Re: Cat 3 cabling
On Sat, Oct 25, 2003 at 05:16:34PM -0400, George Georgalis wrote: > > so use cat3 for ethernet? can't advise it but if you have some on hand > it may suffice; don't stretch, fold or otherwise push it, also concider > the cost of data loss, downtime and rewiring, should you find the need > to rewire. > As I said, cat3 is OK for 10 MBits Ethernet. "OK" means "certified". Depending on a host of factors (some of them you explained), it may be able to carry 100 MBits. Some days. Others not. Believe me, it can be a nightmare. It may work for weeks, and suddenly stop working, just because it's now closer to some other interferring device. I trashed all my cat3 patch cables long ago, after spending quite some time in a mess of cables just to discover that somebody thought that a red cat3 cable would be much prettier than a grey cat5. And we had switched this machine from a 10 MBps port to a 100 MBps one. -- Nicolas Bougues Axialys Interactive
Re: Cat 3 cabling
On Sat, Oct 25, 2003 at 05:16:34PM -0400, George Georgalis wrote: > > so use cat3 for ethernet? can't advise it but if you have some on hand > it may suffice; don't stretch, fold or otherwise push it, also concider > the cost of data loss, downtime and rewiring, should you find the need > to rewire. > As I said, cat3 is OK for 10 MBits Ethernet. "OK" means "certified". Depending on a host of factors (some of them you explained), it may be able to carry 100 MBits. Some days. Others not. Believe me, it can be a nightmare. It may work for weeks, and suddenly stop working, just because it's now closer to some other interferring device. I trashed all my cat3 patch cables long ago, after spending quite some time in a mess of cables just to discover that somebody thought that a red cat3 cable would be much prettier than a grey cat5. And we had switched this machine from a 10 MBps port to a 100 MBps one. -- Nicolas Bougues Axialys Interactive -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: Cat 3 cabling
On Fri, Oct 24, 2003 at 11:45:26AM +0200, Nicolas Bougues wrote: >On Fri, Oct 24, 2003 at 03:27:32AM +0800, Jason Lim wrote: >> >> So in essense, since they are both 4-pairs, just looking at it won't let >> you know which it is (without actually testing it)? >> > >Right. And furthermore, even "testing" with 100 Mbps Ethernet >equipment is not the right thing to do. > >> Any way to turn Cat 5 into Cat 3, and vice versa? >> > >Cat 3 is ok for 10 MHz signal, Cat 5 for 100 MHz. There are of course >other paramters in the spec, like signal attenuation, isolation, >etc. There are devices to certify cables, such as Fluke Networks >tools. They are not cheap, though ($5000 +). > >Simply put, don't use Cat3 for Ethernet. Use Cat 5. Or, since Cat 5 is >deprecated, Cat 5e, which is 100 MHz too, but with enhancements. Or >Cat 6 (250 MHz), or Cat 7 (500 MHz, I think). But then you need to be >rich :) depends what you are doing. I was given a box of cat3 8" (maybe 10"?) lengths. In my super sophisticated tests, there was no difference (and surprising similarity on each test) comparing cat5 in time to transfer something like a 1gb through a 100Mb switch. I've been told longer runs would bring out the problems of interference either from the signal in the wire or external sources like fluorescent lights etc. Determining one from the other, my cat3 is about 75% the diameter of my cat5. can also see the twists and braids through the insulation of the cat5 which I understand limits radio interference. I would guess the cat5 is of higher gauge too. so use cat3 for ethernet? can't advise it but if you have some on hand it may suffice; don't stretch, fold or otherwise push it, also concider the cost of data loss, downtime and rewiring, should you find the need to rewire. // George -- GEORGE GEORGALIS, System Admin/Architectcell: 646-331-2027< Security Services, Web, Mail,mailto:[EMAIL PROTECTED] Multimedia, DB, DNS and Metrics. http://www.galis.org/george
Re: Cat 3 cabling
On Fri, Oct 24, 2003 at 11:45:26AM +0200, Nicolas Bougues wrote: >On Fri, Oct 24, 2003 at 03:27:32AM +0800, Jason Lim wrote: >> >> So in essense, since they are both 4-pairs, just looking at it won't let >> you know which it is (without actually testing it)? >> > >Right. And furthermore, even "testing" with 100 Mbps Ethernet >equipment is not the right thing to do. > >> Any way to turn Cat 5 into Cat 3, and vice versa? >> > >Cat 3 is ok for 10 MHz signal, Cat 5 for 100 MHz. There are of course >other paramters in the spec, like signal attenuation, isolation, >etc. There are devices to certify cables, such as Fluke Networks >tools. They are not cheap, though ($5000 +). > >Simply put, don't use Cat3 for Ethernet. Use Cat 5. Or, since Cat 5 is >deprecated, Cat 5e, which is 100 MHz too, but with enhancements. Or >Cat 6 (250 MHz), or Cat 7 (500 MHz, I think). But then you need to be >rich :) depends what you are doing. I was given a box of cat3 8" (maybe 