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Full Duplex Cable modem. Ideas?

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Snipor

Programmer
Feb 23, 2001
92
US
Since I've connected a router and 5 computers, my network internet connection has been real freaky. Sometimes I would lose my connection, other times, my ping would be so high, I would get disconnected I called the cable company, and the Tech said, the my problme might be that my network cards and Router probably all support full duplex, where my Cable modem doesn't support Full Duplex. I have the surfboard 3100. He saids that that model and the 3com Home connect models don't support Full Duplex. He said I might look into getting a full duplex. He suggested the Surfboard 4100 and the Toshiba's. I went to there websites and couldn't find any documentation stating if these models supported full duplex. Is there a way I can tell, or do you guys have any suggestions for full duplex cable modems?
 
What router are you using?

I'm using an SMC Barricade, and don't recall any reference to full duplex in the WAN port, but it is working fine. I'm still using a crappy LanCity cable modem.

I know of one of these working fine with a Motorola Surfboard 4100 too.

Of couse the Barricade series I'm using are called "broadband routers" and may run half on the WAN port, though I find no reference to half or full duplex in any of the docs for this box. It incorporates a 10/100 autosensing switch, but strangely wnough doesn't mention half/full duplex on the LAN side either.

Sorry I can't be more help, but I think this might be a red herring.

If you're using DHCP on the WAN side and have any choice at all, switch to fixed IP. When I signed up I was assigned a fixed IP (it is right on the invoice) even though the cable jockey set up DHCP. Their DHCP box does about as often as anything else on their network anyway.

Good luck, if anything useful occurs to me I'll post it here later.
 
hey,
i also have cable internet service and i share the connection with 2 other computers using a linksys wireless access point. i often experience disconnections and i dont know if it is the cable service, my modem, or my network.

if u can help, please email me @ george2k@hotmail.com

thanks very much and good luck too all of u others with cable problems :)
 
Greetings,

I presently work for an Cable Modem ISP... The only thing I can tell you is according to my experience. End User cable modem are now only half duplex compatible ...

Any of our user that set their network equipement to work in full duplex mode and More thand 10BaseT will encounter loss of speed and connectivity ...

Hope that Help ...

 
Keep in mind with cable ISP you will have lots of wacky things going on. You are sharing your bandwidth and connection with your entire neighborhood, which *may* account for your connection cuts and speed differentials.

I *didn't* try to run a router with my cable connection and *still* had all kinds of problems, including ones you are reporting. IMO, could just be the provider.

Have you tried Sprint Broadband Direct? (If available.)

-Lara
 
Thanks for all the ideas guys. Just a note. When I was using just a switch and 2 computers, I never had any problems. I needed to have my other computers connected to the internet so I bought a Cable router. That's when I started having problems. I've read some information, and it seems, that if your using one or or two computers, cheap network equipment is fine. For example, I am using $12 D-Link 10/100 network cards, and a CNet 7-port Cable router. Now, these items are extremely cheap. Heck, I think I bought the router brand new for $85. Since my cable provider alows me ot have 3 ips', I did was plugged my two main computers into the switch and plugged the router into the switch. Now, my two main computer are directly connected to my ISP and the other computers, (the ones I don't use often) are connected through the router and sharing the same ip. Since I've done this, I have had less problems, with disconnects, bad pings, and packet loss.

So, I'm sure If I upgraded to 3-com network cards, and a good router, these problems would probably be less.

By the way, this question is for Elteor. I bought a Surboard 4100. And I'm very pleased with it. However, I have to reboot the sucker sometimes cause it seems to lock up. Is this because it's running at full duplex, and my ISP is running at half?
 
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