Сети и телекоммуникации

klZg^Zjlhf gZijbf_j D[bl k LZdZy i_j_kljhcdZ kdhjhklb \h \j_fy k\yab gZau\Z_lky hldZlhf Zg]e fallback KZfu_ kh\_jr_ggu_ ba fh^_fh\ mf_xl hkms_kl\eylv b h[jZlgmx hi_jZpbx

— ih\ur_gb_ fall-forward) kdhjhklb k\yab ©gZ oh^mª ijb memqr_gbb dZq_kl\Z ebgbb

K`Zlb_ bgnhjfZpbb

L_i_jv ^Z\Zcl_ h[km^bf _s_ h^gh \Z`gh_ ihgylb_ — k`Zlb_ bgnhjfZpbb Dhg_qgh \u agZdhfu k ijh]jZffZfb-Zjob\ZlhjZfb b ihgbfZ_l_ dZdmx \u]h^m fh`_l ^Zlv k`Zlb_ bgnhjfZpbb ijb __ i_j_dZqd_ ih dZgZem k\yab aZ ihevah\Zgb_ dhlhjuf ijboh^blky ieZlblv IhgbfZeb wlh b jZajZ[hlqbdb ijhlhdheh\ k\yab b ihwlhfm kZfu_ kh\_jr_ggu_ ba wlbo ijhlhdheh\ ij_^mkfZljb\Zxl k`Zlb_ bgnhjfZpbb i_j_^ kZfhc hlijZ\dhc DZd `_ wlh ijhbkoh^bl"

<kihfgbf gZr_]h iZjZeblbdZ fhj]Zxs_]h h^gbf ]eZahf kf \ur_ ©;blu b [ZcluªDZd \u ihfgbl_ _fm [ueh ^hklZlhqgh ebrv iylb [bl qlh[u i_j_^Zlv ex[mx ba -o [md\ jmkkdh]h ZenZ\blZ Wlh beexkljbjm_l lhl nZdl qlh _keb \ khh[s_gbb bkihevamxlky g_ \k_

kbf\heh\ ASCII, lh ijb _]h i_j_^Zq_ fh`gh h[hclbkv ©mj_aZgguf [Zclhfª — k f_gvrbf dhebq_kl\hf [bl dhg_qgh i_j_^Z\Z_fu_ [Zclu hklZxlky \hkvfb[blh\ufb Z ]jmiiu ba kdZ`_f [bl fh]ml gZqbgZlvky \ h^ghf [Zcl_ b aZdZgqb\Zlvky \ ke_^mxs_f

JZamf__lky \jy^ eb \ \Zr_f khh[s_gbb [m^ml aZ^_ckl\h\Zgu \k_ ^h h^gh]h kbf\heu lZ[ebpu ASCII Ihwlhfm aZ kq_l lZdh]h ©mdhjZqb\Zgby [ZclZª fh`gh aZf_lgh khdjZlblv h[t_f nZceZ g_ ihl_jy\ gbq_]h ba _]h kh^_j`bfh]h ;he__ lh]h ^ebgZ lZdbo mdhjhq_gguo [Zclh\ fh`_l [ulv ^Z`_ i_j_f_gghc ijbq_f [he__ qZklh \klj_qZxsb_ky kbf\heu dh^bjmxlky [he__ dhjhldbfb ihke_^h\Zl_evghklyfb [blh\ Gm b gZdhg_p _s_ [hevr_c wdhghfbb fh`gh ^hklbqv khdjZsZy ih\lhjyxsb_ky ]jmiiu kbf\heh\ ih ijbgpbim

::::: -ª: <••

Dhg_qgh wlbf f_lh^u k`Zlby ^Zgguo g_ bkq_jiu\Zxlky b gZijbf_j ijh]jZffu-Zjob\Zlhju jZ[hlZxl ih ]hjZa^h [he__ keh`guf Ze]hjblfZf Gh d kh`Ze_gbx ijb k`Zlbb ^Zgguo ijyfh \h \j_fy i_j_^Zqb dZd ]h\hjyl ©gZ e_lmª Ze]hjblf \ dZ`^uc fhf_gl \j_f_gb \b^bl ebrv g_[hevrmx qZklv \k_o ^Zgguo — h^bg [ehd kf gb`_ Ihwlhfm [hevrhc wnn_dlb\ghklb ^hklbqv ijb wlhf g_ m^Z_lky kdZ`_f _keb ^\Z ih^jy^ b^msbo [ehdZ kh\_jr_ggh h^bgZdh\u ihkueZxsbc fh^_f g_ fh`_l

ijhklh kdZaZlv qlh \lhjhc [ehd kh\iZ^Z_l k i_j\uf — _fm \k_ jZ\gh ijb^_lky ihkeZlv _s_ jZa l_ `_ ^Zggu_ lZd dZd k`bfZlv bgnhjfZpbx iha\hey_lky lhevdh \ ij_^_eZo h^gh]h [ehdZ

