JPH03173252A - Communication system - Google Patents

Abstract

PURPOSE:To avoid useless operation or mis-reply by providing a communication attribute recognition means, a terminal equipment specifying means and a display means so as to easily discriminate whether or not the terminal equipment is able to reply a holding call depending on the display corresponding to the holding call. CONSTITUTION:When the entry of a changeover key 26 of a data adaptor telephone set is detected, a CPU 1 holds a call in talking, the information is set to a call information setting memory 2 and an LED 24a of an external line key 24 is blinked to represent that it is subject to holding. Then the CPU 1 confirms the matching of the communication attribute of the memory 2 stored in the call (holding call) with the changeover request and the communication attribute in the memory 2 of the data adaptor telephone set and when not matched, they are matched. In this case, since the call information stored in the communication system and the communication attribute of the terminal equipment or the like are displayed on a display section 22 of the terminal equipment operated for each holding or holding reply, whether or not the reply of the terminal equipment to the holding call is available is easily discriminated visually and mis-reply or useless operation is avoided.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a communication system that accommodates a plurality of lines and terminals, and identifies the status of the held line by a display corresponding to the line provided on each terminal. Regarding.

[Prior Art] Conventionally, in a communication system accommodating a plurality of lines and terminals, it has been difficult to display the held call of the line on the terminal and the relationship between the communication capability of the terminal itself or the communication attributes that display the held call display. There wasn't.

Note that communication attributes here include, for example, communication speed, stop bit, data bit length, bit format such as parity bit type, synchronous/asynchronous distinction, character type, flow control information, voice/G3 FAX/G4 F
This refers to information such as media types such as AX/document information, and this information is used to determine the communication format with the communication partner or, in some cases, the network that carries the information.

Data Agebuta is an adapter for a communication system such as an exchange system to accommodate a data terminal device and send and receive data, and supports automatic call/receive procedures such as ■, 25bis, X, and 21. Some are simply connected to the data terminal through an interface port to match the data terminal to a modem boolean in the system, but do not support any communication procedures themselves. Furthermore, a part that supports data communication as part of the functions of a stand-alone terminal device may also be referred to as a data adapter.

[Problems to be Solved by the Invention] In the above conventional example, the user of the communication system cannot judge the communication capability or communication attributes of the terminal from the held call display on the terminal, and is unable to respond to the held call. Until then, the communication attributes required by the held call cannot be determined.

In addition, after responding to a held call with a terminal that cannot support the requested communication attributes, the user may search for a terminal within the same communication system that has the communication attributes that can respond to the held call and then transfer the call, which is a wasteful operation. The disadvantage is that the call is disconnected.

Furthermore, due to the integration of communication services such as 15DN and the multiplication of terminals, there is a need to process calls with various communication attributes on the same line or channel, and accordingly, it is possible to handle held calls with a wide variety of communication attributes. This has the disadvantage of making it difficult to communicate, making the communication system inconvenient and inconvenient for users.

[Means for Solving the Problems] The present invention has been made for the purpose of solving the above-mentioned problems, and includes the following configuration as one means for solving the above-mentioned problems.

That is, communication attribute recognition means recognizes the communication attributes of the held call and the communication attributes of each terminal to accommodate the held call, terminal identification means identifies a terminal having communication attributes that match the communication attributes of the held call, and A display means is provided for displaying a display so that terminals having communication attributes that match the communication attributes of the held call and terminals that do not match the communication attributes can be distinguished.

[Operation] With the above configuration, a terminal having communication attributes that matches the communication attributes required by a held call in the communication system is identified, and due to the difference in the held call display between the identified terminal and other terminals, , it is possible to easily identify whether a terminal is able to answer a held call or not.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of a communication system that is one of the preferred embodiments of the present invention.

In FIG. 1, ■ is a central processing unit (CPLI) that controls each interface, terminal device, and the entire system; 2 is a memory for storing control data, setting data, etc.; 3 is a memory for storing control data, setting data, etc.
is a ROM that stores a call processing program and its lot number type control program. In addition, 4 is a switching section consisting of a time division switch, etc., and 5 is a line termination unit (DSU).
Integrated Digital Services (ISDN) 14 via 15
It accommodates ISDN lines from l5DN layers 1, 2 .
3 is an 15DN interface having a protocol processing unit, V, 110 speed matching unit, etc., and 6 to 8 are extension interfaces for accommodating dedicated telephones and the like of the communication system.

