Does cable length affect available bandwidth or network status?

[spoon805]

I can't get my 80+ft network to work under 100Mbps, but if I force the NICS to 10Mbps it will work. I need some insight.

Basically, I have 2 computers connected to a Netgear 4-port 10/100 DSL router. The router is sitting on top of one of these computers. This computer thus has very little cable between it and the router, and connects at 100Mbps. However, the other computer is connected nearly 80+ feet away (strung across the outside of the third story of a condo complex). If the NIC is set on auto-detect or 100Base, it will not detect the network. However, like I said, if I configure the NIC to 10Base, it work perfectly.

Details:
-Cable: Command Link Cat 5 10/100 Riser Rated (Home Depot crap), for indoor and outdoor use (real thick outer layer)
-Router: Netgear RT314
-NICs: both are intergrated into the motherboards (one is 3com, another is intel)
-Note: The 80+ feet cable connection is not "pure", or not one cable (ASCII diagram)

DSL --> Router --> Cable (10 ft.) --> RJ-45 wall jack --> Cable (6 inches) --> RJ-45 wall jack --> Cable (roughly 70+ feet) --> RJ-45 wall jack --> Cable (6 inches) --> RJ-45 wall jack --> Cable (2 ft.) --> PC

My own ideas about the PROBLEM:
-Because of the distance, there is a degredation of bandwidth well above the threshold of a true 100Base network. Therefore, when the router and nic are both set to auto-detect, they detect that connection can support more than 10Base and thus attempt to connect at 100Mbps, but fails.

My own ideas about the SOLUTION:
-I could upgrade to a high grade Cat 6 Cable(yes, CAT SIX...way expensive IMO)
-Since I need to connect more computers on the distant side, I ordered a netgear 10/100 5 port switch that is coming in today. This might correct some of the packet errors enough to achieve a 100Base network again at this distance.

Does anyone else have any ideas what can be causing this problem or possible solutions. I really want to know if the length of the cable is the true culprit.

 

[Workin']

The problem is probably with all those connections in there. Maybe one or two are bad or noisy. 80 feet is NOT a long distance, at all. The Cat5 spec allows runs up to 100 meters (300+ feet), and in the real world you can often times get away with even more.

 

[spidey07]

Something with that patch-jack-cable-jack-patch combination is not passing CAT5 specs by a large margin (otherwise you should get link, just sporadic performance). Could be any number of things - twists not tight enough, loose punch, interference from outside.

Can you take this cable combination out of the picture by plugging directly into the switch with a patch cord and making sure the NIC and switch can operate at 100 megabit? Try this first just to make sure it is a physical cabling problem.

80 feet is fine for distance. Max is 100 meters for CAT5 and 100 Base-T. TIA standards support 90 meters for horizontal runs between information outlets (jacks) and 5 foot patch cables on each end.

Do you even get a link light at 100 megabit?

hope this helps!

 

[spoon805]

yeah, I didn't think 80 feet was long at all, until I started having this problem.

Can you suggest another cleaner method to substitute the patch-jack-cable-jack-patch combination. Basically, I need to to go thru a drywall on one side and out a brick wall on the other side.

Spidey97- link light on the router? yes, on the computer that's right next to it. No, on the computers 80 feet away. I'll use the switch to test things like you said, once it gets in.

 

[spidey07]

understood spoon.

If it works fine with your cabling then it is for sure a cabling problem.

Check all your patch cords make sure they are cat 5, check your jacks and make sure they are cat 5, check cable between jacks and make sure it is cat 5.

If all components check out OK, then look at your punches and wire colors and make sure the match exactly. Repunch if necessary.

 

[mylam]

I don't think 80 feet is long at all

 

[RTM]

we have some Cat3 running 100 @ the same speed as the cat5 we have - there is some other problem

 

[spoon805]

To anyone that's been following this thread.... It wasn't the patch-jack-cable-jack-patch combination. All those connections proved flawless. It was however the longer cable outside. just FYI

I'm going to try redoing the ends frist. And if that doesn't work, then upgrade the cable.

Thanks EVERYONE for your help and insight.