JP2007116632A - Router apparatus with ip phone call processing function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a router apparatus for guaranteeing call control operation and voice quality regardless of a resource use status varying at all the time in a router apparatus comprising a phone call processing function for IP phone or the like. <P>SOLUTION: The present invention relates to a router apparatus including a routing processing unit and an IP phone call processing unit wherein the processing units share a predetermined transmission band. A call control signal supplied to the IP phone call processing unit is detected and in response to the detection of the call control signal, bandwidth limit processing is performed for limiting transmission bandwidth available for the routing processing unit to a part of full transmission bandwidth of the predetermined transmission band. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a router apparatus having an IP telephone processing function as well as a routing function, and more particularly to a router apparatus including a routing processing unit and an IP telephone processing unit that share resources such as a transmission band and a CPU.

  The main function of a router device connected to an IP network such as the Internet is to perform routing processing and transfer processing on packets to be transmitted and received. However, recently, by providing an interface with a voice communication device such as a telephone or PBX, a voice processing function and a call control function for encoding and packetizing a voice signal from these devices are installed in the router device. The router device itself has come to have an IP telephone processing function.

  For example, the “packet transmission / reception method for voice-capable router” disclosed in Patent Document 1 uses a conventional router function such as bandwidth control, priority control, and discard control to convert voice packets packetized by a voice processing unit into voice. It is said that the quality of voice communication can be assured by processing so as to be optimal for communication.

However, the disclosed technology provides a policy table in which various packets including voice packets are classified into classes classified by parameters such as an allowable delay amount, and packet reading from the buffer is scheduled according to such a table. That is, such a technique is nothing but an attempt to guarantee voice quality by setting in advance so as to preferentially process voice packets.
JP 2001-16254 A

  However, in a router apparatus having a voice processing function, since each of the routing processing unit and the voice processing unit independently occupies system resources such as a transmission band and a CPU, contention between the two becomes a problem. The CPU load by the routing processing unit changes from moment to moment depending on the amount of transmission data. On the other hand, the CPU load due to the voice processing unit increases greatly during the time when the encoding process and the decoding process are operated at the time of outgoing and incoming calls, resulting in a transient shortage of system resources. Such a situation not only delays the routing process and lowers the amount of transmission data per unit time, that is, the throughput, but also causes a problem that the voice process is delayed and the voice quality is lowered in the future.

  An object of the present invention is to provide a router apparatus that guarantees call control operation and voice quality regardless of resource usage state that is constantly changing in a router apparatus having a telephone processing function such as an IP telephone.

  The router device according to the present invention includes a routing processing unit and an IP telephone processing unit, and each of the processing units shares a predetermined transmission band, and detects a call control signal supplied to the IP telephone processing unit. And a bandwidth limiting process for limiting a transmission bandwidth usable by the routing processing unit to a part of the total transmission bandwidth of the predetermined transmission band in response to detection of the call control signal. And limiting means.

  According to the router device of the present invention, a configuration is provided that limits the amount of transmission band used for routing processing according to the supply of a call control signal. Thereby, the call control operation and the voice quality can be guaranteed.

  Embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a first embodiment of the present invention and shows the entire configuration including a router device. The router device 20 is a router device having an IP telephone function as well as a routing function. The router device 20 is connected to the telephone 10 via a telephone interface 21, is connected to a personal computer 30 via a LAN (Local Area Network) interface 22, and is connected to the Internet via a WAN (Wide Area Network) interface 23. Connected to line 40. The WAN interface 23 is an interface for connecting to an Internet line via an xDSL (x Digital Subscriber Line) or an FTTH (Fiber To The Home) ONU (Optical Network Unit). The router device 20 includes a voice processing unit 24 and a call control unit 25 connected to the telephone interface 21, and a routing processing unit 26 connected to the voice processing unit 24, the call control unit 25, the LAN interface 22 and the WAN interface 23. Including. In this embodiment, the IP telephone processing unit, which is a component of the present invention, is realized by the voice processing unit 24 and the call control unit 25.

