  ADSL HOWTO for Linux Systems
  David Fannin, dfannin@sushisoft.com
  v0.92, 10 April 1999
    hisai@din.or.jp
  1999/07/28

  ̃hLǵAAsymmetric Digital Subscriber Loop (ADSL Ώ̃f
  W^Ґ) Linux ŗp@qׂ̂łBADSL ́Adb
  Ђ񋟂VfW^ANZXZpłBdigital sub-
  scriber line (DSL fW^_Ґ)̂ЂƂŁAlZrWlX[
  UÂΓ̉ 384kbps  1.5Mbps̑x𗘗p邱
  Ƃł܂B
  ______________________________________________________________________

  ڎ

  1. 쌠ɂ
  2. 
  3. ADSL T_
     3.1 ADSL Ƃ́H
     3.2 ADSL ̓Kp̈
     3.3 xDSL/DSL Ƃ́H
     3.4 ނ̑x񋟂Ă킯́H

  4. ǂ̂悤ɓ삵Ă邩
     4.1 ڋq[: ADSL ANT  NIC
     4.2 Xvb^[^Ȃ̍\ɂ
     4.3 DSLAM
     4.4 ISP Ƃ̐ڑ

  5. \݂ɂ
     5.1 ƒŕKvȋ@
     5.2 dbЂI
     5.3 ISP I

  6. zĂ݂܂傤
     6.1 Xvb^[^ NID (SNI ̐ݒuꏊɂ܂) ̔z
     6.2 DSL WbN(Rs[^ݒuĂꏊ)
     6.3 ANT ̐ݒu(Rs[^ݒuĂꏊ)

  7. Linux ̐ݒ
     7.1 NIC ̃CXg[Ɛڑ
     7.2 C[TlbgEC^[tF[X̐ݒ
     7.3 [^̐ݒ
     7.4 t@CA[EH[ƃ}XJ[fBO̐ݒ

  8. t^
     8.1 FAQ
     8.2 N
     8.3 ӎ
     8.4 {Ŏӎ
     8.5 p

  ______________________________________________________________________

  1.  쌠ɂ

  ADSL HOWTO for Linux Systems

  Copyright (C)1998,1999 David Fannin.

  ̃hLǵAt[\tgEGAłBFree Softweare Foundation
  oĂ GNU General Public License  ł͂ȍ~̔
  ɏ]A̕zz܂͕ύXł܂B
  ́̕AF̖ɗƂĔzz܂AeɊւĂ
  ۏ؂܂B܂pp̗prɑ΂Ăۏ؂͂
  ܂Bڂ́AGNU General Public License ĂB

  GNU GPL ̃Rs[́ALł܂B
  <http://www.gnu.org/copyleft/gpl.html>

  2.  

  ̃hLgł́ALinux g ADSL T[rX󂯂邽߂ɕKv
  T[rẌ˗@A@ނ̐ݒu@Ɛݒ@܂B

  ADSL(Asymmetric Digital Subscriber Loop)͍ȃC^[lbgEANZ
  XZpŁAdbŎgpĂuΓv(dbƓł)g
  ܂BKϒgAAJ 80% ߂̓dbŗpł
  ɐ݌vĂ܂Bڑx́A384kbps  1.5 Mbps ŁAʏ͏
  AɈقȂxgp܂( " Ώ "  ƌĂ΂Ă
  )B ADSL  ISP(C^[lbgET[rXEvoC_)֒p
  ł܂B

  ADSL ́A}V 5 - 30 ̏K͂ȎƏ( SOHO )Aш
  L邽߂ɂgnCGh Linux [Uɂ҂̃T[rX
  łBقǍLȂшgT[o̐ڑArfI𗬂pr܂
  pł܂B ISDN  T1 T[rX̒Ԃ^[QbgɂĂ
  āAT1 ɋ߂x񋟂ȂAT1 قǃRXg炸p₷
  悤ɐݒ肳Ă܂B܂ ISDN T[rXŐ悤ȉݒu̒x
  {gpXɂ邱Ƃ͂܂B

  ̃hLgł́A܂ ADSL T[rX̉n߂܂BeЂ
  ĂlX ADSL T[rXƁÃT[rXĂ邵݂
  Ăb܂B ADSL T[rX\ނɓĕKvɂȂ邱
  ܂Ƃ߂܂B Linux ւ̂Ȃݒ@̉܂B
   FAQ ⋻郊NƗpt^ƂčڂĂ܂B

  ̃hLgɑ΂Rgdfannin@dnai.com܂łǂǂ񂹂Ă
  B

   FAQ ̍ŐVł́A <http://www.sushisoft.com/adsl/>Ă
  ܂B

  3.  ADSL T_

  3.1.  ADSL Ƃ́H

  Ώ̃fW^Ґ(ADSL)́A

  o  ݂̓db𗘗pdbZpɂƂÂB

  o  ȃf[^]ƃAiOpł(Ƀf[^悹)B

  o  IP ڑs߂̃fW^pB

  o  kĂł̓][g̑g͉L̒ʂłB
     /
     256 kbps/256 kbps
     384 kbps/128 kbps
     384 kbps/384 kbps
     384 kbps/1.5 Mbps
     ̑̑g

  o  C[Tlbg 10base-T C^[tF[X͂߁ALڋq[
     (CPE)p̃IvVB

  o  ISP ւ̐pڑB

  o  IP Tulbgpł(ISP ɂ܂A1  254 ܂ł IP
     AhXpł܂)B

  o  vCx[gȐp(T1) ڑB

  3.2.  ADSL ̓Kp̈

  ADSL ͐pōȃf[^ʐMsȂƂɂāAC^[lbg
  CglbgɃANZXł悤ɐ݌vĂ܂Bڑɂ݂͊̂
  Γ̓db𗘗p܂B܂ ADSL ݂͊̓db邱
  ȂAč 60  80% ŗp邱Ƃł܂B킦 AiOE
  f (56kbps) ISDN(128kbps)ƓgȂAT1(1.5Mbps)ɋ߂
  xŗpł܂B ADSL ͕ʁApfW^T[rXi
  ݒ肳ĂāAT1  ISDN (ISDN {gp܂)̒ԂɈʒuÂ
  ܂B

  dbЂ ADSL P[udbЂ񋟂ĂP[uEfƋ
  鏤iŁAiݒ̖ʂŋ邱ƂɂȂƌĂ܂BP[uE
  f́A 10  30Mbps ƂLшĂ܂A𑼂
  [UƋLĎgƂɂȂ܂B̌ʓgpĂ郆[U
  ̗pʂɂĐ\傫E邱ƂɂȂĂ܂܂B