H[gZjm`_gb_ b dhjj_dpby hrb[hd

<k_ fu agZ_f qlh lZdh_ iehoZy l_e_nhggZy k\yav dh]^Z ba-aZ rmfZ b lj_kdZ ljm^gh [u\Z_l jZkkeurZlv ]hehk kh[_k_^gbdZ IjZ\^Z ihkdhevdm q_eh\_q_kdbc ]hehk ij_^klZ\ey_l kh[hc ZgZeh]h\uc kb]gZe hg ^himkdZ_l ^h\hevgh kbevgu_ bkdZ`_gby [_a ihl_jb bgnhjfZpbb B \k_ `_ _keb dZq_kl\h k\yab kebrdhf iehoh_ fu \ugm`^_gu ijbf_gylv g_dhlhju_ f_lh^u dhjj_dpbb hrb[hd Fh^_fm `_ dhlhjuc h[yaZg Z[khexlgh lhqgh i_j_^Zlv dZ`^uc [bl ijboh^blky ijb[_]Zlv d wlbf f_lh^Zf ]hjZa^h qZs_

Qlh fu ^_eZ_f dh]^Z ]hehk \ ljm[d_ _^\Z keur_g" <h-i_j\uo _keb fu g_ jZkkeurZeb dZdh_-lh keh\h fu ijhkbf kh[_k_^gbdZ _]h ih\lhjblv LZd `_ ihklmiZ_l b fh^_f Hg i_j_^Z_l bgnhjfZpbx g_ kiehrguf ihlhdhfAZ jZa^_eyy gZ [ehdb b ihke_ i_j_^Zqb dZ`^h]h lZdh]h [ehdZ `^_l hl\_lZ hl fh^_fZ gZ ^jm]hf dhgp_ ebgbb — \k_ eb ihgylh ijZ\bevgh ?keb ijbgbfZxsbc fh^_f g_ kfh] jZkkeurZlv hq_j_^ghc [ehd hg ijhkbl _]h ih\lhjblv <hl ihq_fm ijb iehohc k\yab kdhjhklv i_j_^Zqb kgb`Z_lky — qZklv bgnhjfZpbb ijboh^blky ihkueZlv ih g_kdhevdm jZa LZdhc ijbgpbi dhjj_dpbb hrb[hd gZau\Z_lky ARQ (Automatic Repeat reQuest Z\lhfZlbq_kdbc aZijhk gZ ih\lhj_gb_

<h-\lhjuo fh`gh ihijhkblv kh[_k_^gbdZ ]h\hjblv ih]jhfq_ Fh^_f g_ fh`_l ]h\hjblv ]jhfq_ beb lbr_1 gh aZlh hg fh`_l f_gylv kdhjhklv i_j_^Zqb — kgb`_gb_ l_fiZ j_qb ihfh]Z_l jZah[jZlv keh\Z ^Z`_ wnn_dlb\g__ q_f m\_ebq_gb_ ]jhfdhklb Ihwlhfm ihqlb \k_ ijhlhdheu k\yab bo fu [m^_f ih^jh[gh jZkkfZljb\Zlv gb`_ hlke_`b\Zxl dhebq_kl\h hrb[hd b _keb hgh ij_\urZ_l g_dhlhjmx \_ebqbgm ij_^eZ]Zxl fh^_fm-kh[_k_^gbdm i_j_clb gZ [he__ gbadmx kdhjhklv beb mf_gvrblv jZaf_j [ehdh\ l _©]h\hjblv ih [md\Zfª

<u fh`_l_ kijhkblv dZd `_ ijbgbfZxsbc fh^_f magZ_l qlh bgnhjfZpby i_j_^ZgZ k hrb[dhc" <_^v hg \ hlebqb_ hl q_eh\_dZ g_ fh`_l j_rZlv _klv eb kfuke \ lhf qlh hg keurbl — ^ey g_]h wlh ijhklh ihke_^h\Zl_evghklv [blh\

Qlh[u fh`gh [ueh [_a ^he]bo jZafure_gbc ijb^lb d \u\h^m qlh bgnhjfZpby i_j_^ZgZ \_jgh i_j_^Zxsbc fh^_f ^h[Z\ey_l d dZ`^hfm [ehdm bgnhjfZpbb k\h_]h jh^Z©hibkv

fZg^ ?keb \u jZ[hlZeb dh]^Z-gb[m^v k ijbgl_jZfb lh ihfgbl_ qlh m gbo h[uqgh _klv dghidZ b eZfihqdZ ih^ gZa\Zgb_f ©onlineª Dh]^Z wlZ eZfihqdZ ]hjbl ijbgl_j g_ ih^^Z_lky jmqghfm mijZ\e_gbx qlh[u aZ]jmablv ebkl [mfZ]b beb gZkljhblv iZjZf_lju i_qZlb k iZg_eb mijZ\e_gby gm`gh kgZqZeZ \udexqblv j_`bf online.