The voice processing unit 24 performs analog / digital conversion on a voice signal from the telephone 10 or PBX (not shown), performs coding and packetization processing, and RTP (Realtime Transfer Protocol) received via the WAN interface 23. A packet format voice packet is converted from digital to analog and sent to the telephone 10 or PBX as a voice signal. The voice processing unit 24 further has a function of providing a number display service. 32 is provided with a function of sending a number display signal in accordance with 32.

  The call control unit 25 is configured by SIP (Session Initiation Protocol) or H.264. It has a function of performing call connection according to a call control protocol such as H.323, and incoming call processing such as off-hook operation and ringer transmission between the telephone 10 and the PBX.

  The routing processing unit 26 has a function of performing normal routing processing and packet transfer processing on packets transmitted and received via the LAN interface 22 and the WAN interface 23. The routing processing unit 26 also has a function of limiting the bandwidth to be used by buffering and delaying or discarding packets to be transferred.

  FIG. 2 shows a processing procedure for bandwidth limitation according to the call control signal. The processing procedure is executed in cooperation with the telephone 10 and the call control unit 25, the voice processing unit 24, the routing processing unit 26, and the WAN interface 23 included in the router device 20.

  First, when the telephone 10 performs a transmission operation, an off-hook signal, which is a call connection request signal, is sent to the call control unit 25 (step S01). When detecting the off-hook signal, the call control unit 25 sends a bandwidth limit request message to the routing processing unit 26 (step S02). When the routing processing unit 26 receives the bandwidth limitation request message from the call control unit 25, the routing processing unit 26 starts bandwidth limitation by limiting the bandwidth used for the routing processing to a bandwidth according to a predetermined limit value ( Step S03). This bandwidth limitation reduces the used transmission band used by the routing processing unit 26, that is, the throughput, to the band in which the voice processing unit 24 and the call control unit 25 can normally operate in the routing processing of the routing processing unit 26. Is done.

  Referring now to FIG. 8, the graph shows the change in router throughput before and after performing bandwidth limitation. Here, for example, when the predetermined transmission bandwidth of the router device 20, that is, the maximum throughput is 95 Mbps, the maximum throughput allocated to the routing process is limited to a limit value of 75 Mbps. As a result, it is understood that a margin bandwidth of 15 Mbps that can be used for voice processing is secured. The limit value that determines how much the throughput to be subjected to the routing process is limited needs to be determined in a range in which the voice processing unit 24 and the call control unit 25 operate normally by measurement in advance.

  Referring again to FIG. 2, during this bandwidth limitation, a telephone call is made between the telephone 10 and the other party (not shown) via the WAN interface 23 (step S04). Next, when the telephone call is ended, the telephone 10 sends an off-hook signal, that is, a disconnection request signal to the call control unit 25 (step S05). Alternatively, a disconnection request message is supplied from the other party via the WAN interface 23 (step S06). The disconnection request message from the WAN interface 23 is, for example, a BYE message when the SIP protocol is used. When the H.323 protocol is used, it is a RELCOMP message.

  The call control unit 25 detects a disconnection request signal from the telephone 10 or a disconnection request message from the WAN interface 23 (step S07), and sends a bandwidth restriction release request message to the routing processing unit 26 (step S08). ). When receiving the bandwidth limitation release request message from the call control unit 25, the routing processing unit 26 releases the previous bandwidth limitation started in step S03 (step S09). For example, in the previous example in which the maximum throughput of the router device 20 is 95 Mbps, the maximum throughput assigned to the routing process is restored to 95 Mbps again.

  FIG. 3 is a sequence diagram showing a processing procedure for bandwidth limitation according to the SIP message.

  First, when the other party of the WAN interface 23 performs a transmission operation, an incoming request message is sent to the call control unit 25 (step S11). The incoming request message is an INVITE message if the SIP protocol is used. In the case of H.323 protocol, it is a SETUP message.

  When the call control unit 25 detects the incoming request message, it sends a bandwidth limitation request message to the routing processing unit 26 (step S12). When the routing processing unit 26 receives the bandwidth limitation request message from the call control unit 25, the routing processing unit 26 starts bandwidth limitation by limiting the bandwidth used for the routing processing to a bandwidth according to a predetermined limit value ( Step S13). During this bandwidth limitation, a telephone call is made between the telephone 10 and the other party (not shown) via the WAN interface 23 (step S14).