10"?) lengths. In my super sophisticated tests, there was no difference (and surprising similarity on each test) comparing cat5 in time to transfer something like a 1gb through a 100Mb switch. I've been told longer runs would bring out the problems of interference either from the signal in the wire or external sources like fluorescent lights etc. Determining one from the other, my cat3 is about 75% the diameter of my cat5. can also see the twists and braids through the insulation of the cat5 which I understand limits radio interference. I would guess the cat5 is of higher gauge too. so use cat3 for ethernet? can't advise it but if you have some on hand it may suffice; don't stretch, fold or otherwise push it, also concider the cost of data loss, downtime and rewiring, should you find the need to rewire. // George -- GEORGE GEORGALIS, System Admin/Architectcell: 646-331-2027< Security Services, Web, Mail,mailto:[EMAIL PROTECTED] Multimedia, DB, DNS and Metrics. http://www.galis.org/george -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: Cat 3 cabling
On Fri, Oct 24, 2003 at 03:27:32AM +0800, Jason Lim wrote: > > So in essense, since they are both 4-pairs, just looking at it won't let > you know which it is (without actually testing it)? > Right. And furthermore, even "testing" with 100 Mbps Ethernet equipment is not the right thing to do. > Any way to turn Cat 5 into Cat 3, and vice versa? > Cat 3 is ok for 10 MHz signal, Cat 5 for 100 MHz. There are of course other paramters in the spec, like signal attenuation, isolation, etc. There are devices to certify cables, such as Fluke Networks tools. They are not cheap, though ($5000 +). Simply put, don't use Cat3 for Ethernet. Use Cat 5. Or, since Cat 5 is deprecated, Cat 5e, which is 100 MHz too, but with enhancements. Or Cat 6 (250 MHz), or Cat 7 (500 MHz, I think). But then you need to be rich :) -- Nicolas Bougues Axialys Interactive
Re: Cat 3 cabling
On Fri, Oct 24, 2003 at 03:27:32AM +0800, Jason Lim wrote: > > So in essense, since they are both 4-pairs, just looking at it won't let > you know which it is (without actually testing it)? > Right. And furthermore, even "testing" with 100 Mbps Ethernet equipment is not the right thing to do. > Any way to turn Cat 5 into Cat 3, and vice versa? > Cat 3 is ok for 10 MHz signal, Cat 5 for 100 MHz. There are of course other paramters in the spec, like signal attenuation, isolation, etc. There are devices to certify cables, such as Fluke Networks tools. They are not cheap, though ($5000 +). Simply put, don't use Cat3 for Ethernet. Use Cat 5. Or, since Cat 5 is deprecated, Cat 5e, which is 100 MHz too, but with enhancements. Or Cat 6 (250 MHz), or Cat 7 (500 MHz, I think). But then you need to be rich :) -- Nicolas Bougues Axialys Interactive -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: Cat 3 cabling
On Fri, Oct 24, 2003 at 03:27:32AM +0800, Jason Lim wrote: > Any way to turn Cat 5 into Cat 3, and vice versa? > 5 into 3? Easy. Treat it like CAT3. ;) Bend it under 1" radius. Pull it with more than 25# force (25? Not sure). Run it more than 100meters. Leave it in your trunk while it's 90 degrees outside. In other words, exceed the CAT5 spec and you have something equivalent to CAT3 left. (yes, there is some leeway, YMMV) Turn cat3 into cat5? No, can't. It's all in the twist ;) You can't unsheath it, retwist it and resheath it. Nope. Be nice to your CAT5 ;) j -- == + It's simply not | John Keimel+ + RFC1149 compliant!| [EMAIL PROTECTED]+ + | http://www.keimel.com + ==
Re: Cat 3 cabling
Hi Jason, I'm not 100% sure, but the connection pin-to-pin is the same, I think, just it's a straight connection, not done in a proper way so to ensure the Cat5 quality of signal... so, it's not a test of connection, more a test of quality... I cannot see why to downgrade the quality from Cat5 to Cat3, maybe if you remove the wire gauge and wrap the cable around your mobile phone! ;-) Viceversa, the Cat3 cable give strange results on connections, and on my Laptop I cannot link to my hub if not with a Cat5 cable (with Cat4 don't link). .02$ fi Cat 3 cable is the quality of 4-pair wiring used for voice connections between PBXs and analog telephones. Turns out, it is 'good enoug' for 10 M/s Ethernet (10BaseT) but not good enough for 100 M/s or GigEnet. Cat 5 cable is also 4-pairs, but the manufacturing process is more precise (pitch of the twists, different for each pair; wire gauge; insulation thickness; etc.). As a result, the Cat 5 impedance is more uniform and produces lower signal losses. The better impedance matching carries over into the connectors, which are newer designs (almost all IDC, more precise punch-down blocks) than the Cat 3 (screw posts and relatively sloppy "66" punch-downs. Bill So in essense, since they are both 4-pairs, just looking at it won't let you know which it is (without actually testing it)? Any way to turn Cat 5 into Cat 3, and vice versa? Thanks.
