Maximum length of cable 1

[craggus]

I am planning to create a client/server network at work (currently all the PC's are stand-alone). I would like to create a 100BaseT network, but am a bit unsure what the recommended maximum distance of cat5 cabling is between each of the clients and the hub? I have read differing opinions ranging from 20 up to 150 metres (without a repeater) and obviously this figure will play a major part in the network layout and design.

Many thanks

 

[ChrisAC]

100 mts max! Recommended 90mts with up to 10mtrs patch cables.

Chris.
************************
Chris Andrew, CCNA
chrisac@gmx.co.uk
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[randall5]

Chris is absolutely correct. Plan everything with a 90meter or 300 foot maximum horizontal cable length and place your locations with the idea of 10 foot patchcords in the workstation. With the 300 foot distance, try to include "ups and downs" when figuring the maximum distance. Also, try to centrally locate the server room/equipment rack as much as possible to avoid a future location which may not be wired now, but need service later. The last thing you want is to have to run fiber for one computer. Keep in mind that you only want to cable once, the electronics are always upgradeable, so use the highest rated cable you can afford and make sure the terminations are unform and high quality.

Randy

 

[craggus]

Thanks guys. The book I am currently reading said the maximum cable length for Fast Ethernet (100BASE-T) was only 20 metres, so I guess it must be 'dated' now.

Daft question number two: What is a patch cable/cord? It's not a term I've come across before.

 

[jimbopalmer]

the cable one puts in the wall is not very flexable solid wire, designed for max signal strength. the cable from the wall to the PC or from the patchpannel to the switch, is stranded flexible cable designed to be moved frequently. It does not tend to carry signal as far. I tried to remain child-like, all I acheived was childish.

 

[craggus]

Thanks jimbo. So then, (just to recap!) I would have one type of cable (strong signal, not very flexible) running from a patchpanel to some form of connector in the wall by the PC. I would then use another (more flexible) cable to connect the patchpanel to the switch/hub, and from the connector in the wall to the back of the PC?

I'm wondering if the cabling is something I should be doing myself, or whether I should look at getting some 'pros' in to do it. Drilling through walls / ceilings at work is no problem, but I suppose I don't want to do things one way if there is a much better way of doing it that I didn't know about (if that makes sense?!). Although I have lots of knowledge of networks from books I have no 'hands-on' experience... I had imagined it would be as simple as getting cat5 cable with an RJ45 connector on either end, and sticking one end in the hub and the other straight into the PC. Eeek!

 

[mradmin]

Hi craggus,

I have some additional points that may (IMHO) help:

No. 1, You need to have the wiring part of your infrastructure as solid and reliable as possible. You will be supporting a network of devices from different vendors, etc. The last thing you want to do is suspect cabling as part of some problem.

No. 2, The flexibility that a patch panel adds is worth many times the cost of installing one. Even if your business doesn't change very much, having cables run to every likely location in the building greatly increases your ability to respond to move-add-change requests on demand.

No. 3. The short, flexible patch cables used to connect your "installed" wiring to your devices are easily (and cheaply) replaceable as needed. If you don't use wall jacks and a wire breaks or a connector "goes bad"... well, you see where I'm going.

conclusion: an experienced cable installer will be your new best friend. It is worth every penny to get the work done by and to take the advice of those who have done it before (for paying customers). This includes the ability to "certify" and warrant that the installation meets all applicable standards. You certainly can do this job yourself, BUT it would be a bad trade-off (short-term savings vs. long-term headaches!). good luck...

---Will

 

[jimbopalmer]

No. 4 It is MUCH cheaper to have the installer wire everywhere you COULD put a device than it is to keep bring back installers to wire "just one more" connection. I tried to remain child-like, all I acheived was childish.

 

[MasterRacker]

5. Make sure the professional installer doesn't mind having you hang with them, watching, asking questions and learning.
Jeff
Working in IT is like trying to commit suicide with a very small hammer ....

 

[wires]

I certainly don't mind answering as many questions as you have on a time and materials job. However if it is a bid job, please stay out of the way.

If solid and stranded wires of the same gauge have different "signal strength"s that would be truly amazing. The primary reason solid wire is used in walls is cost.

