JP2004166000A - Band management system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a band management system capable of maintaining high quality of communication. <P>SOLUTION: The band management system is provided with a reception processing means for processing a received message by sharing the same band resources among a plurality of communication terminals, communicating, and performing reception processing including sorting of the received messages, and a management means for a party where reception is sorted out for managing every communication terminal by correlating other tolerated communication terminals as sorted-out parties of the received message which specify its own communication terminal. The reception processing means sorts out the received messages corresponding to other communication terminals in accordance with a band utility situation at a current time of its own communication terminal. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a band management system, for example, according to ITU-T Recommendation H.264. It is suitable for application to a PBX that performs VoIP (Voice over IP) in an environment compliant with H.323, such as an IP-PBX.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, the judgment at the time of a slide in the incoming slide function of the IP-PBX is performed based on a situation such as a blocked incoming terminal, occurrence of a failure, and no response. Therefore, if the terminal to be received is normal (no failure has occurred and there is no response) and the terminal is idle (not blocked), incoming processing is performed on the terminal.
[0003]
Conversely, if the receiving terminal is in a failure state, has not responded, or is blocked, the IP-PBX slides the incoming call.
[0004]
Here, the slide of the incoming call refers to distributing the incoming message to a terminal different from the original destination specified by the incoming message (call setting message) and receiving the incoming message.
[0005]
[Non-patent document 1]
ITU-T Recommendation H. 323
[0006]
[Problems to be solved by the invention]
However, in such a method, in a network to which the receiving terminal is connected, even if a sufficient bandwidth cannot be secured by communication of another terminal, the receiving process is performed, so that a sufficient bandwidth cannot be secured. There is a possibility that the quality of communication already being executed before the incoming call processing is performed and / or the quality of communication newly started following the incoming call processing is reduced.
[0007]
It should be noted that this reduction in communication quality may occur regardless of whether the slide is performed or not.
[0008]
[Means for Solving the Problems]
In order to solve this problem, the present invention provides a bandwidth management system for a communication network in which a plurality of communication terminals share an identical bandwidth resource to process an incoming message and perform communication. And (2) associating and managing, for each of the communication terminals, another communication terminal that is permitted as a distribution destination of an incoming message specifying its own communication terminal. (3) the incoming call processing means performs distribution of the incoming message to the other communication terminal in accordance with the current band usage status of the own communication terminal. .
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
(A) Embodiment
Hereinafter, an embodiment will be described with an example in which the band management system according to the present invention is applied to a VoIP network.
[0010]
(A-1) Configuration of the embodiment
FIG. 1 shows an overall configuration example (including a detailed configuration example of components) of the VoIP network 30 of the present embodiment.
[0011]
1, the VoIP network 30 includes an IP network 31 and four bases 32 to 35 connected by the IP network 31.
[0012]
Of these, the IP network 31 can be replaced with the Internet or the like, but here, it is assumed that the IP network is constructed and operated by a specific communication carrier and provided to users. Such an IP network is the same as the Internet in that communication using the IP protocol is performed, but differs in that communication quality can be guaranteed according to equipment prepared by a communication carrier.
[0013]
The IP network 31 may be constructed by the user company itself so as to be used by its own employees or the like. In general, the network 31 is shared by a plurality of user companies, and a VoIP service is provided to each user company. In this case, an IP-VPN is often used so that one user company can connect the bases while maintaining confidentiality.
[0014]
The IP network 31 can be connected to the Internet or an existing subscribed telephone network as needed.
[0015]
The bases 32 to 35 shown in FIG. 1 are LANs (local area networks) corresponding to sales offices, branch offices, head offices, and the like of one user company among a plurality of user companies sharing the IP network 31. Good.
[0016]
There may be various network configurations in the bases (LAN) 32 to 35. In practice, the network configuration often differs between the head office, the branch office, the sales office, and the like. It can be considered that the network configurations of the bases 32 to 35 are substantially the same.
[0017]
FIG. 1 shows a more detailed configuration example of the base 35 among the bases 32-35.
[0018]
That is, the base 35 includes a router 40, an IP-PBX control device 10, a LAN switch 11, hubs (repeaters) 12 to 14, and IP telephone terminals (IP telephones) 20 to 23.