Reference numeral 9 denotes a button telephone dedicated to a communication system that is connected to an extension interface and consists of a keypad, a speaker, a handset, a display unit, etc., and handles only audio; This is a data adapter telephone that can be connected to a data terminal device (DTE2 12) such as a personal computer through a 232C interface, and the communication format such as the communication speed and bit format with the DTE2 can be changed by commands from the CPU i. However, as will be described later with reference to Figure 5, the communication speed is 300bps.
~9600bps asynchronous, stop bit length 1,1
．． 5.2 bits, data length is 5 to 8 bits,
The parity type can be changed within the range of odd number, even number, or none. Also,
II has a built-in R3-422 interface and can be used as a data terminal device (DTE113) such as a personal computer.
This is a data adapter telephone for performing synchronous communication (communication speed is 64 Kbps).

Fig. 2 is an overview diagram of the data adapter telephone used by connecting to the communication system of this embodiment, and Fig. 2 (b) shows the interface section with the outside. are shown respectively.

In FIG. 2(a), 21 is the main body of the data adapter telephone, 22 is a display section composed of an LCD, etc., and displays character information, communication information, etc., 23 is a handset for voice calls, and 24 is an outside line call. Status display LED
24a. Further, 25 is a data key for starting and terminating communication, 26 is a switching key for switching communication, 27 is a dial key pad, and 28 is a hold key.

The LED 24a corresponding to the outside line key 24 has the following lighting patterns depending on the call state.

Lights off, indicating that the corresponding outside line is empty (unused).

Fast blinking green: Indicates that the corresponding external line is receiving a call and is ready to answer.

Green light on: Indicates that the own terminal device is communicating with the corresponding outside line.

Lit in red: Indicates that another terminal device is communicating with the corresponding outside line, and the own terminal device cannot communicate with that call.

Slow blinking green 2 Indicates that the terminal device is holding the corresponding outside line.

Slow flashing of red: Indicates that another terminal device has put the corresponding outside line on hold, and the own terminal device is in a state where it can respond to a hold response.

In FIG. 2(b), 29 is a modular jack connected to extension interfaces 6 to 8 through a modular cord, and 3o is an R3-2320 or R5-42 connected to a data terminal device through a dedicated cable.
This is a data terminal boat with two interfaces.

The general appearance of the key telephone 9, which handles voice exclusively, is the data adapter telephone shown in FIG. 2(b) with the data terminal board 30 removed.

FIG. 3 shows the configuration and setting example of the extension setting memory in the communication system of this embodiment.

FIG. 3(a) shows the memory configuration of the extension setting memory, which includes the extension ID, extension number, terminal class, and additional information for the extension, such as the set communication speed if it is a data adapter telephone. Consists of format information.

Figures 3(b) to (d) are examples of extension setting memory settings.
FIG. 3(b) shows the extension ID in the case of the button telephone 9.
is a, and the extension number is 1234. A voice-only class 1 is set as a terminal class. Also, Figure 3 (C
) is an example of the data adapter telephone 10, the extension ID is 1235, the extension number is 1235, and the terminal class is voice and R5-2.
It is a class 2 that can handle data terminal equipment with a 32G interface, and the communication format (attributes) is asynchronous with a communication speed of 1200 bps, the stop bit is 1 bit, the data bit length is 7 bits, and even parity. . FIG. 3(d) shows the data adapter telephone 11.
This is a setting example, and the extension ID is C1 extension number 1236,
The terminal class is Class 3, which allows connection to voice and data terminal equipment with an R5-422 interface, and the communication format (attribute) is synchronous circuit switching terminal, which is 64.
It is set to communicate at a speed of Kbps.

These setting data can be freely set by the user according to each individual terminal, or can be automatically set by the CPU of the communication system. The extension number also corresponds to the l5DN subaddress.

FIG. 4 shows the configuration of the call information holding memory and an example of the held information in the communication system of this embodiment.

FIG. 4(a) shows the memory structure of the call information holding memory, in which the call status, the extension ID of the own terminal, the outside line type and its number,
Further, additional information regarding the call (for example, communication format, etc.) is held. Also, FIG. 4(b) is an example of a held call, where the other party communicating through No. 1 of the 15DN line is
The extension terminal ID is on hold by the extension of b, the communication attribute is asynchronous circuit switching, the communication speed is 9600 bps,
The call information shows a stop bit of 1 bit, a data bit length of 8 bits, and no parity.