J_`bf i_j_^Zqb ^Zgguo fh^_fZ gZihfbgZ_l j_`bf online ijbgl_jZ kh[kl\_ggh ih-Zg]ebckdb wlh lZd b gZau\Z_lky — « modem is onlineª < wlhf j_`bf_ \k_ qlh ihkueZ_l _fm dhfivxl_j fh^_f \hkijbgbfZ_l dZd ^Zggu_ dhlhju_ gm`gh ij_h[jZah\Zlv \ ZgZeh]h\uc kb]gZe b ihkeZlv ih l_e_nhgghc ebgbb DZd ]h\hjyl fh^_f \ j_`bf_ i_j_^Zqb©ijhajZq_g ^ey ^Zgguoª

<lhjhc j_`bf — j_`bf dhfZg^ — ij_^gZagZq_g ^ey mijZ\e_gby fh^_fhf Ihkdhevdm gbdZdbo dghihd gZ fh^_f_ h[uqgh g_ ^_eZxl_keb g_ kqblZlv lmf[e_jZ \dexq_gby m \g_rgbo fh^_fh\ lh ^ey mijZ\e_gby fh^_fhf ijbf_gyxlky ki_pbZevgu_ dhfZg^u ihkueZ_fu_ k dhfivxl_jZ Fh^_f \ wlhf j_`bf_ jZ[hlZ_l dZd fZe_gvdbc kZfhklhyl_evguc dhfivxl_j ihemqb\ kljhdm kbf\heh\ hg iulZ_lky bgl_jij_lbjh\Zlv __ dZd dhfZg^m ?keb _fm wlh m^Z_lky lh hg \uihegy_l wlm dhfZg^m Z _keb g_l — \u^Z_l khh[s_gb_ h[ hrb[d_

JZagh\b^ghklv j_`bfZ dhfZg^ — j_`bf h`b^Zgby a\hgdZ \ dhlhjhf fh^_f `^_l a\hgdZ ]hlh\uc kjZam `_ kgylv ljm[dm b k\y- aZlvky k fh^_fhf gZ ^jm]hf dhgp_ ebgbb < wlhf j_`bf_ fh^_f \uihegy_l ex[u_ dhfZg^u ihevah\Zl_ey gh ijb a\hgd_ kZfhklhyl_evgh i_j_oh^bl \ j_`bf i_j_^Zqb

Kbkl_fZ dhfZg^ fh^_fZ

GZ[hj dhfZg^ fh^_fZ \hh[s_ ]h\hjy aZ\bkbl hl _]h nbjfuijhba\h^bl_ey fh^_eb ]h^Z \uimkdZ b ^jm]bo oZjZdl_jbklbd L_f g_ f_g__ g_fZeh dhfZg^ ij_^gZagZq_gguo ^ey \uiheg_gby hkgh\guo hi_jZpbc y\eyxlky h[sbfb ^ey \k_o fh^_fh\

Ex[hc fh^_f ihgbfZ_l dhfZg^u kgylby ljm[db gZ[hjZ ghf_jZ mklZgh\db j_`bfh\ jZ[hlu Ki_pbZevgufb dhfZg^Zfb fh`gh ijhl_klbjh\Zlv jZ[hlm fh^_fZ baf_gblv iZjZf_lju gZkljhcdbgZijbf_j ]jhfdhklv \kljh_ggh]h ^bgZfbdZ ihemqblv bgnhjfZpbx h khklhygbb fh^_fZ b l i

KjZam ihke_ \dexq_gby fh^_f gZoh^blky \ j_`bf_ dhfZg^ Z i_j_oh^ \ j_`bf i_j_^Zqb ^Zgguo hkms_kl\ey_lky ih dhfZg^_ kgylby ljm[db b gZ[hjZ ghf_jZ Kms_kl\m_l ki_pbZevgZy dhfZg^Z (lZd gZau\Z_fZy escape-ihke_^h\Zl_evghklv dhlhjZy \hkijbgbfZ_lky fh^_fhf dZd dhfZg^Z b \ j_`bf_ i_j_^Zqb ^Zgguo — hgZ dZd jZa b kem`bl ^ey i_j_oh^Z h[jZlgh \ j_`bf dhfZg^ Wlh ihjh`^Z_l ki_pbnbq_kdmx ijh[e_fm _keb \ kZfbo ^Zgguo ij_^-

gZagZq_gguo ^ey i_j_^Zqb _klv qlh-lh ihoh`__ gZ HVFDSH-ihke_- ^h\Zl_evghklv dhffmgbdZpbhgghc ijh]jZff_ ijboh^blky ijbgbfZlv f_ju qlh[u fh^_f g_ j_rbe qlh d g_fm h[jZsZxlky