[0019]
Of these, to the transmission line L10 connected to the port P1 of the router 40, in addition to the IP-PBX control device 10, a data communication terminal such as a personal computer (not shown) or a server such as a DNS server can be connected.
[0020]
The router 40 may have a plurality of LAN-side ports such as the port P1 in addition to the WAN-side port P0, but here, for simplicity, it is assumed that the LAN-side port is only P1.
[0021]
The IP-PBX control device 10 connected to the transmission line L10 is a control device for the IP-PBX, and stores tables TB0 to TB4 to be described later.
[0022]
The IP-PBX is a server that provides a function of a PBX (private branch exchange) on a network using an IP protocol such as the base 35. In addition to the gatekeeper GK1 used for performing conversion (address conversion function) between a telephone number and an IP address unique to VoIP, various functions as a PBX (functions such as call forwarding and call forwarding) are also controlled by the IP-PBX It can be mounted on the device 10.
[0023]
When a user (for example, U0) of each IP telephone (for example, U20) makes a call on the VoIP network 30, the user U0 inputs to the IP telephone 20 only the telephone number of the other party. Since the only identifier that can be used to identify the communication partner is the IP address, the address conversion function provided by the gatekeeper GK1 is required.
[0024]
The physical range of the extension telephone network provided by the functions of the IP-PBX control device 10 is not limited to the IP telephones 20 to 23 existing under the IP-PBX control device 10 shown in FIG. ~ 34.
[0025]
When communication using this extension telephone network is performed between the bases 32 to 35, communication between the gatekeepers is performed between the gatekeepers of the IP-PBX control devices (corresponding to 10) at each base as necessary. Can be. The gatekeeper (for example, GK1) stores information necessary for the address translation function and the like for terminals (endpoints) in the zone managed by itself, but does not have the information for terminals outside the zone. Communication between gatekeepers is required.
[0026]
It is assumed that the zone managed by the gatekeeper GK1 mounted on the IP-PBX control device 10 includes the IP telephones (20 to 23, etc.) in the base 35.
[0027]
The LAN switch 11 connected to the IP-PBX control device 10 via the transmission line L1 is a network device such as a layer 2 switch or a switching hub, and provides a relay function belonging to the data link layer of the OSI reference model. . The broadcast domain can be expanded by the LAN switch 11 without expanding the collision domain, and the communication efficiency is improved.
[0028]
Although the number of ports of the LAN switch 11 may be any number, in the illustrated example, in addition to the port P11 connected to the transmission line L1, there are ports P12 to P14 connected to the transmission lines L2 to LL4. Therefore, the number of ports is four in total.
[0029]
A hub 12 is connected to the transmission line L2, and one or more IP telephones such as IP telephones 20 and 21 are arranged under the hub 12.
[0030]
Similarly, the hub 13 is connected to the transmission line L3, and one or more IP telephones such as the IP telephone 22 are disposed under the hub 13, and the hub 14 is connected to the transmission line L4 and controlled under the hub 14. , One or more IP telephones such as an IP telephone 23 are arranged.
[0031]
All transmission paths centered on each hub constitute one collision domain.
[0032]
For example, all the transmission lines L2, L20 and L21 around the hub 12 constitute one collision domain, all the transmission lines L3 and L22 around the hub 13 constitute one collision domain, and the hub 14 All transmission lines L4 and L23 constitute one collision domain.
[0033]
In a collision domain, when two or more transmission sources (for example, IP telephones and the like) transmit signals at the same time, the signals are physically destroyed due to collision (collision) and normal communication cannot be performed. Medium access control using CSMA / CD or the like can be performed. When a signal is transmitted from an IP telephone (for example, 20) in the collision domain, the IP telephone becomes a transmission source, but an IP telephone (for example, 20) in the collision domain is transmitted to another IP telephone in another collision domain. When a signal is received from an IP telephone (not shown) at (for example, 22) or another base (for example, 32), the port (for example, P12) of the LAN switch 11 is the transmission source.
[0034]
In this embodiment, one or more IP telephones belonging to the same collision domain constitute one band group.
[0035]
For example, IP telephones 20 and 21 constitute band group G0, IP telephone 22 constitutes band group G1, and IP telephone 23 constitutes band group G2.
