Post by thread:[EE:] 2 computers on a single 4x2 cat-5 cable

i have an ethernet installation with cat-5 s-ftp cable. it's a 4x2 awg24 cable, which has a common shield for all 4 pairs, but no individual shields for the 4 pairs. as 100base-t only uses 2 pairs, I wonder if I can use such a cable to connect 2 computers, each using 2 pairs, or if I have to add another cable to connect a 2nd computer in the same room. thanx! -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

maybe, i wasn't clear enough. from the room, I have a cable, about 10meters (30feet) to a switch. now I want to add a second computer in this room, which has to be connected to the same switch. so my question is, if I have to use a second cable, or if I can use the 2 free pairs of the existing cable (cable specification see below). thanx! tino ****************************************************************************************************** >{Original Message removed}

Bühler, Martin wrote: >i have an ethernet installation with cat-5 s-ftp cable. it's a 4x2 awg24 cable, which has a common shield for all 4 pairs, but no individual shields for the 4 pairs. >as 100base-t only uses 2 pairs, I wonder if I can use such a cable to connect 2 computers, each using 2 pairs, or if I have to add another cable to connect a 2nd computer in the same room. >thanx! > > Yes, just use the other two pairs for the second network connection. No problem. It's done all the time. David... -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

>>> i have an ethernet installation with cat-5 s-ftp cable. it's a 4x2 awg24 >>> as 100base-t only uses 2 pairs, I wonder if I can use such a cable to >>> connect 2 computers, each using 2 pairs, or if I have to add >>> another cable to connect a 2nd computer in the same room. > maybe, i wasn't clear enough. > from the room, I have a cable, about 10meters (30feet) to a switch. > now I want to add a second computer in this room, which has to be > connected to the same switch. > so my question is, if I have to use a second cable, or if I can use the > 2 free pairs of the existing cable (cable specification see below). It will (usually) work for shorter (well under 100M) cable runs. But it's a measure of last resort -- like you're setting up a trade show booth, the carpet is already down, and you need to add another device on one of the free standing pedestals. It's not long term reliable and consumes all of the margin built into 100baseTX (plus consuming quite a bit of your karma). Run another cable. 1 device == 1 cable. Cat-5e UTP(*) is cheap. Lee Jones (*) you don't need the shield. -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Hi Martin, I wired my house with cat5 UTP and each cable supplies two computers. I have had no problems whatsoever at 10 or 100 mbps. Longest run was 65 feet. Cheers, Bob On 7 May 2004 at 10:11, Bühler, Martin wrote: > i have an ethernet installation with cat-5 s-ftp cable. it's a 4x2 awg24 cable, which has a common shield for all 4 pairs, but no individual shields for the 4 pairs. > as 100base-t only uses 2 pairs, I wonder if I can use such a cable to connect 2 computers, each using 2 pairs, or if I have to add another cable to connect a 2nd computer in the same room. > thanx! > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics > -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Bob Blick wrote: >Hi Martin, > >I wired my house with cat5 UTP and each cable supplies two >computers. > >I have had no problems whatsoever at 10 or 100 mbps > > And did you really reach the 10 or 100 mbps ?? You won't be aware of a bad cable, because the transmission is repeated if an error occures. So if you've bad communication, you won't detect anything, except that the real throughput slows down. Stef Mientki {Quote hidden}>Longest run was 65 feet. > >Cheers, > >Bob > > >On 7 May 2004 at 10:11, Bühler, Martin wrote: > > > >>i have an ethernet installation with cat-5 s-ftp cable. it's a 4x2 awg24 cable, which has a common shield for all 4 pairs, but no individual shields for the 4 pairs. >>as 100base-t only uses 2 pairs, I wonder if I can use such a cable to connect 2 computers, each using 2 pairs, or if I have to add another cable to connect a 2nd computer in the same room. >>thanx! >> >>-- >>http://www.piclist.com hint: The list server can filter out subtopics >>(like ads or off topics) for you. See http://www.piclist.com/#topics >> >> >> > >-- >http://www.piclist.com hint: The list server can filter out subtopics >(like ads or off topics) for you. See http://www.piclist.com/#topics > > > -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

You should not have any issues using both cables for different computers. Twisted pair is quite resistant to outside noise, (say another line). They use a differential pair on the inputs of the cards, so that should cancel the noise seen as a result of the second pair. Only real disadvantage is you don't get to use POE. :-( -Shawn Stef Mientki wrote: {Quote hidden}> Bob Blick wrote: > >> Hi Martin, >> >> I wired my house with cat5 UTP and each cable supplies two >> computers. >> >> I have had no problems whatsoever at 10 or 100 mbps >> >> > And did you really reach the 10 or 100 mbps ?? > You won't be aware of a bad cable, > because the transmission is repeated if an error occures. > So if you've bad communication, you won't detect anything, > except that the real throughput slows down. > > Stef Mientki > >> Longest run was 65 feet. >> >> Cheers, >> >> Bob >> >> >> On 7 May 2004 at 10:11, Bühler, Martin wrote: >> >> >> >>> i have an ethernet installation with cat-5 s-ftp cable. it's a 4x2 >>> awg24 cable, which has a common shield for all 4 pairs, but no >>> individual shields for the 4 pairs. >>> as 100base-t only uses 2 pairs, I wonder if I can use such a cable to >>> connect 2 computers, each using 2 pairs, or if I have to add another >>> cable to connect a 2nd computer in the same room. >>> thanx! >>> >>> -- >>> http://www.piclist.com hint: The list server can filter out subtopics >>> (like ads or off topics) for you. See http://www.piclist.com/#topics >>> >>> >> >> >> -- >> http://www.piclist.com hint: The list server can filter out subtopics >> (like ads or off topics) for you. See http://www.piclist.com/#topics >> >> >> > > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics > -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Shawn Wilton wrote: > You should not have any issues using both cables for different > computers. Twisted pair is quite resistant to outside noise, (say > another line). They use a differential pair on the inputs of the > cards, so that should cancel the noise seen as a result of the second > pair. > > Only real disadvantage is you don't get to use POE. :-( and what's POE ? Stef > -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Power over Ethernet. :-) There's even a new standard out that completely describes how you should implement POE - 802.3af. Most people just hook up their wall warts to the additional twisted pair and then break it back out near the device. Do a google search for poe or power over ethernet. -Shawn Stef Mientki wrote: {Quote hidden}> Shawn Wilton wrote: > >> You should not have any issues using both cables for different >> computers. Twisted pair is quite resistant to outside noise, (say >> another line). They use a differential pair on the inputs of the >> cards, so that should cancel the noise seen as a result of the second >> pair. >> >> Only real disadvantage is you don't get to use POE. :-( > > > and what's POE ? > Stef > >> > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

I've seen splitter adapters in a computer catalogue to do exactly this. >>>> i have an ethernet installation with cat-5 s-ftp cable. it's a 4x2 >>>> awg24 cable, which has a common shield for all 4 pairs, but no >>>> individual shields for the 4 pairs. >>>> as 100base-t only uses 2 pairs, I wonder if I can use such a cable to >>>> connect 2 computers, each using 2 pairs, or if I have to add another >>>> cable to connect a 2nd computer in the same room. >>>> thanx! -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> And did you really reach the 10 or 100 mbps ?? Absolutely. > You won't be aware of a bad cable, Although some people might not, I would be aware of it, since I am a linux user and occasionally run diagnostics and generally look at traffic to make sure my Windows machines aren't doing things they shouldn't. Cheers, Bob -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics