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3 Messages

Tuesday, January 10th, 2023 4:21 PM

New BGW320-505, IP Passthrough, Asus RT-AX55 router, CAT5 ethernet cable - HEADS UP!

Just a heads up, or maybe a "duhhh". Yesterday we said goodbye to our old 100 MB cable service and hello to ATT 1 GB fiber. We first checked speed via a router wifi connection, and were shocked at how slow it was. We then checked the BGW320-505 wifi speed, and it was as expected. To our surprise, the BGW320-505 reported only a 100 MB link between its 5 GB port and the router 1 GB port. We read that CAT5 cable could carry 1 GB for short distances, but with nothing else to do, we found a CAT6 cable to connect the BGW320-505 and the router, and viola, problem solved.

I searched for hours trying to find a layman's explanation of how cable performance affects auto-negotiation link speed, and couldn't. What I guess is there must be some error occurrence in the auto-negotiation algorithm "fast link pulses" that tells the link hardware this speed (1 GB) just isn't going to work.


New Member


79 Messages

5 months ago

Technically, you just hit upon the major difference between cat 5, cat 5e and cat 6.

Cat 6 cables have their 4 pairs of wires separated by a small plastic (usually) separator, that helps eliminate cross-talk betwen each pair, thus getting better through-put.

Cat 6 cables (usually) are better than cat 5 or 5e cables in speed because of this separation.

Cat 5 was NEVER designed for over 100MBps.

that's what cat 5e did. (provide speeds to 1GBps.)

 Bet if you get a cat 5e cable you'll get similar speeds to the cat 6 cable.

PS:  that flimsy piece of plastic DOES run the entire length of the cable, and in theory it can go much faster than 1GBps.

Now, regarding speed on the bgw320-505...

Good luck.  there are lots of other threads discussing how that is going to be a theoretical 1GBps (especially via wifi).

try searching for those to give you more info...

PS: there are RJ45 cable 'certifiers' (running from $50 to $2,000) that will look at both ends of a cable (or wall run) and

certify if the wiring can do cat 3, cat 5, cat 5e or cat 6 [or even higher I guess].

Will it be worth it for you to get one? 

Not likely UNLESS:

You just bought your house/condo  AND you were told you had cat 5e (or Gigabyte certified) cabling.

IF you are in that position, you could always either buy one, or advertise for someone that owns one (on craigslist) to test your cable runs.

(and as an FYI), I haven't run cat 3 (old fashioned voice over copper) cable in perhaps 6-8 years, and even if it were a voice only project, UNLESS it was THAT big, I'd likely use my normal stock of cat 5 (or more likely cat 5e) cable in my truck!

Hope that puts a bit to rest.

Bottom LINE:

It's the interference, cross-talk, and lack of shielding that gets you the faster speeds.

Oh, and shielded vs. un-shielded cable:

shielded cable will have another wrapper outside of your 4 pairs, for better insulation/cross-talk prevention.

and I'm not even going to discuss indoor vs. outdoor cable. (google that one yourself for a fascinating 4-20 hours!)


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