  ADSL ͍ȃC^[lbgڑKv SOHO ɓKĂ܂B܂ ADSL
  ͐pŃC^[lbgɐڑ܂̂ŁAC^[lbgoRł̂
  ǍLшKvƂȂT[oԐڑ 5  20  PC 鎖Ə
  ڑ̂ɂKĂ܂B܂獂ڑ]ł Linux
  p[E[UɂƂĂœKł:-)B

  3.3.  xDSL/DSL Ƃ́H

  fW^Ґ(DSL)́AAiO̓dbgĎƓdbЂfW
  ^Ōт܂B`lĂ̂ŁAdb FAX ̑
  ƕsčȃf[^]sł܂Bgpgш́A0 
  4kHz AiO 4  22MHz f[^]Ɏgp܂BxDSL ͐
  pT[rX̑̂łB " x" ɂT[rX́A

  o  ADSL Asymmetric Digital Subscriber Line:     1.5
     Mbps-384kbps/384-128kbps

  o  HDSL High-bit-rate Digital Subscriber Line:  1.5 Mbps/1.5 Mbps
     (4Wire)

  o  SDSL Single-line Digital Subscriber Line:    1.5 Mbps/1.5 Mbps
     (2Wire)

  o  VDSL Very high Digital Subscriber Line:      13 Mbps-52 Mbps/1.5
     Mbps- 2.3 Mbps.

  o  IDSL ISDN Digital Subscriber Line:   128 Kbps/128 Kbps.

  o  RADSL Rate Adaptive Digital Subscriber Line:  384kbps/128kbps

  o  UDSL Universal Digital Subscriber Line:
     1.0Mbps-384kbps/384kbps-128kbps
     " Xvb^[Ȃ"  DSL  DSL-Lite ƂĂ΂܂B̖
     ̒ʂAXvb^[܂B Xbps/Ybps  X dbЂ
     rbgE[gŁAY dbЂւ̃rbgE[g\܂B

  3.4.  ނ̑x񋟂Ă킯́H

  ADSL ݂͊̓dbŃT[rX񋟂܂Adb̂ 100 NO
  ݌vꂽ̂ŁAfW^ET[rXlĂ킯ł͂܂
  (ڍׂ FAQ Ă)BVT[rXȂ̂ŁAvoC_
  eЂ͎sɎ󂯓ł낤KȗƋ@\̑g͍Ă
  ܂B

  ϓIȃ[Û߂ɁA{Iɂ̓IvV3̃JeSɕčl
  Ă܂B

  o  [Ghȉƒ

       x 384kbps-128kbps ŔΏ̐ڑ

  o  nCGhȉƒ̓[GhȃrWlXE[U

       x 1.5Mbps-384kbps ŔΏ̐ڑ

  o  nCGhȃT[o

       x +2.0Mbps-1.1kbps őΏ̐ڑ

  4.  ǂ̂悤ɓ삵Ă邩

  ADSL ͂̕琬藧Ă܂(} 1  2 Ă)B

  o  ADSL lbg[NI[@(ANT)ƃlbg[NEC^[tF[XEJ
     [h(NIC)

  o  Xvb^[  Xvb^[Ȃ̍\

  o  DSLAM ƓdbЂ̉

  o  ISP ڑ

  <!--
  Figure 1: ADSL Block Diagram (POTS Splitter)

  <-------Home/Office--------------->              <-----Telco Central Office---->
                                 NID
                                -----               -----
  2 wire     X-----------Voice-=| S |               | D |
  phone                         | P |               | S |=----- Voice Switch
  line                          | L |    2 wire     | L |
                                | I |=-------------=| A |
                                | T |   Local Loop  | M |=----- ISP Connection
  10baseT       ---------- Data | T |               |   |
  Ethernet  X--=|        |=----=| E |               -----
    or          ----------      | R |
  ATMF            ADSL          -----
  NIC             ANT
  -->
  } 1: ADSL \}(Xvb^[)

  <-------ƒ/Ə--------------------->             <---dbВǓ--->
                                       NID
                                      ------               -----
  2 c           X---------------=| X |               | D |
  db                              | v |               | S |=--- @
                                      |  |    2 c       | L |
                                      | b |=-------------=| A |
                                      | ^ | Odb  | M |=--- ISP ڑ
  10baseT           ---------- f[^ | b |               |   |
  C[Tlbg  X--=|        |=------=|    |               -----
            ----------        |    |
  ATMF                ADSL            ------
  NIC                 ANT

  4.1.  ڋq[: ADSL ANT  NIC

  ADSL Ŏgpڋq[(CPE) ANT Ɓ^ NIC Ȃ܂B
  ADSL lbg[N̏I[@(ANT)́A} 1 Ă킩悤ɉƒ⎖
  Əɐݒu܂B IP ڑs܂B

  o  10/100baseT C^[tF[X [^[^Cv ANT

  o  10/100baseT C^[tF[X ubW^Cv ANT

  o  ATMF C^[tF[X ANT

  o  USB C^[tF[X ANT

  o  ANT  NIC @\킹J[h

  ǂ̏ꍇAISP ւ̃[^̃AhX ANT  NIC 񋟂܂B
  dbЂ͂ꂼŗL̐ݒ@w肵Ă܂BLinux [UɂƂ
  œKȕ@́A10baseT C^[tF[X ANT 𗘗p邱Ƃ
  BpʂłZbgAbv̊ȒPłꂪԂłB̑̂̂́A
  ʂȃhCopӂȂ΂Ȃ炸A܂̂Ƃ Linux ŗp邱
  Ƃ͂ł܂BATM NIC p̃hCoJĂ܂Bڂ́A
  <http://icawww1.epfl.ch/linux-atm/> QƂĂBcOȂƂɁA
  voC_ɂẮALinux ̃hCoȂ ANT  NIC ̗̋@\
   PCI J[hF߂ĂȂƂ܂B

  x!ŃT[hEpeB ANT/NIC J[hwꍇ́AdbЂ
  pӂ̂ƌ݊̂IłB ADSL ŎgpG
  R[h͂ɂQ̕(CAP, DMT)A܂ IP GLvV
  [Vɂ̕܂BdbЂ͂ǂ̕p\
  JĂ͂ł̂ŁAmFĂB

