket.", WSAGetLastError()); MessageBox (hWnd,buf,"Windows Sockets Error",MB_OK); shutdown_app(); }

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 26 of 50

/* Resolve port information for TFTP service */ srv_info=getservbyname("tftp","udp"); if (srv_info== NULL) { sprintf(buf,"Windows Sockets error %d: Couldn’t resolve TFTP service port.", WSAGetLastError()); MessageBox (hWnd,buf,"Windows Sockets Error",MB_OK); shutdown_app(); } srv_addr.sin_family = AF_INET; srv_addr.sin_addr.s_addr = inet_addr(SERVER); srv_addr.sin_port=srv_info->s_port; if (connect(cli_sock,(LPSOCKADDR)&srv_addr,sizeof(srv_addr))==SOCKET_ERROR){ sprintf(buf,"Windows Sockets error %d: Couldn’t connect socket.", WSAGetLastError()); MessageBox (hWnd,buf,"Windows Sockets Error",MB_OK); shutdown_app(); } /* Client-server network interaction takes place here */ 6LQFHDFRQQHFWLRQOHVVFOLHQWVXFKDV7)73 ZLOOXQGRXEWHGO\EHGRLQJVXFFHVVLYHWUDQVPLVVLRQVZLWKWKHVHUYHUHVSHFLDOO\GXULQJORQJ WUDQVIHUV ZHKDYHFKRVHQWRFRQQHFWWKHVRFNHWDOORZLQJWKHXVHRIWKHVHQG DQGUHFY $3,VUDWKHUWKDQVHQGWR DQGUHFYIURP 7KH XVHRIFRQQHFW ZLWKGDWDJUDPVRFNHWVLVSXUHO\RSWLRQDO

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

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 27 of 50

DSSOLFDWLRQGLGDUHFY ZLWKDEXIIHURIE\WHVLWZRXOGJHWDOOWKHGDWDDWRQFH 7KHUHIRUHDQDSSOLFDWLRQPXVWQRWPDNHDQ\DVVXPSWLRQVDERXWKRZGDWDZLOODUULYH$VHUYHUZKLFKH[SHFWVWRUHFHLYHE\WHVVKRXOGFDOO UHFY LQDORRSXQWLOLWKDVUHFHLYHGDOORIWKHGDWD

SOCKET int char char int

s; bytes_received; buffer[1000]; *buffer_ptr; buffer_length;

. . buffer_ptr = buffer; buffer_length = sizeof(buffer); /* Receive all outstanding data on socket s */ do { bytes_received = recv(s, buffer_ptr, buffer_length, 0); if (bytes_received == SOCKET_ERROR) { sprintf(buf,"Windows Sockets error %d: Error while receiving data.", WSAGetLastError()); MessageBox (hWnd,buf,"Windows Sockets Error",MB_OK); shutdown_app(); } buffer_ptr += bytes_received; buffer_length -= bytes_received; } while (buffer_length > 0); /LNHZLVHDQDSSOLFDWLRQZKLFKZDQWVWRVHQGE\WHVVKRXOGVHQG LQDORRSXQWLODOORIWKHGDWDKDVEHHQVHQW

SOCKET int char char int

s; bytes_sent; buffer[1000]; *buffer_ptr; buffer_length;

buffer_ptr = buffer; buffer_length = sizeof(buffer); /* Enter send loop until all data in buffer is sent */

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 28 of 50

do { bytes_sent = send(s, buffer_ptr, buffer_length, 0); if (bytes_sent == SOCKET_ERROR) { sprintf(buf,"Windows Sockets error %d: Error while sending data.", WSAGetLastError()); MessageBox (hWnd,buf,"Windows Sockets Error",MB_OK); shutdown_app(); } buffer_ptr += bytes_sent; buffer_length -= bytes_sent; } while (buffer_length > 0);

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

SOCKET SOCKADDR_IN int BYTE int

s; remoteAddr; remoteAddrLength = sizeof(remoteAddr); buffer[1024]; bytesReceived;

for ( ; ; ) { /* Receive a datagram on socket s */

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 29 of 50

bytesReceived = recvfrom( s, buffer, sizeof(buffer),0, (PSOCKADDR)&remoteAddr, &remoteAddrLength ); /* Echo back to the server as long as bytes were received */ if ( bytesReceived != SOCKET_ERROR || sendto( s, buffer, bytesRecieved, 0, (PSOCKADDR)&remoteAddr, remoteAddrLength ) == SOCKET_ERROR ){ sprintf(buf,"Windows Sockets error %d: Error while sending data.", WSAGetLastError()); MessageBox (hWnd,buf,"Windows Sockets Error",MB_OK); shutdown_appl(); } } $VPHQWLRQHGHDUOLHULWLVSRVVLEOHWRFRQQHFW DGDWDJUDPVRFNHW2QFHDGDWDJUDPVRFNHWLVFRQQHFWHGDOOGDWDLVVHQWDQGUHFHLYHGIURP WKHUHPRWHDGGUHVVWRZKLFKWKHGDWDJUDPLVFRQQHFWHGVRLWLVSRVVLEOHWRXVHWKHVHQG DQGUHFY $3,VRQFRQQHFWHGGDWDJUDPVRFNHWV

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

LINGER INT SOCKET

lingerInfo; err; s;

/* First set the linger timeout on the socket to 0. /* cause the connection to be reset. */

This will */

lingerInfo.l_onoff = 1;