[0036]
Since the IP telephones (for example, 20 and 21) belonging to the same band group are physically directly connected via the hub (for example, 12), at least physically, the LAN switch 11 or the IP-PBX control device 10 It is possible to communicate without passing through the LAN switch 11. However, in order to communicate with an IP telephone belonging to another band group in the same base (here, 35), it is necessary to physically pass through the LAN switch 11. is there. Further, when communicating with an IP telephone (not shown) belonging to another site, it is necessary to physically pass through the IP-PBX control device 10, the LAN switch 11, and the router 40.
[0037]
In the LAN switch 11, various settings can be made as to how much physical band is prepared for the port P11 and the ports P12 to P14 on the hubs 12 to 14 side. The physical band corresponds to the speed of communication performed through the port, and in order to perform high-quality voice communication with little delay or interruption, communication between IP telephones within the range of the physical band prepared for each port is required. You need to communicate.
[0038]
In the general case where there is no significant difference in the number of IP phones belonging to each band group, any IP phone (eg, 20) in any band group has the highest probability of communicating with an IP phone belonging to another location. The second is considered to have the highest probability of communicating with IP telephones belonging to another band group in the same base, and the lowest probability of communicating with IP telephones belonging to the same band group. It is necessary to allocate a band on the assumption that communication is performed with an IP telephone belonging to the base.
[0039]
In this case, it is desirable to allocate the physical bandwidths of the ports P12 to P14 on the hubs 12 to 14 so that the total value is equal to or less than the physical bandwidth of the port P11.
[0040]
As long as the distribution is performed in this manner, the value of the physical band between the ports P12 and P14 may be set in any manner. However, in general, the larger the number of IP telephones belonging to the band group (connected to the hub) and the higher the operation rate, the better the band should be allocated.
[0041]
When there is a difference between the functions of the individual IP telephones 20 to 23, it is desirable that the distribution reflect the difference.
[0042]
In general, an IP telephone is a telephone that supports VoIP and is capable of directly transmitting and receiving IP packets containing voice data by directly connecting to an IP network, and is capable of at least performing voice communication using VoIP. Recommendation H. A call control function for processing a call control protocol corresponding to H.323, SIP, or the like can be installed.
[0043]
An IP telephone can be said to be at least capable of making a voice call corresponding to the VoIP. In addition, it has a function of transmitting and receiving IP packets containing moving image data (video data) and reproducing moving images. It may be compatible with video conference or data communication. Generally, a port (for example, a port connected to a band group including an IP telephone (for example, 23) corresponding to a video conference) requires a much larger amount of information than a voice to represent a moving image. , P14), it is necessary to allocate a large physical band.
[0044]
Audio data and video data communicated by the IP telephone belong to stream-type data that is reproduced while being downloaded. On the other hand, the data communicated by the data communication refers to data other than the stream type data (non-stream type data), and the reproduction is performed after the download is completely completed.
[0045]
There are various types of external appearances of IP telephones, such as those having the same appearance as ordinary telephones, those having a personal computer equipped with a speaker or a microphone so as to function as an IP telephone, and those having the appearance of a PDA terminal. There are things to have.
[0046]
Although depending on the physical functions of the IP telephones 20 to 23, the transmission lines L2 to L4 and L20 to L23 are not necessarily wired transmission lines, but may be wireless transmission lines. .
[0047]
For transmission of a control signal (call control message) exchanged between IP telephones for call control, a different transmission path from that shown in FIG. 1 may be used. The transmission line (L10, L1, etc.) shown in FIG. For example, when a transmission path different from that shown in FIG. 1 is used, it is possible not to use the IP packet for transmitting the call control message, if necessary.
[0048]
When the call control message is exchanged using the transmission path shown in FIG. 1, strictly speaking, the physical band of each port is consumed even in the transmission of the call control message. Separately, a band for transmitting the call control message may be reserved in advance, but usually, the physical band consumed by the transmission of the call control message is consumed by the transmission of the voice data and the video data. Is much less than the physical bandwidth of
[0049]
If the port on the LAN side of the router 40 is only P1 and the bandwidth consumption by the data communication terminals and servers that can be arranged on the transmission line L10 is sufficiently small, the physical bandwidth of the port P11 of the LAN switch 11 Can be the same value as the physical band of the port P1.
