Care este viteza maxima pt o placa de retea Ethernet

HI

Ma pricep la hardware, dar de retele nu prea m-am lovit pina acum, asa ca
am si eu o intrebare:

Care este viteza maxima pt o placa de retea Ethernet 10/100
De ce scrie pe ea 10Mb?
Ce trebuie sa fac s-o accelerez (am o retea BNC)?
O retea UTP intre 2 PCuri e mai rapida decit o retea BNC?
Cum pot sa-mi fac o retea UTP fara hub (Cum leg firele de UTP intre cele doua placi)?
Daca placile mele de retea au si UTP si BNC, pot sa le folosesc in acelasi timp (adica la o placa de retea sa folosesc in acelasi timp si iesirea UTP si iesirea BNC)?

Bun, nu a fost o intrebare, au fost mai multe.

  :help:

Vorbim despre viteza teoretica si nu reala, care difera mult de cea teoretica.
... daca scrie ca este de 10, probabil este de 10 indiferent ca tu ai doua iesiri UTP si BNC
... reteaua BNC nu poate fi accelerata, dar poate fi tinuta in parametrii prin diverse mooduri (ceea ce inseamna ca nu va depapsi 10Mb)
... o retea UTP este mai rapida, decat una BNC, cu conditia ca placa sa suporte 100Mb (asta daca ai doua iesiri)
...o retea intre doua calculatoare, este de fapt un cablu UTP sau BNC (la asta iti trebuie si terminatori) pe care il bagi in ambele placi de retea
... trebuie sa te hotarasti daca vei folosi hub, pentru ca mufarea se face diferit pentru un cablu pc-pc si un calu pc-hub (se inverseaza TX si RX)
... cat priveste ultima ta problema, n-am incercat niciodata, dar probabil ca nu merge, sau in orice caz nu cu o placa obisnuita ... i just don't know


EndLess Point

Multam pt raspuns!

Intrebari in continuare:
Care sunt acele conditii ideale in care placa mea ar atinge 10M/sec? Ma streseaza sa stiu ca placa AR putea duce 100M (e o placa ethernet 10/100), iar mie imi merge sub 1M/sec!
Mi-am facut reteaua pe BNC dar vreau s-o trec pe UTP daca e mai rapida si stiu ca se poate fara HUB (inversind niste fire, da care?)

Daca placa suporta 100 nu va merge cu 100 pe BNC, ai nevoie de UTP.

DACA retea inseamna doua calculatoare, atunci mufarea se face direct fir la fir (tii cont de culori si pozitie si cum le bagi intr-o mufa, le bagi si in cealalta. Dar asta inseamna NUMAI 2 calculatoare. Daca sunt mai mult de 2 ai nevoie de hub sau switch, si trebuiesc inversata mufarea

Iti atasez o schema, ca ma grabesc la lucru si nu mai am timp de povesti

EndLess Point

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Placile 10/100 transmit date cu maxim 10Mbps respectiv 100Mbps.
Intotdeauna se face confuzie intre 10MB/s si 10Mb/s - desi raportul intre cele doua viteze este de 8 la 1 (Byte vs bit)  

In practica poti sa mizezi pe maxim 70-75% din capacitatea mediului pentru a face transfer de fisiere, deci pe o retea BNC de 10Mbps ar trebui sa ai rate de transfer pe undeva intre 900KB/s si maxim 1.2MB/s (maxim pe care il atingi doar daca ai 2 computere active in retea  :cool: )

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la UTP ai (daca imi aduc bine aminte) la
TX: firele 1 si 2
RX: firele 3 si 6
(numarate de la st la dr, gaura prizei spre tine, clama in jos)

deci pentru un cablu UTP cross-over (aka pc-to-pc) inversezi la unul din capete firele 1 cu 3 si 2 cu 6.

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Nota bene: placile cu mufe duble UTP/BNC sunt doar de 10Mbps!  :cool:

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Daca ai urmat sfatul... ai f**** deja 2 mufe :yeah baby

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Merge, am incercat io, da' numa' una - UTPu ... daca ai retzeaua pe BNC shi bagi un UTP in fundu' placii, moare BNCu, dar UTPu functzioneaza la parametrii normali ... deshi exista zvonuri ca se poate arde placa ... Tot ce e posibil ... Io folosesc metoda dn cand in cand ... din lene ... mai am cate ceva de transferat in camera ... shi nu mai scot BNCu ... infig UTPu, tag ce e de tras, il scot shi mere iar BNCu ...

Cam asta ie!

Baftau!

Well, cu a doua chestie ai dreptate ... si daca ai mufat deja cablu, atunci il poti folosi pc -> hub, si nu pc - > pc.

Corect este asa :
pc -> pc
TX+       1    <-------->     3         RX+
TX-       2    <-------->     6         RX-
RX+       3    <-------->     1         TX+
RX-       6    <-------->     2         TX-

pc -> hub
TX+       1    <-------->     1
TX-       2    <-------->     2
RX+       3    <-------->     3
RX-       6    <-------->     6

Cu prima insa gresesti. Eu am un Winbond, care este de 10/100 si care are BNC si UTP. Pur si simplu are 2 mufe. Iar viteza este calculata dupa timpul in care imi trag prin cablu diverse filme, de la niste vecini, pentru ca si eu am zis la fel ca tine si nu incetam sa ma minunez ce rapida este placa mea

EndLess Point

Multumesc mult la toata lumea care m-a ajutat (CHIAR FOARTE MULT!!!)

