DIVA T/A ISDN Modem User’s Guide ◆ Page 49
The DIVA Terminal Adapters Program for Windows95/98/NT
X.25 Facilities options
X.25 facilities are optional network services that let you perform tasks such as reversing
charges on your calls, accessing a Closed User Group, or specifying a Network User
Identification (NUI). The options you select must be supported by your Se rvice Provider.
Facilities fall into two groups: those specified at subscription time, and those specified on a
per-call basis. X.25 Facilities you configure must match your X.25 subscription as agreed with
your Service Provider.
The X.25 tab's default parameters are suitable for most configurations. In some cases (such as
with certain X.25 long distance providers), you might need to modify them. Use the table
below as a guideline.
Parameter Description
Request
Reverse
Charging
Determines who is charged by the X.25 network for the call. Select ‘No’ to pay for the
call locally, or select ‘Yes’ to charge the remote DTE. Select ‘Yes’ only if the remot e
system accepts reverse charging, otherwise the call may not be accepted.
Throughput
class
negotiation
Assigns a ‘Throughput Class’ for the virtual circuit. The Throughput Class specifies
the effective throughput of the virtual circuit in bits per second (bps). Effective
throughput may be limited by a number of factors such as level of link utilization,
network congestion, and host processing.
Select ‘Default’ to use the Throughput Class specified in your network subscription,
or select one of the values between 75 and 9,600 bps. If you select a ‘bps’ value, the
local and remote DTEs can negotiate to use a lower value on a per-call basis.
Fast selection Increases the amount of Call User Data that you can include in the Call Request
packet to 128 bytes, and specifies the type of response requested from the host. Fast
selection is designed for short-duration, low-volume, transaction-oriented
applications.
•‘No’: Turns off Fast Selection.
•‘Without Restriction’: Host replies with a Call Accept packet that can contain up to
128 bytes of data. The connection is established and data transfer can occur.
•‘With Restriction’: Host replies with a Call Clear packet that can contain up to 128
bytes of data. The connection is terminated.
Closed user
group
selection
Specifies the type of closed user group (CUG) subscribed to. CUGs can restrict the set
of DTEs calls that can be made to or accepted from. Select the option that
corresponds to the CUG specification in your network subscription.
•‘None’: Does not subscribe to any CUG.
•‘Standard’: Subscribes to a CUG. Enter the CUG number in the Group Number box.
•‘Outgoing Access’: Can receive calls only from members of the CUG, but can make
calls to any DTE.
•‘Bilateral’: Can receive calls from or make calls to only a specific DTE.
Group
number
Specifies the number of the closed user group you have subscribed to. Obtain this
number from your system administrator or network subscription.