[0050]
Further, if the port on the LAN side is only P1, the physical band of the port P1 can be set to the same value as the physical band of the port P0 on the WAN side (that is, the physical band of the access line L40). The physical band of the port P11 of the LAN switch 11 can be the same as the physical band of the access line L40.
[0051]
FIGS. 2 to 6 show detailed configuration examples of the tables TB0 to TB4 stored in the IP-PBX control device 10 described above.
[0052]
(A-1-1) Configuration example of each table
Table TB0 shown in FIG. 2 is a terminal communication specification table in which the bandwidth required for each IP telephone (for example, 20) to execute various communications is arranged for each IP telephone (that is, for each terminal). is there.
[0053]
The terminal communication specification table TB0 includes, as column names (data items), a terminal number, an audio bandwidth, a video bandwidth, and a data bandwidth, and "-" in the table indicates a null value. . The fact that the bandwidth (eg, video bandwidth) is null (“−”) means that the terminal (eg, IP telephone 20) corresponding to the row performs the communication (eg, video data communication). It has no function.
[0054]
The terminal number is identification information for uniquely identifying each of the IP telephones 20 to 23 in the entire band group G0 to G2 under the control of the IP-PBX control device 10. Various information can be used as the terminal number. For example, the telephone number (extension telephone number) assigned to each IP telephone may be used as it is.
[0055]
When an IP address (either global or private) is fixedly assigned to each of the IP telephones 20 to 23, the IP address can be used as a terminal number, and the IP address is a global IP address. In such a case, FQDN or the like can be used instead of the number.
[0056]
Further, when an IP address assigned to each IP telephone is dynamically changed by a DHCP server (not shown), the value of the terminal number may be updated in response to the change.
[0057]
In the examples of FIGS. 2 to 4, the terminal number of each IP telephone shown in FIG. 1 with “TE” added to the front of the code is used. Therefore, the terminal number of IP telephone 20 is TE20, the terminal number of IP telephone 21 is TE21, the terminal number of IP telephone 22 is TE22, and the terminal number of IP telephone 23 is TE23.
[0058]
The audio bandwidth indicates the bandwidth used by each IP telephone for audio data in the stream type data.
[0059]
Similarly, the video bandwidth indicates the bandwidth used by each IP telephone for video data in the stream type data.
[0060]
The data bandwidth indicates the bandwidth used by each IP telephone for data communication that is the non-stream type data.
[0061]
In the example of FIG. 2, the IP telephones 20 to 21 have a function of performing voice data communication and data communication, but do not have a function of performing video data communication, and the IP telephone 23 has a function of performing voice data communication and video data communication. It has a function to perform communication and data communication.
[0062]
However, this is only an example, and the functions of each of the IP telephones 20 to 23 need not be those shown in FIG. 2 as necessary. For example, all of the IP telephones 20 to 23 may be capable of performing voice data communication, video data communication, and data communication.
[0063]
However, in order to utilize the function of each IP telephone in actual communication, it is necessary that each transmission path (for example, L2) has a band that can perform communication corresponding to the function. . For example, if a function capable of performing video data communication is added to the IP telephone 20 and if 512 kbps is required for video data communication and 128 kbps is required for voice data communication, the voice data communication is required. In order to enable a video conference using both the communication of video and video data, it is usual to prepare a bandwidth of at least about 640 kbps (512 kbps + 128 kbps) as the physical band of the transmission line L2 (that is, the physical band of the port P12). It is.
[0064]
In the terminal communication specification table TB0, the same number of rows as the number of IP telephones (20 to 23, etc.) in the band groups G0 to G2 (for example, in FIG. 2, the top row is “TE20, 128, −, 64 ").
[0065]
Next, the table TB1 shown in FIG. 3 is a belonging band group table having the terminal numbers and band group identifiers as column names.
[0066]
Here, the band group identifier is information for uniquely identifying each band group G0 to G2 under the control of the IP-PBX control device 10. Here, a code obtained by adding “T” before the code assigned to each band group is used as a band group identifier. Therefore, the band group identifier of the band group G0 is TG0, the band group identifier of the band group G1 is TG1, and the band group identifier of the band group G2 is TG2.
