Communication system including management terminal and plurality of communication terminals and enabling quick maintenance and management

A communication system including a management terminal and a plurality of communication terminals connected to a communication network via network termination unit etc., wherein the management terminal instructs the type of the status information and requests transmission of the status information or suspension of transmission of the same to the communication terminals by the user-user information in the call setup message and wherein the communication terminals receiving the request for transmission extract and hold the address information indicating the management terminal contained in the call setup message and, when detecting an occurrence of a failure or other specific phenomenon, transmit the indicated type of the status information to the management terminal by the user-user information in the call setup message while defining address information indicating the management terminal as the termination address information. Thus, only the desired type of the status information is collected and therefore quick maintenance and management are made possible.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a communication system including a 
management terminal and a plurality of communication terminals and 
enabling quick maintenance and management, in more detail, relates to a 
method for managing the status of communication terminals by a management 
terminal and to a management terminal and communication terminals for the 
same. 
In the communication system in which a plurality of communication terminals 
such as telephone terminals, data terminals, facsimile terminals, and 
other communication terminals are accommodated in communication network 
and communicate for each other, the number of communication terminals has 
been increased steadily and therefore results in increasingly larger 
system size. As a result, a need has arisen for a means for facilitating 
the management of the terminals in the large sized communication system. 
2. Description of the Related Art 
As will be explained in detail later referring to the drawings, the 
management terminal manages to operate the communication system stably, by 
collecting the status information of the communication terminals such as 
data terminals, telephone terminals, facsimile terminals, and other 
communication terminals, by judging whether or not the different parts are 
operating normally, and by instructing maintenance personnel etc. to 
repair parts where abnormalities have occurred. 
In such a communication system, conventionally, when the management 
terminal requests status information from communication terminals, the 
management terminal has to request the status information by specifying 
the desired communication terminals. In a large sized communication 
system, however, there is a problem that it is not easy to specify the 
most suitable communication terminals. Further, a communication terminal, 
even if a failure occurs, cannot send out status information unless it 
receives a request from the management terminal. Accordingly, the 
collection of information by the management terminal becomes slow and 
there is a problem of a long time required for the maintenance and 
management. 
Further, in a large sized system, a plurality of management terminals 
sometimes are distributed at different locations. In this case, status 
information can only be transmitted to a particular management terminal 
and therefore there is a problem of a lack of flexibility. Further, the 
status information is transmitted by occupying a speech path, so there is 
a problem that the communication terminals cannot communicate during this 
period. 
Further, the status information transmitted from a communication terminal 
includes all of the status information held in that terminal, which means 
that the management terminal must process an enormous amount of 
information. That is, various types of information are included other than 
the information most required for the troubleshooting, so there is the 
problem that the time required for analysis of the information in the 
management terminal becomes long. Further, the communication terminals are 
not provided with means for confirming whether or not the status 
information transmitted to the management terminal has actually reached 
it, so there is a problem that it is impossible to guarantee that all of 
the desired status information was able to be collected when a management 
terminal manages the communication terminals. 
SUMMARY OF THE INVENTION 
Therefore, an object of the present invention is to enable a management 
terminal to manage communication terminals without occupying a speech path 
and by collecting only the desired type of the status information. 
To attain the above object, the present invention provides a communication 
system including a management terminal connected to a communication 
network via network termination unit etc. and a plurality of communication 
terminals, wherein user-user information in a call setup message from the 
management terminal is used to indicate the type of the status information 
and to request its transmission or request its suspension to the 
communication terminals. A communication terminal receiving a transmission 
request extracts address information identifying the management terminal 
contained in the call setup message and holds the same. When an occurrence 
of a failure or other specific phenomenon is detected, it sends the 
indicated type of status information to the management terminal by the 
user-user information in the call setup message using the address 
information indicating the management terminal as the termination address 
information. 
Due to this, it becomes possible to collect only the desired type of the 
status information and thereby perform maintenance and management quickly.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Before describing the embodiments of the present invention, the related art 
and the disadvantages therein will be described with reference to the 
related figures. 
FIG. 14 is an explanatory view of a communication system in which 51 
denotes a management terminal, 52 a communication network, 53 a switching 
office, 54 a network termination unit such as a digital service unit 
(DSU), 55 a data terminal, 56 a telephone terminal (TEL), and 57 a 
facsimile terminal (FAX). Where the communication network 52 is comprised 
by an ISDN, if communication terminals such as the data terminal 55, 
telephone terminal 56, facsimile terminal 57, etc. are not ISDN terminals, 
they are connected via terminal adapters having modem functions. 
The management terminal 51 collects the status information regarding the 
communication terminals such as data terminal 55, telephone terminal 56, 
facsimile terminal 57, and other communication terminals, decides whether 
or not the different parts are operating normally, instructs maintenance 
personnel etc. to repair any parts in which abnormality occurred, and 
thereby enables the management of the communication system to operate 
stably. 