Gug_ rbjhdh jZkijhkljZg_gguc klZg^Zjl gZ kbkl_fm dhfZg^ fh^_fZ [ue jZajZ[hlZg nbjfhc Hayes dhlhjZy i_j\hc klZeZ \u- imkdZlv fh^_fu ^ey dhfivxl_jh\ IBM PC >jm]b_ ijhba\h^bl_eb fh^_fh\ qlh[u g_ hlklZ\Zlv hl eb^_jZ \ugm`^_gu [ueb \kljZb\Zlv \ k\hb fh^_fu lZdhc `_ gZ[hj dhfZg^ b k_cqZk ijZdlbq_kdb ex[hc fh^_f ihgbfZ_l dhfZg^u fh^_fZ +D\HV bgZq_ ]h\hjy y\ey_lky GZm_Z-kh\f_klbfuf >Z`_ fh^_fu m dhlhjuo _klv k\hc kh[kl\_gguc gZ[hj dhfZg^ h[yaZl_evgh ih^^_j`b\Zxl b klZg^Zjl +D\HV ohly g_dhlhju_ fh^_fu ihgbfZxl g_ \k_ dhfZg^u wlh]h klZg^ZjlZ Z ^jm]b_ gZh[hjhl bf_xl ^hihegbl_evgu_

:L-dhfZg^u

;hevrbgkl\h dhfZg^ klZg^ZjlZ +D\HV ij_^klZ\eyxl kh[hc kljhdb kbf\heh\ gZqbgZxsb_ky k ^\mo [md\ AT hl Zg]e attention — ©\gbfZgb_ª b aZdZgqb\Zxsb_ky kbf\hehf i_j_\h^Z dZj_ldbdeZ\brZ Enter Ihwlhfm dhfZg^u klZg^ZjlZ +D\HV qZklh gZau\Zxl ©:L-dhfZg^Zfbª Kibkhd klZg^Zjlguo :L-dhfZg^ ijb\_^_g \ ijbeh`_gbb gZ klj

D kqZklvx _s_ h^bg yaud dhfZg^ mqblv kh\k_f g_ h[yaZl_evgh < ijbgpbi_ \hafh`gh mijZ\eylv fh^_fhf kj_^kl\Zfb h^ghc ebrv DOS gZ[bjZy AT-dhfZg^u k deZ\bZlmju Gh kms_kl\m_l h]jhfgh_ dhebq_kl\h dhffmgbdZpbhgguo ijh]jZff k m^h[guf kh\j_f_gguf bgl_jn_ckhf dhlhju_ \havfml gZ k_[y \k_ \aZbfh^_ckl\b_ k fh^_fhf Lbiu dhffmgbdZpbhgguo ijh]jZff b ijbgpbiu bo jZ[hlu fu jZkkfhljbf \ ]eZ\_

Ijhlhdheu

@bl_ckdh_ mihlj_[e_gb_ keh\Z ©ijhlhdheª gZijbf_j ©ijhlhdhe ^hijhkZª ^h\hevgh lhqgh hljZ`Z_l lhl kfuke dhlhjuc \ g_]h \deZ^u\Z_lky \ fbj_ l_e_dhffmgbdZpbc JZagbpZ ebrv \ lhf qlh _keb ijhlhdhe ^hijhkZ ibr_lky \h \j_fy beb ihke_ kZfh]h ^hijhkZ lh ijhlhdhe k\yab ^he`_g [ulv ba\_kl_g klhjhgZf aZjZg__

— bgZq_ k\yav [m^_l g_\hafh`gZ

?keb [u gZr iZjZeblbd ba gZqZeZ wlhc ]eZ\u [ue [u ^ey qbklhlu wdki_jbf_glZ _s_ b ]emobf lh qlh[u i_j_^Zlv gZf dZdmx-lh bgnhjfZpbx g_ keurZ \hijhkh\ hg ^he`_g [ue [u aZjZg__ agZlv dZdb_ \hijhku b \ dZdhf ihjy^d_ fu [m^_f _fm aZ^Z\Zlv Bgufb keh\Zfb hg ^he`_g [ulv hk\_^hfe_g h ijhlhdhe_ k\yab

DZd \u ihgbfZ_l_ ^h]h\hjblvky h[ wlhf gZ oh^m h[f_gb\Zykv ebrv ihlhdZfb [blh\ ^h\hevgh aZljm^gbl_evgh b[h k kZfh]h gZqZeZ g_ykgh dZd wlb [blu bgl_jij_lbjh\Zlv

G_hiulguo ihevah\Zl_e_c ijhlhdheu qZklh ih\_j]Zxl \ [_kijhk\_lgh_ hlqZygb_ >_eh \ lhf qlh bo hq_gv fgh]h Z jZaebqby f_`^m gbfb j_^dh dh]^Z ijhklu b hq_\b^gu B \k_ `_ kZfu_ aZimlZggu_ \_sb \k_]^Z fh`gh baeh`blv ^hklmigh — qlh y b ihklZjZxkv k^_eZlv a^_kv ihevamykv \k_f l_f qlh \u m`_ agZ_l_

BlZd \ wlhf jZa^_e_ fu jZkkfhljbf

‡l_e_dhffmgbdZpbhggu_ klZg^Zjlu \hh[s_ — dlh dZd b aZq_f bo mklZgZ\eb\Z_l

‡ dhffmgbdZpbhggu_ iZjZf_lju — klZjlh\u_ b klhih\u_ [blu dhgljhev q_lghklb mijZ\e_gb_ ihlhdhf klZg^Zjl V.14);

‡ ijhlhdheu Afh^_fghc k\yab — klZg^Zjlu ITU-T V.21, V.22, V.22bis, V.32, V.32bis, V Z lZd`_ nbjf_ggu_ ijhlhdheu