Figure 4(c) is an example of a call in progress, where the extension terminal ID is b and the other party is communicating through the 15DN line 2, the communication attributes are asynchronous circuit switching, and the communication speed is 120.
This indicates that the speed is 0 bps, the stop bit is 1 bit, the data bit length is 7 bits, and the parity is an even number.

FIG. 5 shows communication attributes and classes corresponding to the communication attributes that can be allowed by the terminals (dedicated button telephones and data receiver telephones) of the communication system in this embodiment. Class l to the dedicated button phone 9, class 2 to the data adapter phone 10, and class 3 to the data adapter phone 11.
correspond to each.

FIG. 6 is an example of a display on the display section of a dedicated button telephone and a data adapter telephone.

In Figure 6(a), the calling number is 123-4567 and 96
00bps, data bit length 8 bits, no parity,
This is an example of an incoming call requesting asynchronous/circuit-switched data communication with 1 stop bit.
This is an example of a display during asynchronous/circuit switching communication at 0 bps, data bit length of 7 bits, even parity, and 1 stop bit. In addition, Fig. 6(C) shows that the same telephone
This is an example of a display when one call is being communicated, the other is on hold, and communication is being switched while switching between calls.

Figure 6(d) is an example of the display when the call in progress as shown in Figure 6(b) is put on hold, and this display state can be used to either re-answer the held call or respond to a new incoming call. This continues until communication begins. Further, in FIG. 6(e), the communication attribute settings of the terminal are automatically changed. This is an example of the display.

Next, a call processing procedure by the CPU of the communication system in this embodiment will be described with reference to flowchart 1 shown in FIGS. 7A, 7B, 7C, and 7D. Note that in the following description, a terminal refers to both a dedicated button telephone and a data adapter telephone unless otherwise specified.

In step S1 of FIG. 7A, the I5DN interface 5 determines whether there is an incoming call to the communication system of this embodiment based on the call setting message received from the I5DN network 14 via the DStJ I5. When an incoming call is detected, in step S2, the CPU 1 sets information about the incoming call in the call information holding memory, and determines whether or not there is a terminal in the communication system that is acceptable for the communication attributes of the incoming call. Check. Specifically, it is checked whether the incoming call can match the terminal attribute classes 1 to 3 shown in FIG. For example, the transmission capability information element (lower layer compatibility information element may also be used) is that the transmission capability is unrestricted digital, asynchronous 9600 bps, stop bit 1 bit, data bit length 8 bits, no parity, rate matching V, and 110 makes a call. If the receiving subaddress is 1235 and data communication is requested through the data adapter phone 10, it is allowed, but even though the subaddress is 1235 and the data adapter phone 10 is specified, G4FAX communication is not allowed. If specified, the call will not be accepted.

As a result of checking the communication possibility, there is no terminal whose communication attributes match the incoming call. is rejected, the call information holding memory is released, and the process ends.

However, if it is determined in step S2 that there is a terminal whose communication attribute is acceptable for the incoming call, the process proceeds to step S4, and for the acceptable terminal, the LED of the incoming outside line lights up in a lighting pattern ( For other unacceptable terminals, set the lighting pattern to indicate that other terminals are communicating (red lighting). And step S
In step 5, all allowable states of the terminals are searched, and processing is branched according to the state.

As for processing for an idle terminal, a ringtone is sounded in step S70 of FIG. 7B, and a response from the called terminal and termination of incoming calls due to abandonment by the calling party are monitored in steps S71 and S72. If the incoming terminal (called terminal) responds before the incoming call stops, the process advances to step S75, where it sends a response message to the 15DN network, and connects the reverse path in response to the incoming call. In the next step S76, the ringtone is stopped.

Next, in step S'77, the external line LED of the terminal that responded
Set it to turn green to indicate that your device is communicating, and
Set the outside line LED of the other terminal to light red, which indicates that the other terminal is communicating with the other terminal. However, if the incoming call stops before the call is answered, the ringtone is stopped in step S73, and the LE that was blinking or lit in response to the incoming call continues in step S74.
D is turned off, the terminal, interface, and call information holding memory are released and left in an empty state, and the process ends.