FIG. 15 is an explanatory view of a method of management of communication 
terminals in the related art. In this example, a request A1 for status 
information is transmitted from the management terminal 51 to a 
communication terminal 58 such as a data terminal via the communication 
network 52 as indicated by the broken arrow. Due to this, the 
communication terminal 58 transmits the status information A2 held in it 
to the management terminal 51 as indicated by the broken arrow. This 
management terminal 51 decides whether or not the communication terminal 
58 and the channel thereof are operating normally based on the collected 
status information A2 and thereby monitors the status of the communication 
terminal 58. 
In this case, the status information request A1 is transmitted as for 
example user-user information in the call setup message from the 
management terminal 51. Further the communication terminal 58 can transmit 
the status information A2 as user-user information in the response message 
sent in response to the call setup message. 
In this method of management of communication terminals, it is the 
management terminal 51 which requests and collects the status information 
from the communication terminals 58, but the communication terminals 58 
supervise their own operations as well, and when one detects a failure or 
other specific phenomenon, it will originate a call to the management 
terminal 51, and a speech path will be formed via the communication 
network 52, then the communication terminal 58 will transmit status 
information B1 as indicated by the dot-dash line via the speech path. The 
management terminal 51 manages the status of the communication terminals 
58 by collecting this status information B1 as well. 
When the management terminal 51 requests status information from the 
communication terminals 58 in the related art, the management terminal 51 
has to request the status information while specifying the desired 
communication terminals 58. In a large sized communication system, 
therefore, there is the problem that it is not easy to specify the most 
suitable communication terminals 58. Further, a communication terminal 58, 
even if a failure occurred in its, cannot transmit status information 
unless there is a request from the management terminal 51. Accordingly, 
there is a problem that collection of information by the management 
terminal 51 becomes slow and the time required for the maintenance and 
management becomes long. 
Further by having the communication terminals 58 supervise their own 
internal operations and, when detecting a failure or other specific 
phenomenon, if the communication terminal 58 originates a call to the 
management terminal 51 to send the status information, it is possible to 
quickly send status information indicating the occurrence of the failure 
to the management terminal 51, but originating a call to the management 
terminal 51 requires the accurate setting of the number of the management 
terminal 51. If there is an error in the set number, the occurrence of the 
failure cannot be notified to the management terminal 51. 
Further, in a large sized communication system sometimes a plurality of 
management terminals 51 are distributed at different locations. In this 
case, status information can only be transmitted to a particular 
management terminal 51 and therefore there is a problem of a lack of 
flexibility. Further, the status information is transmitted by occupying a 
speech path, so there is a problem that the communication terminals 58 
cannot communicate during this period. 
Further, the status information transmitted from a communication terminal 
58 includes all of the status information held in that terminal, which 
means that the management terminal 51 must process an enormous amount of 
information. That is, various types of information are included other than 
the information most required for the troubleshooting, so there is the 
problem that the time required for analysis of the information in the 
management terminal 51 becomes long. Further, the communication terminals 
58 are not provided with means for confirming whether or not the status 
information transmitted to the management terminal 51 has actually reached 
it, so there is a problem that it is impossible to guarantee that all of 
the desired status information was able to be collected when a management 
terminal 51 manages the communication terminals 58. 
The present invention enables a management terminal to manage the 
communication terminals without occupying a speech path and by collecting 
only the desired type of status information. 
The method of managing communication terminals according to the present 
invention will now be explained by referring to FIG. 1. 
According to a first aspect of the present invention, there is provided a 
method of management of communication terminals 3 accommodated in a 
communication network 2 wherein status information of the communication 
terminals 3 is collected and managed by a management terminal 1, wherein 
the management terminal 1 uses the information for users at the time of 
setting up a call to the communication terminals 3 to request the 
transmission of the status information autonomously or the suspension of 
the transmission of the same autonomously, the communication terminals 3 
transmit their status information to the management terminal 1 using the 
information for users at the time of response during a call setup or at 
the time of a call autonomously setup in response to a request for 
transmission of status information, and the management terminal 1 includes 
a function of extracting and collecting the status information from the 
information for users from the communication terminals 3 at the time of a 
response or at the time of a call setup via the communication network 2. 
That is, the management terminal 1 instructs a designated communication 
terminal 3 to transmit status information according to need or, after 
instructing transmission, instructs the above communication terminal 3 to 
stop the transmission when the status information becomes unnecessary. 
Further, the communication terminal 3 requested to transmit status 
information will autonomously originate a call to the management terminal 
1 and transmit the status information when detecting a failure or other 
specific phenomenon. The instruction for transmission of the status 
information from the management terminal 1 or the instruction for 
suspension of transmission, and the transmission of the status information 
from the communication terminals 3 can be carried out by using the 
information for users at the time of a call setup, for example, the 
user-user information in the call setup message. Accordingly, 
predetermined status information can be transmitted without the use of 
speech paths at the time of detection of an occurrence of a failure or 
other specific phenomenon. 
According to a second aspect of the present invention, the communication 
terminal 3 can include a function of extracting and holding address 
information indicating the management terminal 1 at the time of receiving 
a request for transmission of the status information from the management 
terminal 1 and of transmitting the status information of the communication 
terminal 3 by the information for users at the time of a call autonomously 
setup using this address information. 
