Toshiba Strata Ctx100, Ctx670 General Description Manual

							Features
Call Park
Strata CTX General Description    06/0347
that telephone as “redirected” and on the telephone that answers the call as “answered.” If a call is 
not answered, it is stored on the line or [DN] owner’s telephone as “abandoned.”
To store call records, a telephone must be allocated Call History memory by the System 
Administrator. The number of call records allowed per station and the total number of call records 
per system is provided in Table 7 on page 14.
Call Park
Call Park gives any station, regardless of type, a method for holding calls. By parking a call, you 
are free to make other calls and retrieve the call at a later time or use the paging system to 
announce a call to be picked up by someone else on the system. Any call can be parked. Parking a 
call to your phone is known as Local Park, parking a call on someone else’s phone is known as 
Remote Park, and if a general orbit is used, it called Auto Park. 
Call Park Orbits
The Call Park feature enables a station user to place a call temporarily in an orbit so that the call 
can be retrieved by any user, either from the same station or from a different station. Personal Park 
Orbits are available to any type of telephone, including standard telephones. If a call is parked, but 
not retrieved within a preprogrammed time period, it will recall the parking telephone. The Park 
recall time is set individually for each station.
Refer to Table 7 on page 14 for the number of General Park and Personal Park Orbits, depending 
on the system processor. 
Park and Page
This feature enables station users to park a call (in a General or Personal Park Orbit), enter a Page 
Zone or Group access code, and then announce the orbit number of the waiting call to the Paged 
party. A pre-programmed One Touch button can be assigned to telephones to automatically 
connect to a predesignated External Paging circuit, a Telephone Paging group or both. 
Call Pickup
Call Pickup enables station users to pick up all types of ringing or held calls including internal, 
[PDN] or [PhDN] calls ringing or on hold at other stations. Station users can also pick up CO/DID/
Tie line calls ringing or on hold at other stations, CO lines ringing during Night Mode to External 
Page or night bell, tandem CO line connections and Door Phone calls. Call pickup can be 
performed through programmable buttons (Directed Pickup, Group Pickup), or with an access 
code.
Call Waiting
When a station is busy with a call and another call is directed to that station’s busy  or [DN] 
button, two short beeps are issued to alert the telephone user of the pending call. To answer the 
Call Waiting, the user must transfer or disconnect the existing call. 
Call Waiting works for calls originating from within or outside the system. The length of the Call 
Waiting beeps is different for internal and external Call Waiting. The different beeps distinguish 
which type of call is waiting. 
						

							Features
Caller Identification
48Strata CTX General Description    06/03
Caller ID DNIS or ANI information appears on LCD telephones for 10 seconds. If Caller ID 
information is not available, the device name, such as the CO line or DNIS name or number is 
shown.
Digital telephones can be adjusted to receive or not receive Call Waiting tone over the handset or 
headset receiver, as well as the speaker. Standard telephones will receive Call Waiting tone twice 
from the handset receiver. Call Waiting tones can also be turned off on each station by a System 
Administrator.
When a station is busy with a call and another call is being received, a tone alerts the caller of a 
pending call. On LCD telephones, the Caller ID information displays for 10 seconds. The 
combined effect of the Call Waiting alert tone with the displayed information enables users to 
identify whether or not they want to interrupt their current call for the waiting call.
To answer the Call Waiting, the current call must be put on hold, terminated or transferred. 
Multiple calls can be queued to a single station, all waiting for that station to become free; the call 
at the head of the queue provides the Call Waiting signal and LCD indication.
This feature works with both digital and analog single-line telephones. The tone (two beeps) 
signaling Call Waiting tone is provided through the speaker of the digital phone. For standard 
analog telephones, the tone is inserted into the speech path. Caller ID display is not available with 
standard telephones.
Caller Identification
Caller Identification (Caller ID) is the general term for the information provided identifying the 
originating party of a public network call. The name and telephone number of the calling party 
displays on the ringing telephone’s LCD. Incoming calls with Caller ID or Automatic Number 
Identification (ANI) information may be optionally recorded into a rolling list for individual 
stations. Station users with LCD displays can access this list to select and redial these calls (see 
Call History). Caller ID service from the carrier must be subscribed on analog CO lines or T1 ANI 
in order to receive calling number and name into the Strata CTX system.
Caller ID lists can include the number, name (if provided), time and date of the call, and status of 
the call (answered, abandoned, or redirected). Digital stations are assigned memory for creating 
the Call History. See Table 7 on page 14 for the number of call records per station and system.
ISDN Calling ID Name and Number
Both Caller ID name, if available from service provider, and number are supported for incoming 
calls using either ISDN NI-1 or NI-2 BRI or PRI lines. Caller ID names can be accepted by the 
Strata CTX from a CO with NI-1 or NI-2. NI-2 is the only way a 5ESS CO delivers Caller ID 
names on PRI and BRI. Nortel DMS CO with NI-2 installed also uses NI-2 to deliver Caller ID 
names. Only a Nortel DMS CO can provide Calling Names for NI-1.
Camp on Busy
Automatic Camp On
When a call comes in to a busy station from an outside line and that station does not have an idle 
button for the call to ring in on, and Station Hunting or Call Forward is not applied, the call 
automatically camps on to the busy station. This permits incoming calls to be accepted even if the 
station is busy. The outside caller will receive ring-back-tone immediately and the called station 
will receive two bursts of Call Waiting tone.  
						