[0067]
In the belonging band group table TB1, the band groups to which the IP telephones 20 to 23 belong are stored in association with the terminal numbers TE20 to TE23 and the like. By searching the belonging band table TB1 using, for example, a terminal number as a search key, it can be found that, for example, the IP telephone set 20 with the terminal number TE20 belongs to the band group G0.
[0068]
The table TB3 shown in FIG. 4 is a slide destination table having terminal numbers and slide destinations as column names. In the slide destination table TB3, a slide destination IP telephone is stored in association with the terminal numbers TE20 to TE23 and the like. The designation of the slide destination is also performed using the terminal number of the IP telephone.
[0069]
A null value “−” of the slide destination means that no slide destination is specified.
[0070]
If the incoming call cannot be received by the original destination IP telephone (for example, 20) due to lack of bandwidth in the transmission path (for example, L2), the destination of the incoming call designated as the slide destination Is to be called. If a band shortage is also recognized at the destination specified as the slide destination, the slide may be repeated a plurality of times.
[0071]
Various methods are conceivable as to how to determine the slide destination of a certain IP telephone (for example, 20). For example, according to the work range of the user (U0, U2, etc.) of each IP telephone, etc. It is good to decide.
[0072]
For example, if the business range of the user U2 of the IP telephone 22 is wide and the business range of the user U0 of the IP telephone 20 or the business range of the user U3 of the IP telephone 23 belongs to the business range, the IP telephone 20 Can be specified as the slide destination of the IP telephone 22 and the IP telephone 22 can be specified as the slide destination of the IP telephone 23.
[0073]
The table TB2 shown in FIG. 5 is a maximum bandwidth table for each bandwidth group having a bandwidth group and a maximum bandwidth as column names. In the maximum bandwidth table TB2 for each bandwidth group, the value of the maximum bandwidth is stored in association with the bandwidth groups G0 to G2.
[0074]
This maximum bandwidth (the maximum bandwidth for each band group) is equal to the physical band of the above-described transmission path (for example, the transmission path L2 in the case of the band group G0) corresponding to each band group.
[0075]
A table TB4 shown in FIG. 6 is a used bandwidth table for each band group having a band group and a used bandwidth as column names. In the used bandwidth table TB4 for each bandwidth group, the value of the bandwidth currently in use (used bandwidth) is stored in association with the bandwidth groups G0 to G2.
[0076]
Since the value of the used bandwidth is the bandwidth actually used, it dynamically fluctuates during the operation of the VoIP network 30.
[0077]
The upper limit of the used bandwidth is the maximum bandwidth for each band group.
[0078]
If the bandwidth used (bandwidth used for each band group) exceeds the maximum bandwidth for each band group, the quality of communication deteriorates. Therefore, when an incoming call is made to one of the IP telephones in the band group, the IP-PBX is used. It is necessary for the control device 10 to perform control so that the used bandwidth does not exceed the maximum bandwidth for each band group by communication of stream type data that can be performed after the incoming call. For this control, the slide or the like is required.
[0079]
On the other hand, FIG. 8 shows a configuration example of a main part of the IP-PBX control device 10.
[0080]
(A-1-2) Internal configuration example of IP-PBX control device
8, the IP-PBX control device 10 includes a communication unit 50, a control unit 51, a storage unit 52, a database 53, a search unit 54, a search result processing unit 55, and a slide processing unit 56. Have.
[0081]
The communication unit 50 transmits and receives a call control message, the stream type data, and the IP packet containing the non-stream type data via the transmission lines L10 and L1 at a portion connected to the transmission lines L10 and L1. obtain.
[0082]
Here, it is assumed that the call control message is accommodated in the IP packet and transmitted through the transmission path (L10, L1, etc.) shown in FIG.
[0083]
The control unit 51 corresponds to a central processing unit (CPU) of the IP-PBX control device 10 in terms of hardware, and a portion corresponding to an operating system (OS), a DBMS, the gate keeper GK1, and the like in software. is there.
[0084]
In order for the gatekeeper GK1 to provide the above-described address conversion function and the like, it is, of course, necessary to equip various databases in which correspondences between IP addresses and telephone numbers are registered. It is not shown in FIG.
[0085]
The storage unit 52 is a work storage area, and is used by the control unit 51 and other components 54 to 56 to advance processing. The storage unit 52 can be configured using, for example, a RAM (random access memory).
