work like this: 7
application interface
6
presentation formatting & code conversion
5
session co-ordination between processes
4
transport control of quality service
3
network set up and maintenance
2
link reliable transfer terminalphysical bitstream
** page 74 moment agreement has only been reached on lowest three network. above that there battle in progressibm which solutions problems under name sna (systems architecture) most remainder principal main- frame manufacturerswhose solution osi (open systems interconnection). single so much for background explanation. how does affect user? users can accessone two ways. use special terminals able create packets an appropriate form--called (in original book diagram showing dial-up termials connecting pad system directly connected pss. note added by electronic images)
75
jargon--and these sit switch circuitaccessing it via nearest pss exchange permanent dataline modems operating speeds 240048009600or 48k bauddepending level traffic. alternatively customer ordinary asynchronous without packet-creating capabilities connect into facility handles assembly him.such devices are assembler/ disassemblers pads. jargon said character terminals. pads accessed either leased line 300 1200 thosebut also 110 1200/75. readers if used will done their own computers as dialling pad. phone numbers uk found directory published telecom national networks. order you individual need identity (nui) registeredyour local (pse). pse throw off dont give recognisable nui. extremely flexible configure ports suit equipmentboth speed screen addressingrather bulletin board (though accurate mimics pad). speed: (std) 1200/75 duplex aberdeen birmingham bristol 82511 edinburgh glasgow leeds
(0224) (021) (0272) 82411 (031) (041) (0532)
642242 642484 2145139 2146191 216411 216511 82111 337 9141 9121 9393 204 2011 2031 2051 470711 470611
file:///E|/Books/Hackers Handbook.htm (73 of 133) [11/28/2000 5:58:49 AM]
642644 241 3061 216611cambridge
470811
(0223)