  ANT ͉ƒ̔z(2 c̓db)ɐڑAXvb^̃f[^ʐM
  ɂȂ܂BXvb^[Ȃ\ł́AO̓dbЂ̓dbɒ
  ܂B} 1 ̓Xvb^[A} 2 ̓Xvb^[Ȃ̍\}
  B

  ̏ꍇ́AAlcatel  ANT x܂B ANT  10baseT(N
  XEP[up) RJ45 ̃WbNĂ܂B̂ PC ɐ
  ł NIC pł悤ɂȂƎvĂ܂B

  <!--
  Figure 2: ADSL Block Diagram (Splitterless Design)

  <-------Home/Office--------------->           <-----Telco Central Office---->
                               SNI
                                -               -----
  2 wire    X-[RJ11]---Voice----|               | D |
  phone       Filter            |               | S |=----- Voice Switch
  line                          |    2 wire     | L |
                                |=-------------=| A |
                                |   Local Loop  | M |=----- ISP Connection
  10baseT       ---------- Data |               |   |
  Ethernet  X--=|        |=-----|               -----
    or          ----------
  ATMF            ADSL
  NIC             ANT
  -->
  } 2: ADSL \} (Xvb^[Ȃ)

  <-------ƒ/Ə----------------->           <-----dbВǓ---->
                                    SNI
                                     -               -----
  2 c      X-[RJ11]-------------|               | D |
  db      tB^               |               | S |=----- @
                                     |    2 c       | L |
                                     |=-------------=| A |
                                     | Odb  | M |=----- ISP ڑ
  10baseT           ----------f[^ |               |   |
  C[Tlbg  X--=|        |=------|               -----
            ----------
  ATMF            ADSL
  NIC             ANT

  4.2.  Xvb^[^Ȃ̍\ɂ

  ADSL 삷邽߂ɂ̓fW^MƃAiOMǂɂK
  v܂B̂߉̂ǂɕ̂߂̃tB^Ȃ
  Ȃ܂B邽߂ 2 ̕@܂B̓Xvb
  ^[ݒu@ŁA RJ11 dbpWbNɂtB^
  pӂ@łB

  ܂Xvb^[gdbT[rXƂ̕łAdbЂ̉
  ĂuƂ̊Oǁvɐݒu܂BXvb^[ 2 ̋@\A
  ͓dbЂ̔zƉƒ̔z𕪂邽߂́uE_v݂邱
  ŁA f[^E`lƉ`l𕪗邱Ƃɂēd
  bЂ DSL MƉMuvƂłB`l͒
  ̃AiO̓db(2 c)ŁAf[^E`l ANT ɂȂ܂B
  Xvb^[͎dsvœ삵܂Bƒ낪dĂ`l
  ͓삷͂łBdbЂ̐ḾA݂ 2 c̓dboR
  ăXvb^[ɓĂ܂B̃Xvb^[͉Ƃ̊Oǂɐݒu
  lbg[NEC^[tF[XEfoCX(NID)ɑgݍ܂Ă
  B

  ɃXvb^[Ȃ̍\łA} 2 Ă΂킩悤
  ɁAO̓dbځA҃lbg[NEC^[tF[X(SNI)ɐ
  ܂B͂łɉƒŎgpĂdbڑ̂߂̋@
  ̂łBWbNgĂāAAiOdb\
  WbNɁAfW^M邽߂̃tB^ꂢ
  WbNt܂B RJ11 tB^ƌĂ΂Ă܂(RJ11  4
   6 c̓dbWbNӖAdbЂ̌Ȍď̂ł)B
  ̃WbN ANT ڑ邽߂̂̂ŁAtB^͕Kv܂
  (tB^Ɠ삵܂)BȂɓƂ͂ȂłˁI
  ᑬx ADSL  RJ-11 tB^KvȂꍇ邱ƂoĂ
  B

  Xvb^[Ȃ̍\͓dbЂɂƂčDsłBƒ֐ݒ̂߂
  oKv܂񂵁AႢRXg ADSL 񋟂ł邩łB
  ͗p҂ɂƂĂǂłƂłBۃAiOdb́A RJ11 tB
  ^tȂĂgpł܂B̏ꍇɋCÂƂƂ΁Adbg
  ɂɍŃq[Ƃ\邱Ƃ炢łB
  rIŋ߂̂̂łƁAdb@Ƀ_[W^Â
  ȖNꍇ̂ł߂܂B

  4.3.  DSLAM

  DSLAM ͓dbЂɐݒu@ŁAM𕪗ĉ@ ISP 
  ڑł悤ɂ܂B[UƂĒmĂׂƂ͂̂炢ł
  Ǝv܂B

  4.4.  ISP Ƃ̐ڑ

  ISP Ƃ̊Ԃ DSLAM ʂčȃf[^ERlNV͂Ă܂B
  ʏ ATM over T3 (45Mbps) OC-3 (155Mbps)𗘗p܂Bő؂
  Ƃ́AȂ_񂵂ĂdbЂ ISP ̂悤Ȍ_ł
  邩ƂƂłB

  5.  \݂ɂ

  {Iɂ͎̎菇𓥂ނƂɂȂ܂B

  o  Ȃ̊ ADSL 𗘗p̂ɕKvȉL̏𖞂Ă邩
     `FbNB

  o  dbЂ ISP IŁAǂ̂悤Ȑݒ񋟂Ă邩𒲂
     B

  o  dbЂɘAāA\ށB

     -->

  T[rX\ނƁAdbЂ͊JʓAĂ͂łB̏ꍇ
  ́AdbЂɈdbŁASĂ̎葱܂Bdb
   ISP Ƃ̌_zĂ܂BTԌɖ\ʂɊJʂ
  B

  5.1.  ƒŕKvȋ@

  o  ADSL gpł NIC

     ADSL ANT ɒڐڑVXe(PCA[NXe[VA[^[A
     nu)

  o  z

     dbЂƂ̋E_(Ƃ̊O) PC uĂƂ܂Ŕz(2 c
      4c) Ȃ΂Ȃ܂BɂdbƂ\
     A̐ɂ ANT ȂȂȂA̓db⑝݂@
     ڑłȂȂ܂BdbЂ͎{HƎ҂ɐV
     ĂāAɐڑ邱Ƃł܂B

  o  CXg[

     N̔z\ł傤H Xvb^[gꍇȂ玩
     Ŕz邱Ƃł܂(̒n̓dbЂ͔zLbgƔz̐
     pӂĂ܂)BdbЂɒǉxė
     ΁AzĂ܂Bł 150-250 hߖł܂B
     ܂B̓Y܂Ȃ΁AłĂ
     ł傤B̃hLgɏĂǂł
     Aǂ邩߂Ǝv܂BłAȂ̊
     ́Adb LAN ̔zsȂĂ邩ǂłBz邱
     ƂɂȂȂȂAł邱ƂlĂׂ݂łB
     łȂAЂpoĂꂻȂAƎ҂ɗ񂾂ق
     ł傤B