[0086]
The database 53 is a part for storing the tables TB0 to TB4, and includes a storage device such as a hard disk in hardware.
[0087]
The search unit 54 performs a search on each of the tables TB0 to TB4 stored in the database 53, and supplies the obtained search results to the search result processing unit 55.
[0088]
The search result processing unit 55 performs a predetermined determination process based on the search result supplied from the search unit 54, and outputs a determination result signal corresponding to the result of the determination process to the control unit 51 or the slide processing unit. To 56.
[0089]
The determination process is a process executed for a call setting message requesting call setting among various call control messages. The control of the above-mentioned band group usage bandwidth so as not to exceed the band group maximum bandwidth depends on the function of the determination processing.
[0090]
The slide processing section 56 is a section which functions according to the determination result signal supplied from the search result processing section 55 when the slide is required, and realizes the slide. There are various methods for realizing the slide on the VoIP network 30. For example, the following method can be used.
[0091]
That is, the source IP telephone (for example, 21) requesting a call setup between a certain IP telephone (for example, 23) and the IP telephone of the gate keeper GK1 perform the address conversion function before transmitting the call setup message. In order to inquire about the IP address of the IP telephone 23, if the slide processing unit 56 returns the IP address of the slide destination IP telephone 22 instead of the IP address of the IP telephone 23, the IP packet containing the call setting message becomes The slide is delivered to the IP telephone 22 at the slide destination, and the slide is realized.
[0092]
Alternatively, when the IP-PBX control device 10 relays an IP packet containing the call setting message with the IP address of the IP telephone 23 as the destination IP address in response to the inquiry, The destination IP address may be rewritten to the IP address of the IP telephone 22 at the slide destination. However, this method can be used only when the IP-PBX control device 10 physically intervenes between the source IP telephone and the destination IP telephone.
[0093]
Both the source IP telephone and the destination IP telephone exist under the IP-PBX control device 10 in the base 35, and in the case of adopting the network configuration shown in FIG. 1, the IP address of the IP telephone 23 is changed to the destination IP address. Since there is a possibility that the IP packet is received by the IP telephone 23 and the incoming response is executed before being received by the IP-PBX control device 10, the IP-PBX control device 10 itself, for example, responds to the inquiry. It is necessary to return the IP address of the server.
[0094]
Hereinafter, the operation of the present embodiment having the above configuration will be described with reference to the flowchart of FIG.
[0095]
The flowchart of FIG. 7 includes steps S10 to S19.
[0096]
(A-2) Operation of the embodiment
Here, as an example, the case where IP telephone 21 requests call setting to IP telephone 23 is taken as an example.
[0097]
When an inquiry is made from the source IP telephone 21 to the address conversion function of the gate keeper GK1 based on the telephone number of the destination IP telephone 23 (S10), the conventional incoming call determination processing is performed. It is executed (S11). In this incoming call determination processing, the presence or absence of the above-described blocked, faulty, unanswered, or other conditions is checked for the destination IP telephone 23.
[0098]
In step S11, if the destination IP telephone 23 is blocked, corresponds to any of the failure occurrences, and does not respond, the corresponding processing is performed. If not, the processing proceeds to step S12. This is different from the conventional method in which the call is immediately received by the IP telephone 23 when none of the above applies.
[0099]
In step S12, the terminal communication specification table TB0 is searched using the terminal number as a search key, and when the call setting message is received by the IP telephone 23, how much bandwidth is consumed for communication of stream type data after the call setting. Find out what to do.
[0100]
Only the destination IP telephone 23 or the source IP telephone 21 may be examined, but both may be examined and the smaller one may be set as the band required for the communication. .
[0101]
If the communication specifications (contents stored in the table TB0) of both the IP telephones 23 and 21 that communicate with each other are the same, only one of the source and the destination may be checked. May be different, and in that case (assuming that communication is possible even if the communication specifications are different), it is considered that communication is performed in a form that matches the lower grade of the communication specification. is there.
[0102]
A lower grade means that less bandwidth is required or less communication functions are available.
[0103]
For example, in the example of FIG. 2, the terminal communication specification table TB0 indicates that the destination IP telephone 23 has a function of communicating video data at 512 kbps, while the source IP telephone 21 has a function of communicating video data. Since it does not have this, the bandwidth required for communication is 128 kbps of the audio bandwidth (192 (= 128 + 64) kbps if there is a possibility of executing data communication simultaneously and in parallel).
