jack sayed posted 01 May 2000
1000 Base-T cables
We have a Lan network in a printing press.Composed of 3com 10/100 Base-T switch hubbs and a Cat 5 UTP Horizontal Cables.
This system is working properly so far;except in one single department,which is the photo scanning departement.
Users in this departement deal with files that,sometimes reach more than 1gb each.Which resulting a waste of time for those files to get to their destinations.
We're thinking of implementing a 1000 Base-T switch hubb for that department.
The question is:What kind of cables do you suggest us to use? or the cat 5 could do the job.
N.B:The departement is at 20 meters far from the main switch hubb.
Many thanks and Best regards
Dmitri Abaimov posted 01 May 2000
When you consider to move to Gigabit Ethernet, there are some costs, associated with that. Of course, you need to buy an equipment. Besides, you'll need a cabling system that meets at least Category 5E requirements. If your cabling systems was built one-two years ago, it may be so that you're OK for CAT5E since it's just a set of additional parameters, applied over regular CAT5 ones. Quality vendors started to produce CAT5E compliant hardware about 2-3 years ago. You may check, whether your system is CAT5E compliant by means of new generation cabling tester like Fluke DSP-4000, Microtest Omniscanner etc. If your system is older that 2 years (or you aren't sure about the quality), you'll most likely need to reinstall everything, including cables, cords, panels and jacks. If you're pushed to do that, I would suggest that you use only Category 6 compliant hardware, because otherwise, after several years, you may approach the same problem again. Pricewise, newly installed CAT6 system costs about 10-15% more than CAT5E. It's really worth the performance that you get - two times more bandwidth.
Before you start everything, take a look at how optimized your network is. Do you actually use switches or hubs (you call them switched hubbs). There is a big difference between the two. If it's switch, you can get full 100Mbit/s channel per every workstation. But your switch may have only switching capability between groups of ports. Within that group it's still shared media hub. It means that your users share the same 100Mbit/s channel, and if all the powerful users are in one group, there is a bandwidth problem.
If your hubs and NICs have speed autosensing, are you sure they found it 100, not 10? Just try to switch autosensing off to see how it runs on real 100.
Besides, overall speed may be affected by such a factors as quality of cabling installation and/or quality of cords that you use to connect stations. There are lots of reports that say cords are one of the most sensitive parts of the cabling system. Improper cable installation may cause bit errors that require NIC-hub to resend packets, therefore bringing throughput down.
Just let me express it in this way - before you spend your money on brand new Gigabit Ethernet equipment, there are whole lots of things to do to optimize your existing network. And if everything is tried already, then it's right time to move on Gigabit over good quality CAT6 cabling system.
With best regards,
Dmitri Abaimov, RCDD
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