That is, the communication terminal 3 extracts and holds the origination 
address added to the call setup message or the origination address added 
to the packet for requesting a call when receiving an instruction for 
transmission of the status information from the management terminal 1. 
Accordingly, the call setup message or the packet for requesting a call 
can be transmitted to the management terminal 1 requesting the 
transmission of the status information using this address information. 
According to a third aspect of the present invention, the management 
terminal 1, using the user-user information in the call setup message or 
the call user information in the packet for requesting the call to the 
communication terminal 3, specifies the type of status information which 
should be transmitted and instructs that the terminal 3 should 
autonomously transmit the status information or stop the transmission of 
the same, while the communication terminal 3, using the user-user 
information in a call setup message or call user information in the packet 
for requesting a call autonomously transmitted at the time of detection of 
a specific phenomenon in response to the request for transmission of the 
status information from the management terminal 1, transmits the specified 
type of the status information. 
That is, the management terminal 1 transmits the call setup message or 
packet for requesting a call to a specified communication terminal 3. At 
this time, the terminal 1 using the user-user information or the call user 
information, specifies the type of the status information and requests the 
transmission or the suspension of transmission. The communication terminal 
3 autonomously transmits a call setup message or packet for requesting a 
call to the management terminal 1 when detecting an occurrence of a 
failure or other specific phenomenon after receiving a request for 
transmission of status information. At this time, the terminal 3 transmits 
the specified type of the status information using the user-user 
information or the call user information. Accordingly, the management 
terminal 1 can collect the preliminarily specified type of status 
information at the time when detecting an occurrence of a failure or other 
specific phenomenon at the communication terminal 3. 
According to a fourth aspect of the present invention, the communication 
terminal 3, when detecting a specific phenomenon, uses the user-user 
information in the call setup message or the call user information in the 
packet for requesting a call to autonomously transmit status information 
to the management terminal 1 and, when detecting an abnormal state where 
this status information does not normally reach the management terminal 1, 
analyzes the cause behind this abnormal state, and thus performs 
processing for retransmission based on the result of this analysis. 
That is, when transmitting status information using the user-user 
information in the call setup message or the call user information in the 
packet for requesting a call, if abnormal termination occurs due to a 
disconnection message etc., the communication terminal 3 analyzes the 
cause behind the disconnection and, if the disconnection is due to the 
line being busy etc., performs processing for retransmission since a retry 
is possible. 
According to a fifth aspect of the present invention, the management 
terminal 1 is provided with a user information setting unit which 
specifies the type of status information which should be collected and 
requests transmission of the status information or the suspension of 
transmission of the same via the communication network 2 to the 
communication terminal 3 by using the information for users at the time of 
call setup and with a user information collection unit which extracts the 
information for users at the time of a response or at the time of a call 
setup, received from the communication terminal 3 via the communication 
network 2, and collects the status information contained in this 
information for users. 
That is, the user information setting unit of the management terminal 1 
specifies the type of the status information to the communication terminal 
3 via the communication network 2 by using the information for users, such 
as the user-user information or the call user information at the time of a 
call setup, and, at the same time, requests the transmission or the 
suspension of transmission. Further, the user information collection unit 
extracts the information for users such as the user-user information or 
call user information received from the communication terminal 3 via the 
communication network 2 and collects the status information contained in 
that information. 
According to a sixth aspect of the present invention, the communication 
terminal 3 is provided with an information analyzing unit which extracts 
the information for users at the time of a call setup from the management 
terminal 1 and identifies the type of status information and request for 
transmission or suspension of transmission, a status supervising and 
holding unit which supervises the state of the different parts and 
collects and holds the status information, and a status information 
transmitting unit which adds to the information for users at the call 
setup the status information according to the type of the status 
information held in the status supervising and holding unit at the time of 
detection of a specific phenomenon and analyzed by the information 
analyzing unit, and transmits the thus added information. 
That is, the information analyzing unit of the communication terminal 3 
extracts and analyzes the information for users such as the user-user 
information or the call user information at the call setup from the 
management terminal 1 and identifies the type of the status information 
and a request for transmission or suspension of transmission. Further, the 
status supervising and holding unit supervises the status of the different 
parts, detects an occurrence of a failure and other specific phenomenon, 
and temporarily holds the status information at that detection. Further, 
the status information transmitting unit selects the status information 
according to the specified type, reads the same from the status 
supervising and holding unit at the time of detection of an occurrence of 
a failure or other specific phenomenon, and transmits the status 
information by using the information for users such as the user-user 
information or call user information at the call setup. 
According to a seventh aspect of the present invention, the communication 
terminal 3 can be provided with an abnormality cause analyzing unit for 
analyzing the cause behind a detected abnormal state when detecting the 
abnormal state where the status information transmitted by the 
communication terminal 3 from the status information transmitting unit is 
not normally received at the management terminal 1 and with a 
retransmission processing unit for performing processing for 
retransmitting the status information from the status information 
transmitting unit based on the result of analysis of the cause of the 
abnormal termination in this abnormality cause analyzing unit. 