[0104]
Here, it is assumed that the bandwidth required for communication between the IP telephones 21 and 23 is 128 kbps.
[0105]
In searching the terminal communication specification table TB0, it is necessary to specify a terminal number as a search key. For this specification, the telephone number of the IP telephone 23 used for the inquiry in step S10, The source IP address of the IP packet, the contents stored in various databases provided in the gatekeeper GK1 for the address conversion function, and the like can be used.
[0106]
In step S13 following step S12, the band group identifier of the band group to which the destination IP telephone set 23 belongs is checked by searching the belonging band group table TB1 using the terminal number TE23 as a search key. Using the search key (here, TG2) as a search key, the bandwidth usage table TB4 for each bandwidth group is searched to check the bandwidth usage of the bandwidth group G2 at the present time.
[0107]
Then, the required bandwidth 128 kbps obtained in step S12 is added to the used bandwidth to obtain an addition result (S14). In the example of FIG. 6, since the used bandwidth of the band group G2 is 128 kbps, the addition result is 256 kbps.
[0108]
Next, the maximum bandwidth 1024 kbps of the bandwidth group G2 obtained by searching the maximum bandwidth table TB2 for each bandwidth group using the bandwidth group identifier TG2 as a search key is compared with the magnitude of this addition result (S15).
[0109]
In this example, since the addition result is 256 kbps, which is smaller than the maximum bandwidth, step S15 branches to the No side, and in response to the inquiry in step S10, the IP address of the IP telephone 23 is returned. The call setting message is received by the telephone 23 (S18). In this case, even if the communication between the IP telephones 21 and 23 is started after the incoming call, the communication quality of the IP telephones (other than 23 is not shown) belonging to the band group G2 does not deteriorate.
[0110]
On the other hand, if the addition result exceeds the maximum bandwidth of the band group G2, step S15 branches to Yes and step S16 is executed.
[0111]
In step S16, the slide destination table TB3 is searched using the terminal number of the IP telephone 23, which is the destination, as a search key, and it is checked whether the slide destination of the IP telephone 23 is specified to be valid.
[0112]
In the example of FIG. 4, since the IP telephone 22 of the terminal number TE22 is specified as the slide destination of the IP telephone 23, the step S16 branches to the Yes side, and the IP-PBX control device 10 responds to the inquiry of the step S10. Returns the IP address of the IP telephone 22 (S17).
[0113]
Thereafter, the process returns to step S10.
[0114]
At this time, since the IP address of the IP telephone 22 at the slide destination has already been obtained, the IP packet containing the call setting message can be transmitted from the IP telephone 21 to the IP telephone 22 as needed, if necessary. It is.
[0115]
However, even within the band group G1 to which the IP telephone 22 of the slide destination belongs, it is necessary to prevent the used bandwidth from exceeding the maximum bandwidth and to prevent the communication quality from being lowered. The process returns to step S10.
[0116]
The loop composed of steps S10 to S17 is repeatedly executed, and when step S15 branches to No, the destination (slide destination) at that time becomes the destination of the IP packet containing the call setting message.
[0117]
Since the step S15 is branched to the No side, before the incoming call processing is performed, the communication that is already being executed in the band group to which the destination IP telephone belongs and / or the call incoming processing is newly started. Communication quality is not degraded.
[0118]
If there is no designation of the slide destination in the row corresponding to the IP telephone 23 in the slide destination table TB3, the process at step S16 branches to No and the terminal closing process is executed (S19). Various specific examples of the processing when the terminal is blocked can be considered. For example, the user U0 of the source IP telephone 21 may hear a predetermined busy tone.
[0119]
Further, by performing the slide, the load associated with the incoming call can be distributed as much as possible within the band groups G0 to G2 as compared with the case of simply executing the process at the time of closing (corresponding to S19). The likelihood of a quick response (call setting acceptance message) being obtained at an early stage increases the availability and improves the usability for the source user U0.
[0120]
(A-3) Effects of the embodiment
As described above, according to the present embodiment, high communication quality can be maintained.
[0121]
In addition, in the present embodiment, by executing the slide, it is possible to increase availability while maintaining high communication quality.