  5.2.  dbЂI

  o  db̕i

     Ă̏ꍇAdbЂ͐\݂󂯕tȑOɁA ADSL
     ŗpł邩ǂeXgĂ܂B܂ƂdbЂ 2-3 }
     C(3.4-4.9 km) ȓłKv܂B܂ɂ͑׃RCA
     ubWE^bvA DAML Ȃǂ̏QƂȂ̂ȂKv
     BISDN 𗘗płȂ ADSL Ă̏ꍇpł܂
     AADSL ̕萧Aۏ؂̌ł͂܂Bȏ̏
     ɓĂ͂܂ꍇ́AdbЂɑkĂ݂ĂB
     ҒFDAML  Digital Added Main Line ̗́Bq̃yAEQC
     Ɠ`B

  o  Ȃ̌_񂵂ĂdbЂ ADSL 𗘗pł邩

     ADSL  DSLAM Ȃ̗pĂn̋ǂŖ{ɗpł܂
     HxAȂ̒nŖ{ɗpł邩dbЂɊmF
     Bč̑dbЂAADSL Ƀ^[Qbg𓖂ĂĂVv
     oC_̑́A ADSL ̃v\Ă܂B 99 Nl
     ɂ͑啝ȃT[rXg傪҂łƎv܂B

  o  ʐMx

     ADSL ͒ʐMxŗ̌nĂ܂̂ŁA`FbNĂ݂Ă
     Bʂ́A128kA256kA384kA 1.5M ̑g\łB
     A̕iɂĐ\߂ʐMx肳邩܂
     BɎ̌_񂵂ĂdbЂ́Aƒł̗pƃrWlXł̗
     pł́ǍnقȂĂ܂B

  o  dbT[rX

     ADSL ̃T[rXƂƂɓdbT[rX񋟂ĂvoC_
     ܂ (Ă͑̓dbЂł)B̃T[rX󂯂ƁA
     ǂ̔ԍ(V̂]̂̂ǂ炩)dbɂ邩߂K
     v܂B܂A݂̓db ADSL ɒuĂ܂AV
     ԍdbɊ蓖Ă邩łBISDN T[rX𗘗pĂẲ
     gȂA܂ ISDN T[rX~߂Kv܂B̃T[
     rX񋟂ĂȂdb(ʂ DSL ̃voC_)܂
     AӂKvłB

  5.3.  ISP I

  o  ISP ɐ\ޑO

     ISP IԑO ADSL T[rX󂯂dbЂƌ_񂷂Kv
     B ISP ̓dbЂɐڑĂ邩ǂ`FbNĂ
     BڑĂȂA ISP ɏ芷邩AISP ɐڑ
     悤邩AȂ ADSL gp̂߂邩
     ̂ǂ炩łB

  o  IP AhXƃTulbg

     ܂mȂ΂ȂȂƂ ȂɊ蓖Ă IP AhX
     ÓIȂ̂Ȃ̂AIȂ̂Ȃ̂ƂƂłBIɊ蓖Ă
     ꍇ DHCP gĂ܂B

     ÓIȏꍇ́AISP  ADSL Ɋ蓖ĂĂ 1  254 
     IP AhX̓̂ǂꂩÃAhXɑΉϒ̃Tulb
     gE}XN (VLSM)ƂƂɊ蓖Ăł傤B

     ̌_񂵂Ă ISP ́AzXg̐xɒǉ𐿋
     B炭̊ł́A1 ̃zXg(32 rbgE}XN) 6 
     ̃zXg (29 rbg }XN)ŎgpĂ̂ł͂ȂƎv܂B
     ̈ӖȂȂ΁AIP-Subnetting HOWTO ǂł݂Ă
     B܂zXg̃Tulbg蓖ĂꍇA1  ISP ̃[^
     ̃AhXpɎĂKv܂(܂ 6 䕪̃zXg̃Tu
     lbg̓Ŏ̃}VɎgpł̂ 5 䕪ƂƂł)B
      IP }XJ[fBO(HOWTO QƂ̂)lbg[NEAh
     XEgX[V (NAT) gƂ̂āAȂ LAN ɐ
     Ă鉽̃}V痘p邱Ƃ\ɂȂ܂B 30
     ȏ̃zXgڑȂA̎|\쐬Ă
     B

  o  Q[gEGC̃AhX

     ftHg̃Q[gEGCEAhXɂẮAȂ̃Tulbg
     ̍ŏ̃zXg AhXgpĂ(Ƃ΁ATulbg
     WƃAhX 192.168.1.240/29 Ƃ zXg 241  246
     ̒犄蓖ĂāA241 ftHgEQ[gEGCɂȂ܂)B

  o  MAC AhX̐

     ANT   MAC AhXp\łBƂΎ̎gĂ
     ̂́Aő 16  MAC AhXpł܂B̂炢΂
     Ă̊ł͏\Ǝv܂BƂ̃}V ANT
     ɒڐڑĂnuɐڑȂAő剽܂ŉ\Ȃ̂܂
     mFׂł傤B

  o  DNS T[o

     ISP  hČ邽߂ 1 ȏ DNS T[opӂ
     ͂łBISP ̒ɂ ʂ̃T[rXƂăhCEl[ET
     [õzXeBOT[rX(vC}̓ZR_ T[ô
     ꂩ)񋟂ĂƂ܂Bڂ ISP ɑkĂ݂
     B

  o  [U ID ƃpX[h

      ISP  shell AJEg T[rX⃁[̑̃T[rXpɃ
     [U^pX[hx܂B̌_񂵂Ă ISP ł́Al web
     p̗̈ƃ[ET[o̃T[rX񋟂Ă܂B