That is, when the status information is transmitted from the status 
information transmitting unit, the abnormality cause analyzing unit of the 
communication terminal 3 analyzes the information indicating inability of 
reception at the management terminal 1 or inability of acceptance in the 
communication network 2 and determines the cause of the abnormality. 
Further, the retransmission processing unit performs processing for 
retransmission when the result of analysis of the cause of abnormality in 
the abnormality cause analyzing unit is a busy line etc. since 
retransmission is possible. 
According to an eighth aspect of the present invention, the communication 
terminal 3 can be provided with a priority selection unit which selects 
status information of a priority from status information concerning the 
contents of failures when the simultaneous occurrence of several types of 
failures has been detected and causes the selected status information to 
be transmitted from the status information transmitting unit to the 
management terminal 1. 
That is, the priority selection unit of the communication terminal 3 
selects the status information of the highest priority from the status 
information concerning contents of failures when the failures have 
simultaneously occurred and causes the status information having the 
highest priority to be transmitted from the status information 
transmitting unit. 
FIG. 1 is an explanatory view of the principle of the present invention. 
The communication system is comprised of a plurality of communication 
terminals 3 connected to a communication network 2 via network termination 
units (DSU) 4 and a management terminal 1 connected to the communication 
network 2 via a network termination unit 4. The management terminal 1 
specifies the communication terminal 3 from which it wishes to collect the 
status information and, when the communication network 2 is an ISDN, 
indicates the type of the status information and transmission of the same 
by the user-user information in the call setup message. The telephone 
number of the management terminal 1 is added to this call setup message as 
the origination address information. When the communication network 2 is a 
packet switching network, it indicates the type of the status information 
and transmission of the same by the call user information in the packet 
for requesting a call. In this case, the telephone number of the 
management terminal 1 is transmitted while accompanying to the call user 
information etc. in the packet for requesting a call as the origination 
address information. 
The communication terminal 3 identifies the type of the status information 
and the instruction of transmission of the same by the user-user 
information or call user information, that is, the information for users 
in the call setup message or call origination request message. The 
terminal 3 extracts and holds the origination address information and 
transmits the indicated status information to the management terminal 1 by 
the user-user information or call user information based on this 
origination address information at the time of detection of an occurrence 
of a failure or other specific phenomenon as the call setup message or the 
packet for requesting a call. The broken arrows between the management 
terminal 1 and the communication terminal 3 indicate the instruction for 
transmission of the status information and the transmission of status 
information by the call setup message or the packet for requesting a call 
etc. 
Where it is no longer necessary to collect the status information, the 
management terminal 1 can transmit a call setup message or a packet for 
requesting a call to the communication terminal 3 which the management 
terminal 1 had instructed to transmit the status information and uses the 
user-user information or the call user information in the call setup 
message or the packet for requesting a call so as to instruct the 
suspension of transmission of the status information. Namely, as indicated 
by the broken arrow, the management terminal 1 requests transmission of 
the status information or instructs suspension of transmission of the same 
using the information for users, that is, as indicated by the another 
broken arrow, the communication terminal 3 receiving the request for 
transmission transmits the status information to the management terminal 1 
using the information for users when detecting an occurrence of a failure 
or other specific phenomenon. 
FIGS. 2A and 2B are views explaining an embodiment of the present 
invention. As shown in the figure, the management terminal 1 includes a 
user information setting unit 5, a user information collection unit 6, and 
a transmission and reception interface unit 7. It further includes 
input/output devices such as a display, printer, keyboard, etc., 
illustration of which is omitted. The communication network 2 may be an 
integrated service digital network (ISDN) or packet switching network. The 
explanation will be made below of the case of an ISDN. 
The communication terminal 3 includes an information analyzing unit 10; a 
status supervising and holding unit 17 including a signaling relation unit 
11, a packet relation unit 12, and a lower layer relation unit 13; a 
status information transmitting unit 14; a retransmission processing unit 
15; a priority selection unit 16; and a transmission/reception interface 
unit 18. It further includes a display, printer, keyboard, telephone set, 
etc., illustration of which is omitted. 
The management terminal 1 designates the communication terminal 3 from 
which the status information is to be collected and indicates the type of 
status information to be collected to this communication terminal 3. For 
this, by the above input indication, the user information setting unit 5 
sets the instruction of the type of the status information and the 
instruction for transmission of the same in the user-user information and 
instructs the transmission of the call setup message to the 
transmission/reception interface unit 7. The transmission/reception 
interface unit 7 forms the call setup message including termination 
address information indicating the communication terminal 3 and the 
origination address information indicating the management terminal 1, adds 
the user-user information indicating the instruction of the type of the 
status information and the instruction of transmission, and transmits the 
same. 