In step 378, the input of the held key on the terminal in the communication state is monitored, and if there is key input, step S79 is performed.
If there is no key human power, the end of communication is monitored in step S91. In step S79, the call in progress is put on hold, and a call information holding memory corresponding to the hold is set. Then, in step S80, the outside line LED of the held call is set to slow green blinking for the terminal that held the call, and slow blinking red or solid red for other terminals depending on the communication attribute of the terminal. do. Furthermore, in step S81, communication attributes of the held call are displayed on the held terminal.

In step S82, input of the outside line key is monitored, and in step 383, it is determined whether it is the outside line key corresponding to a held call. If the result of the determination is that the outside line key corresponding to the held call has been input, it is determined in step S84 whether the terminal that responded to the held external line matches the communication attributes of the held call. If they match, the terminal and the held call are connected in step S89, and if they do not match, the communication attributes of the terminal are set to match the communication attributes of the held call in step S85.

Next, in step S86, a message indicating that the communication attribute of the terminal has changed is displayed and a tone is sounded, and in step S87, the terminal and the held call are connected. Then, in the following step S88,
The display and tone stop processing performed in the previous step S86 is performed, and in step S90, the corresponding outside line LED of the hold response terminal lights up in green, meaning that the terminal itself is communicating, and the LEDs of other terminals light up in red. , and returns to step S78 again.

On the other hand, if it is recognized that the terminal is in communication in step S5 of FIG. , bit format, etc.) (6th
Display example in figure (a)). Therefore, in step S14, we monitored the pressing of the switching key 26 and the incoming outside line key 24 while the LED was flashing, and found that no keys were pressed.
In step S15, the stoppage of incoming calls due to abandonment by the calling party is monitored, and if the stoppage of incoming calls is recognized, in the following step S16, the terminal's in-communication ring tone is stopped and the display is cleared. Next, step S1
At step 7, the outside line LED that was turned on in response to the incoming call is turned off, the call information holding memory is released, and the process ends.

If it is detected in step S14 that the incoming outside line key 24 is pressed next to the switching key 26 while the LED is blinking, step S1
Proceed to step 8, put the currently communicating call on hold, set the call information in the call information holding memory, and in step S19 make the corresponding outside line LED blink green to indicate that the own terminal is on hold. . Then, in step S20, the communication attribute requested by the calling party included in the incoming call setup message (
It is determined whether the communication format (communication speed, number of stop bits, data bit length, parity information, etc.) matches the communication attributes set in the receiving terminal by comparing the call information holding memory and the extension setting memory.

As a result of the above comparison, if there is a match, step S21
The ring tone during communication is stopped at step S22, and the display section is cleared at step S22. Then, in the next step S23, a response message to the incoming call is sent to the 15DN network to complete the response to the incoming call, the communication path of the communication system is connected, and the call information holding memory is set to a communicating state.

However, if it is determined in step S20 that there is no consistency (for example, the current settings of the data adapter telephone 10 are 1200 bps, 1 stop bit, 7 bits data bit length, even parity, as shown in FIG. 3(c)). When the incoming call is set to 9600bps,
(If 1 bit stop bit, 8 bit data bit length, and no parity are specified), the settings of the receiving terminal (in this case, the terminal is limited to a data adapter telephone) are automatically set according to the incoming call in step S24. Reset and automatically rewrite the extension setting memory. Also, step S
At step 25, the terminal sounds a tone to notify the user that the communication format has changed, and the changed communication format is displayed on the display (see FIG. 6(e)). Then, in step S26, a response message to the incoming call is sent to the 15DN network to complete the response to the incoming call, and the communication path of the communication system is connected. In step S27,
The 1.- ring that sounded in step S25 is stopped, the display is cleared, and the call information holding memory is set to the communicating state.

In FIG. 7C, in step 328, the outside line LED of the terminal in communication corresponding to the communication is set to a green cj light indicating that the own terminal is in the communication state, and the corresponding LED of the other terminal is turned on. Set it to turn red to indicate that the device is communicating with another device. In the following step S29, information (communication format) regarding the call in progress and the held call is displayed on the data adapter telephone in communication (see FIG. 6(c)).
.

In steps S30 to S33, the switching key 26,
Monitors the disconnection of a held call, the disconnection of a call in progress by the other party, and the disconnection of a call on the own terminal side (for voice communication, the call is on-hook; for data communication, the call is disconnected by pressing the data key) .