  6.  zĂ݂܂傤

  łɓdbЂɔzT[rX\łꍇ́ÃZNV
  ΂ " Linux ̐ݒ" ɐiłBł͂ꂩẑ
  ɂĐ}ȂĂƎv܂BAȂ̏Zł
  nƂ͈邩ȂƂmB܂Ad
  bЂ̒ӎɏĂe炵ĂB
  񂠂ȂʐMЂ̔z@ɖ邢ƂOɂȂ܂B

  iḰAdbЂ̉ڑłB̉ł̃T[rXJn
  ƂƃXvb^[ DSL WbN邱ƂmFĂB

  6.1.  Xvb^[^ NID (SNI ̐ݒuꏊɂ܂) ̔z

  Xvb^[Ȃ̍\̏ꍇ́Aǂݔ΂Ă\łB

  Xvb^[ Xvb^[{̂ƃlbg[NEC^[tF[XEfo
  CX(NID)ƌĂ΂鉮OɎt鏬Ȕ 2 ̕\
  BdbЂ̉ɂƃXvb^[ NID ͉҃lbg[NE
  C^[tF[X(SNI)̂Ƃɐݒu܂BʁAdbĂ
  Ƃ̊OǂɂƎv܂BdbЂXvb^[̃eiXs
  ߂ɂKv邩炾Ǝv܂B킯œdbЂG
  鉮Oɐݒu邱ƂK؂Ȃ킯łBdbЂ 2 c̐Xv
  b^[ " LINE" ɐڑĂB牮炫Ăd
  bp̐A "VOICE" ɁAANT p "DATA" ɂȂłB

  `FbNE|Cg܂ōsȂAXvb^[̉Ń_CAE
  g[ ͂łB߂ȂAẑAdb
  Бł܂ ADSL T[rXJnĂȂ̂ǂ炩łB

  6.2.  DSL WbN(Rs[^ݒuĂꏊ)

  Rs[^uĂƂ DSL WbN(RJ11)ɐڑ܂傤(
  Xvb^[ DATA ɎhĂ)BXvb^[̂^Ȃ̂
  ꂼ̃P[XłقȂƂłB{I DSL WbN
  ڑ 2 c̃yA邱Ƃɂ͂肠܂Bǂɂ
  Ă邩`FbNĂBDSL  RJ11 Ԃ̔z͓db ADSL
  WbN̔zƂ͈Ⴂ܂B̏ꍇAԁ^΂̃yA(RJ11 WbN̓
   2 ̃IXs)dbŁA^̃yA(RJ11 WbN̊O 2
  ̃IXs) ADSL WbN֔z܂B

  6.3.  ANT ̐ݒu(Rs[^ݒuĂꏊ)

  ANT ̓dR[hhāADSL WbN ANT Ԃ db(JeS 3 P
  [u) ŐڑĂB̃P[u͂ĂdbЂx
  ܂B

  `FbNE|Cg  ܂łAANT dbЂ̐MƓ
  邩mF܂傤BقƂǂ ANT ́AM OK ̎ɗΐFɌ
  LED ͂łBĂȂAzmFāAdb
  MĂĂ邩mFĂ(dbЂɓdbāAT
  [rXJnĂ邩mF܂傤B_CAEg[
  ƂāAADSL ̃f[^MĂƂ͌Ȃ̂ŒӂĂ
  )B

  ܂łǂA ƂƂ Linux ڑiKɂƂɂȂ
  ܂B

  7.  Linux ̐ݒ

  ANT ̐ڑIēMmFłALinux ݒ肷鏀
  ƂɂȂ܂B܂ ISP ւ̐ڑmF̏łĂ܂B
  ł Linux ɐĂ܂A10BaseT foCX̂ł
  Ήł ANT ɐڑł܂BƂ΃[^AnuAPCAȂǎg
  ̂Ȃ牽ł OK łB

   ! ISPɐڑOɁAADSL oRŃC^[lbgɒڐڑۂ
  KvƂȂAZLeBɂĂ̖SėĂ邱ƂKvƂ
  ܂BISP ɂ܂AC^[lbĝAȂ̃VX
  eɃANZXł悤ɂȂ܂BłA|[gӂAT
  [rX𗎂肷@\炩̃t@CA[EH[ׂ݂
  B܂C^[lbgɃ}VڑOɂ̓pX[hݒ肷Kv
  ܂BZLeBɂĂ̊Tvm肽ȂA Security-HOWTO
  ǂނƂ߂܂B

  7.1.  NIC ̃CXg[Ɛڑ

  Linux }V NIC CXg[āAJ[lݒ肵āAꂩ
  ...B̓eɂẮAe Linux ̎QlĂB܂
  Ethernet-HOWTO ɏڍׂȋLq܂̂ŁAĂĂB

  NIC  ANT  RJ45 P[uŐڑĂBtL ANT ̒ɂ͂ł
  10baseT ̃NXEP[uŔz邱ƂOɂĂ̂
  B NIC 𒼐ڂȂ̂ɂ NXł͂ȂXg[g̃JeS 5 P[
  uKvłB͂ꂪ킩܂ŁAԂĂ܂܂B
  ߂Ȃ悤ɂ܂ǂŊmFĂB

  7.2.  C[TlbgEC^[tF[X̐ݒ

  IP AhXATulbgE}XNAftHgEQ[gEFCADNS T[o
  ̏ݒ肵ĂBLinux ̃fBXgr[V(RH, debian,
  Slackware, S.U.S.E.)Ƃɐݒ@قȂ܂B̏ꍇ͂ǂȂ̂
  mFĂB ifconfig  route R}hgĐݒ肷
  Ƃł܂Bڂ NET3-HOWTO ĂB

  ݒ肪IAISP w肳ꂽ ftHgEQ[gEFC̃AhX
   ping ł邩mFĂB΁A20 ms 炢̃Ehg
  bvE^CŐڑ͂łB߂łƂ܂BC^[lb
  g̐Eւ悤I

  7.3.  [^̐ݒ

  Ȃ̐ݒɂ܂AlȂ΂ȂȂ肪
  Bt@CA[EH[̐ݒ₻Ɋ֘AݒłB̏ꍇA} 3
  ɗᎦ܂BÂ i486 }Vt@CA[EH[[^Ƃ ADSL
   c̃}VԂɒuĂ܂B vCx[g LAN  vCx[gE
  AhXgpĂāALAN ƃC^[lbgԂ̓[^ IP }XJ[
  fBOƃt@CA[EH[sĂ܂Bڂ
  ́AIP_Masquerading-HOWTO  Firewall-HOWTO ĂB̌o
   Linux ̓[eBOt@CA[EH[ɗDꂽ\͂𔭊܂B
  ܂Ɏŝ̃[^ł̂ŁAƂŃhAXgbp[ȂĂÂ
  386  486 ̃}VȂ{Ă݂ĂB