The signaling relation unit 11 of the status supervising and holding unit 
17 in the communication terminal 3 supervises the state of call control in 
relation to the channel switching and, when detecting an occurrence of a 
failure, sends the supervising information to the priority selection unit 
16 and holds the status information. The packet relation unit 12 
supervises the state of call control in relation to the packet switching 
and, when detecting an occurrence of a failure, notifies the failure to 
the priority selection unit 16 and holds the status information. The lower 
layer relation unit 13 supervises the electrical and physical states and 
the state of the data link and, when detecting an occurrence of a failure, 
notifies the failure to the priority selection unit 16 and hold the status 
information thereof. 
When receiving a call setup message from the management terminal 1 via the 
transmission/reception interface unit 18, the information analyzing unit 
10 extracts and analyzes the user-user information, and thereby the unit 
10 identifies the instruction for transmission of the status information. 
Then the unit 10 identifies the instruction of the type of the status 
information, notifies the same to the status supervising and holding unit 
17, extracts the origination address information contained in the call 
setup message, and holds the same. 
Further, when notified that an occurrence of a failure or other specific 
phenomenon has been detected in the status supervising and holding unit 
17, the priority selection unit 16 activates the status information 
transmitting unit 14 and transfers the necessary status information and 
address information of the management terminal 1 to the status information 
transmitting unit 14. For example, where the management terminal 1 
indicates the status information, as the type of status information, on 
the state supervised by the signaling relation unit 11, the priority 
selection unit 16 activates the status information transmitting unit 14 
and makes it send the status information only when the signaling relation 
unit 11 detects the occurrence of a failure in the call control in 
relation to the channel switching. That is, control is possible so that 
status information of types which are not instructed is not sent. 
When the types of status information for two or all of the signaling 
relation unit 11, packet relation unit 12, and the lower layer relation 
unit 13 is instructed and the occurrences of several failures are 
simultaneously detected, the priority selection unit 16 selects the type 
of the status information of the highest priority for transmission. For 
example, it gives priority to the detection of a failure by the lower 
relation unit 13 and transmits the status information of that failure. 
Further, when continuously detecting the same type of failure, control is 
performed so as to first transmit the first detected status information. 
The retransmission processing unit 15 includes an abnormality cause 
analyzing unit 15'. When status information is given from the status 
information transmitting unit 14, and if status information cannot 
normally reach the management terminal 1 due to a busy state at the 
management terminal 1 or congestion at the communication network 2, the 
retransmission processing unit 15 transfers a notification of the 
inability of reception by the user-user information from the management 
terminal 1 and disconnection cause information contained in the 
disconnection message from the communication network 2 from the 
information analyzing unit 10 or the transmission/reception interface unit 
18 to the abnormality cause analyzing unit 15' in the retransmission 
processing unit 15 and analyzes the same in this abnormality cause 
analyzing unit. If retransmission is possible, the retransmission 
processing unit 15 activates the status information transmitting unit 14 
again and makes it transmit the status information to the management 
terminal 1 again. 
FIGS. 3A and 3B are explanatory views of sequences of an embodiment of the 
present invention, in which FIG. 3A shows a startup sequence; and FIG. 3B 
shows a sequence for transmission of status information. In the startup 
sequence of FIG. 3A, when the management terminal 1 specifies a 
communication terminal 3 and it starts by instructing the transmission of 
status information and instructing the type of status information, the 
user information setting unit 5 and the transmission/reception interface 
unit 7 transmit a call setup message SETUP (U-U) to the communication 
network 2. The communication network 2 transmits the call setup acceptance 
message CALL PROC to the management terminal 1 in response to this call 
setup message and sends a call setup message SETUP (U-U) to the 
communication terminal 3 identified by the termination address 
information. Note that, U-U indicates the user-user information which 
contains the instruction for transmission of status information and 
instruction of the type of status information as mentioned before. 
The communication terminal 3 receives the call setup message SETUP (U-U) 
from the management terminal 1 via the communication network 2, transfers 
that call setup message SETUP (U-U) to the information analyzing unit 10 
via the transmission/reception interface unit 18, extracts and analyzes 
the user-user information U-U in the information analyzing unit 10, and, 
when identifying the instruction for transmission of the status 
information and instruction of the type of the status information from the 
management terminal 1, extracts the origination address information 
indicating the management terminal 1 and holds the same and controls the 
status supervising and holding unit 17 according to the instruction of the 
type of the status information. Then, it transmits a release completion 
message RELCOM (U-U) to the management terminal 1 from the 
transmission/reception interface unit 18 to the communication network 2 
using the origination address information. 
The communication network 2 transmits a disconnection message DISC (U-U) to 
the management terminal 1. The management terminal 1 identifies the 
disconnection message from the communication terminal 3, judges that the 
startup has been normally completed, and transmits the release message 
REL. The communication network 2 transmits a release completion message 
RELCOM in response to this. In this case, it is also possible to insert 
and transmit the status information concerning the type indicated by the 
management terminal 1 into the user-user information U-U in the release 
completion message RELCOM (U-U) from the communication terminal 3. The 
user-user information U-U in this case is transferred as the user-user 
information in the disconnection message DISC (U-U) from the communication 
network 2 to the management terminal 1. 
