On Mon, Feb 09, 2004 at 04:30:29PM -0600, Ben Neigebauer wrote: > I have my cable split about 6 ways and get frequent drop-outs. > > Will one of those bi directional broadband amplifiers work? The way I did it (and hopefully the cable company guy will also respond) is by splitting it when it first comes into the house with a good, two way splitter. The one split goes straight to the cable modem. The second, goes to an amplifier, and then to a n-way splitter for the tvs. So, we have a regular amplifier on the line, but it only amplifies the signal for the TVs. hth, dan > > > > > > -----Original Message----- > From: tclug-list-bounces at mn-linux.org [mailto:tclug-list-bounces at mn-linux.org] On Behalf Of Daniel Rysztak > Sent: Monday, February 09, 2004 4:19 PM > To: TCLUG Mailing List > Subject: RE: [TCLUG] New Comcast speeds > > As I work for a cable company and am a Network Engineer, I can attest that > sub-optimal modem levels impact speed. However, this is dependant on the > modem. (Some seem to handle a less clean plant.) Essentially you are > looking for approximately 40 to 50 dB on the Reverse and between 5 to -5 dB > on the Forward. The further you are from those ranges, the more likely you > are to accumulate errors, dropped packets, retransmits and other networking > headaches which chew up your bandwidth. > > Amazingly, that's why those little numbers on splitters and pads are > important. They actually add up to something. > > Except for a directional coupler, every split in a splitter accounts for > approximately 3.5 dB. > > 2 way = (2)3.5dB > 3 way = (1)3.5dB, (2)7dB > 4 way = (4)7dB > > As you can see to make a 3 way, you need to split one that is already split. > > These help pad and adjust the levels in addition to thelevels coming into > the house. (Incoming levels could vary depending on equipment at the > street.) > > Now, if you have a dirty plant where signal to noise is down at 20dB, a 35dB > reverse could be impacted by the noise even though DOCSIS modems supposedly > can handle a reverse down at 8dB to 58dB. That's the difference between a > test bench controlled environment and the real world with snow and cold > weather, cars hitting polls and peds, humidity, and a billion other > variables. > > I think you'll now see, cable is NOT either ON or OFF. > > ============================ > Daniel Rysztak, CCNA > > -----Original Message----- > From: tclug-list-bounces at mn-linux.org > [mailto:tclug-list-bounces at mn-linux.org]On Behalf Of Jack Ungerleider > Sent: Saturday, February 07, 2004 10:49 PM > To: TCLUG Mailing List > Subject: Re: [TCLUG] New Comcast speeds > > > On Saturday 07 February 2004 02:56 pm, David Phillips wrote: > > Jima writes: > > > My immediate guess is that maybe the coax feed to your cable modem is > > > sub-optimal. I'm not a cable expert, though. > > > > Cable is either on or off. A bad signal (often caused by too many > > splitters) will cause failure, not lower speeds. > > The way I understood it from the guy who did the cable check for my cable > modem in Duluth was that there are optimal signal voltage levels for the > data > channels. If the signal is outside that level the modem can have trouble. To > me that implies the possibility of sub-optimal performance. > > But like Jima I'm no cable expert. > > -- > Jack Ungerleider > jack at jacku.com > > > _______________________________________________ > TCLUG Mailing List - Minneapolis/St. Paul, Minnesota > http://www.mn-linux.org tclug-list at mn-linux.org > https://mailman.real-time.com/mailman/listinfo/tclug-list > > > _______________________________________________ > TCLUG Mailing List - Minneapolis/St. Paul, Minnesota > http://www.mn-linux.org tclug-list at mn-linux.org > https://mailman.real-time.com/mailman/listinfo/tclug-list > > --- > Incoming mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.577 / Virus Database: 366 - Release Date: 2/3/2004 > > > --- > Outgoing mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.577 / Virus Database: 366 - Release Date: 2/3/2004 > > > _______________________________________________ > TCLUG Mailing List - Minneapolis/St. Paul, Minnesota > http://www.mn-linux.org tclug-list at mn-linux.org > https://mailman.real-time.com/mailman/listinfo/tclug-list _______________________________________________ TCLUG Mailing List - Minneapolis/St. Paul, Minnesota http://www.mn-linux.org tclug-list at mn-linux.org https://mailman.real-time.com/mailman/listinfo/tclug-list