  <!-- Figure 3: My  SOHO Network Setup -->
  } 3:  SOHO lbg[N̍\

  <!--
  <-Private Subnet-->         <-Public Subnet->    <-ADSL Line--------->
                                       |
                                  X----|
                                       |
       X------|                   X----|     |----|
              |      |--------|        |     |ADSL|            Internet
              |      | Linux  |        |-----|ANT |----------> Service
       X------|------| System |--------|     |    |            Provider
              |    E1|(Router)|E0      |     |----|            Router
              |      |--------|        |
       X------|        IP_Masq      10baseT
                     IP_Firewall     Hub
  -->
  <-vCx[g-->          <-pubN->       <-ADSL ->
    Tulbg                   Tulbg
                                         |
                                    X----|
                                         |
       X------|                     X----|     |----|
              |      |---------|         |     |ADSL|            C^[lbgE
              |      | Linux   |         |-----|ANT |----------> T[rXE
       X------|------| VXe|---------|     |    |            voC_
              |    E1|([^) |E0       |     |----|            [^
              |      |---------|         |
       X------| IP }XJ[fBO  10baseT
                IP t@CA[EH[   nu

  ̓[^ƂāA2 ̃C[TlbgEC^[tF[X}V
  (i486  Linux RH 5.0 ̂)ݒ肵܂BC^[tF[X
  ̂ 1  ISP ̃TulbgƃQ[gEFCւ̃[eBÔ
  ŁA 1 ͂NX̃vCx[gElbg[ÑAhX(
  192.168.2.x)̂߂łB[^̉ɂvCx[gElbg[N
  ݂邱ƂŁAZLeBXɂ܂BƂ̂́AISP ̊O
  ڃANZX邱ƂłȂȂ邩łB̂߂ɃC^[lbg
  ڑɂ́AvCx[gEAhX}XJ[fBOKv
  ܂B

   J[l IP tH[fBO@\gݍŃRpCĂ
  邱ƂmFĂAIP tH[fBO𓮂ĂB`FbN
  ̂́A

  cat /proc/sys/net/ipv4/ip_forward

  ʂ 1 LA0 疳ɂȂĂ܂Behco gēK
  ȒlɕύXł܂B

  (e.g.) echo 1 > /proc/sys/net/ipv4/ip_forward

  ŗLɂȂ܂B

  7.4.  t@CA[EH[ƃ}XJ[fBO̐ݒ

  C^[lbgɒڐڑĂȂAt@CA[EH[ɂǗƃ}
  XJ[fBO@\]ނ̂ł͂Ȃł傤B} 4 ̍\łB

  ӁI  ĂƂ́A̐ݒ͈SȊ肠
  ̂ق̈ꕔɂȂAƂƂłB̑ɂ̍lׂ
  ܂B[^ ftp  telnet ̑̃T[rX𗎂AS
  ẴpX[h⃍OCEAJEg؂...Bɂ
  ݒĂBSecurity-HOWTO ǂނƂYꂸɁB

  <!-- Figure 4: Firewall/Masquerading for ADSL -->
  } 4: ADSL ɂt@CA[EH[ƃ}XJ[fBO

  <!--
         |-------|       |-------|     |-X
  ======X| ADSL  |=------| Linux |-----|
  ADSL   |  ANT  |     E0|       |E1   |-X   Private Network
  Line   |-------|       |-------|     |     (e.g. 192.168.2.x)
                 <------->             |...
               ISP Subnet or host
              (Public Net Address)
  -->
         |-------|       |-------|     |-X
  ======X| ADSL  |=------| Linux |-----|
  ADSL   |  ANT  |     E0|       |E1   |-X   vCx[gȃlbg[N
     |-------|       |-------|     |     ( 192.168.2.x)
                 <------->             |...
               ISP Tulbg
                zXg
              (pubN ȃAhX)

  Linux [^Ƃē߂̃J[ĺAIP tH[fBOƃ}X
  J[fBOLɂăRpCĂ̂łB "ipfwadm"
  (IPx[X̃t@CA[EH[ \tgEGA)CXg[āÂ
  ɐݒ肵܂B
  󒐁F J[l 2.2.x ȏ̏ꍇ ipfwadm ̂ ipchains g
  pĂBڍׂ <http://netfilter.filewatcher.org/ipchains/> 
  QƂĂB

  file: /etc/rc.d/rc.firewall  (RH5.0  rc.sysinit ł)

  echo "Setting up the firewall"
  #
  # From the "Firewall-HOWTO"
  #
  # flushes all setting
  #
  ipfwadm -F -f
  #
  # set the firewall
  #
  ipfwadm -F -p deny
  #
  # allow any machine with address 192.168.2.x to masquerade.
  #
  ipfwadm -F -a accept -m -S 192.168.2.0/24 -D 0.0.0.0/0
  #
  # allow the domain name server to work (udp 53)
  #
  ipfwadm -F -a accept -b -P udp -S 0.0.0.0/0 53 -D 192.168.2.0/24
  ipfwadm -F -p masquerade
  #
  # the rest just list out the options for your enjoyment
  #
  ipfwadm -F -l
  ipfwadm -O -l
  ipfwadm -I -l

  ̃W[(ftpAreal audio, ̑)ȂƓ삵ȂT[r
  X܂̂ŁAӂKvłBipfwadm ̃hLgɏڂ
  Ă܂̂ŁAׂĂ݂ĂB͂̃hLĝ
  ŊȒPɐݒł܂B

  āAvCx[gElbg[NEAhX LAN \ƈ
  Zʂ̂ݒ肪ł܂B}XJ[fBOsƁAyɐڑ
  łzXg̑䐔̐łĂƂ_܂B܂ zXg
  AhX𗘗p IP x[X̃AvP[V̒ɂ͓삵Ȃ̂
  ܂AقǑ͂܂B