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 30 of 50

lingerInfo.l_linger = 0; setsockopt( s, SOL_SOCKET, SO_LINGER, (char *)&lingerInfo,sizeof(lingerInfo) ); closesocket(s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

SOCKET INT BYTE

s; err; buffer[1024];

err = shutdown( s , 1 ); if ( err == SOCKET_ERROR ) { sprintf(buf,"Windows Sockets error %d: Error during shutdown.", WSAGetLastError()); MessageBox (hWnd,buf,"Windows Sockets Error",MB_OK); shutdown_appl(); } /* Receive the rest of the pending data */ while ( (err = recv( s, buffer, sizeof(buffer), 0 ) != 0 ) { if ( err == SOCKET_ERROR ) { sprintf(buf,"Windows Sockets error %d: Error while receiving data.", WSAGetLastError()); MessageBox (hWnd,buf,"Windows Sockets Error",MB_OK); shutdown_appl(); } . . /* do something with the data we received. */ . . }

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List /* The other side has also terminated.

Page 31 of 50 we can safely close now */

closesocket( s ); 1RWHWKDWLQWKLVH[DPSOHWKHDSSOLFDWLRQNHHSVFDOOLQJUHFY XQWLOLWUHWXUQV]HURE\WHVUHFHLYHG,IDQDSSOLFDWLRQFORVHVDVRFNHWDQGWKHUHLV GDWDDYDLODEOHWREHUHFHLYHGRUGDWDODWHUDUULYHVWKHQWKHV\VWHPZLOODERUWWKHFRQQHFWLRQDQGWKURZRXWWKHGDWDVLQFHWKHUHLVQRERG\WR JLYHWKHGDWDWR:HOOEHKDYHGDSSOLFDWLRQVVKRXOGHQVXUHWKDWWKH\UHFHLYHDOOGDWDEHIRUHFORVLQJDVRFNHW

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

‡

GDWDDUULYHVRQWKHVRFNHW

‡

LWLVSRVVLEOHWRVHQGGDWDRQWKHVRFNHW

‡

WKHUHPRWHHQGKDVFORVHGWKHVRFNHW

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 32 of 50

/* Static IP address for remote server for example. In reality, this would be specified as a hostname or IP address by the user */ #define #define #define

SERVER

"131.107.1.121"

SOCKET_MESSAGE SERVER_PORT

WM_USER+1 4000

struct sockaddr_in srv_addr; SOCKET cli_sock; . . . /* Create client-side socket */ cli_sock=socket(PF_INET,SOCK_STREAM,0); if (cli_sock==INVALID_SOCKET){ sprintf(buf, "Windows Sockets error %d: couldn’t open socket.", WSAGetLastError()); MessageBox(hWnd,buf,"Windows Sockets Error",MB_OK); shutdown_appl(); } srv_addr.sin_family = AF_INET; srv_addr.sin_addr.s_addr = inet_addr(SERVER); srv_addr.sin_port=SERVER_PORT; /* Connect to server */ if (connect(cli_sock,(LPSOCKADDR)&srv_addr,sizeof(srv_addr))==SOCKET_ERROR){ sprintf(buf,"Windows Sockets error %d: Couldn’t connect socket.", WSAGetLastError()); MessageBox (hWnd,buf,"Windows Sockets Error",MB_OK); shutdown_appl(); } /* Set up async select on FD_READ, FD_WRITE, and FD_CLOSE events */ err = WSAAsyncSelect(cli_sock, hWnd, SOCKET_MESSAGE, FD_READ|FD_WRITE|FD_CLOSE); if (err == SOCKET_ERROR) { sprintf(buf,"Windows Sockets error %d: WSAAsyncSelect failure.", WSAGetLastError());

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 33 of 50

MessageBox (hWnd,buf,"Windows Sockets Error",MB_OK); shutdown_appl(); } :KHQRQHRIWKHVSHFLILHGQHWZRUNHYHQWVRFFXUVWKHVSHFLILHGZLQGRZKDQGOHK:QGUHFHLYHVDPHVVDJHFRQWDLQLQJDZ0VJRI 62&.(7B0(66$*(7KHZ3DUDPILHOGRIWKHPHVVDJHZLOOKDYHWKHVRFNHWKDQGOHDQGO3DUDPFRQWDLQVWZRSLHFHVRILQIRUPDWLRQWKHORZ ZRUGFRQWDLQVWKHHYHQWWKDWRFFXUUHG)'B5($')'B:5,7(RU)'B&/26( DQGWKHKLJKZRUGFRQWDLQVDQHUURUFRGHRULIWKHUHZDVQR HUURU&RGHVLPLODUWRWKHIROORZLQJIUDJPHQWZKLFKZRXOGEHORQJLQDQDSSOLFDWLRQ VPDLQZLQGRZSURFHGXUHPD\EHXVHGWRLQWHUSUHWD PHVVDJHIURP:6$$V\QF6HOHFW 

long FAR PASCAL _export WndProc(HWND hWnd, UINT message, UINT wParam, LONG lParam) { INT err; switch (message) { case ...: /* handle Windows messages */ . . . case SOCKET_MESSAGE: /* A network event has occurred on our socket. Determine which network event occurred. */ switch (WSAGETSELECTEVENT(lParam)) { case FD_READ: /* Data arrived. Receive it. */ err = recv(cli_sock, Buffer, BufferLength, 0); if (WSAGetLastError() == WSAEWOULDBLOCK) { /* We have already received the data. */ break; } if (err == SOCKET_ERROR) { sprintf(buf, "Windows Sockets error %d: receive error.", WSAGetLastError()); MessageBox(hWnd,buf,"Windows Sockets Error",MB_OK); shutdown_appl(); } . . /* Do something useful with the data. */ . .