PEP, HST, V.FC, x2, K56Flex;

‡ijhlhdheu nZdkbfbevghc k\yab ‡ijhlhdheu dhjj_dpbb hrb[hd b k`Zlby ^Zgguo — MNP1-MNP5,

V.42, V.42bis;

‡ijhlhdheu i_j_^Zqb nZceh\ — Xmodem, Kermit, Zmodem b ^jm]b_

‡iZjZf_lju wfmeypbb l_jfbgZeZ

Hij_^_ebfky k l_jfbgheh]b_c

Keh\h ©ijhlhdheª \ ijbf_g_gbb d fh^_fZf qZklh mihlj_[eyxl ^ey h[hagZq_gby lj_o kh\_jr_ggh jZaguo \_s_c — ijhlhdheh\ k\yab gZijbf_j V.22 ijhlhdheh\ dhjj_dpbb hrb[hd gZijbf_j MNP b ijhlhdheh\ k`Zlby ^Zgguo gZijbf_j 9 ELV Ihfbfh wlh]h kms_kl\mxl _s_ b ijhlhdheu \ukhdh]h mjh\gy j_Zebah\Zggu_ m`_ g_ \ fh^_f_ Z \ l_o ijh]jZffZo dhlhju_ k gbf jZ[hlZxl \ wlhc ]eZ\_ fu ihagZdhfbfky lhevdh k h^ghc bo jZagh\b^ghklvx — k ijhlhdheZfb i_j_^Zqb nZceh\ lZdbfb dZd Zmodem). QblZl_ev ^he`_g ohjhrh ihgbfZlv jZagbpm f_`^m jZagufb lbiZfb ijhlhdheh\ b g_ kf_rb\Zlv kdZ`_f k`Zlb_ ^Zgguo \ ZiiZjZlguo ijhlhdheZo k`Zlby b \ ijhlhdheZo i_j_^Zqb nZceh\ < l_o f_klZo ]^_ \_jhylghklv aZimlZlvky gZb[he__ \_ebdZ y [m^m h[jZsZlv \Zr_ \gbfZgb_ gZ wlb jZaebqby

Djhf_ lh]h a^_kv \u gZc^_l_ k\_^_gby h ^jm]bo oZjZdl_jbklbdZo k\yab lZdbo dZd dhffmgbdZpbhggu_ iZjZf_lju klZjlh\u_ b klhih\u_ [blu dhgljhev q_lghklb b wfmeypby l_jfbgZeZ Hgb g_ hlghkylky d ijhlhdheZf \ madhf kfuke_ keh\Z gh ih eh]bd_ \_s_c kZfh_ ^ey gbo ih^oh^ys__ f_klh

— bf_ggh \ wlhf jZa^_e_ Ihijhklm ]h\hjy y ihevamxkv a^_kv qbklh ijZdlbq_kdbf hij_^_e_-

gb_f keh\Z©ijhlhdheª ©lh qlh ^he`gh kh\iZ^Zlv m fh^_fh\ b dhfivxl_jh\ gZ h[hbo dhgpZo ebgbb qlh[u h[_ki_qb\Zehkv \aZbfhihgbfZgb_ b hlkmlkl\b_ bkdZ`_gbcª

Fbj klZg^Zjlh\

< dhfivxl_jghf fbj_ klZg^Zjlbabjh\Zgh \k_ Khhl\_lkl\b_ klZg- ^ZjlZf gZau\Z_fh_ kh\f_klbfhklvx `bag_ggh g_h[oh^bfh ^ey jZ[hlu ex[h]h pbnjh\h]h mkljhckl\Z Gh _keb gb k d_f b gb k q_f g_kh\f_klbfuc dhfivxl_j jZ[hlZlv \k_-lZdb [m^_l lh g_klZg- ^Zjlguc fh^_f fh`_l ijb]h^blvky jZa\_ qlh \ dZq_kl\_ ij_kkZ ^ey [mfZ] <_^v _]h ]eZ\gh_ gZagZq_gb_ — h[sZlvky k ^jm]bf fh^_fhf Z [_a kh\f_klbfhklb h[ wlhf g_q_]h b ^mfZlv

M kZfuo i_j\uo fh^_fh\ kh klZg^ZjlbaZpb_c [ueh iehoh — dZ`^uc ijhba\h^bl_ev aZqZklmx bf_e k\hb kh[kl\_ggu_ ijhlhdheu b _]h fh^_fu fh]eb jZ[hlZlv lhevdh k fh^_fZfb lhc `_ nbjfu Ihkl_i_ggh iheh`_gb_ klZeh \uijZ\eylvky b k_cqZk m`_ keh`gh gZclb ^\Z fh^_fZ dhlhju_ g_ kfh]eb [u ^h]h\hjblvky ^jm] k ^jm]hf