							Features
Cancel Button
Strata CTX General Description    06/0349
If the calling line has Caller ID, ANI, or DNIS information, it will be displayed on the called 
station’s LCD for 10 seconds. Auto Camp On also applies to incoming line calls directed to Hunt 
Groups, Voice Mail systems, etc.
Various types of internal calls from one station to a busy station, voice mail system or hunt group 
can also Camp On automatically with system programming options. For details on these types of 
calls see the Camp On-Busy and Station Hunting descriptions.
Off-hook Camp On
A station caller who dials a busy station or line access code can remain off-hook to be 
automatically connected when the station or line becomes idle. After dialing a busy [DN] and 
receiving busy tone, the caller can just remain off-hook and Camp On will be initiated 
automatically after a predetermined time or the user can dial a 
 and remain off-hook to initiate 
Camp On immediately. When camp-on is activated, the caller will receive success tone followed 
by Ring Back Tone. The station that is the object of a camped-on call will receive two bursts of 
call waiting tone (see Call Waiting).
Even if Voice First is set at the called [DN], the station will be called by tone ringing when it is 
connected by Camp On. Internal and external stations can be the object of a Camp On. Calls may 
be camped on to the pilot number of Station Hunting groups and will be delivered to the first 
station in the group to become idle. ACD pilot numbers cannot be the object of a Camp On.
Incoming calls from outside lines to busy DNs camp-on automatically (see “Automatic Camp 
On,” previous section). When a station dials the access code for an outside line and receives busy 
tone because all lines are busy, the user can remain off-hook and dial 
 to camp on to the busy line 
group. When a line becomes available, the station will connect to the line and receive dial tone.
When more than one party is camped on (queued) to a destination, the party with the highest 
Queuing Priority Level (QPL) will be connected first when the destination becomes available. If 
the parties have the same QPL, the longest waiting call will be connected first.
Calls will camp on to hunt groups when all members of the group are busy (see “Station Hunting” 
on page 77 for more details).
Cancel Button
The  button voids the last entry or step in a procedure. This enables the station user to 
correct an error and then continue without having to starting over. 
It is important to consider the consequences of this button in regards to the overall task. For 
example, during a conference call, 
 will disconnect the last party added to the conference.
Centrex/PBX Compatible
All system features are compatible with Centrex/PBX operation, including repeat of Centrex/PBX 
ringing cadence, one-button access to Centrex/PBX features, a two- to five-digit station numbering 
plan, and Delayed Ringing to selected stations.
Centrex Ringing Repeat
The system can mimic CO/Centrex/PBX ringing cadences received from outside lines when it 
rings a called station. 
						

