ISDN Line Simulator User’s Manual
40-400-00012, Rev. E
17
an error. Usually the text indicates the name and Directory Number of the
called or calling party. If the Terminal uses Call Appearances, the Call
Appearance identifier is also displayed for the current call.
Some devices specify a switch provision indicating that the Display feature
be enabled or disabled. To change the setting,
STEP 1
Run the Windows based configuration software.
STEP 2
Select the Terminal Display Text setting.
STEP 3
Change the setting.
STEP 4
Select SAVE to save the setting.
STEP 5
Remove all communications devices from the Simulator and
press the DOWNLOAD button. An automatic RESTART is
issued as part of the
DOWNLOAD.
When set to ON, the Simulator sends formatted display text to every device,
which includes the Call Appearance, Called (or Calling) Party Name, and
Directory Number.
When the Simulator is configured for National ISDN-1, this text is sent in a
Display Text
Information Element following a
Locking Shift 5
(National
Codeset) Information Element. For AT&T devices, the text is sent in multiple
Display Field
Information Elements which follow a
Locking Shift 6
(Network
Codeset) Information Element.
If one or more devices do not support display text but others do, enable the
Terminal Display Text. The device(s) that cannot support these Information
Elements simply ignore them.
NOTE: The Simulator does not send display text if Caller Identification
is disabled.
Electronic Key Telephone Service (EKTS)
EKTS is not new and most people are familiar with the office telephones that
employ it. With a telephone and switch that support EKTS, multiple Directory
Numbers may share the same physical line.
The main protocol difference between standard ISDN devices, or Basic Mode
Terminals, and EKTS Mode Terminals is that the former are addressed using
the
Called Party Number
Information Element, while the latter support the
Endpoint ID
Information Element. The Called Party Number is simply the
Directory Number associated with the physical telephone line when service
was established. When an incoming SETUP Message is received, all
telephones connected to that line alert the user. The user must then decide
which device to use when accepting the call.
Using EKTS services, one or more telephones may be addressed
individually. ISDN-BRI terminals send a Service Profile ID (SPID) to the
switch during initialization, and the switch returns an
Endpoint ID
(TEI)