User manual

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SCD speeds telephone scanning in two ways:
• Reduces the time necessary to detect voice responses and second dial tones.
• Reduces the total number of calls PhoneSweep has to make in order to accurately identify data
and fax devices (Voice lines and second dial-tone lines are not called back a second time).
With SCD, the dialing modem quickly identifies the response and terminates. Note: Numbers that
PhoneSweep identifies as voice, second dial tone, or timeout will not be called again in fax mode, as they
would be in the course of a conventional telephone scan.
2.9.2 Many off-the-shelf modems support SCD
SCD works with many popular modems. In general, most, but not all, modems with a Rockwell/
Conexant chipset support SCD.
To determine if a particular modem supports SCD, you can use the program checkmodems.exe, which is
available on the PhoneSweep CD-ROM and downloadable from Sandstorm’s web site
(http://www.sandstorm.net
). Sandstorm also maintains an updated list of modems that work with SCD
and modems that are known not to work well with SCD at
http://www.sandstorm.net/support/phonesweep/recmodems.shtml
.
If you use PhoneSweep to identify both fax and data devices with a modem that does not support SCD,
PhoneSweep will automatically place two phone calls to each number in the profile to distinguish among
data modems, fax modems, and fax machines. If you use a multiple modem version of PhoneSweep with
a mix of different modems that do and do not support SCD, your results will vary based on which modem
was used to place a specific call. Sandstorm does not recommend using a mix of SCD and non-SCD
modems when sweeping.
2.9.3 Modems that do not support SCD
Please note that as of July 2002, modems manufactured by these companies or that fall into these
categories do not support SCD:
• 3Com
• IBM
• Lucent
• USRobotics (USR modems other than the Courier Imodem have a bad performance record with
PhoneSweep and are strongly not recommended).
• Any modem that is called a “WinModem”, or claims to use "HSP" or "HST".
• Internal modems included with your Laptop or Desktop (most turn out to be WinModems). We
strongly recommend that you avoid internal modems.
• ISDN-capable modems
The contents of the above list may change, because modem manufacturers may change chipsets, introduce
new models, and phase out old models. Please visit Sandstorm’s web site at
http://www.sandstorm.net/support/phonesweep/recmodems.shtml
to get an updated list of modems that
support SCD before purchasing a modem to use with PhoneSweep.
Sandstorm is a reseller for some modems that work well with PhoneSweep in the U.S. See Section 3.7 for
more information about modems and SCD.