 

[gavrc]

Wires is correct. CAT5 is a standard whether it be solid core or stranded and it's obiously easier (read cheaper) to make a wire that is solid rather than one made up of lots of little tiny wires <technical term>.

Gav
A problem with your PC??? Never...

 

[jarhan]

how far do you need to stay away from electric trunks so you dont get any stray voltage crossover ????

 

[4eyes]

I beleive 12&quot; is a standard distance to keep. However, it is advisable to keep as large a distance as possible between Cat-5 and 240v cabling. If Cat-5 and 240v do come into contact then the Cat-5 should pass directly across the 240v. Do not run Cat-5 parallel with 240v cabling at close quarters for any distance.

 

[jiwanko]

I know that some of this is covered above but let me explain what I would like to do. Maybe I can get some &quot;low cost&quot; suggestions....

I am planning on networking three pcs. Each one is in a different building. The server and internet connection is to be located in my building, while the additional 2 pcs are ~100ft and ~500ft away in different buildings. I am considering a wireless hub for the nearest machine, but I dont believe that any current wireless technology will work for the farther machine. I know NOTHING about oc connections and would prefer to avoid getting involved with it (as I know nothing about it).

I have heard rumours that it is possible to use parabolic dishes to extend the range of wireless but cant find any information on that topic....

Any help or thoughts or suggestions???

Thanks!

jiwanko

 

[daronwilson]

Wow, I can't believe you are having a hard time finding info on wireless. My first google web search turned up a bunch of links to vendors and suppliers of wireless LAN antennas and systems.

To answer your question quickly though, yes, you can achieve long distances (many miles) with the proper antennas and path. Keep in mind you need line of sight, you need to physically be able to see the other antenna, and you need it off the ground high enough to not have interference in the fresnel zones from ground obstacles. Avoiding the technical engineering, you can just picture a string being pulled tight between the two antennas. You should have this line of sight clear. If you let the string sag a bit and swing it around like a jumprope, that area inside also needs to be generally clear of obstructions.

You can find all kinds of wireless LAN antennas on ebay, and doing a web search with google found me many companies selling them. Panel antennas are smaller and will have some gain, Yagi antennas will be somewhat small and have good gain, Parabolic reflectors will be larger and generally provide higher gain. Remember there is no free lunch with antenna gain. When you make it stronger in one direction, you are doing so by taking signal away from another direction. Aiming can be rather critical with higher gain antennas.

Hope that helps. It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com

 

[wires]

If you have line of sight, even sort of, at 500' you should be able to use 802.11b wireless. You will need some directional antennas and they will need to be aimed at each other for best results.

I did a test shot last month that went 500' through two rows of trees and three rows of 1 and 2 story buildings and still had 11MBit connectivity. I could not see the antenna at the other end and alingment was a bit critical. The antennas were Andrews 16dBi Microceptor panels connected to Linksys WAP11 wireless access points. Links of up to 20 miles have been done with off the shelf equipment.

Here is a nice place for antennas and related items:

http://www.fab-corp.com

Some cool 802.11b links:

http://www.pbs.org/cringely/pulpit/pulpit20010712.html

http://www.graniteisland.com/webcamp.shtml

http://www.cwne.com/index.html

http://www.netnimble.com/

http://www.llnl.gov/asci/discom/ucrl-id-147478.html

REQUIRED READING about 802.11b (in)security

http://www.oreillynet.com/pub/a/wireless/2002/04/19/security.html

http://www.bsdtoday.com/2001/August/News546.html

The easiest securtiy solution is to: &quot;Treat all systems that are connected via 802.11 as external. Place all access points outside the firewall.&quot;

 

[daronwilson]

Great selection of links, thanks. I didn't know you could link up two access points like that, is that something specific to the Linksys line? My installations required a bridge at one end, or a station adapter. Did linksys add some bridging or something to make that work? If so it would save some money indeed. It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com

 

[wires]

The Linksys WAP11 is quite a value.

It can be configured as either a Access point, a Point to Point Bridge or a Point to Multipoint Bridge. The antenna connectors are reverse TNC's so connection to better antennas is easy. The two antenna connectors are configurable so using one antenna is not a problem.

Most bang for the buck I have seen. I was going to use a preconfigured Orinoco wireless bridge in a box setup but their &quot;training&quot; requirements left me cold. This does the same thing at less than 1/2 the cost.