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 34 of 50

break; case FD_WRITE: /* We can send data. */ err = send(cli_sock, Buffer, BufferLength, 0); if (err == SOCKET_ERROR) { if (WSAGetLastError() == WSAEWOULDBLOCK) { /* Send buffers overflowed. */ break; } sprintf(buf, "Windows Sockets error %d: send failed.", SAGetLastError()); MessageBox(hWnd,buf,"Windows Sockets Error",MB_OK); shutdown_appl(); } break; case FD_CLOSE: /* The remote closed the socket. */ closesocket(cli_sock); break; } break; }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

$V\QFKURQRXV'DWDEDVH5RXWLQHV -XVWDVVLPSOHQHWZRUNRSHUDWLRQVOLNHUHFY FDQEORFNIRUH[WHQGHGSHULRGVRIWLPHVRFDQWKHGDWDEDVHURXWLQHVOLNHJHWKRVWE\QDPH  HVSHFLDOO\LVWKH\JRWKURXJK'16ZKLFKFDQUHTXLUHFRQVLGHUDEOHWLPHGXHWRWKHQHWZRUNDFWLYLW\LQYROYHG,QRUGHUWRDOORZZHOOEHKDYHG

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 35 of 50

:LQGRZV$SSOLFDWLRQVWRXVHWKHGDWDEDVHURXWLQHVWKH:LQGRZV6RFNHWV$3,VXSSOLHVDV\QFKURQRXVYHUVLRQVRIWKHGDWDEDVHURXWLQHV7KHLU XVHLVVLPLODUWRWKHV\QFKURQRXVGDWDEDVHURXWLQHVZLWKWZRLPSRUWDQWH[FHSWLRQV

‡ ‡

&RPSOHWLRQRIWKHRSHUDWLRQLVLQGLFDWHGYLDD:LQGRZVPHVVDJHDVZLWK:6$$V\QF6HOHFW  7KHDSSOLFDWLRQLVUHTXLUHGWRLQFOXGHDEXIIHUZKLFKLVILOOHGLQE\WKH:LQGRZV6RFNHWV'//ZLWKWKHLQIRUPDWLRQUHTXHVWHGE\WKH DSSOLFDWLRQ7KLVLVLQFRQWUDVWWRWKHV\QFKURQRXVGDWDEDVHURXWLQHVZKLFKUHWXUQDSRLQWHUWRVSDFHRZQHGE\WKH:LQGRZV6RFNHWV'//

,QRUGHUWRPDNHDQDV\QFKURQRXVGDWDEDVHFDOODQDSSOLFDWLRQSDVVHVLQLQIRUPDWLRQDERXWWKHFDOODZLQGRZKDQGOHWRUHFHLYHWKH FRPSOHWLRQPHVVDJHDPHVVDJHFRGHDQGDEXIIHUIRUWKHRXWSXWLQIRUPDWLRQ7KH:LQGRZV6RFNHWV$3,GHILQHVDFRQVWDQW 0$;*(7+2676758&7ZKLFKLVWKHPD[LPXPVL]HRIDKRVWHQWVWUXFWXUH$QDSSOLFDWLRQVKRXOGXVHDEXIIHURIWKLVVL]HWRSDVVWRWKH DV\QFKURQRXVGDWDEDVHURXWLQHVLQRUGHUWREHJXDUDQWHHGWKDWDOOWKHRXWSXWLQIRUPDWLRQZLOOILWLQLWVEXIIHU$FDOOWR :6$$V\QF*HW+RVW%\1DPH PD\EHDVIROORZV

#define GETHOST_MESSAGE BYTE HANDLE TaskHandle;

WM_USER+2

HostBuffer[MAXGETHOSTSTUCT];

/* Resolve hostname "hostname" asynchronously */ TaskHandle = WSAAsyncGetHostByName(hWnd, GETHOST_MESSAGE, "hostname", HostBuffer,

MAXGETHOSTST

if (TaskHandle == SOCKET_ERROR) { sprintf(buf, "Windows Sockets error %d: Hostname couldn’t be resolved.", WSAGetLastError()); MessageBox(hWnd,buf,"Windows Sockets Error",MB_OK); shutdown_appl(); } :6$$V\QF*HW+RVW%\1DPH DQGWKHRWKHUDV\QFKURQRXVGDWDEDVHURXWLQHVUHWXUQDWDVNKDQGOHZKLFKXQLTXHO\UHIHUVWRWKHRSHUDWLRQLQ SURJUHVV7KLVWDVNKDQGOHDOORZVDQDSSOLFDWLRQZKLFKPD\KDYHPXOWLSOHRXWVWDQGLQJDV\QFKURQRXVGDWDEDVHURXWLQHVWRDVVRFLDWHFRPSOHWLRQ PHVVDJHVZLWKWKHUHTXHVWVLQFHWKHWDVNKDQGOHLVUHWXUQHGLQWKHFRPSOHWLRQPHVVDJHDVZ3DUDP 7RUHFHLYHDQGSURFHVVWKHFRPSOHWLRQPHVVDJHDQDSSOLFDWLRQZLOOGRWKHIROORZLQJLQLWVZLQGRZSURFHGXUH

long FAR PASCAL _export WndProc(HWND hWnd, UINT message, UINT wParam, LONG lParam) { INT err;