The type of status information to be collected can be instructed from the 
management terminal 1 to a desired communication terminal 3 by the above 
startup sequence. Further, in this case, it is possible to transmit the 
status information held at the time of the startup by using the user-user 
information in the release completion message which is sent in response to 
the call setup message. 
In the sequence for transmission of status information of FIG. 3B, when a 
specific phenomenon is detected, such as indicated by the "occurrence of 
abnormality" in the communication terminal 3, the communication terminal 3 
transmits a call setup message SETUP (U-U) to the management terminal 1 by 
the status supervising and holding unit 17, the priority selection unit 
16, the status transmitting unit 14, and the transmission/reception 
interface unit 18. The user-user information U-U in this case, as 
mentioned before, includes the status information of the type instructed 
by the management terminal 1. 
The communication network 2 transmits this call setup message SETUP (U-U) 
to the management terminal 1 and, at the same time, transmits a call setup 
acceptance message CALL PROC to the communication terminal 3. Further, the 
management terminal 1 transfers the call setup message SETUP (U-U) from 
the communication network 2 to the user information collection unit 6 via 
the transmission/reception interface unit 7, extracts and analyzes the 
user-user information U-U, and, when identifying that it is status 
information from the communication terminal 3, applies the result of 
analysis to a display, alarm equipment, etc. to notify the occurrence of 
the abnormality to the maintenance personnel. 
The management terminal 1 transmits a release completion message RELCOM in 
response to the received call setup message SETUP (U-U). The communication 
network 2 transmits a disconnection message DISC to the communication 
terminal 3 by this release completion message RELCOM, and the 
communication terminal 3 transmits the release message REL. In response to 
this, the communication network 2 transmits the release completion message 
RELCOM. 
Accordingly, when a failure occurs while supervising a specified type of 
status, the status information can be immediately transmitted to the 
management terminal 1 without setting a speech path in the communication 
network 2. Also, in this case, all of the status information is not 
transmitted but only the status information required in the management 
terminal 1 is transmitted. Therefore, the total amount of status 
information collected at the management terminal 1 can be minimized, the 
processing for analysis etc. can be completed in a short time, and thus 
quick maintenance and management can be achieved. 
FIG. 4 is an explanatory view of a sequence for dealing with an abnormality 
in packet information in an embodiment of the present invention. Assume 
that an abnormality occurs after a call origination request packet CR 
(call request) is transmitted from the communication terminal 3 to the 
communication network 2 and a clear indication packet CI (clear 
indication) is received from the communication network 2. When this 
happens, the status information transmitting unit 14 is activated from the 
priority selection unit 16 in a state where the clear confirmation packet 
CF (clear confirmation) is transmitted, that is, by detecting an 
occurrence of a failure or other specific phenomenon in the packet 
relation unit 12 of FIG. 2B. The status information collected in the 
packet relation unit 12 is transferred to the status information 
transmitting unit 14, that status information is set as the user-user 
information, and the call setup message SETUP (U-U) is transmitted from 
the transmission/reception interface unit 18 to the management terminal 1. 
The communication network 2 transmits this call setup message SETUP (U-U) 
to the management terminal 1 and transmits the call setup acceptance 
message CALL PROC to the communication terminal 3. The management terminal 
1 extracts and analyzes the user-user information U-U in the call setup 
message SETUP (U-U), collects the status information from the 
communication terminal 3, and transmits the release completion message 
RELCOM to the communication network 2. The communication network 2 
transmits the disconnection message DISC to the communication terminal 3, 
the communication terminal 3 transmits the release message REL to the 
communication network 2, and the communication network 2 transmits the 
release completion message RELCOM to the communication terminal 3. 
FIGS. 5A and 5B are explanatory views of the sequence for dealing with an 
abnormality in the lower layer information and a sequence for suspension 
of transmission of an embodiment of the present invention, respectively. 
The occurrence of an abnormality is recognized by detection of a loss of 
synchronization (such as L1 DEACT) on the channel to which the 
communication terminal 3 is connected. A data link is established by 
detecting the establishment of synchronization (such as L1 ACT) on the 
channel after this and then by the transfer of the SABME and UA with the 
communication network 2. 
This loss of synchronization is detected in the lower layer relation unit 
13 of FIG. 2B. When the management terminal 1 indicates loss of 
synchronization as the desired type of status information, the priority 
selection unit 16 activates the status information transmitting unit 14, 
the status information collected by the lower layer relation unit 13 is 
transferred, and the call setup message SETUP (U-U) is transmitted as the 
user-user information from the transmission/reception interface unit 18. 
The communication network 2 transmits this call setup message SETUP (U-U) 
to the management terminal 1 and, at the same time, transmits the call 
setup acceptance message CALL PROC to the communication terminal 3. The 
management terminal 1 extracts and analyzes the user-user information U-U 
in the call setup message SETUP (U-U), collects the status information of 
the communication terminal 3, and transmits the release completion message 
RELCOM to the communication network 2. Due to this, the disconnection 
message DISC, release message REL, and the release completion message 
RELCOM are transferred between the communication network 2 and the 
communication terminal 3. 