  Thereafter, similarly to the processing procedure shown in FIG. 2, the call control unit 25 detects a disconnection request signal (step S15) from the telephone 10 or a disconnection request message (step S16) from the WAN interface 23 (step S16). In step S17, a bandwidth limitation release request message is sent to the routing processing unit 26 (step S18). The routing processing unit 26 releases the previous bandwidth limitation (step S19).

  FIG. 4 shows a bandwidth limit processing procedure for guaranteeing the display of the number display. Here, when the other party of the WAN interface 23 performs a transmission operation, an incoming request message is sent to the call control unit 25 (step S21). The incoming request message is an INVITE message if the SIP protocol is used. In the case of H.323 protocol, it is a SETUP message. When detecting the incoming request message, the call control unit 25 sends a bandwidth limit request message to the routing processing unit 26 (step S22). When the routing processing unit 26 receives the bandwidth limitation request message from the call control unit 25, the routing processing unit 26 starts bandwidth limitation by limiting the bandwidth used for the routing processing to a bandwidth according to a predetermined limit value ( Step S23).

After the routing processing unit 26 performs the bandwidth limitation, the voice processing unit 24 performs ITU-T V. The number display signal according to 32 is sent to the telephone 10 (step S24).
. Thereby, the telephone 10 can display the caller telephone number.

In the first embodiment described above, the bandwidth of the routing processing unit is limited at the time of outgoing or incoming calls, so that the bandwidth is limited even when a routing process with the maximum throughput occurs. Is suppressed, and it is guaranteed that the voice processing unit and the call control unit operate normally. As a result, it is possible to avoid the deterioration of the voice quality due to the voice processing unit not operating normally, the phenomenon that the call control unit does not operate normally and the outgoing or incoming calls cannot be performed, and the number display processing failure. On the other hand, in a state in which no outgoing or incoming calls occur and voice processing is not operating, the routing processing unit can achieve its original maximum throughput performance.
<Second embodiment>
FIG. 5 shows a second embodiment of the present invention and shows the entire configuration including the router device. As in the case of the first embodiment, the router device 20 in the second embodiment includes a voice processing unit 24 and a call control unit 25 connected to the telephone interface 21, a voice processing unit 24, and a call control unit 25. And a routing processing unit 26 connected to the LAN interface 22 and the WAN interface 23. In this embodiment, the IP telephone processing unit, which is a component of the present invention, is realized by the voice processing unit 24 and the call control unit 25.

  The routing processing unit 26 is provided with a throughput monitoring unit 28. In addition, the call control unit 25 holds a control request permission flag 27 for designating whether the transmission of the bandwidth control request message is permitted (ON) or prohibited (OFF), and its initial value is set to prohibited (OFF). Has been. As a result, the bandwidth control function operates only in an environment where the throughput related to the routing process, that is, the router throughput affects the voice call.

  FIG. 6 shows a processing procedure for throughput monitoring processing. Such a throughput monitoring process is executed by cooperation between the throughput monitoring unit 28 and the call control unit 25 included in the router device 20. Here, the call control unit 25 sets the initial value of the restriction request permission flag to OFF in advance (step S31).

  Throughout the state where there is no voice call, the throughput monitoring unit 28 monitors the throughput (step S32). Then, it is determined whether or not the maximum throughput that instantaneously uses the maximum bandwidth exceeds a predetermined limit value (step S33). If exceeded, the throughput monitoring unit 28 transmits a determination message to the call control unit 25. If not exceeded, the throughput monitoring unit 28 continues monitoring (step S32). The predetermined limit value is determined so as to have a bandwidth of 80 Mbps as in the case of the first embodiment, for example.

When the call control unit 25 receives the determination message from the throughput monitoring unit 28, the call control unit 25 updates the held control request permission flag 27 to ON (step S34).
Set. Although not shown, when the maximum throughput falls below the limit value, the determination message is also notified to the call control unit 25, and the value of the limit request permission flag is returned to the initial value OFF again.