[0122]
(B) Other embodiments
The IP-PBX control device 10 in the above embodiment can be replaced with a combination of a VoIP gateway and an existing PBX. In this case, however, the constituent elements 11 to 14, 20 to 23 under the control of the IP-PBX control device 10 are also changed. For example, the IP telephones 20 to 23 are ordinary telephones having no VoIP function.
[0123]
Further, in the above-described embodiment, an extension telephone network having a plurality of locations has been described as an example. However, an extension telephone network which can be completed only within one LAN (corresponding to one location) may be used as necessary. Is natural.
[0124]
Further, in the flowchart of FIG. 7 of the above-described embodiment, for only the band group to which the destination IP telephone (for example, 23) belongs, it is checked whether the band group use bandwidth does not exceed the band group maximum bandwidth. However, the same check may be performed on the band group to which the source IP telephone (for example, 21) belongs.
[0125]
This is because even if the used bandwidth does not exceed the maximum bandwidth at the destination, it may exceed the maximum bandwidth at the source, and in that case, the communication quality is reduced.
[0126]
However, when the source IP telephone belongs to another base (for example, 32), such consideration is not necessary. This is because the IP-PBX control device 10 manages only the IP telephones (20 to 23, etc.) in the base 35.
[0127]
Further, in the above embodiment, VoIP for performing voice communication and the like on the IP network has been described as an example, but the IP network can be replaced with another network. For example, the present invention is also applicable to VoFR for performing voice communication on a frame relay network.
[0128]
Further, the network configuration in the base 35 in the above embodiment need not necessarily be limited to the above-described one. For example, the present invention can be applied to a network configuration including a plurality of LAN switches 11 and a network configuration having a router (different from 40) inside the base 35.
[0129]
Note that the configurations (schema) of the tables TB0 to TB4 shown in FIGS. 2 to 6 are merely examples, and various tables having the same function as a whole can be used.
[0130]
In the above embodiment, the tables TB0 to TB4 based on the relational data model are used. However, if necessary, a database based on a data model other than the relational data model (network type or hierarchical type data model) may be used. Good.
[0131]
In the above description, the present invention is mainly realized by hardware, but the present invention can also be realized by software.
[0132]
【The invention's effect】
As described above, according to the present invention, high communication quality can be maintained.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an example of the overall configuration of a VoIP network according to an embodiment.
FIG. 2 is a schematic diagram illustrating a configuration example of a table used in the embodiment.
FIG. 3 is a schematic diagram illustrating a configuration example of a table used in the embodiment.
FIG. 4 is a schematic diagram illustrating a configuration example of a table used in the embodiment.
FIG. 5 is a schematic diagram illustrating a configuration example of a table used in the embodiment.
FIG. 6 is a schematic diagram illustrating a configuration example of a table used in the embodiment.
FIG. 7 is a flowchart illustrating the operation of the embodiment.
FIG. 8 is a schematic diagram showing a configuration example of a main part of an IP-PBX control device used in the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... IP-PBX control apparatus, 11 ... LAN switch, 12-14 ... Hub, 20-23 ... IP telephone, 30 ... VoIP network, 31 ... IP network, 32-35 ... Base, 50 ... Communication part, 51 ... Control Unit, 52 storage unit, 53 database, 54 search unit, 55 search result processing unit, 56 slide processing unit, TB0 to TB4 table.

Claims (2)

In a bandwidth management system of a communication network that processes an incoming message by sharing the same bandwidth resource among a plurality of communication terminals and performs communication,
For the plurality of communication terminals, incoming processing means for performing incoming processing including sorting of the incoming message,
For each of the communication terminals, an incoming call destination management unit that manages in association with another communication terminal that is allowed as a destination of the incoming message specifying the own communication terminal,
The bandwidth management system according to claim 1, wherein the incoming call processing means distributes the incoming message to the other communication terminal according to a current band usage status of the own communication terminal. The bandwidth management system according to claim 1,
Among the bandwidth resources, an assigned bandwidth management unit that manages the value of the assigned bandwidth resource assigned to each communication terminal in association with each communication terminal,
Allocated bandwidth management means for managing, in association with each communication terminal, a value of a used bandwidth resource currently used by each communication terminal for communication at the present time among the bandwidth resources. Management system.

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