  8.  t^

  8.1.  FAQ

  ̃ZNV ADSL  FAQ łB

  1. F ADSL ̕W͂ǂȂĂH

     F ܂BThe U.S. Bell Operating Companies ́Aŋ
     Discrete Multi-Tone (DMT)  ANT (ANSI T1.413) WƔ\
     ܂Bč̑ DMT ͂ɏ͂łB ANT Ƃ
     Ėڗ̂́A Carrier-less Amplitude Phase Modulation (CAP) 
     B񗼕ɂ͌݊͂܂B

     WɊւ DMT ̗px_[̎_猩̔r
     ́A Aware <http://www.aware.com> Ō邱Ƃł܂B̘b
     čłڍׂȏ񋟂Ă܂B

     ANSI ̋Ki̎ʂ͍łÂƂɒ邱Ƃł
     B American National Standards Institute ANSI Home Page
     <http://www.ansi.org>
     Asymmetric Digital Subscriber Line (ADSL) Metallic Interface
     ANSI TI.413-1995
     ӁF ANSI TI.413 2   1997 N 9  26 ɔ܂B
  2. F ADSL  ANT  ATM ڑł܂H

     F \łBADSL  ANT (ȂƂ Alcatel o[W) ̂
     ́AATM  25Mbps C^[tF[XĂ܂B PCI 
     NIC ɎhƂł܂B̂悤ȃJ[hp Linux hCo
     邱ƂɂƂ͂܂B

  3. F  ADSL ͗lXȑx̎(384/1.5/8M/20M/̑)
     H

     F {IȖ́AΓ̉ 100 NO̐݌vɂƂÂ
     邱ƂłBAiOdbȂ牽͂܂񂪁AfW^M
     𗬂Ƃ́A̕iɒލsׂƂȂ܂BYĂ͂Ȃ
     ́A̓dbЂ̋Ȃ΂ȂقǁAʐMx
     ܂ƂƂłBœKZp̂ŁAĂfW^M
     ܂܂BSĂ̊œш敝mۂ邱Ƃ͂
     ܂Bɒ(5.5 km ȏ)ɂȂ΂ȂłBx_[̍L
     ɏoĂlXȑш敝̐ݒ́AlXȎsꋣ̌ʂfo
     ܂BdbЂ͉ƂĒʐMx́uWvm悤Ƃ
     ɂȂĂ܂B́A384k  1.5 Mbps WɂȂ̂ł͂Ȃ
     vĂ܂B荂ȉ́Aȏ󋵂ɂpAL
     s𓾂邱Ƃ͂ȂƎv܂B

     ̎ǂł݂ĂBƂ̂̏Q́AlXȉ
     x𐶂ݏo 1 łB

  4. F ubWE^bvA׃RĈ悤ȉQƁAADSL
     gpłȂ̂ł傤H

     F [fBOERĆAdbł̉`g̓`
     コCCEC_N^XłB{IɁA"gp
     "ƍg̃GlM[gɗ^܂BƂĂdb(2.7
     km ȏ)̏ꍇɂ悭p܂B

     P"ubW"Ƃꍇɂ́AubWE^bvӖ邱ƂƂ
     BÂdbĂnł́Adb̔z͉ 1 {
     ňĂ܂B񂻂̏Z̏Z͈Ⴂ܂ߏ
     łBzĂȂꍇ́AȂ"ubWE^bv"gĊ
     ڑĂzĂ܂܂B

     fW^E[vELAF 2 c̐ 1 {ŕ̉̓`ł
     邢낢ȃVXe܂B̃VXe͎gpg
     AfW^AԂR[hȂɂēdb
     𕪊邱Ƃł܂ByAEQCƌĂ΂邱ƂƎv
     ܂B

     L̋@ނ́Ag𗘗pf[^]ɗlXȈe^܂B

     [fBOERĆAgSɃtB^OAg
     ʂ܂B܂uxGx[vvƌĂ΂Ag𑼂̎
     gɗD悳Ď󂯎邵݂ύXĂ悤łB܂A
     鉹f[^ɗׂf[^WQ\܂B

     ubWE^bv́AM̔gꍇ̓VgELpV^X
     Ƃē삵Ag 悻 1/4 ̏ꍇ͑шʉ߃tB^Ƃē
     ܂B܂肠̎gRɒʉ߂邱ƂɂȂ܂BDMT
     f̓̉M͕Ă܂AM̃fɓ͂Ȃ
     ȂAʓIɂɓdb̑ш߂Ă܂܂B

     yAEQĆAŕ̓`𓯎ɍs߂ɁA̓`
     gш𐧌܂B̓AiOMɂfW^MɂKp
     ܂BDMT ɂ`Ŏgg̓yAEQCɂătB
     ^Ă܂܂B

     uҐɂMƓ`@̎v(Whitham D. Reeve
     A IEEE Press 1992, ISBN 0-87942-274-2) ́Adbɂ`
     ̓ɑ΂ĉ̒AubWE^bv^e̒@
     ̏W听łAȂ荂łB

  5. F ADSL ANT ɂĂ̎͂܂񂩁H

     F ܂B̋Zp̔B͓iŁAHOWTO ł͒ǂ܂
     B ADSL ANT ɂĂ ADSL Forum Home Page
     <http://www.adsl.com>.  QƂƗǂł傤Bex
     _[̃z[Ey[Wɍs΁A󂪂킩͂łB

     񋟂łZp 1998 N 6 ݂̂̂łB

     o  10/100baseT C^[tF[X ANT [^

        F Examples: Flowpoint 2000 DSL (CAP), Netspeed Speedrunner
        202 (CAP), Speedrunner 204 (CAP), 3COM Viper-DSL (CAP), StarNet
        Ezlink 500/100 (DMT), Westell ATU-R-Flexcap (CAP), Aware x200

     o  10/100baseT C^[tF[X ANT ubW

        F Alcatel A1000 (DMT),  Westell ATU-R-Flexcap2 (CAP)

     o  ATMF C^[tF[X ANT

        F Alcatel A1000 (DMT), Netspeed Speedrunner 203 (CAP), Ariel
        Horizon II

     o  V.35 VAEC^[tF[X ANT ubW(T1 
        VAgp郋[^)

        F Westell ATU-R

     o  USB C^[tF[X ANT

        Intel ЂiĂ悤łB

     o  ANT/NIC J[h

        F Netspeed PCI Runner (CAP), Efficient Networks Speedstream
        3020 (DMT)

        ɏグꂽi̓mF͂Ă܂BƂĂ
        łB;-)