Further, in the sequence for suspension of transmission of FIG. 5B, when 
the management terminal 1 specifies a communication terminal 3 and 
instructs it to suspend transmission, the user information setting unit 5 
sets the instruction for suspension of transmission in the user-user 
information and the transmission/reception interface unit 7 transmits the 
call setup message SETUP (U-U) containing the information. The 
communication network 2 transmits this call setup message SETUP (U-U) to 
the communication terminal 3 and transmits the call setup acceptance 
message CALL PROC to the management terminal 1. 
The communication terminal 3 receives the call setup message SETUP (U-U), 
extracts and analyzes the user-user information U-U by the information 
analyzing unit 10, and, when identifying that it is an instruction for 
suspension of transmission of the status information, transmits the 
release completion message RELCOM (U-U) and controls the status 
supervising and holding unit 17 and the status information transmitting 
unit 14 so as not to transmit the status information from the terminal 3. 
The communication network 2 transmits the disconnection message DISC (U-U) 
to the management terminal 1 by the release completion message RELCOM 
(U-U) from the communication terminal 3. The management terminal 1 
transmits the release message REL when judging normal completion, and the 
communication network 2 transmits the release completion message RELCOM. 
FIG. 6 is an explanatory view of the commands and codes of an embodiment of 
the present invention. It shows first the code resulting from the command 
for startup and the code resulting from the command for suspension. The 
"report S information" shows the code at the time of detection of a 
specific phenomenon by the signaling relation unit 11 in FIG. 2B, while 
the "report P information" shows the code at the time of detection of a 
specific phenomenon by the packet relation unit 12 in FIG. 2B. The "report 
lower layer" shows the code at the time of detection of a specific 
phenomenon by the lower layer relation unit 13 in FIG. 2B. 
FIGS. 7A and 7B are explanatory views of the user-user information of the 
embodiment of the present invention. MT denotes a management terminal, and 
CT a communication terminal. The figure shows a case where the 
communication terminal CT side is started from the management terminal MT 
side. The user-user information contains a user-user information element 
identifier, user-user information element length, protocol identifier, 
remote maintenance function identifier, function identifier, content 
length, data port number, data sort, data type 1 (alarm type), data type 2 
(alarm cause), etc. 
Further, the "S information" of the 0-th bit in the type 1 format shows the 
status information by the signaling relation unit 11 in FIG. 2B; the "P 
information" of the 1st bit shows the status information by the packet 
relation unit 12 in FIG. 2B; the "lower layer" of the 2nd bit shows the 
status information by the lower layer relation unit 13 in FIG. 2B; and the 
"modem line" of the 3rd bit shows the status information of the modem line 
of terminal connected to the communication terminal. Further, the 0-th bit 
in the type 2 format shows an abnormal disconnection, the 1st bit shows 
busy disconnection, and the 2nd bit shows a normal disconnection. 
The call setup message SETUP (U-U) is transmitted from the management 
terminal MT to the communication terminal CT, the communication terminal 
CT is started by the function identifier of the alarm report, the data 
sort of the startup, the data type 1 of the alarm type, etc. in the 
user-user information U-U thereof, and the indicated status information is 
transmitted at the time of detection of an occurrence of a failure or 
other specific phenomenon. 
FIG. 8 is another explanatory view of the user-user information of an 
embodiment of the present invention. The figure shows a case where the 
communication terminal CT started by a call setup message from the 
management terminal MT notifies the completion of startup by the user-user 
information U-U in the release completion message RELCOM (U-U). The 
user-user information includes a function identifier showing the 
notification of completion. The management terminal MT can receive and 
analyze the release completion message RELCOM (U-U) containing the 
user-user information U-U indicating the completion of startup to confirm 
the startup of the communication terminal CT. 
FIG. 9 is another explanatory view of the user-user information of an 
embodiment of the present invention. The figure shows a case where a 
startup error occurs in the communication terminal CT started by the call 
setup message SETUP (U-U) from the management terminal MT and the startup 
error is notified by the user-user information U-U in the release 
completion message RELCOM (U-U). The user-user information includes a 
function identifier for notification of the error. The management terminal 
MT can for example restart the communication terminal CT in which this 
startup error occurred. 
FIG. 10 is another explanatory view of the user-user information of an 
embodiment of the present invention. The figure shows the case where 
suspension of transmission of status information is instructed to the 
communication terminal CT by the call setup message SETUP (U-U) from the 
management terminal MT. The call setup message SETUP includes the data 
sort for suspension. The communication terminal CT can receive this call 
setup message SETUP (U-U), extract and analyze the user-user information 
U-U, and discriminate that it is an instruction for suspension of 
transmission of the status information. The completion of suspension is 
notified from the communication terminal CT to the management terminal MT 
in response to this request for suspension by the release completion 
message RELCOM (U-U). The user-user information U-U at this time becomes 
the same as that of the case of notification of completion of startup of 
FIG. 8. 
