PDA

View Full Version : Cat 5/5e network cable.



Nomad
22-06-2013, 05:50 PM
Can someone tell me if cat5 works at 1,000 or is that just cat5e? I have some cables from the 1998 days from my PCMCIA Xircom/USR/3Com cards and they work at 1Gbps. But I have a newer cable that came with an ADSL2+ modem router - it would work at 1Gbps with the laptop but with the base unit (docking station) it only connects at 100Mbps. My other cabls incl those from 1998 connects fine at 1Gbps without/without the dock.

Speedy Gonzales
22-06-2013, 06:27 PM
Everything needs to be 1gb (the nics), for it to connect @ 1gb. So, if the dock is only 10/100 it will only connect @ 100

pcuser42
22-06-2013, 06:30 PM
As far as I know Cat5 can operate at 1Gbit/s, but not very well - you'd be better off going with Cat5e or Cat6.

Nomad
22-06-2013, 07:20 PM
That is the thing. If i use a older cable from 1998 on the same laptop, same dock, same network switch i get 1Gbit, same if i undock. If i use a cable given to me by one of my ex isp i get 1Gbps but then when i dock i get 100.

Laptop, dock and my 8 port switch is gigabit versions. I have just installed cat6 solid cables behind walls and wallplates.

Every other cable even older does 1Gbps on laptop or with the dock.

stormdragon
22-06-2013, 07:45 PM
Is the cable slimer then the others some of the cables bundled with routers only have 6 wires instead of the full 8

dugimodo
22-06-2013, 08:14 PM
As far as I know Cat5 can operate at 1Gbit/s, but not very well - you'd be better off going with Cat5e or Cat6.

Common misconception, CAT5 works just fine at 1Gb/s. On longer runs or if you have a lot of cabling close together, or a noisy environment with a lot of EM interference, then sure CAT5e and CAT6 work better.
Gigabit ethernet was developed to work on CAT5, then the cabling was improved to help it perform better. However in a normal household situation where cable runs are typically < 20M and there are usually only a handful of them at most you'd have a hard time proving any difference. By design ethernet cables between equipment can go up to 100M, when you start getting close to that the cable type matters a lot more.

All I can suggest to the OP is the dock must be limiting you somehow. If you put a cable that can only do 100M between hardware that can do Gb speeds it simply doesn't work because both ends detect each other as being capable of Gb and use that speed which then fails. If you put a 100M device in the circuit however, the other end typically detects the 100M signal and drops itself down to match and it works. In other words a cable won't force you to 100M only hardware will, a cable will just either work properly or not at whatever speeds the hardware negotiates.

CYaBro
22-06-2013, 08:53 PM
Is the cable slimer then the others some of the cables bundled with routers only have 6 wires instead of the full 8

This, except they often only have the required 4 (not 6 :))wires inside so will only ever connect at 100mbps.
You need all 8 wires to get 1gb.
CAT5 cables will do 1gbps but probably not for a very long distance.

Nomad
22-06-2013, 09:09 PM
The cable in question - same width, looking at the plug it has 8 wires.

I do have another cable that is thinner, 4 wires, came with yet another ISP, this one goes at 100Mbps without the dock.

For that original cable (8 wires), I know it was 1Gbit without dock and 100Mbps with dock. I am now gonna connect it to the laptop alone and test a file copy. But just now it reported 100Mbps connection, I reinsert the cable and got back 1Gbps. Maybe lesser workmanship? For a 1GB single video file, Windows reported speeds avg of 70MB/sec. I tried another cable and got faster speeds average of 100MB/sec and then slowing to about 80MB near the end. Maybe with the dock if I reinsert the cable it would hit 1Gbps too ........

Chilling_Silence
23-06-2013, 01:23 PM
Common misconception

This man speaks the truth :-)

tmrafi
25-06-2013, 02:34 PM
Wow, lot of misconceptions here!

Cat 5 cable and connector is designed to operate at 100MHz. So technically you can only get 400Mbps when using all 4 pairs
Cat 5e cable and connector is designed to operate at 150 MHz. So can reach 600Mbps when using all pairs
Cat 6 cable and connector is designed to operate at 250MHz. So will operate at true 1Gbps
Yes you can use old Cat5 cable on Gigabit port. The port will negotiate 1Gbps but can only operate at 400Mbps sustained error free throughput.

dugimodo
25-06-2013, 03:12 PM
TLDR; Cat 5 can do GigE and always could.


Wow, lot of misconceptions here!

Cat 5 cable and connector is designed to operate at 100MHz. So technically you can only get 400Mbps when using all 4 pairs
Cat 5e cable and connector is designed to operate at 150 MHz. So can reach 600Mbps when using all pairs
Cat 6 cable and connector is designed to operate at 250MHz. So will operate at true 1Gbps
Yes you can use old Cat5 cable on Gigabit port. The port will negotiate 1Gbps but can only operate at 400Mbps sustained error free throughput.

rubbish, GigE was designed to work on CAT 5 which yes is rated for 100Mhz but it uses clever modulation to achive a similar effective frequency as 100M and therefore can run on the same cable for the same distance. Mhz <> Mbps (an extreme example a phone line works on 0-4Khz and can achieve 64Kbps in that band or 33.6 if it does 2 A-D conversions). It can and does work at full speed without errors for up to 100M on CAT 5. Cat 5e and CAT 6 were designed to improve the crosstalk and noise charateristics of CAT 5 to improve performance when a lot of cabling is run together etc. CAT 6 is designed and standardised for GigE but that doesnt mean CAT 5 won't work.



1000BASE-T[edit]
1000BASE-T capable network interface card made by Intel, which connects to the computer via PCI-X1000BASE-T (also known as IEEE 802.3ab) is a standard for gigabit Ethernet over copper wiring.

Each 1000BASE-T network segment can be a maximum length of 100 meters (328 feet), and must use Category 5 cable or better (including Cat 5e and Cat 6).

Autonegotiation is a requirement for using 1000BASE-T[9] according to Section 28D.5 Extensions required for Clause40 (1000BASE-T).[10] At least the clock source has to be negotiated, as one endpoint must be master and the other endpoint must be slave.

In a departure from both 10BASE-T and 100BASE-TX, 1000BASE-T uses all four cable pairs for simultaneous transmission in both directions through the use of adaptive equalization and a 5-level pulse amplitude modulation (PAM-5) technique. The symbol rate is identical to that of 100BASE-TX (125 Mbaud) and the noise immunity of the 5-level signaling is also identical to that of the 3-level signaling in 100BASE-TX, since 1000BASE-T uses 4-dimensional trellis coded modulation (TCM) to achieve a 6 dB coding gain across the 4 pairs.


also



Category 5 vs. 5e[edit]The category 5e specification improves upon the category 5 specification by tightening some crosstalk specifications and introducing new crosstalk specifications that were not present in the original category 5 specification. The bandwidth of category 5 and 5e is the same - 100 MHz.[13][14]