O ultima intrebare:
vreau sa existind reteaua (eu am 2 PCuri apropiate care pina acum erau pe paralel, acum sunt pe BNC) catre un prieten din blocu' vecin.
Problema este distanta - probabil peste 170m.
Credeti ca va merge o retea pe o distanta asa de mare?
As prefera s-o fac tot pe BNC ca sa nu mai dau banii pe HUB (daca se poate, daca nu mai bag mina in buzunar... asta e)

Ce ma sfatuiti? Merita sa trec totul pe UTP?

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Nu pot folosi UTP pe distanta asta, deci nu iti trebuie HUB  

Vezi detalii mai jos
---
Standard Thick Ethernet:

o A standard Ethernet cable can have a maximum length of 500m (1640ft)

o Up to 100 transceivers can be attached to a 500m cable length.

o Transceivers must be at least 2.5m (8.2ft) apart. Note: To ensure
  proper spacing, a standard Ethernet cable is premarked every 2.5m.

o A transceiver cable is required for each transceiver on the network.

o A standard transceiver drop cable can have a maximum length of 50m
  (165ft). Be advised that some devices have an internal cable equivalency
  and this should be taken into consideration.  To find this internal
  equivalency, it would be best to consult your user's manual.

o When using the more flexible office transceiver cabling, the maximum
  cable length is 12.5m.

o In a standard Ethernet network, you are limited to 101 segments (1
  backbone plus 100 branch segments).

o The maximum number of stations on a standard Ethernet network is 1024.

o Both ends of a standard Ethernet cable segment must be terminated by
  50 ohm terminator.

o Repeaters are used to continue the signal from one segment to another.
  This allows the overall cable segment length to be increased. However,
  data should not pass through more than two repeaters before reaching its
  final destination.

Thin Ethernet:

o ThinWire cabling is RG-58 type coax cable.

o A ThinWire cable segment should not exceed 185m (606ft).

o External transceivers must be at least .5m (16ft) apart.

o Both ends of a ThinWire cable segment must be terminated with a 50
  ohm terminator.

o When directly attached to a station rather than using a transceiver, it
  is imperative that the "T" connector be used at the workstation.

o Up to 30 devices can be attached directly to a 185m cable segment.

o A local repeater may be attached to the ThinWire cable to extend the
  distance.

o Data may not pass through more than 2 repeaters, multi-port repeaters
  or in combination before it reaches its destination.

o Each ThinWire cable segment should have at least one end grounded.
  Never configure the cable in a closed loop.

Twisted pair Ethernet:

o Twisted pair cabling is unsheilded twised pair (UTP).

o Since 10 Base T is wired as a star topology, an active concentrator or
  hub must be employed.  To ensure compatibility with existing or future
  equipment, be certain your hub complies fully with the 10 Base T and
  other IEEE 802.3 standards.

o Typically you can attach your hub to the network devices in one of two
  ways:

  a). Via a 10 Base T media access unit (MAU), also referred to as a 10
      Base T transceiver.  The 10 Base T transceiver has an RJ-45 jack
      and a DB-15 male connection for attachment to the AUI port on a
      standard Ethernet device.

  . Direct connection with a 10 Base T patch cord, provided your
      network device has a built-in 10 Base T transceiver.

o 10 Base T requires 4 pair 22-24 AWG solid UTP cable.  When selectin
  new cable, be certain it can handle a maximum data rate of 10 Mbps.
  Likewise, if you are planning to use existing telephone cabling, verify
  that it can handle the 10 Mbps maximum data rate.

o Although twisted pair cabling is a reliable transmission medium, there
  are factors that must be considered when using it, such as:

  a). UTP cabling is inherently sensitive to electromagnetic and radio
      frequency interference (EMI/RFI), so try to install it as far away
      as possible from flourescent lights.

  . To avoid the possibility of induced spikes or noise, do not
      install UTP in a consuit with electrical wiring.

o 10 Base T is wired according to the AT&T 258A cabling specification;
  however, only pins 1 & 2 and pins 3 & 6 are used.  As a general rule,
  never try to operate more than one station on any cable drop.  Also,
  it is not recommended to pass voice and data on any single cable drop.

o 10 Base T cable drops can be a maximum of 100m (330ft).

o No flat satin telephone cable should be used anywhere in the network
  configuration.

o Concentrators or hubs may be daisy chained together via UTP cabling.
  They may also be attached to optical fiber or standard thick or ThinWire
  coax backbones.

pe UTP, nu, BNC, da

8000 de kilo bytes / s , intre doua placi RealTek 8139, prin switch-ri Surecom/8 port. Cablu STP aerian, in lungime de 83 de metri.
Amcopiat 47 de mega in ~ 5 secunde.
(ecranajul cablului STP nu a fost legat la masa/impamantare la nici un capat)