H^bg ba klZg^Zjlh\ \ fbj_ fh^_fh\ fu m`_ mihfbgZeb — wlh gZ[hj :L-dhfZg^ +D\HV-kh\f_klbfh]h fh^_fZ dhlhju_ kem`Zl ^ey mijZ\e_gby fh^_fhf kh klhjhgu dhfivxl_jZ Kms_kl\h\Zgb_ wlh]h klZg^ZjlZ iha\hey_l k\_klb d fbgbfmfm gZkljhcdm dhffmgbdZpbhgghc ijh]jZffu gZ dhgdj_lguc fh^_f — k ihfhsvx klZg^Zjlguo :L-dhfZg^ ijh]jZffZ kfh`_l [_a ljm^Z h[ma^Zlv ex[hc fh^_f

Gh ih`Zemc kZfu_ \Z`gu_ ^ey fh^_fZ klZg^Zjlu — l_ qlh hij_^_eyxl kdhjhklv _]h jZ[hlu b f_lh^ fh^meypbb < gZklhys__ \j_fy wlb klZg^Zjlu mklZgZ\eb\Zxlky k_dlhjhf klZg^ZjlbaZpbb l_e_dhffmgbdZpbc F_`^mgZjh^gh]h l_e_dhffmgbdZpbhggh]h khxaZ

Zg]e ITU-T, International Telecommunication Union — Telecommunication Standardization Sector1). JZkiheh`_gguc \ @_g_\_

ITU hkms_kl\ey_l dhhj^bgZpbhggu_ b dhgkmevlZlb\gu_ nmgdpbb \ h[eZklb k\yab ih ijh\h^Zf b ih jZ^bh \dexqZy b pbnjh\mx k\yav WlZ hj]ZgbaZpby y\ey_lky Z\lhjhf fgh`_kl\Z klZg^Zjlh\ hij_^_eyxsbo mkljhckl\h l_e_nhgguo l_e_]jZnguo b ijhqbo k_l_c \h \k_f fbj_

=jmiiZ klZg^Zjlh\ ,78-7 hlghkysboky d i_j_^Zq_ pbnjh\hc bgnhjfZpbb ih l_e_nhgghc ebgbb \_kvfZ h[rbjgZ DZ`^uc lZdhc klZg^Zjl bgh]^Z bo gZau\Zxl ©j_dhf_g^Zpbyfbª bf__l h[h- agZq_gb_©V.xxª]^_ oo — g_dbc ghf_j gZijbf_j V Bgh]^Z

ITU-T \uimkdZ_l memqr_ggmx \_jkbx dZdh]h-eb[h ba k\hbo klZg^Zjlh\ HgZ ihemqZ_l \ h[hagZq_gbb ^h[Z\e_gb_©bis» , a ke_^mxsZy aZ g_c —

« terboª lZd \ke_^ aZ V ihy\bebkv V.26bis b V.26terbo,

^hihegyxsb_ b jZa\b\Zxsb_ bkoh^guc klZg^Zjl Wlb klZg^Zjlu ho\Zlu\Zxl kZfuc rbjhdbc djm] \hijhkh\

gZijbf_j V ij_^klZ\ey_l kh[hc kibkhd l_jfbgh\ ba h[eZklb pbnjh\hc k\yab gZ lj_o yaudZo Zg]ebckdhf njZgpmakdhf b bkiZgkdhf V hij_^_ey_l i_j_^Zqm ih l_e_nhgghc ebgbb f_^b- pbgkdbo we_dljhdZj^bh]jZff Z klZg^Zjl V.I mklZgZ\eb\Z_l iZjZf_lju i_j_^Zqb nZdkbfbevgh]h bah[jZ`_gby gZ kdhjhklb ^h

D[bl k AgZqbl_evgh_ qbkeh klZg^Zjlh\ V.xx ihk\ys_gh fh^_fghc k\yab

LZd klZg^Zjl V.22bis hibku\Z_l f_lh^u fh^meypbb ^_fh^meypbb ^ey kdhjhkl_c ^h [bl k Qlh[u bf_lv ijZ\h gZau\Zlvky ©fh^_fhf gZ [bl kª fh^_fm g_^hklZlhqgh ijhklh jZ[hlZlv k wlhc kdhjhklvx — hg ^he`_g lZd`_ kdjmime_agh kh[ex^Zlv \k_ qlh gZibkZgh \ khhl\_lkl\mxs_c j_dhf_g^Zpbb,78-7Z bf_ggh V.32.

>jm]Zy \Z`gZy ]jmiiZ klZg^Zjlh\ — ijhlhdheu dhjj_dpbb hrb[hd b k`Zlby ^Zgguo iha\heyxsb_ aZf_lgh ih\ukblv dZq_kl\h k\yab gZ lhc `_ kZfhc kdhjhklb A^_kv \Z`gZy jhev ijbgZ^e_`bl nbjf_ Microcom dhlhjZy j_Zebah\ZeZ \ k\hbo fh^_fZo k_jbx ijhlhdheh\ MNP (Microcom Networking Protocol ©K_l_\hc ijhlhdhe

0LFURFRPª Wlb ijhlhdheu b k_cqZk jZkijhkljZg_gu ^hklZlhqgh rbjhdh ohly b hlhreb gZ \lhjhc ieZg k ihy\e_gb_f klZg^Zjlh\ ITU- T V b V.42bis.