  FIG. 7 shows a processing procedure for bandwidth limitation involving throughput monitoring processing. Here, it is assumed that the initial value of the control request permission flag 27 is set to OFF.

  First, when the telephone 10 performs a transmission operation, an off-hook signal is sent to the call control unit 25 (step S41). When the call control unit 25 detects the off-hook signal, the call control unit 25 determines whether the value of the restriction request flag is ON or OFF (step S42). If it is determined to be ON, the call control unit 25 sends a bandwidth limitation request message to the routing processing unit 26 (step S43). When receiving the bandwidth limitation request message from the call control unit, the routing processing unit 26 limits the bandwidth set in advance to start bandwidth limitation (step S44).

  On the other hand, when it is determined that the value of the restriction request flag is OFF, the bandwidth restriction request message is prohibited, so that the call control unit 25 does not transmit the bandwidth restriction request message. As a result, the routing processing unit 26 does not execute bandwidth limitation (step S45). Thereafter, a telephone call is made between the telephone 10 and the other party (not shown) via the WAN interface 23 (step S46).

  In the second embodiment described above, unlike the configuration of the first embodiment in which the bandwidth control request message is unconditionally transmitted from the call control unit 25 to the routing processing unit 26 in response to outgoing or incoming calls, The bandwidth control request message is transmitted only when the request permission flag 27 is ON. When the control request permission flag 27 is OFF, the call control unit 25 does not transmit a bandwidth control request message to the routing processing unit 26 even if a call request or an incoming request is detected. In a network environment such as ADSL (Asymmetric Digital Subscriber Line) having a separate telephone line, the routing process does not affect the voice call. In such a usage mode, there is a disadvantage that the bandwidth message transmission processing of the call control unit and the bandwidth limitation processing of the routing processing unit impede the performance of the original routing processing. The configuration of this embodiment can avoid such inconvenience.

  In the above embodiments, the example of the router apparatus having the wired LAN interface has been described. However, the communication control method and apparatus according to the present invention is not limited to the router apparatus having the wired LAN interface, but the wireless LAN interface. The present invention can also be applied to a router device with a wireless access point function having an ace.

1 is a block diagram illustrating an overall configuration including a router device according to a first embodiment of this invention. FIG. It is a sequence diagram which shows the processing procedure of the bandwidth restriction | limiting according to a call control signal. It is a sequence diagram which shows the processing procedure of the bandwidth restriction | limiting according to a SIP message. It is a sequence diagram which shows the processing procedure of the bandwidth restriction | limiting for guaranteeing the display of a number display. It is a block diagram which shows the 2nd Example of this invention and shows the whole structure containing a router apparatus. It is a sequence diagram which shows the process sequence of a throughput monitoring process. It is a sequence diagram which shows the processing procedure of the bandwidth restriction | limiting according to a call control signal. It is a graph which shows the change of the router throughput before and after starting a bandwidth restriction | limiting.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Telephone 20 Router apparatus 30 Personal computer 40 Internet line 21 Telephone interface 22 LAN interface 23 WAN interface 24 Voice processing part 25 Call control part 26 Routing processing part 27 Control request permission flag 28 Throughput monitoring part

Claims (5)

A router device including a routing processing unit and an IP telephone processing unit, each of the processing units sharing a predetermined transmission band,
Detecting means for detecting a call control signal supplied to the IP telephone processing unit;
Limiting means for performing a bandwidth limiting process for limiting the transmission bandwidth usable by the routing processing unit to a part of the total transmission bandwidth of the predetermined transmission band in response to detection of the call control signal;
A router device comprising:   2. The router device according to claim 1, wherein the detecting means detects a call connection request signal or a call connection request message in an IP telephone system as the call control signal.   2. The router device according to claim 1, wherein the limiting unit performs the bandwidth limiting process by causing the routing processing unit to delay or discard a transmission packet supplied thereto.   The limiting means includes means for monitoring a maximum instantaneous transmission bandwidth used by the routing processing unit and prohibiting the execution of the bandwidth limiting process unless the maximum instantaneous transmission bandwidth exceeds a predetermined width. The router device according to claim 1.   2. The router device according to claim 1, wherein the IP telephone processing unit has a call control function, a voice processing function, and a number display display function.

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