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 36 of 50

switch (message) { case ...: /* handle Windows messages */ . . . case GETHOST_MESSAGE: /* An asynchronous database routine completed. */ if (WSAGETASYNCERROR(lParam) != 0) { sprintf(buf, "Windows Sockets error %d: Hostname couldn’t be resolved.", WSAGetLastError()); MessageBox(hWnd,buf,"Windows Sockets Error",MB_OK); shutdown_appl(); } . . /* HostBuffer now contains a host buffer, use info from it. */ . . }

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Š$QDSSOLFDWLRQZULWWHQWRXVHWKHDV\QFKURQRXVURXWLQHVFDQEHHDVLO\SRUWHGWR:LQVZLWKRXWWKH QHJDWLYHV\VWHPLPSDFWVRIEORFNLQJFDOOV

7UDQVSRUW,QGHSHQGHQFH file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 37 of 50

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

s_tcp = socket( AF_INET, SOCK_STREAM, IPPROTO_TCP ); ZKLOHDQ63;VRFNHWLVRSHQHGZLWK

s_spx = socket( AF_IPX, SOCK_SEQPACKET, NSPROTO_SPX ); $IWHURSHQLQJDVRFNHWIRUDVSHFLILFSURWRFRODOODFWLRQVSHUIRUPHGRQWKHVRFNHWJRWKURXJKWKHVSHFLILHGSURWRFRO,QWKHDERYHH[DPSOHLI WKHDSSOLFDWLRQGLGDOLVWHQ RQWKHVBWFSVRFNHWEXWQRWRQWKHVBVS[VRFNHWLWZRXOGUHFHLYHLQFRPLQJFRQQHFWVWKURXJK7&3EXWQRWUHFHLYH LQFRPLQJFRQQHFWVWKURXJK63;

3URWRFRO&KDUDFWHULVWLFV $QDSSOLFDWLRQZKLFKXVHVGLIIHUHQWWUDQVSRUWSURWRFROVPXVWEHDZDUHRIWKHGLIIHUHQWFKDUDFWHULVWLFVRIWUDQVSRUWSURWRFROV:KLOHDOOWUDQVSRUW SURWRFROVVKDUHWKHVDPHIXQGDPHQWDOSXUSRVHRIELGLUHFWLRQDOGDWDWUDQVIHUPDQ\GHWDLOVRIWKHGDWDWUDQVIHUGLIIHU)ROORZLQJLVDOLVWRINH\ FKDUDFWHULVWLFVRIWUDQVSRUWSURWRFROVRIZKLFK:LQGRZV6RFNHWVDSSOLFDWLRQVQHHGWREHDZDUH

$GGUHVVLQJ 7KHPRVWREYLRXVGLIIHUHQFHEHWZHHQGLIIHUHQWWUDQVSRUWSURWRFROVLVWKHZD\LQZKLFKHDFKXVHVWUDQVSRUWDGGUHVVHVRUVRFNDGGUVLQ :LQGRZV6RFNHWVWHUPV9LUWXDOO\DOOWUDQVSRUWSURWRFROVH[SRVHGLIIHUHQWDGGUHVVIRUPDWVWRDSSOLFDWLRQVWKHRQHH[FHSWLRQEHLQJ1HW%,26 SURWRFROVZKLFKDOOXVHWKHVDPHDGGUHVVIRUPDW $QXPEHURI:LQGRZV6RFNHWV$3,VWDNHVRFNDGGUVDVLQSXWRURXWSXWSDUDPHWHUVLQFOXGLQJELQG FFHSW VHQGWR UHFYIURP  JHWVRFNQDPH DQGJHWSHHUQDPH )RUDOOWKHVH$3,VDVRFNDGGULVUHDOO\WZRDUJXPHQWVDSRLQWHUWRWKHVRFNDGGIUVWUXFWXUHLWVHOIDQGD

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 38 of 50

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

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 39 of 50

7\SLFDOO\FRQQHFWLRQRULHQWHGSURWRFROVDUHUHOLDEOHZKLOHFRQQHFWLRQOHVVSURWRFROVDUHXQUHOLDEOH:KLOHWKLVLVWUXHRIDOOWKHWUDQVSRUW SURWRFROVVXSSRUWHGE\:LQGRZV17LWLVQRWUHTXLUHGWKDWWKHVHDOZD\VJRKDQGLQKDQG

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

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 40 of 50

([SHGLWHG'DWD 6RPHFRQQHFWLRQRULHQWHGWUDQVSRUWSURWRFROVVXSSRUWWKHFRQFHSWRIH[SHGLWHGGDWDDOVRUHIHUUHGWRDVXUJHQWGDWDRURXWRIEDQGGDWD'DWD VHQWZLWKWKH06*B22%IODJLQWKHVHQG $3,LVVHQWDVH[SHGLWHGGDWDDQGWKHWUDQVSRUWSURWRFROPDNHVHYHU\HIIRUWWRGHOLYHUWKHGDWDDV TXLFNO\DVSRVVLEOH2IWHQWKHGDWDLVGHOLYHUHGRXWRIRUGHUVRWKDWLWJHWVWRWKHRWKHUDSSOLFDWLRQDVTXLFNO\DVSRVVLEOH$SSOLFDWLRQV LQWHUHVWHGLQPD[LPXPSRUWDELOLW\VKRXOGDYRLGH[SHGLWHGGDWDVLQFHLWLVQRWVXSSRUWHGE\DOOWUDQVSRUWSURWRFROV

&RQQHFWDQG'LVFRQQHFW'DWD $IHZWUDQVSRUWSURWRFROVVXSSRUWFRQQHFWDQGGLVFRQQHFWGDWDZKHUHDVPDOODPRXQWRIGDWDLVVHQWE\HDFKVLGHZKHQDYLUWXDOFLUFXLWLV HVWDEOLVKHGRUWHUPLQDWHG7KLVGDWDFDQEHDQ\WKLQJEXWLVRIWHQQHJRWLDWLRQLQIRUPDWLRQDERXWWKHYHUVLRQRIVRIWZDUHFRQQHFWLQJHWF $JDLQDSSOLFDWLRQVGHVLULQJSURWRFROSRUWDELOLW\VKRXOGDYRLGWKLVIHDWXUHVLQFHLWLVQRWXQLYHUVDOO\VXSSRUWHG

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

*XLGHOLQHVIRU7UDQVSRUW,QGHSHQGHQFH 7KH:LQGRZV6RFNHWVLQWHUIDFHVRI:LQGRZV17DQG&KLFDJRDUHGHVLJQHGWRIXOO\VXSSRUWDOORIWKHWUDQVSRUWSURWRFROFKDUDFWHULVWLFVOLVWHG DERYH7KLVDOORZVWUDQVSRUWVSHFLILFDSSOLFDWLRQVWRIXOO\XWLOL]HDOOWKHLGLRV\QFUDVLHVRIDSDUWLFXODUSURWRFRO+RZHYHUZKHQZULWLQJ WUDQVSRUWLQGHSHQGHQWDSSOLFDWLRQVLWLVLPSRUWDQWWRPLQLPL]HRUSUHIHUDEO\HOLPLQDWHDOOXVHVRIIHDWXUHVWKDWDUHQRWVXSSRUWHGE\DOO WUDQVSRUWSURWRFROV 0DQ\RIWKHUHVXOWLQJJXLGHOLQHVDUHIDLUO\REYLRXV

‡

'RQ WVHQGRUDWWHPSWWRUHFHLYHH[SHGLWHGGDWD,I\RXPXVWEHDEOHWRUHFHLYHH[SHGLWHGGDWDWREHFRPSDWLEOHZLWKROGHUVRIWZDUHXVH WKH62B22%,1/,1(VRFNHWRSWLRQDQGWUHDWH[SHGLWHGGDWDDVQRUPDOGDWDLQ\RXUGDWDUHFHSWLRQFRGH

‡

1HYHUXVHFRQQHFWRUGLVFRQQHFWGDWD,I\RXQHHGWRLQFOXGHLQIRUPDWLRQDWWKHVWDUWRUHQGRIDWUDQVPLVVLRQSXWLWLQWKHQRUPDOGDWD VWUHDP

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List ‡

Page 41 of 50

,I\RXFRQWURO\RXUDSSOLFDWLRQ VRQWKHZLUHGDWDIRUPDWSHUIRUP\RXURZQPHVVDJHIUDPLQJIRUERWKVWUHDPDQGPHVVDJHSURWRFROV 0HVVDJHIUDPLQJPHDQVWRPDNHWKHOHQJWKRIWKHPHVVDJHVHOIGHVFULELQJIRUH[DPSOHE\LQFOXGLQJWKHPHVVDJHOHQJWKDVWKHILUVW WZRE\WHVRIWKHPHVVDJH7KHDSSOLFDWLRQFDQWKHQUHDGWZRE\WHVNQRZWKHWRWDOPHVVDJHVL]HDQGUHDGWKHUHPDLQGHURIWKH PHVVDJH7KLVDEVWUDFWVWKHGLVWLQFWLRQEHWZHHQPHVVDJHRULHQWHGDQGVWUHDPRULHQWHGWUDQVSRUWSURWRFROV

‡

$VVXPHWKDWWKHWUDQVSRUWSURWRFROGRHVQ WVXSSRUWDJUDFHIXOFORVH,WLVDOZD\VSRVVLEOHWRGRDQDERUWLYHFORVHEXWDJUDFHIXOFORVHLV QRWDOZD\VVXSSRUWHG8VHDQDSSOLFDWLRQOHYHOSURWRFROWRHQVXUHWKDWDOOGDWDKDVEHHQFRUUHFWO\WUDQVPLWWHG

‡

7\SLFDOO\ERWKFRQQHFWLRQOHVVDQGFRQQHFWLRQRULHQWHGWUDQVSRUWSURWRFROVZLOOEHDYDLODEOHRQDQ\JLYHQPDFKLQH7KHUHIRUHLWLV UHDVRQDEOHWRXVHZKLFKHYHULVPRVWFRQYHQLHQWIRU\RXUDSSOLFDWLRQZKLFKZLOOW\SLFDOO\EHFRQQHFWLRQRULHQWHGVLQFHLWIUHHVWKH DSSOLFDWLRQIURPKDYLQJWRZRUU\DERXWUHOLDEOHGDWDGHOLYHU\

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

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 42 of 50

VLJQLILFDQWSHUIRUPDQFHSUREOHPVDQGODUJHLPSURYHPHQWVLQWKH&38XWLOL]DWLRQRIWKHDSSOLFDWLRQPD\KDYHDQHJOLJLEOHHIIHFW:LWKDIDVW FDUGKRZHYHUWKHERWWOHQHFNZLOOXVXDOO\EHWKHDSSOLFDWLRQLWVHOIVRSHUIRUPDQFHSUREOHPVDQGLPSURYHPHQWVVKRZTXLFNO\

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Š:ULWH)LOH DQG5HDG)LOH $3,VWRIDFLOLWDWHPXOWLSOH[LQJDQG PLQLPL]HWKHQXPEHURIWKUHDGVUHTXLUHGE\WKHVHUYLFH,Q:LQGRZV17,2FRPSOHWLRQSRUWVPD\EHXVHGIRUDGGLWLRQDOHIILFLHQF\:KLOH WKLVWKUHDGLQJPRGHOLVWKHPRVWHIILFLHQWIRUODUJHQXPEHUVRIFOLHQWVLWLVDOVRWKHPRVWFRPSOH[7KHUHIRUHLWVKRXOGRQO\EHXVHGZKHUHLWLV UHTXLUHGWRKDYHKLJKSHUIRUPDQFHZLWKODUJHQXPEHUVRIFRQQHFWHGFOLHQWV

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

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 43 of 50

XVHG+LJKSHUIRUPDQFHDSSOLFDWLRQVDQGVHUYLFHVXVHEXIIHUVL]HVLQWKHUDQJHRI.WR.WREDODQFHEHWZHHQWKHSK\VLFDOPHPRU\FRVWRI WKHORFNHGGRZQEXIIHUDQGWKH&38RYHUKHDGRIHDFK,2FDOO7KHEHVWZD\WRGHWHUPLQHDVSHFLILFQXPEHUIRU\RXUDSSOLFDWLRQLV H[SHULPHQWDWLRQ $QRWKHUSUREOHPZLWKVPDOO,2LVWKHHIIHFWRI1DJOLQJ1DJOLQJZKLFKRFFXUVRQO\ZLWK7&3,3LVDQDWWHPSWE\WKHWUDQVSRUWSURWRFROWR FRDOHVFHVPDOOEXIIHUVLQWRODUJHUEXIIHUVVRWKDWWKHUHDUHQRWDORWRIWLQ\SDFNHWVRQWKHSK\VLFDOQHWZRUN:KLOH1DJOLQJKHOSVWRUHGXFH VPDOOSDFNHWVRQWKHQHWZRUNLWGRHVLWE\GHOD\LQJVHQGVXQWLOWKHUHLVPRUHGDWDDYDLODEOHWRVHQG:LWKVPDOOEXIIHUVSDVVHGWRVHQG  WKHVHGHOD\VFDQVLJQLILFDQWO\LPSDFWSHUIRUPDQFHVORZLQJGRZQWKHDSSOLFDWLRQE\DVPXFKDV

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

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 44 of 50

FDOOVVRWKDWWZRXVHUEXIIHUVDUHDYDLODEOHWRWKHV\VWHP7KHQZKHQGDWDDUULYHVLWGRHVGLUHFWO\LQWRRQHRIWKHEXIIHUV:KLOHWKH DSSOLFDWLRQLVSURFHVVLQJWKDWGDWDWKHUHLVVWLOODQRWKHUEXIIHUWRUHFHLYHLQFRPLQJGDWDWKHUHE\DYRLGLQJWKHZLQGRZZKHUHWZRFKXQNVRI GDWDDUULYHEDFNWREDFNWKHILUVWJRLQJLQWRDXVHUEXIIHUDQGWKHVHFRQGLQWRDV\VWHPEXIIHU

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

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 45 of 50

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

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 46 of 50

EDQGZLGWKRIWZR(WKHUQHWVZLWKILOHGDWD $QRWKHUQRWHRQ7UDVQPLW)LOH IRUKLJKSHUIRUPDQFHILOHWUDQVIHULVWKDWLWLVUHODWLYHO\VLPSOHWRXVH7KHPDSSHGILOHPHFKDQLVPXVHG DERYHWRRNOLQHVRIVRXUFHFRGHZKLOH7UDQVPLW)LOH XVHGRQO\

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

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 47 of 50

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

3257

1$&.

7UDQVDFWLRQ,'

7UDQVDFWLRQ,'

7UDQVDFWLRQ,'

)LOHOHQJWK

3RUW1XPEHU

(UURUFRGHRSWLRQDO

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 48 of 50

)LOHQDPH

%HFDXVHWKHFRQQHFWLRQUHTXHVW),/( DFNQRZOHGJPHQW3257 DQGUHIXVH1$&. IUDPHVDUHDOOWUDQVPLWWHGRQWKHQHWZRUNXVLQJDQ XQUHOLDEOHGDWDJUDPSURWRFROLWLVTXLWHSRVVLEOHIRUWKHVHIUDPHVWREHORVWLQWKHVKXIIOHRIQHWZRUNDFWLYLW\7KLVVDLGWKH:RUP+ROHSURWRFRO DOVRLPSOHPHQWVVRPHUHWU\WLPHUVWRDOORZDFOLHQWWRUHWU\DIDLOHGFRQQHFWLRQUHTXHVW$:RUP+ROHFOLHQWZLOOUHWU\DFRQQHFWLRQUHTXHVWE\ UHWUDQVPLWWLQJXSWRIRXU),/(IUDPHVWRWKHVHUYHU7RNHHSWKLQJVVLPSOHWKHVHUYHUGRHVQRWLPSOHPHQWDUHWU\WLPHURQSRVVLEOHORVW3257 RU1$&.IUDPHV:HLQVWHDGUHO\RQWKHFOLHQWWRUHVHQGD),/(UHTXHVWLQWKHHYHQWWKDWD3257IUDPHJHWVORVW 6LQFHWKHVHUYHUFUHDWHVDORFDOZLQGRZWUDQVDFWLRQDVVRFLDWLRQDQGWKHOLNHXSRQUHFHLSWRID),/(IUDPHLWGRHVPDLQWDLQDWLPHUSHUILOH WUDQVDFWLRQWRDOORZIRUWKHFOHDQXSRIDFNQRZOHGJPHQW3257 IUDPHVZKLFKJRXQDQVZHUHG)LQDOO\VLQFHWKHILOHWUDQVIHULWVHOIWDNHVSODFH RYHUUHOLDEOHVWUHDPVRFNHWVLWLVQRWQHFHVVDU\WRLPSOHPHQWWKHVHW\SHVRISUHFDXWLRQVIRUWKHDFWXDOILOHWUDQVIHU:RUP+ROHVLPSO\UHOLHVRQ WKHIDLOXUHRIWKHVHQG DQGUHFY $3,VLQWKHHYHQWRIQHWZRUNRUFRQQHFWLRQSUREOHPV