DhffmgbdZpbhggu_ iZjZf_lju

IZjZf_lju dhlhju_ ijbgylh gZau\Zlv dhffmgbdZpbhggufb

(communication settings, line settings hij_^_eyxl qlh ijhbkoh^bl k ^Zggufb _s_ ^h lh]h dZd hgb ihiZ^Zxl \ fh^_f >_eh \ lhf qlh jZa[b_gb_ bgnhjfZpbb — kiehrgh]h ihlhdZ [blh\ — gZ hl^_evgu_ [ehdb lh _klv kbgojhggh-Zkbgojhggh_ ij_h[jZah\Zgb_ klj , ijhba\h^blky \ dhfivxl_j_ \k_]^Z dh]^Z wlZ bgnhjfZpby ihkueZ_lky gZ ihke_^h\Zl_evguc ihjl gZijbf_j KHF beb&20 Ihwlhfm fh^_f dZd b ex[h_ ^jm]h_ mkljhckl\h ih^dexq_ggh_ d ihke_^h\Zl_evghfm ihjlm ihemqZ_l ^Zggu_ bf_ggh \ lZdhf f_edh gZj_aZgghf \b^_

>ey wlh]h ij_h[jZah\Zgby \ dhfivxl_j_ _klv ki_pbZevgZy fbdjhko_fZ gZau\Z_fZy UART (Universal Asynchronous Receiver Transmitter ©Mgb\_jkZevguc Zkbgojhgguc ijb_fh-i_j_^Zl-qbdª Wlhl qbi k\yaZgguc k dhfivxl_jhf iZjZee_evgh Z k

ihjlZfb — ihke_^h\Zl_evgh h[kem`b\Z_l lhevdh bf_xsb_ky \ dhfivxl_j_ ihke_^h\Zl_evgu_ ihjlu ihwlhfm \gmlj_ggbc fh^_fklj dhlhjuc©kZf k_[_ ihjlª\ mkem]Zo UART g_ gm`^Z_lky — hg ij_h[jZam_l ^Zggu_ \ Zkbgojhgguc nhjfZl kZfhklhyl_evgh

Kbgojhggh-Zkbgojhgghfm ij_h[jZah\Zgbx ihk\ys_g hl^_evguc klZg^Zjl ITU-T Z bf_ggh V beb qlh lh `_ kZfh_ Zkbgojhgguc ijhlhdhe RSQlh `_ ijhbkoh^bl ijb wlhf k ^Zggufb"

KlZjlh\u_ klhih\u_ b dhgljhevgu_ [blu

Ij_`^_ \k_]h ^Zggu_ ij_h[jZamxlky \ ihke_^h\Zl_evguc nhjfZl lh _klv \ kiehrgmx p_ihqdm [blh\ AZl_f qlh[u ^Zggu_ fh`gh [ueh i_j_^Z\Zlv Zkbgojhggh wlZ p_ihqdZ jZa[b\Z_lky gZ [ehdb dhlhju_ \ ^Zgghf kemqZ_ jZ\gu h^ghfm [Zclm B gZdhg_p dZ`^uc [ehd kgZ[`Z_lky fZjd_jZfb — ijbagZdZfb gZqZeZ b dhgpZ [ehdZ

< 9 wlbfb fZjd_jZfb y\eyxlky klZjlh\uc [bl (start bit b klhih\uc [bl (stop bit KlZjlh\uc [bl \k_]^Z jZ\_g H klhih\uc —

IhkeZ\ h^bg aZ ^jm]bf klZjlh\uc [bl [Zcl ^Zgguo b klhih\uc [bl i_j_^Zlqbd fh`_l ih\lhjylv klhi-[bl ^h l_o ihj ihdZ ijb_fgbd g_ [m^_l ]hlh\ ihemqblv ke_^mxsbc [Zcl Lh]^Z ihkueZ_lky klZjlh\uc [bl kem`Zsbc kb]gZehf gZqZeZ gh\hc ihjpbb ^Zgguo

LZdhc f_oZgbaf h[_ki_qb\Z_l ]b[dbc dhglZdl i_j_^ZlqbdZ b ijb_fgbdZ gh g_ aZsbsZ_l hl hrb[hd dhlhju_ fh]ml ijhbahclb ijb i_j_^Zq_ Qlh[u h[_ki_qblv h[gZjm`_gb_ hrb[hd klZg^Zjl 9 ij_^ibku\Z_l \klZ\dm kjZam ihke_ [ZclZ ^Zgguo i_j_^ klhih\uf [blhf _s_ h^gh]h [blZ — dhgljhevgh]h (parity bit ?]h agZq_gb_ hij_^_ey_lky kh^_j`bfuf i_j_^Z\Z_fh]h [ZclZ b l_f dZdhc ba ^\mo j_`bfh\ dhgljhey mklZgh\e_g — dhgljhev q_lghklb (even parity beb dhgljhev g_q_lghklb (odd parity).

