
 Area: R-USR 
  Msg#: 7617                                         Date: 09-26-94  22:08
  From: Bill Garfield                                Read: Yes    Replied: No 
    To: Ray Bornstein                                Mark:                     
  Subj: 28.8 CONNECTS

 -=> Quoting Bill Garfield to Ray Bornstein <=-

 BG> Expecting 28,800 bps?  Your results may vary.

 BG> If you find that you're unable to achieve full speed 28,800 bps
 BG> connections or your modem sometimes behaves erratically, the reason is
 BG> possibly a phone line problem. Either insufficient bandwidth, poor
 BG> signal to noise ratio, or an imbalance in the phone lines... either
 BG> yours, the phone lines of the system you are calling, or in the lines
 BG> and telephone switching equipment anywhere along the way.

 BG> Here are the minimums:
 BG> ^^^^^^^^
 BG> 28,800 bps V.FC/V.34 -REQUIRES- 3200 Hz bandwidth, from 320 - 3520 Hz.
 BG> 26,400 bps V.FC/V.34 -REQUIRES- 3000 Hz bandwidth, from 375 - 3375 Hz.
 BG> 24,000 bps V.FC/V.34 -REQUIRES- 2800 Hz bandwidth, from 467 - 3267 Hz.

 BG> by contrast..

 BG> A 21,600/19,200/16,800 link requires a usable bandwidth of only 2400
 BG> Hz, from 600 - 3000 Hz. This is the same amount required for V32 &
 BG> V32-bis (4800, 9600 & 14,400).

 BG> Alas, while most U.S. domestic phone lines can easily support the
 BG> requirements of 9600/V.32 and 14400/V.32 bis, some may not have
 BG> the technical parameters necessary to support V.FC and V.34 at
 BG> *FULL* speed.  This, in a nutshell, is what you (and some others) may
 BG> be experiencing.

 BG> Compared to V.32 & V.32 bis, 28,800 bps requires 33% more bandwidth,
 BG> 26,400 bps requires 25% more bandwidth and 24,000 bps needs 17% more
 BG> bandwidth. This additional bandwidth *MUST* be there from end to end,
 BG> from one modem to the other.  Either you have it or you don't, and
 BG> your modem is telling you by its performance.

 BG> As the domestic telephone companies race to install fiber optic
 BG> cables, the bandwidth situation should gradually improve.  Until
 BG> then... 
 BG> ***********************************************************************
 BG> ***** * There ARE several things you can -try- for improving at home
 BG> modeming:   * * Go throughout the house and disconnect -ALL- telephonic
 BG> devices attached * * to the phone line.  This includes extension
 BG> phones, answering machines,  * * fax machines, caller-id boxes,
 BG> line-in-use indicators, cordless phone    * * base units, demon
 BG> dialers, and voltage spike protectors or line filters  * * like those
 BG> commonly found in PC Desktop master-switch power directors    * * and
 BG> power line conditioning units. If you find that any of this helps,   *
 BG> * then start plugging things back in one by one until the culprit is  
 BG> * * identified.  It may even be a combination of things.           
 BG> * *                                                           
 BG> * * If your telephone wiring is a rat's nest and/or
 BG> you've strung some       * * extension lines yourself and not used
 BG> genuine telephone-type wiring,     * * consider having a professional
 BG> replace your haywired additions. Your     * * telephone wiring should
 BG> also be WELL AWAY FROM the A/C power wiring in   * * walls & ceilings. 
 BG> *
 BG> ***********************************************************************
 BG> ***** As always, your mileage will vary.


 BG> * OLX 3.0 * HANGING: Bungee-jumping in beta trials