							Features
Classes of Service (COS)
50Strata CTX General Description    06/03
Classes of Service (COS)
Classes of Service are the mechanisms for assigning features and services to lines and stations 
within the system. The Class of Service for a given device, such as a station, is defined using 38 
parameters. There are 32 Class of Service patterns available, each pattern can be set up to allow a 
unique combination of features. Each station and line group can be assigned independently to one 
of the 32 COS patterns.
Computer Telephony Integration (CTI)
CTI combines the capabilities of the Strata CTX digital business telephone system with custom 
functionality provided by computer applications. This can be provided through the optional Digital 
Telephone Integrated PC Interface or a system connection using the LAN connection.
Digital Telephone Integrated PC Interface
For CTI applications, digital telephones interface to a PC that runs the application software using 
the Microsoft Telephone Application Programming Interface (TAPI), to provide customized 
functionality. The PC must run Microsoft Windows software.
Any TAPI-enabled PC software is compatible with Strata CTX systems. The most common types 
of application are database look-up and pop-up screens that provide information on the calling 
party. From a Strata CTX system, Caller ID, ANI, DNIS and call processing information can be 
passed from the digital telephone to the application computer.
The 3000-series digital telephone uses an integrated PC Interface Unit (BPCI) for TAPI and data 
switching simultaneous voice/data applications. The 3000-series digital telephone must be 
connected to the system through a BDKU digital station card. The BPCI provides a highly 
functional interface for fast, positive call control via a USB port and supports media streaming 
with TAPI 2.0 functionality.
Conference Calls
Conference calling enables other people to join your conversation. These additional people can be 
inside or outside the Strata CTX system. Any station can set up a conference with other stations or 
outside lines. A conference is defined as any time three or more parties join into one conversation. 
A maximum of eight parties are allowed into a conference with up to six from outside lines or 
standard stations. The originator of the first conference is the “master” and controls adding and 
deleting conference parties. The conference “master” can drop off the last added party by using the 
 button.
Conference On-Hold
A conference call may be put on Hold so that all the remaining conferees remain connected and no 
Music-on-hold is applied. The person putting the conference on hold may rejoin the conference by 
pressing the 
 button on his phone. The Hold state of the conference can be released from 
another station by pressing the 
 button of that station. At this time, the station that released 
the Hold state becomes Conference Master. This enables one person to establish a conference call 
for others.
Join Button
Join allows an attendant or digital station user to connect two established calls to each other. 
						

							Features
Continuous DTMF Tone
Strata CTX General Description    06/0351
Releasing from Tandem CO Line Connections
This feature enables unattended line-to-line connections for the Strata CTX, freeing the 
conferencing analog station or voice mail port for other calls and important tasks. When a tandem 
connection is set up with a [DN] button, the [DN] button will go idle after releasing from the 
connection. The [DN] can then be used to make or receive calls from the originating digital 
telephone.
Standard telephones and/or VM devices can establish tandem analog CO line connections and then 
release from them without disconnecting the tandem connection in the Strata CTX. After releasing 
from a tandem call, reconnecting to the call can be accomplished by dialing an access code. This 
reconnect feature does not work if one or both of the CO lines are digital.
Whether or not tandem line buttons appear on a telephone, the telephone user can enter the 
connection and release the line that was connected to the original line or release both lines by 
pressing the 
 button.
Voice Mail Conference
Voice Mail ports may be included in conference calls. This enables all members of the conference 
to listen to and play voice mail messages.
Continuous DTMF Tone
Dual-Tone Multi-Frequency (DTMF) dial signal is transmitted to the CO line or voice mail/Auto 
Attendant device for as long as the telephone user presses a button on the dial pad. This feature 
may be selected for each digital telephone. Standard telephones always provide continuous DTMF 
tone operation.
Credit Card Calling
Callers can make “0+” telephone credit card calls from selected toll restricted stations. When 
dialing from toll restricted stations, if the caller does not enter a credit card number after dialing 
“0,” the call will be disconnected. Calls are billed to the credit card instead of the Strata CTX CO 
line. The “0+” credit card calling feature can be enabled, selectively, or assigned to stations and 
CO lines capable of supporting this service.
CTX WinAdmin
CTX WinAdmin is the Strata CTX administration software application for programming and 
maintaining the system. It operates with Microsoft Windows 2000 Professional® and Windows 
XP Professional, with Windows Explorer 6.0 or higher. It has a user-friendly GUI and provides 
access levels for technicians and end-user administrators.
Strata CTX WinAdmin connects to the system processor’s network jack or maintenance modem 
(33.6Kpbs/V.34) modem. Direct wire connection, LAN connection or remote connection over the 
Internet or PSTN is also available.
Data Privacy
This option blocks calls to data devices that are in use. This prevents override calls and warning 
tones from interfering with data devices such as modems and ISDN data terminals.  
						

							Features
Day/Night Mode – Auto Schedule
52Strata CTX General Description    06/03
Day/Night Mode – Auto Schedule
The system has three operating modes that are based on the time-of-day, day-of-the-week, and up 
to 128 holiday schedules. The operating modes are Day, Day2, and Night. Each mode controls the 
routing of incoming line calls and settings for station and line Class Of Service restrictions. The 
system can be programmed to use all three modes, Day/Night mode only, or just the Day mode. 
The system switches automatically from one mode to the next based on the system’s time-of-day 
clock.
Example Day/Night Mode Applications:
Incoming Calls – Incoming line call routing of individual DID and DNIS numbers or ground/
loop start lines, change their ringing destinations automatically according to the date and the 
time of day. 
For example: On workdays, calls are routed to the attendant, individual telephones, ACD 
groups, etc., until 5:00 p.m. After 5:00 p.m., calls are routed off-primes to another office, to the 
Night Bell, or to night announcements and voice mail message boxes. On holidays and 
weekends, calls are routed independently to the appropriate holiday announcements or voice 
mail message boxes.
Class Of Service – Station, lines, and DID numbers are assigned 38 options in Class of 
Service. These include Toll Restriction, Override privileges, allowed tandem connection, 
security code administration, etc. Any of these options can be changed independently for each 
telephone, line and DID number when the system switches from one operating mode to 
another. 
For example: When the system changes from the Day to Night mode, selected stations can be 
automatically restricted from dialing outside or long distance calls. Note that outgoing route 
selections set in LCR are switched using a route selection schedule that is independent of the 
Day/Night mode schedule. 
System Call Forward – The System Call Forward settings for stations can be changed 
automatically when the system changes from the Day to Night mode. For example: During the 
day, a telephone can forward to a person’s car or cell phone, and at night automatically forward 
to the person’s voice mailbox.
The system also enables users to manually change the Day/Night operating mode, even if the 
system is using the Auto Schedule feature. A 

 button can be set on telephones for 
manually switching at any time from one mode to another. The button’s LED flash rate indicates 
the system’s operating mode. 
If used with the System Auto Schedule operation, the 
 button overrides the 
current Auto Schedule mode. However, when it is time for the system to switch to another mode 
per the Auto Schedule timer, the system will switch to the mode set by the Auto Schedule. 
Example: If the system is switched from Day to Night at 2 p.m. manually with the Night Transfer 
button (Auto Schedule is set to switch from Day to Night at 6 p.m.), the system will still 
automatically switch back to the Day mode at 8 a.m. the next morning per the Auto Schedule.
Delayed Ringing
If an incoming CO, DID or Tie line or internal [DN] call rings a station [DN] and is unanswered, 
alternate DKTs can be programmed to ring at a later time. A separate delayed ring time can be set 
for each CO line group. The stations that were ringing initially will continue to ring after the 
Delayed Ringing begins. This feature is assigned for each line or [DN] button independently for 
each DKT. 
						

							Features
Destination (Toll) Restriction
Strata CTX General Description    06/0353
With Strata CTX Release 1.3 and higher, you can assign Delayed Ringing to voice mail and auto 
attendants. This feature can also be used to ring multiple (25 max.) telephones immediately or with 
a delay to voice mail, auto attendant and/or standard telephones by dialing a group pilot number. 
Each group member can have Immediate, Delayed Ring 1 or Delayed Ring 2. Delayed Ring times 
are adjustable (1~180 seconds) for each Multiple Call Group.
Destination (Toll) Restriction
Strata CTX offers Destination Restriction as a major expansion of traditional Toll Restriction. 
Historically, Toll Restriction was used to prevent the unauthorized use of toll prefixes to the PSTN: 
long distance (1), operator assistance (0) or international (011). 
Strata CTX has expanded this to include restriction based on any string of dialed digits. A true, 
international business telephone system, Strata CTX can restrict any string of up to 11 dialed 
digits, including 
  and !. Eleven-digit screening allows control of access to individual telephone 
numbers in remote Area Codes. Restriction of 
  and ! controls users’ access to vertical service 
codes from the CO, such as Camp On and Call Forwarding.
A stations’s Destination Restriction level can be changed automatically with Day/Night mode 
Auto Scheduling. One use of this feature is to allow a telephone to make outside calls during the 
day, but to restrict them at night.
Through Dialing
A telephone user or an attendant can connect a destination-restricted station to a trunk enabling 
temporary access to an outside line. The connected station can then use external dial tone to 
complete the call, and revert back to destination-restricted status after the call is completed. This 
maintains the integrity of toll restriction, while still extending outgoing calling privileges when 
necessary. 
Direct Inward Dialing (DID)
This feature allows external callers to dial directly to individual extensions or groups of telephones 
without intervention by an operator, IVR or auto attendant. Each incoming DID number, which is 
sent to the CTX on a DID line from the CO, can be routed individually to an extension, pooled or 
group line button, ACD group, maintenance modem, external page, night bell, voice mail box, or 
back out over the public or private telephone network. DID routing assignments can change 
automatically when the system switches between the Day and Night Modes.
DID numbers can vary between 1~7 digits in length for each DID line group. Each DID number 
can be assigned to 1 of 15 possible music-on-hold sources. 
DID service is provided by DID analog, T1, or ISDN line interfaces.
Dialed Number Identification Service (DNIS)
DNIS lines receive 800- and 900-type telephone calls that provide the number the caller dialed to 
reach the Strata CTX. The Strata CTX translates the DNIS number into a name that displays on the 
telephone’s LCD. This allows the user to identify where the call is coming from and the purpose of 
the call before the call is answered. 
The DNIS Name/Number routes calls to specific telephones, departments or ACD groups. When 
the call is ringing and after it is answered, the DNIS Name/Number displays on the telephone’s 
LCD. The name and number display can also be sent to an agent computer to be used by a CTI 
application.  
						