If the input of the switching key 26 is detected in step S30,
Proceeding to step S34 in FIG. 7D, the active call is put on hold,
The information is set in the call information holding memory, and step S3
In step 5, the LED of the corresponding outside line key is set to a state indicating that the key is on hold, that is, it flashes slowly in green.

In step 836 (see FIG. 7D), a switching operation is performed with the communication attributes of the call information holding memory of the call for which the switching request was made, that is, the call that was on hold at step S30 (FIG. 7C). Check whether the communication attributes in the extension setting memory of the data adapter telephone set match. If the consistency is confirmed, the held call for which the switching request was made is connected in step S37, the contents of the call information holding memory of the connected held call are set to the communicating status, and the process returns to step S28 in FIG. 7C. .

However, if it is determined in step 336 of FIG. 7D that they do not match, in step 838 the communication attributes of the terminal (data adapter telephone) that performed the switching operation are changed to the communication attributes set in the call information holding memory. Make settings to match, rewrite the contents of the extension setting memory, and proceed to the next step S.
At step 39, a tone is sounded to notify that the communication attribute has changed, and a display indicating the communication attribute is displayed (Fig. 6(e)).
reference). Then, in step S40, the held call for which the switching request has been made is connected, the contents of the call information holding memory for the connected held call are set to a communicating state, and the process moves to step S41, where the tone notifying that the communication attribute has changed is stopped. , the display is also cleared and the process returns to S28 in FIG. 7C.

If the disconnection of the held call by the other party is detected in step S31 of FIG. 7C, the process proceeds to step S42 of FIG. 7D, where the call information holding memory of the disconnected held call is released;
Turn off the LED that was flashing as a held call. and,
In step S43, a tone notifying that the held call has been disconnected is sounded, in step S44, the display of the held call is cleared, and in the next step S45, the tone notifying that the held call has been disconnected is stopped. The process ends.

In FIG. 7C, if disconnection by the other party during communication is detected in step S32, the process proceeds to step S62, where a tone is sounded to notify that the other party has disconnected, and in step S63, the own terminal side disconnects (voice communication (in the case of on-hook, in the case of data communication, the data key 25 is pressed), the terminal response 59 is monitored. If disconnection of the own terminal is detected in step S63, the tone emitted in step S62 is stopped and the display during communication is cleared in step S64. Then, in step S47,
Performs processing to release the call information holding memory for the disconnected call.

If disconnection by the own terminal (on-hook in the case of voice communication, by input of the data key 25 in the case of data communication) is detected in step S33, step S34
In step S47, the call information holding memory of the call in progress is released and the outside line is disconnected and released, and in step S47, the LED corresponding to the outside line of the disconnected call is turned off. Also, step S48
Then, the LED of the outside line key corresponding to the call that was on hold,
If the terminal that was on hold remains on hold (slow blinking green), other free terminals that can accept the held call will be placed on hold (slow blinking red). At the same time, terminals that are not acceptable are placed in a state where they are communicating with other terminals (lit red).

In step S49, a display indicating that there is a held call and information about the held call such as communication attributes is displayed, and in step S50, a tone is sounded to notify that there is a held call. Then, in steps S51 and S52, a hold response (in the case of voice communication, pressing the outside line key of the held call after off-hook; in the case of data communication, pressing the data key 25 and the outside line key of the held call) and disconnection of the held call are performed. If it is detected in step S52 that the called party has disconnected the call on hold, the tone is stopped and the display is cleared in step S60. In the subsequent step S61, the LED of the disconnected call is turned off, the call information holding memory of the call on hold is released, and the process ends.

If a pending response is detected in step S51, step S51
At step 53, it is checked whether the communication attributes in the call information holding memory of the call on hold match the communication attributes in the extension setting memory of the data adapter telephone that performed the hold response operation. If consistency is confirmed in this step S53, the held call that received the hold response is connected in step S54, and
59, the LED of the corresponding outside line key indicates that the data adapter phone is communicating (lit green).
, the other terminals are set to the communicating state (lit red), the call information holding memory of the connected held call is set to the communicating state, and the process returns to step S78 in FIG. 7B.

However, if it is determined in step 353 that they do not match, the communication attributes of the data adapter telephone are set to match the communication attributes set in the call information holding memory in step S55, and the extension setting memory is also set. In step 356, a tone is sounded and displayed to notify that the communication attribute has changed (Fig. 6(e)).
reference).

