The information in this article applies to:
- Microsoft Windows for Workgroups version 3.11
SUMMARY
The following article provides general information about setting up the
Remote Access Services (RAS) client in Microsoft Windows for Workgroups
3.11 with an integrated services digital network (ISDN) configuration. This
article should be used as a supplement to the documentation provided with
the ISDN. Contact your ISDN provider to obtain information on the proper
settings for specific ISDN cards.
MORE INFORMATION
The ISDN configuration offers a much faster communication speed than
standard telephone lines because it replaces the analog telephone system
with a digital system. For example, a standard telephone line can typically
transfer data with a modem at a speed of 9600 bits per second (bps); ISDN
communicates without a modem at speeds of 64 or 128 kilobits per second. As
with a local area network, you can connect to an ISDN system from a remote
location using RAS, provided that the proper ISDN lines, service, and
adapters are in place.
Below are the steps required to configure ISDN parameters in Windows for
Workgroups 3.11 RAS:
- Choose the Remote Access Services icon and choose Add from the Phone
Book toolbar.
- In the Phone Book Entry dialog box, choose Advanced and then select the
Any ISDN Port option as the PORT setting.
- Choose the ISDN icon to configure ISDN settings.
- Select an appropriate Line Type setting for the ISDN connection. The
Line Type options are 64K Digital (highest quality), 56K Digital, and
56K Voice (lowest quality). Contact the ISDN provider for details on the
Line Type selection.
- Both the Negotiate Line Type and Enable Hardware Compression options
are selected by default.
Negotiate Line Type allows RAS to communicate at the selected line
type but negotiates to a lower quality line type if necessary. This
negotiation depends on the condition of the ISDN line (for
example, noise on the line affects negotiation).
Below are examples of when Negotiate Line Type option may be disabled:
- The ISDN tariff rates and the capability of the ISDN line have
been previously set up to support a specific line type.
- The ISDN system supports only Voice grade lines in the area. Choose
the 56K Voice option as the line type.
- Negotiate line type is unnecessary if 64K Digital connection is
supported in the your area and is selected as the line type in RAS.
NOTES:
Do not disable Negotiate Line Type if channel negotiation is needed.
Channel negotiation is automatically enabled when the Negotiate Line
Type option is selected. If you disable the Negotiate Line Type option,
RAS cannot operate when channel negotiation is needed.
You must use channel negotiation if you connect to an ISDN system that
has two or more ISDN lines and has been set up to use channel
negotiation. If you enable the RAS software portion of channel
negotiation and do not have the ISDN card in the hardware-selected
channel negotiation mode, your system may stop responding (hang), or you
may be unable to communicate with RAS on the ISDN lines. (RAS will not
know how to format the data for transmission and will also have problems
communicating with the hardware.) Contact your ISDN provider to find out
if your card supports channel negotiation.
The Enable Hardware Compression option uses the ISDN card's built-in
compression techniques to compress data before transmitting it. To use
the card's hardware compression, RAS software compression must first be
turned off. To turn off RAS software compression, choose Options from
the Phone Book toolbar and select Disable Software Compression.
- The Channels To Use setting is set to 1 by default. The number of
channels set should not be changed unless the ISDN card supports the use
of more than one ISDN channel.
- If your ISDN card supports the use of more than one ISDN channel
(known as channel aggregation) and the card is set up accordingly,
you can increase the number of channels in use to improve throughput.
If more than one channel is selected, you must enter each telephone
number for the number of channels selected (separated by colons, not
spaces). For example, if three channels are selected, the Phone Number
entry might read as follows:
555-5555:444-4444:333-3333
- Not all ISDN drivers let you restrict channel aggregation. If
your computer is configured to receive calls and you have a non-
restricting driver, ensure that remote clients specify only one or two
channels. This prevents one user with several ISDN cards from
monopolizing all the channels on the server.
The online help file available in Remote Access Services is a valuable
resource for configuring RAS with an ISDN configuration. Online help
provides information on how to set up RAS with ISDN and details many of the
supported configurations for an ISDN system.
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