							Features
Digital Pad
54Strata CTX General Description    06/03
Applications include sending DNIS calls to a group of agents that take orders for a number of 
different companies and products. The agents know how to answer the calls from the DNIS 
display. Using DNIS capabilities allows one group of lines to be used to serve multiple 
applications. DNIS service is provided by DID analog, T1 or ISDN line interfaces and provides the 
same call routing options and destinations as DID calls.
Digital Pad
The Strata CTX digital pad (decibel loss) is activated for the receiving path of the terminal, 
external line or resource.
The system adjusts for differing transmission levels between internal and external devices. This is 
very useful for conference calls when external parties have difficulty hearing due to public 
network loss. The Strata CTX can be programmed to insert the appropriate digital pad for each 
terminal and call type when establishing speech paths between telephones, external lines, and 
resources such as conference circuits, external paging devices, and external sound sources. This 
minimizes volume loss in conference calls. 
The system recognizes these devices:
 Standard analog telephone (Type 500, Type 2500 and the equivalent) 
 Toshiba digital telephone, cordless, wireless, door phone
 Analog trunk
 T1 trunk
 ISDN extension terminal (Audio and Speech) 
 ISDN trunk/Tie line (Audio and Speech) 
 Conference circuit 
 Holding music source 
 External paging device
Direct Inward System Access (DISA)
Direct Inward System Access (DISA) allows outside callers to connect to the Strata CTX and 
make station or trunk calls as if they were stations within the system. An incoming call may be 
directed to DISA by Direct Inward Dialing lines, ground/loop start lines or Automated Attendant.
NoteDISA lines require DTMF receivers.
DISA security code is changeable from a specific station. The station to change the security code 
needs to be allowed by Class of Service. This security code can also be changed using the Strata 
CTX WinAdmin administration console.
DISA provides access to the features listed below:
 Station Calls
 Station Calls over Private Network
 Attendant Access
 Account Codes 
						