FIG. 11 is another explanatory view of the user-user information of an 
embodiment of the present invention. The figure shows the user-user 
information U-U in the release completion message RELCOM (U-U) in a case 
where suspension of transmission of the status information is instructed 
from the management terminal MT to the communication terminal CT by the 
call setup message SETUP (U-U) and a suspension error occurs in the 
communication terminal CT. This user-user information U-U includes a 
function identifier for notification of error and the data sort for 
suspension. The management terminal MT can extract and analyze this 
user-user information U-U and determine that suspension of transmission of 
the status information has not been set in the communication terminal CT. 
In this case, it can make another request for suspension to the 
communication terminal CT again. 
FIGS. 12A and 12B are other explanatory views of the user-user information 
of an embodiment of the present invention. The figure shows the user-user 
information in a case where the status information is notified from the 
communication terminal CT to the management terminal MT. In this case, the 
status information can be transmitted to the management terminal MT by the 
user-user information U-U in the call setup message SETUP (U-U) including 
the function identifier for an alarm report, data sort of report, and 
indicated type of the status information. 
FIG. 13 is an explanatory view of the startup sequence in the packet 
switching network of an embodiment of the present invention. When the 
management terminal designates and starts up a communication terminal, the 
management terminal instructs the type of the status information and 
instructs the transmission of the same by the call user information DATA 
in the call origination request packet CR as indicated as CR (DATA). The 
communication network transmits a call termination packet CN containing 
the call user information DATA to the communication terminal as indicated 
by CN (DATA) in response to a call origination request packet CR. 
The communication terminal receives this call termination packet CN, 
extracts and analyzes the call user information DATA, and, when 
identifying that it is a request for startup from the management terminal, 
transmits a restore request packet CQ. The communication network transmits 
a clear indication packet CI to the management terminal, and the 
management terminal transmits a clear confirmation packet CF in response 
to this. This call user information DATA has a 128 bytes structure similar 
to the user-user information. Accordingly, it can adopt the same format as 
that for the user-user information. 
When a failure occurs in the communication terminal and the status 
information is transmitted to the management terminal, transmission of a 
call origination request packet CR comprising the call user information 
including the status information from the communication terminal enables 
the status information to be transmitted to the management terminal 
without forming a speech path in the communication network. 
When the status information transmitted from the communication terminal is 
not normally received by the management terminal, for example, in the case 
of the occurrence of a failure or a busy state of the management terminal 
1 or in the case where the communication network 2 is congested, analysis 
of the notification by the user-user information from the management 
terminal 1 and the disconnection factorial information of the clear 
indication packet CI from the communication network 2 enables the cause of 
the abnormal completion to be analyzed. Namely, the cause is analyzed by 
the abnormality cause analyzing unit included in the retransmission 
processing unit 15 of FIG. 2B. When retransmission is possible, the status 
information transmitting unit 14 is activated after a predetermined time 
interval and the status information is transmitted again to the management 
terminal 1 by using the user-user information. 
As explained above, the method of management of terminals of the present 
invention has the management terminal 1 side specify the communication 
terminal 3 and instruct the type of status information and request 
transmission of the status information or suspension of transmission of 
the same and has the communication terminals 3 transmit the specified 
status information when detecting an occurrence of a specified failure or 
other specific phenomenon. In both cases, use is made of for example the 
user-user information in the call setup message SETUP for transmission, so 
there is no need to form a speech path in the communication network 2 and 
it becomes possible to collect only the status information required by the 
maintenance personnel on the management terminal 1 side. Thus, the status 
information to be analyzed becomes the minimum and there is an advantage 
that quick maintenance and management become possible. 
Further, since the management terminal 1 of the present invention can 
specifies the communication terminals 3 from which the status information 
is collected and can instruct the type of the status information thereof, 
even in a large sized communication system, it becomes possible to collect 
the minimum amount of the status information required. Due to this, quick 
maintenance and management become possible. Also even when the 
communication system is large in size and includes several management 
terminals 1 connected to the communication network 2, the communication 
terminals 3 can identify the management terminal 1 concerned by referring 
to for example the origination address information contained in the call 
setup message SETUP, so there is an advantage that the status information 
can be transmitted to the management terminal 1 requesting the 
transmission without confusion of status information. 
Further, since the communication terminals 3 of the present invention 
transmit the status information only when started up by the management 
terminal 1 and detecting an occurrence of a specified failure or other 
specific phenomenon, they can quickly transmit the status information by 
the user-user information in the call setup message SETUP etc. without 
forming a speech path in the communication network 2. 
Further, when the status information transmitted from a communication 
terminal 3 is not normally received at the management terminal 1, the 
abnormality cause analyzing unit included in the retransmission processing 
unit 15 in FIG. 2B can analyze the cause of the abnormality and, when the 
cause is that the management terminal 1 is busy etc., can activate the 
status information transmitting unit 14 after a predetermined time to 
perform processing for retransmission. Accordingly, there is an advantage 
that the status information can be reliably transmitted to the management 
terminal 1 when a failure of the type indicated from the management 
terminal 1 occurs.