>himklbf i_j_^Z_lky [Zcl Hg kh^_j`bl q_luj_ l _ q_lgh_ dhebq_kl\h _^bgbp Ihwlhfm _keb \dexq_g j_`bf dhgljhey g_q_lghklb dhgljhevguc [bl mklZgZ\eb\Z_lky \ qlh[u h[s__ qbkeh _^bgbp klZeh g_q_lguf B gZh[hjhl dh]^Z mklZgh\e_g j_`bf dhgljhey q_lghklb dhgljhevguc [bl ijbjZ\gb\Z_lky qlh[u khojZgblv dhebq_kl\h _^bgbp q_lguf

BlZd \hl qlh ijhbkoh^bl k [Zclhf ^Zgguo ijb _]h ij_h[jZah- \Zgbb ba iZjZee_evghc \ ihke_^h\Zl_evgmx b ba kbgojhgghc \ Zkbgojhggmx nhjfm ih klZg^Zjlm9jbk

Ihke_ i_j_^Zqb gZijbf_j ih l_e_nhgghfm dZgZem 8$57 ijbgbfZxs_]h dhfivxl_jZ ij_h[jZam_l ^Zggu_ h[jZlgh \ h[uqguc 8-[blh\uc nhjfZl

<_kv wlhl ijhp_kk ih^^Z_lky g_dhlhjhc gZkljhcd_ <h-i_j\uo ^ebgZ [ZclZ ^Zgguo fh`_l [ulv jZ\gZ g_ lhevdh \hkvfb [blZf gh b k_fb — ijb wlhf klZjrbc [bl dZ`^h]h [ZclZ b]ghjbjm_lky k_cqZk lZdhc j_`bf bkihevam_lky hq_gv j_^dh <h-\lhjuo fh`gh mijZ\eylv dhgljhevguf [blhf — mklZgZ\eb\Zlv j_`bf dhgljhey q_lghklb beb g_q_lghklb eb[h \hh[s_ hldexqZlv dhgljhev ijb wlhf dhgljhevguc [bl g_ \klZ\ey_lky B gZdhg_p fh`gh mijZ\eylv fbgbfZevguf dhebq_kl\hf klhih\uo [blh\ — beb \ ihke_^g_f kemqZ_ i_j_^ZqZ g_kdhevdh aZf_^ey_lky gh gZ^_`ghklv __ ih\urZ_lky

Wlb ljb iZjZf_ljZ fh`gh f_gylv ba dhffmgbdZpbhgghc ijh]jZffu JZamf__lky hgb ^he`gu kh\iZ^Zlv m ijb_fgbdZ b i_j_^ZlqbdZ bgZq_ ^Zggu_ [m^ml bkdZ`Zlvky QZklh agZq_gby wlbo iZjZf_ljh\ ibrml khdjZs_ggh gZijbf_j N hagZqZ_l © [blh\ ^Zgguo hlkmlkl\b_ None dhgljhey q_lghklb h^bg klh-ih\uc [blª QZs_ \k_]h bkihevamxlky bf_ggh wlb agZq_gby lZd qlh _keb \u g_ agZ_l_ dZdb_ iZjZf_lju mklZgh\e_gu gZ ^jm]hf dhgp_ ebgbb ihijh[mcl_1

V.I b ijhlhdheu dhjj_dpbb hrb[hd

KlZg^Zjl V h[_ki_qb\Z_l hq_gv keZ[mx aZsblm hl hrb[hd g_ba[_`gh \hagbdZxsbo ba-aZ ihf_o \ dZgZe_ k\yab Djhf_ lh]h wnn_dlb\ghklv i_j_^Zqb ijb wlhf ^h\hevgh gbadZ lZd dZd gZ dZ`^uc [Zcl ihe_aguo ^Zgguo ijboh^blky fbgbfmf ^\Z [blZ kem`_[ghc bgnhjfZpbb Ihwlhfm kh\j_f_ggu_ fh^_fu j_Zebamxl [he__ wnn_dlb\gu_ ijhlhdheu jZaf_j [ehdZ \ dhlhjuo [hevr_ Z Ze]hjblf \uqbke_gby dhgljhevghc kmffu agZqbl_evgh keh`g__ q_f ijZ\beZ mklZgh\db dhgljhevgh]h [blZ \9

LZd _keb \ fh^_f_ j_Zebah\Zg ZiiZjZlguc ijhlhdhe dhjj_dpbb hrb[hdgZijbf_j V.42) lh kbgojhggh-Zkbgojhggh_ ij_h[jZah\Zgb_ ih klZg^Zjlm 9klZgh\blky g_gm`guf Ihwlhfm fh^_f ihemqb\ hl dhfivxl_jZ ^Zggu_ kjZam `_ m[bjZ_l klZjlh\u_ klhih\u_ b dhgljhevgu_ [blu Ihke_ wlh]h [Zclu ^Zgguo kh[bjZxlky \ [he__ djmigu_ [ehdb b kgZ[`Zxlky dhgljhevghc kmffhc dZd ij_^mkfhlj_gh ijhlhdhehf9klj