Re: Cat 3 cabling
On Fri, Oct 24, 2003 at 03:27:32AM +0800, Jason Lim wrote: > Any way to turn Cat 5 into Cat 3, and vice versa? > 5 into 3? Easy. Treat it like CAT3. ;) Bend it under 1" radius. Pull it with more than 25# force (25? Not sure). Run it more than 100meters. Leave it in your trunk while it's 90 degrees outside. In other words, exceed the CAT5 spec and you have something equivalent to CAT3 left. (yes, there is some leeway, YMMV) Turn cat3 into cat5? No, can't. It's all in the twist ;) You can't unsheath it, retwist it and resheath it. Nope. Be nice to your CAT5 ;) j -- == + It's simply not | John Keimel+ + RFC1149 compliant!| [EMAIL PROTECTED]+ + | http://www.keimel.com + == -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: Cat 3 cabling
> Cat 3 cable is the quality of 4-pair wiring used for voice connections between PBXs and analog telephones. Turns out, it is 'good enoug' for 10 M/s Ethernet (10BaseT) but not good enough for 100 M/s or GigEnet. > > Cat 5 cable is also 4-pairs, but the manufacturing process is more precise (pitch of the twists, different for each pair; wire gauge; insulation thickness; etc.). As a result, the Cat 5 impedance is more uniform and produces lower signal losses. The better impedance matching carries over into the connectors, which are newer designs (almost all IDC, more precise punch-down blocks) than the Cat 3 (screw posts and relatively sloppy "66" punch-downs. > > Bill So in essense, since they are both 4-pairs, just looking at it won't let you know which it is (without actually testing it)? Any way to turn Cat 5 into Cat 3, and vice versa? Thanks.
Re: Cat 3 cabling
Hi Jason, I'm not 100% sure, but the connection pin-to-pin is the same, I think, just it's a straight connection, not done in a proper way so to ensure the Cat5 quality of signal... so, it's not a test of connection, more a test of quality... I cannot see why to downgrade the quality from Cat5 to Cat3, maybe if you remove the wire gauge and wrap the cable around your mobile phone! ;-) Viceversa, the Cat3 cable give strange results on connections, and on my Laptop I cannot link to my hub if not with a Cat5 cable (with Cat4 don't link). .02$ fi Cat 3 cable is the quality of 4-pair wiring used for voice connections between PBXs and analog telephones. Turns out, it is 'good enoug' for 10 M/s Ethernet (10BaseT) but not good enough for 100 M/s or GigEnet. Cat 5 cable is also 4-pairs, but the manufacturing process is more precise (pitch of the twists, different for each pair; wire gauge; insulation thickness; etc.). As a result, the Cat 5 impedance is more uniform and produces lower signal losses. The better impedance matching carries over into the connectors, which are newer designs (almost all IDC, more precise punch-down blocks) than the Cat 3 (screw posts and relatively sloppy "66" punch-downs. Bill So in essense, since they are both 4-pairs, just looking at it won't let you know which it is (without actually testing it)? Any way to turn Cat 5 into Cat 3, and vice versa? Thanks.
Re: Cat 3 cabling
> Cat 3 cable is the quality of 4-pair wiring used for voice connections between PBXs and analog telephones. Turns out, it is 'good enoug' for 10 M/s Ethernet (10BaseT) but not good enough for 100 M/s or GigEnet. > > Cat 5 cable is also 4-pairs, but the manufacturing process is more precise (pitch of the twists, different for each pair; wire gauge; insulation thickness; etc.). As a result, the Cat 5 impedance is more uniform and produces lower signal losses. The better impedance matching carries over into the connectors, which are newer designs (almost all IDC, more precise punch-down blocks) than the Cat 3 (screw posts and relatively sloppy "66" punch-downs. > > Bill So in essense, since they are both 4-pairs, just looking at it won't let you know which it is (without actually testing it)? Any way to turn Cat 5 into Cat 3, and vice versa? Thanks. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