:LQGRZV6RFNHWV$3,)XQFWLRQ2YHUYLHZ 6RFNHW)XQFWLRQV DFFHSW

$QLQFRPLQJFRQQHFWLRQLVDFNQRZOHGJHGDQGDVVRFLDWHGZLWKDQLPPHGLDWHO\FUHDWHGVRFNHW7KHRULJLQDOVRFNHWLVUHWXUQHG WRWKHOLVWHQLQJVWDWH

ELQG

$VVLJQDORFDOQDPHWRDQXQQDPHGVRFNHW

FORVHVRFNHW

5HPRYHDVRFNHWGHVFULSWRUIURPWKHSHUSURFHVVREMHFWUHIHUHQFHWDEOH2QO\EORFNVLI62B/,1*(5LVVHW

FRQQHFW

,QLWLDWHDFRQQHFWLRQRQWKHVSHFLILHGVRFNHW

JHWSHHUQDPH 5HWULHYHWKHQDPHRIWKHSHHUFRQQHFWHGWRWKHVSHFLILHGVRFNHWGHVFULSWRU JHWVRFNQDPH 5HWULHYHWKHFXUUHQWQDPHIRUWKHVSHFLILHGVRFNHW JHWVRFNRSW

5HWULHYHRSWLRQVDVVRFLDWHGZLWKWKHVSHFLILHGVRFNHWGHVFULSWRU

KWRQO

&RQYHUWDELWTXDQWLW\IURPKRVWE\WHRUGHUWRQHWZRUNE\WHRUGHU

KWRQV

&RQYHUWDELWTXDQWLW\IURPKRVWE\WHRUGHUWRQHWZRUNE\WHRUGHU

LQHWBDGGU

&RQYHUWVDFKDUDFWHUVWULQJUHSUHVHQWLQJDQXPEHULQWKH,QWHUQHWVWDQGDUG

QRWDWLRQWRDQ,QWHUQHWDGGUHVVYDOXH

LQHWBQWRD

&RQYHUWVDQ,QWHUQHWDGGUHVVYDOXHWRDQ$6&,,VWULQJLQ

QRWDWLRQLHDEFG



LRFWOVRFNHW

3URYLGHFRQWUROIRUGHVFULSWRUV

OLVWHQ

/LVWHQIRULQFRPLQJFRQQHFWLRQVRQDVSHFLILHGVRFNHW

QWRKO

&RQYHUWDELWTXDQWLW\IURPQHWZRUNE\WHRUGHUWRKRVWE\WHRUGHU

QWRKV

&RQYHUWDELWTXDQWLW\IURPQHWZRUNE\WHRUGHUWRKRVWE\WHRUGHU

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List UHFY

5HFHLYHGDWDIURPDFRQQHFWHGVRFNHW

UHFYIURP

5HFHLYHGDWDIURPHLWKHUDFRQQHFWHGRUXQFRQQHFWHGVRFNHW

VHOHFW

3HUIRUPV\QFKURQRXV,2PXOWLSOH[LQJ

VHQG

6HQGGDWDWRDFRQQHFWHGVRFNHW

VHQGWR

6HQGGDWDWRHLWKHUDFRQQHFWHGRUXQFRQQHFWHGVRFNHW

VHWVRFNRSW

6WRUHRSWLRQVDVVRFLDWHGZLWKWKHVSHFLILHGVRFNHWGHVFULSWRU

VKXWGRZQ

6KXWGRZQSDUWRIDIXOOGXSOH[FRQQHFWLRQ

VRFNHW

&UHDWHDQHQGSRLQWIRUFRPPXQLFDWLRQDQGUHWXUQDVRFNHWGHVFULSWRU

Page 49 of 50

7KHVHIXQFWLRQVPD\EORFNLIDFWLQJRQDEORFNLQJVRFNHW 'DWDEDVH)XQFWLRQV JHWKRVWE\DGGU

5HWULHYHWKHQDPHV DQGDGGUHVVFRUUHVSRQGLQJWRDQHWZRUNDGGUHVV

JHWKRVWQDPH

5HWULHYHWKHQDPHRIWKHORFDOKRVW

JHWKRVWE\QDPH

5HWULHYHWKHQDPHV DQGDGGUHVVFRUUHVSRQGLQJWRDKRVWQDPH

JHWSURWRE\QDPH

5HWULHYHWKHSURWRFROQDPHDQGQXPEHUFRUUHVSRQGLQJWRDSURWRFROQDPH

JHWSURWRE\QXPEHU 5HWULHYHWKHSURWRFROQDPHDQGQXPEHUFRUUHVSRQGLQJWRDSURWRFROQXPEHU JHWVHUYE\QDPH

5HWULHYHWKHVHUYLFHQDPHDQGSRUWFRUUHVSRQGLQJWRDVHUYLFHQDPH

JHWVHUYE\SRUW

5HWULHYHWKHVHUYLFHQDPHDQGSRUWFRUUHVSRQGLQJWRDSRUW

7KHVHIXQFWLRQVPD\EORFNLIDFWLQJRQDEORFNLQJVRFNHW :LQGRZV6RFNHWV$V\QFKURQRXV([WHQVLRQV :6$$V\QF*HW+RVW%\$GGU

$VHWRIIXQFWLRQVZKLFKSURYLGHDV\QFKURQRXVYHUVLRQVRIWKHVWDQGDUG%HUNHOH\JHW;E\< IXQFWLRQV)RU

:6$$V\QF*HW+RVW%\1DPH

H[DPSOHWKH:6$$V\QF*HW+RVW%\1DPH IXQFWLRQSURYLGHVDQDV\QFKURQRXVPHVVDJHEDVHG

:6$$V\QF*HW3URWR%\1DPH

LPSOHPHQWDWLRQRIWKHVWDQGDUG%HUNHOH\JHWKRVWE\QDPH IXQFWLRQ

:6$$V\QF*HW3URWR%\1XPEHU :6$$V\QF*HW6HUY%\1DPH :6$$V\QF*HW6HUY%\3RUW :6$$V\QF6HOHFW

3HUIRUPDV\QFKURQRXVYHUVLRQRIVHOHFW 

:6$&DQFHO$V\QF5HTXHVW

&DQFHODQRXWVWDQGLQJLQVWDQFHRID:6$$V\QF*HW;%\< IXQFWLRQ

file:C:\TEMP\01becc72.htm

9/3/99

The Windows Sockets Electronic Discussion List

Page 50 of 50

:6$&DQFHO%ORFNLQJ&DOO

&DQFHODQRXWVWDQGLQJEORFNLQJ$3,FDOO

:6$&OHDQXS

6LJQRIIIURPWKHXQGHUO\LQJ:LQGRZV6RFNHWV'//

:6$*HW/DVW(UURU

2EWDLQGHWDLOVRIODVW:LQGRZV6RFNHWV$3,HUURU

:6$,V%ORFNLQJ

'HWHUPLQHLIWKHXQGHUO\LQJ:LQGRZV6RFNHWV'//LVDOUHDG\EORFNLQJDQH[LVWLQJFDOOIRUWKLVWKUHDG

:6$6HW%ORFNLQJ+RRN

+RRNWKHEORFNLQJPHWKRGXVHGE\WKHXQGHUO\LQJ:LQGRZV6RFNHWVLPSOHPHQWDWLRQ

:6$6HW/DVW(UURU

6HWWKHHUURUWREHUHWXUQHGE\DVXEVHTXHQW:6$*HW/DVW(UURU 

:6$6WDUWXS

,QLWLDOL]HWKHXQGHUO\LQJ:LQGRZV6RFNHWV'//

:6$8QKRRN%ORFNLQJ+RRN

5HVWRUHWKHRULJLQDOEORFNLQJIXQFWLRQ

2EWDLQLQJWKH6SHFLILFDWLRQ %HIRUH\RXJHWWRRH[FLWHGDERXWZULWLQJD:LQGRZV6RFNHWVDSSOLFDWLRQLW VSUREDEO\DJRRGLGHDWRJHW\RXUKDQGVRQWKHVSHFLILFDWLRQLWVHOI 7KHFXUUHQWYHUVLRQRIWKHVSHFLILFDWLRQLVDQGLWLVGLVWULEXWHGHOHFWURQLFDOO\RQWKH,QWHUQHWDQG&RPSX6HUYHŠ,I\RX UHQRWDEOHWRREWDLQ WKHVSHFLILFDWLRQHOHFWURQLFDOO\DVND:LQGRZV6RFNHWVYHQGRU²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

7KH:LQGRZV6RFNHWV(OHFWURQLF'LVFXVVLRQ/LVW ,I\RX UHLQWHUHVWHGLQ:LQGRZV6RFNHWV\RXUFRPPHQWVH[SHULHQFHDQGIHHGEDFNLVZHOFRPH&XUUHQWO\WKHUHLVDQHOHFWURQLFPDLOLQJOLVWRI VHYHUDOKXQGUHG:LQGRZV6RFNHWVGHYHORSHUVXVHUVDQGZL]DUGVZKLFKRIIHUWHFKQLFDOVXSSRUWDQGGLVFXVVLRQRIWKH:LQGRZV6RFNHWV$3,7R VXEVFULEHHPDLOOLVWVHUY#VXQVLWHXQFHGXLQFOXGLQJDVERWKVXEMHFWDQGERG\WKHOLQH68%6&5,%(:,162&.\RXU,QWHUQHWDGGUHVV!,I \RX UHD8VHQHWXVHUWKHPDLOLQJOLVWLVFURVVSRVWHGWRWKHDOWZLQVRFNQHZVJURXS,QDGGLWLRQ\RXDOVRPLJKWZDQWWRSHUXVHWKH FRPSSURJUDPPHUZLQDQGFRPSSURWRFROVWFSLSLEPSFJURXSVZKLFKIUHTXHQWO\VHH:LQGRZV6RFNHWVUHODWHGWUDIILF

file:C:\TEMP\01becc72.htm

9/3/99