							Features
Directory Numbers
Strata CTX General Description    06/0355
DISA also provides access to these features, which require a security code:
LCR
 Direct line access
 Outgoing line group access
Emergency Call
 Call Forward Remote Control
Directory Numbers
A Directory Number [DN], sometimes called an “extension number,” is the number someone must 
call to reach a destination within the system. Each [DN] is assigned to a flexible button on a digital 
telephone or as the main directory number of a standard telephone. To maximize call coverage 
flexibility. Any [DN] can appear on multiple telephones. Also, individual telephones can have 
multiple [DN] buttons with different Directory Numbers.
The system provides Primary and Phantom [DN] buttons on telephones. All [DN] buttons can be 
used to originate and answer calls. If you press a [DN] while on a call, it releases the existing call 
and provides dial tone to make another call.
Primary [DN] Buttons
Primary Directory Number buttons [PDNs] are needed to make calls and receive calls. It is a 
telephone’s main extension number. Each telephone is assigned only one [PDN] and that telephone 
is designated as the owner of the [PDN]. This [PDN] button can be made to appear multiple times 
on the owner telephone and on other telephones (see Phantom [DN] Buttons). Features, Class of 
Service, etc., are associated only with the station assigned as the owner of the [PDN]. [PDNs] that 
appear on telephones other than the owner telephone are referred to as Secondary DNs [SDNs].
Phantom [DN] Buttons
Phantom [DN] buttons [PhDNs] are additional directory numbers appearing on telephones as 
extension buttons. [PhDNs] can be used as independent extensions on the phone or can appear on 
multiple phones to be used to allow call handling for departments or groups of telephones. 
[PhDNs] can be used to make a telephone appear to have multiple [PDN] extension buttons. When 
assigning a [PhDN] for use as another appearance of the [PDN], the display properties are set the 
same as the [PDN] and a hunting sequence is set up to roll the calls from the [PDN] over to the 
other [PhDN]s associated with the [PDN]. With this arrangement, Call Forward will send calls to 
the [PDN]’s destinations and Voice Mailbox. 
Pilot [DN]
A Pilot [DN] is a pseudo-location that is assigned a [DN] where calls may be directed. Unlike 
[PDNs] and [PhDNs], a Pilot [DN] is 
not a button on any telephone. A Pilot [DN] is used as a 
device where calls can ring and be held while an external application using the Computer 
Telephony Interface (CTI) can control the call. To ensure calls do not get lost in the Strata CTX, a 
time-out and overflow service is provided to redirect the call when the link is down. Calls being 
held on the Pilot [DN] using the CTI link can specify any of the 15 on-hold music sources that are 
possible on the Strata CTX.
Pilot DNs are also assigned to Station Hunt Groups (for details, refer to Station Hunting). 
						

							Features
Distinctive LED Indicator
56Strata CTX General Description    06/03
Distinctive LED Indicator
Each feature button on a digital telephone has a Light Emitting Diode (LED) indicator. Distinctive 
LED indicators provide a method for quickly identifying the status of a line or feature button. The 
LED color or flash pattern can identify the call you are currently on, as well as other calls you are 
controlling, versus other calls that may appear on your telephone. Each telephone uses dual-color 
LEDs: green for lines you are using; red for lines used by someone else.
Distinctive Ringing
Users sometimes need to distinguish the ringing of one button on their phone from another button 
and sometimes stations in close proximity to one another need to distinguish the calls on one desk 
from another. Typically, multiple sounds are used to provide this distinction. Distinctive ringing 
can be assigned to each 
 or [DN] button on each telephone.
With Strata CTX Release 1.3 and higher, you can set up to ten different incoming ringing tones for 
internal, as well as external calls. Previously, distinctive ring was not provided for internal calls.
Do Not Disturb (DND)
Station users with digital telephones can activate DND to prevent any calls from ringing their 
telephone. Callers will hear a fast busy tone when calling stations in the DND mode. Stations in 
DND mode can originate calls normally; however, they receive DND stutter dial tone (optional) 
when originating calls. With Release 1.3 and higher, users can disable DND stutter dial tone (1/2 
sec. burst of busy tone before dial tone) in programming.
Call Forward-Busy will forward calls directed to a telephone with DND set, even if the telephone 
has idle [DNs]. Telephones with DND Override capability can ring DND telephones (see “Do Not 
Disturb (DND) Override” on page 73).
Direct Station Selection (DSS) Buttons
[DSS] buttons can be placed on digital telephones, add-on modules and DSS consoles. When 
placed on one of these devices, these buttons serve two functions: to make direct calls or transfer 
calls to other stations; and to display the status of other stations and [PDNs]. 
The [DSS] button is numbered with a station’s [PDN] and when pressed, calls that [PDN]. [DSS] 
buttons are not [DN] buttons, so they do not provide dial tone when pressed. The [DSS] button 
LED shows the status of the station and [PDN] it represents (idle, busy, DND or ringing). The 
[DSS] LED will turn on steady or flash at a unique rate, depending on the status (see “[DSS] 
Button Status Display.”
The [DSS] LED displays the telephone’s status for any type of call on any button, including 
[PhDN] and 
 buttons. The [DSS] LED also indicates the status of the station’s [PDN] itself. If 
the [PDN] appears as a Secondary DN [SDN] on multiple telephones, the DSS status will display 
Busy if any telephone is using the [SDN].