  8.2.  N

  o  ADSL Forum Home Page <http://www.adsl.com> ADSL x_[񋟂ɂ
     IȃEGbuETCgłBADSL ɊւĂ̂ƂĂ[񂪓
     ܂B

  o  Dan Kegels ADSL Page
     <http://www.alumni.caltech.edu/~dank/isdn/adsl.html> xDSL Ɋւ
     ̑Iȏ񂪂܂Bx_[AT[rXEvoC_Ȃ
     N܂B

  o  PacBell's ADSL Page
     <http://www.pacbell.com/products/business/fastrak/adsl/index.html>
     Pacific Bell ͒ndbЂŁApĂ ADSL ̃voC_
     B

  o

  o  Jeremie's Unofficial Ameritech ADSL FAQ
     <http://www.rc.lsa.umich.edu/~jeremie/adsl/>

  o  Telechoice xDSL News Page
     <http://www.telechoice.com/xdslnewz/indexDSL.cgi>

  o  ADSL Deployment 'round the World
     <http://www.geocities.com/Paris/Metro/5013/adsl.html> mȈꗗ\
     - voC_AzAڑx etc - 蕨łB̒nɂĂ
     ͂Ȃ悤łB

  o  Bell Atlantic ADSL Home Page <http://www.bell-atl.com/adsl>

  o  comp.dcom.xdsl FAQ <http://homepage.interaccess.com/~jkristof/xdsl-
     faq.txt>

  8.3.  ӎ

   hLgɂāA񂹂ĂFɊ
  ܂BvĂX(܂߂āI)̈Ŝ߁AXpE
  [悯Ă܂BAhX\L "X" ƂĂ悤肢
  ܂B

  o  B Ediger (Xbediger@csn.net) QɂĂ̏ڍׂȉ

  o  C Wiesner ( Xcraig@wkmn.com)  ADSL ֘A URL ̈ꗗ

  o  J Leeuw ( Xjacco2@dds.nl) Ƀ[bpɂ ADSL ɂĂ
     tips

  o  J Kass ( Xjeremie@umich.edu)  Ameritech  ASDL FAQ

  o  N Silberstein ( Xnick@tpdinc.com)  Netrunner ƕčň̃voC_
     Ƃ̂kɂ

  8.4.  {Ŏӎ

  |ɓāAL̕ɂbɂȂ܂B肪Ƃ܂B

  o  \ 

  o  ꎓ  

  8.5.  p

   FAQ ɂłĂp̉łB

      Γ
        dbЂzĂ 2 c̃cCXgEyAP[uŁAڋq
        ŏI[ĂB

     ADSL
        Asymmetric Digital Subscriber Line  Ώ̃fW^ҐB

     ANT
        ADSL Network Termination  ADSL lbg[NI[u(ADSL f
        )B

     ATM
        Asynchronous Transfer Mode 񓯊][h - ɃpPbg̃X
        Cb`OsƂɂāA 155 Mbps  2Gbps(ł)̑
        x񋟂܂BC^[lbgւ̃obN{[ڑ̂߂ɗp
        Ă܂B

     ATMF-25Mbps
        ATM tH[F̃C^[tF[X - 25Mbps ̑xoA
        PCIoX NIC ŎgpĂ܂BANT  PC ԂŎgpC^
        [tF[ẌłB

     Central Office
        ǁB 2 ̈Ӗ܂B- 1) db֘A@킪ݒuĂ
        dbЂ̌B 2) db̃_CEg[o͂鉹@B

     CPE
        Customer Premises Equipment ڋq[ - dbЂ̗pŁAڋq
        ɐݒu@ނӖ܂B (܂肠ȂɊǗ̐ӔC
        )BCSU/DSUAfAANTAdbɓ܂B

     DHCP
        Dynamic Host Configuration Protocol IɃzXgݒs߂
        vgR - I IP AhX̊sۂɗp IP vg
        RB

     DS0
        dbЂ񋟂{fW^B- 56kbps  64kbps 
        񋟂Ă܂BЂƂ̃AiO`l|[gł܂B

     DSLAM
        Digital Subscriber Line Access Multiplexer fW^Ґd
        u - dbГݒu@ŁADSL Wd܂B

     xDSL
        x Digital Subscriber Line fW^Ґ - DSL T[rX̗lX
        ȌĂѕ\킵܂B ADSL, SDSL, VDSL Ȃǂɓ܂B

     HDC
        2 ͂ĂB

     ISDN
        T[rXfW^ʐM(Integrated Service Digital Detwork)B
         Innovations S ubscribers Don't Need (҂KvƂȂ
        ZpvV)łB 1 {̂ΓP[uŁA2B (64k) + 1D(16k)
        ̃`lgAƃf[^Ƃ肵܂B

     ISP
        Internet Service Provider C^[lbgET[rXEvoC_

     NID
        Network Interface Device lbg[NEC^[tF[XEfoC
        X - ADSL ̃Xvb^[ی삷邽߂ɐݒu@B

     NIC
        Network Interface Card lbg[NEC^[tF[XEJ[h -
        lbg[NEC^[tF[X񋟂 PC J[hiPCI  ISA
        oXpjBʏ 10baseT  ATMF-25Mbps J[hg
        B

     POTS
        Plain Old Telephone Service ̂Ȃ̓dbT[rX - AiOd
        b̃T[rX(Ⴆ΂Ȃ̓db)B

     Recursion
        Recursion ĂB

     SNI
        Subscriber Network Interface ҃lbg[NEC^[tF[
        X - dbЂ̗pŁAƒ둤̓dbzӖ܂BdbЂ
        ƒz̕ڕ\܂BE_ (Demarcation Point)ƂĂ
        ܂B

     Xvb^[
        SNI ɂdsṽfoCX(gшtB^) ADSL ̐M
        ƃf[^`lɕ܂B

     Xvb^[Ȃ
        Xvb^[ݒuȂ ADSL gp@BŎgp
         AiOdbރWbNƂ RJ11 tB^
        NID ŃtB^ɃWbN̂Ƃł܂BᑬŎgp
        ꍇ́AtB^͗v܂B

     SOHO
        Small Office Home Office lƏ͏K͎ƏB

     T1 DS1 ƂĂт܂B - 1.544 Mbps ̃fW^pB24 { DS0 
        ĎgAƃf[^`ŗpĂ܂B

     T3 DS3 ƂĂт܂B - 44.736 Mbps ̃fW^pB672 { DS0
         28 { DS1 ƂĎgAƃf[^`ŗp
        ܂B