In addition, in step S57, the call information holding memory of the held call is set to a communicating state, and the held call for which the holding response request has been requested is connected, and in step S58, the call information holding memory for the held call is set to a communicating state, and in step S58, a message is sent to notify that the communication attribute has changed in step 856. Stops the tone played and clears the display.

As explained above, according to this embodiment, the LED corresponding to a held call or an incoming call on a terminal connected to a communication system
The display makes it easy to determine whether it is possible or impossible to answer a call on hold or answer an incoming call on the terminal, eliminating the user's confusion about the answer and eliminating unnecessary call transfer operations, incorrect answers, and incorrect disconnections. It has the effect of being evasive.

In addition, call information stored in the communication system, communication attributes of the terminal, etc. are displayed on the display of the terminal operated each time a hold or hold response operation is performed. In addition to checking whether or not the communication attributes match, the specific communication attributes can be visually confirmed, which has the effect of making mutual communication more reliable by matching the communication attributes.

Note that the above embodiment is not limited to the display pattern of the LED display corresponding to the outside line key as an indication of whether the terminal matches the communication attribute of the held call. Multiple tones corresponding to attributes, L
It may be possible to distinguish them by the color of the ED or by the voice message.

In addition, we used information elements (transmission capability, low layer consistency, high layer consistency, etc.) included in the 15DN message as a means to identify the communication attributes of held calls and incoming calls. A method of uniquely registering communication attributes may be adopted.

Furthermore, in the above embodiment, the communication attributes of the data adapter telephone are set to match the held call or incoming call only when the communication attributes being set do not match the held call or incoming call. If it is determined that the communication attributes of the held call or incoming call are within the allowable change range of the data adapter phone, the held call or incoming call is unconditionally changed. It may be set to match the communication attributes of.

[Effects of the Invention] As explained above, according to the present invention, it is possible to easily determine from the display corresponding to the held call whether the terminal is capable of responding to the held call or not, thereby avoiding erroneous responses and unnecessary operations. There is an effect that can be done.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a communication system according to an embodiment of the present invention, FIG. 3(a) is a diagram showing the memory configuration of the extension setting memory of the communication system according to the embodiment; FIG. 3(b) shows the setting of the extension setting memory for the button telephone 9. FIG. 3(c) is a diagram showing an example of setting the extension setting memory for the data adapter telephone 10; FIG. 3(d) is a diagram showing an example of setting the extension setting memory for the data adapter telephone 11; 4(a) is a diagram showing the memory configuration of the call information holding memory of the communication system according to the embodiment, FIG. 4(b) is a diagram showing an example of a held call in the call information holding memory, FIG. 4(c) 5 is a diagram showing an example of the communication middle ear of the call information holding memory, FIG. 5 is a diagram showing the correspondence between communication attributes and classes of terminals accommodated in the communication system according to the embodiment, and FIG. FIG. 6(b) is a diagram showing an example of an incoming call display on the display unit of a terminal accommodated in the communication system according to the example; FIG. 6(b) is a diagram showing an example of the amount of messages in progress; FIG.
6(d) is a diagram showing an example of the mooring display. FIG. 6(e) is a diagram showing an example of the communication attribute setting change display. Figure 7D shows the CP of the communication system according to the embodiment.
3 is a flowchart showing U's call processing procedure. In the figure, ■...CPU, 2...Memory, 3...RO
M, 4...Switching unit, 5...15DN interface, 6-8...Extension interface, 9...Key telephone, 10.11...Data adapter telephone, 12゜13...Data Terminal device, 14...l5DN network, 1
5... DSU, 21... Data adapter telephone body, 22... Display section, 23... Handset, 24...
...Outside line key 24a...LED for call status display, 25
...Data key 26...Switching key, 27...Dial key pad, 28...Hold key 29...Modular jack, 30...Data terminal boat.

Claims (1)

[Claims] In a communication system that accommodates a plurality of lines and terminals and can respond to a held line at any terminal, there is provided a communication attribute recognition means for recognizing a communication attribute of a held call and a communication attribute of each terminal to be accommodated; Terminal identifying means for identifying a terminal having a communication attribute that matches the communication attribute; and display means for displaying a held call so that a terminal having a communication attribute that matches the communication attribute of the held call can be distinguished from a terminal that does not match the communication attribute. A communication system comprising: