JP2002290478A - Communication route optimizing method for voice packet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To optimize a route for voice over IP packet before a call starts. SOLUTION: In a network where a route optimization is implemented between a general terminal and a mobile terminal by a home agent 6 and a call agent 8 via a gateway 9 via a general gateway, the gateway 9, through which the general terminal is routed is equipped with a step 411 which transmits dummy voice packets in response to a ringing or ringing message 409 made by the mobile terminal before the phone call starts, and the home agent 6, which controls the general terminal, sends a bind message containing the address of the mobile terminal after receiving the dummy voice packet transmission, in a step 414. The gateway 9 starts the route optimizing procedure 415 after receiving the bind message.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to Mobile I
The present invention relates to a procedure for optimizing a route of a voice IP (VoIP) packet in a network that realizes P (Internet Protocol).

[0002]

2. Description of the Related Art IP (Internet Protocol)
ol) When a terminal having an address moves across subnets, as a method for maintaining communication without interrupting the session, the MT uses Internet Entrance (IETF).
gining TaskForce)
Obile IP has been proposed. This Mobile
In IP, an IP packet destined for MT must be HA
, So-called triangular routing is formed,
Transmission delay increases. When transmitting data such as VoIP that does not allow delay, such transmission delay becomes a serious problem.

[0003] Therefore, an Internet draft of IETF (draft-ietf-mobileip-opt) has been proposed.
im-10. txt), route optimization (Ro) is a method for eliminating the transmission delay caused by the above-described triangular routing.
Optimize) mechanism is proposed. That is, CN (correspondig Nod)
e) without going through HA (Home Agent)
This is a protocol for setting a shortcut path to a care-of address of T (Mobile Terminal).
FIG. 15 shows a Mobile I supporting route optimization.
On a Pv4 network, an operation in which a signaling message when VoIP is operated is route-optimized,
FIG. 16 shows an operation in which the route of the voice IP packet is optimized.

In FIG. 15, 1 is an IP network,
2 is PSTN (Public Switched Te)
lephone Networks), 3 is MT, 4 is BTS (base station), 5 is RNC (Radio Network).
ork Controller), 6 is MT3 HA,
7 is an FA (Fore) for the MT3 in the RNC5.
8 is a CA (Call Agent) that processes VoIP signaling, and 9 is a GW (Gateway) that connects the IP network 1 and the PSTN 2.
y) 10, 10 is the communication partner terminal CN of MT3 communication, 11 is HA
IP tunnel from 6 to FA7, 12 is set by the route optimization mechanism and C to which signaling messages are transferred
This is an IP tunnel from A8 to FA7. In FIG. 17, reference numeral 16 denotes a voice IP set by the route optimization mechanism.
This is an IP tunnel from the GW 9 to the FA 7 where packets are transferred.

[0005] The operation of transmitting a VoIP signaling message from the CN 10 to the MT 3 and optimizing the route will be described with reference to FIG. Se sent from CN10
The tap message 13 arrives at the CA 8 via the GW 9. In CA8, the callee's I
The P address is searched, and the message 14 is transmitted to the MT3 home address. Message 14 is H
The packet is encapsulated in A6 and transmitted to the MT3 via the IP tunnel 11. In HA6, message 14
, The route optimization mechanism operates, and the message 15 is used to notify the CA 8 of the FA 7 address, which is the care-of address of the MT 3, using the message 15. With this notification, the IP tunnel 12 from the CA 8 to the FA 7 is set,
Thereafter, a message from the CA 8 to the home address of the MT 3 is transmitted to the FA 7 by using the shortest tunnel IP tunnel 12 without passing through the HA 6, and the route optimization is performed.

Referring to FIG. 17, a description will be given, with reference to FIG. 17, of an operation of starting a call after exchanging the signaling message shown in FIG. C
The voice from N10 is IP-packetized by GW9,
It is transmitted to the home address of MT3. Voice IP
The packet 17 is encapsulated in the HA 6 and transmitted to the MT 3 via the IP tunnel 11. In the HA 6, by receiving the voice IP packet 17, the route optimization mechanism works, and the GW 9 is transmitted using the message 18.
Is notified of the address of FA7, which is the care-of address of MT3. By this notification, GW9 to FA7 IP
After the tunnel 16 is set, a message from the GW 9 to the home address of the MT 3 is transmitted using the shortest tunnel IP tunnel 16 without passing through the HA 6.
The data is transmitted to the FA 7 and the route optimization is performed.

[0007]

As described above, VoI
Since the route optimization of the signaling message of P and the voice IP packet is performed independently, immediately after the voice call starts,
For voice IP packets, route optimization has not been performed yet, so that the delay time is large and voice is disturbed. In addition, the route optimization mechanism works for the first time by the voice IP packet immediately after the start of the voice call, and the voice IP packet before the route optimization has not been performed may be overtaken by the route-optimized voice packet. There is. In this case, there is a problem that the overtaken voice IP packet is discarded. Furthermore, there is a lifetime in the route optimization path, and if no packet is transmitted for a certain period of time or more, the path returns to a normal triangle path passing through the HA. Therefore, if a silent state continues for a certain period of time or more during a call, the path returns to a normal triangle path passing through the HA, and the overtaken voice IP packets are discarded.

The present invention has been made to solve the above-mentioned problem, and obtains an optimized voice IP route before a call, thereby eliminating the possibility of discarding packets. The same applies to a silent state during a call.

[0009]

A voice packet communication channel optimizing method according to the present invention is generally used in a network for optimizing a route between a general terminal and a mobile terminal via a gateway by a home agent and a call agent. The gateway through which the terminal passes is a step of transmitting a dummy voice packet in response to a call or response from the mobile terminal prior to the start of a call, and the home agent managing the mobile terminal receives the dummy voice packet transmission and moves. Bind containing the terminal address
Sending a message, wherein the gateway initiates route optimization upon receiving the bind message.

Further, the gateway transmits a dummy voice packet as a response to the ringing from the mobile terminal.

Further, the gateway transmits a dummy voice packet in response to a call from the mobile terminal.

[0012] Furthermore, a timer is provided in the gateway, and the silence state is triggered after the start of the call to operate the timer, and when the silence state continues for a certain period of time, a dummy voice packet is transmitted.

Still further, the management agent provided in the network stores the management agent address of the mobile terminal in response to the call from the general terminal, adds the stored address to the call response from the mobile terminal, and transmits the response to the gateway. Instead of transmitting the dummy voice packet and transmitting the bind message, the gateway starts route optimization in response to the transmission from the management agent.

In place of the general terminal via the gateway, a call is made with another mobile terminal, and in place of the gateway, an agent for managing the other mobile terminal and an agent for managing the mobile terminal are provided. A step of transmitting a dummy voice packet is provided, and route optimization is started.

[0015] A step of making a call with the Internet terminal instead of the general terminal via the gateway, the step of transmitting the dummy voice packet by the Internet terminal instead of the gateway, and starting the route optimization are provided. .

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a network configuration diagram showing an embodiment of a voice optimizing routing method according to the present invention. In FIG. 1, 1 is an IP network, and 2 is a PSTN (Public Switch).
head Telephone Networks), 3
Is MT (Mobile Terminal), 4 is BT
S (base station), 5 is RNC (Radio Network)
k Controller), 6 is the MT3 HA (Ho)
me Agent), 7 is an FA for the MT 3 in the RNC 5, 8 is a CA (Call Agent), and 9 is a GW (Ga) connecting the IP network 1 and the PSTN 2.
teway), 10 is CN (Correspondin)
g Node), 11 is an IP tunnel from the HA 6 to the FA 7, 17 is a dummy voice IP packet transmitted from the GW to the MT, and 19 is the dummy voice IP packet 1
From GW9 to FA7 route optimized by IP7
It is a tunnel. In the present embodiment, VoI
Session Initiat as P protocol
e Protocol (hereinafter referred to as SIP) is assumed. Other protocols such as H.323 may be used.

FIG. 2 shows a network model shown in FIG. 1. In the case where the CN 10 transmits to the MT 3, the GW 9 transmits a dummy voice IP packet to the MT 3 when receiving a Ringing message before the completion of call setup. This is an operation sequence for setting a route optimization path for voice IP packets before starting a call. In FIG. 2 and the subsequent sequence diagrams,
The (BTS) base station is omitted because it is always transparent transfer.

FIG. 3 is a diagram showing a bind for performing route optimization.
13 shows a format of an ing Update message. Here, Mobile Node Home Ad
address 1200 indicates the home address of the MT;
are-of Address 1201 indicates the care-of address of the MT. Book Binding Upd
ate message is received by the Mobile.
When a packet addressed to the Node Home Address 1200 is received, the Care-of Addresses
The route optimization is performed by encapsulating the IP packet to the care-of address indicated by s1201 and performing tunneling.

Next, the sequence will be described with reference to FIGS. 1, 2 and 3. First, in FIG.
3 and a 400 Setup message is transmitted to the GW 9. G that received the Setup message 400
W9 transmits the 401 Invite message to CA8. The CA 8 that has received the Invite message 401 searches for the home address of the MT3, which is the IP address of the called party, from the called telephone number of the message,
A 402 Invite message is transmitted to MT3. The Invite message 402 is received by the HA 6 and encapsulated, and the Invite message 403 is transferred to the FA 7 via the IP tunnel 11. FA7 that received the Invite message 403
Performs decapsulation, and sends an Invite message 40
4 is transmitted to MT3 via BTS4. here,
The HA 6 that has received the Invite message 402 performs Mobile Node Home according to the format of FIG. 3 in order to optimize the route of the signaling packet.
The address 1200 is set to the home address of the MT3, and the Care-of Address 1201 is set to F
After setting the address of A7, Bind Update
The message 405 is transmitted to CA8. Bind U
The CA 8 having received the update message 405 encapsulates the signaling packet for the MT 3 received thereafter and transmits the encapsulated signaling packet to the FA 7 without passing through the HA 6.
Route optimization 406 of the signaling packet is performed.

The FA 7 having received the Ringing message 407 sends the Ringing message 408 to the CA 8.
The CA 8 that has received the Ringing message 408 transmits a Ringing message 409 to the GW 9. The GW 9 that has received the Ringing message 409 sends an Alert message 410 to the CN 10.
Send Here, the Ringing message 409
The GW 9 that has received the message transmits the dummy voice IP packet 411 to the MT3 from the address of the MT3 in the Ringing message. After the dummy voice IP packet 411 is received by the HA 6 and encapsulated, the dummy voice IP packet 412 is transferred to the FA 7 via the IP tunnel 11. The FA 7 that has received the dummy voice IP packet 412 performs decapsulation, and the dummy voice IP packet 413 is transmitted to the MT 3 via the BTS 4. Here, the HA 6 that has received the dummy voice IP packet 411 follows the format of FIG.
ile Node Home Address 1200
Is set to the home address of MT3, and Care-of
After setting the address of FA7 in Address 1201, a Bind Update message 414 is sent to the GW.
9 Bind Update message 41
The GW 9 that has received the packet No. 4 encapsulates the voice IP packet destined for the MT 3 to be received thereafter, without passing through the HA 6,
By transmitting the packet to A7, route optimization 415 of the voice IP packet is started, and optimization is performed at the start of call 424.

Next, F which has received the OK message 416
A7 sends an OK message 417 to CA8,
The CA 8 that has received the message 417 transmits an OK message 418 to the GW 9. OK message 418
The GW 9 which has received the message transmits a Connect message 419 to the CN 10. The GW 9 that has received the Connect ACK message 420 transmits an ACK message 421 to the CA 8. The CA 8 having received the ACK message 421 transmits an ACK message 422 to the FA 7 by optimizing the route of the signaling packet,
FA 7 sends an ACK message 423 to MT 3.

Here, the CN 10 and the MT 3 enter a call start state 424, and the voice IP packet 425 received by the GW 9 is routed to the voice IP packet 42 without passing through the HA 6 by route optimization of the voice IP packet.
6 is transmitted to the FA 7, and finally arrives at the MT 3 as a voice IP packet 427.

As described above, the voice I is transmitted before the communication state is established.
Since the setting of the route optimization of the P packet is started, the route optimization is performed immediately after the start of the voice call, and the fluctuation of the delay time is small and the voice is not disturbed. In addition, since route optimization is completed immediately after the start of the voice call, the disorder of the order of arrival of IP packets is reduced, so that the possibility of discarding packets is reduced as much as possible.

In the sequence of FIG. 2, the GW 9 has transmitted a dummy voice IP packet to the MT 3 upon receiving the Ringing message from the MT 3, but before the reception of the Ringing message, the GW 9 transmits the dummy voice IP packet to the MT 3.
At the time of resource negotiation performed at 0, a dummy voice IP packet may be transmitted to start route optimization of the voice IP packet. FIG. 4 is a sequence diagram showing such a case.

The sequence will be described with reference to FIGS. 1, 4 and 3. In FIG. 4, the setup is the same as in FIG.
Following the sequence from 500 to Bind Update 505, route optimization of the signaling packet is started. After this, Session Progress5
In the sequence of 07 to 509, a Session Progress message is transmitted from the MT3 to the GW 9 via the CA8. Session Progress
Upon receiving the ss message 509, the GW 9
The dummy voice IP packet 510 is transmitted to the MT3 from the address of the MT3 in the on Progress message. The dummy voice IP packet 510 is
The data is transmitted to the MT 3 via the HA 6 and the FA 7 as a dummy voice IP packet.

Here, the HA 6 receiving the dummy voice IP packet 510 follows the format of Mobile N according to the format of FIG. 3 in order to optimize the route of the voice IP packet.
The home address of MT3 is set in the mode Home Address 1200, and the Care-of Address is set.
After setting the address of FA7 in ss1201, Bin
The d Update message 513 is transmitted to the GW 9. The GW 9 that has received the Bind Update message 513 encapsulates the voice IP packet for the MT3 received thereafter and transmits the encapsulated voice IP packet to the FA 7 without passing through the HA 6, thereby performing the route optimization 514 of the voice IP packet. Therefore, by transmitting the dummy voice IP packet in this embodiment, the route optimization of the voice IP packet can be started at the time of resource negotiation, and therefore, at the time of starting a call, the route optimization of the voice IP packet is performed.

In the sequence of FIG. 4, MT3 and C3
At the time of resource negotiation performed in N10, G
Although W9 has transmitted the dummy voice IP packet to the MT3, the dummy voice IP packet may be transmitted to start route optimization of the voice IP packet when resources are secured between the MT3 and the CN 10. FIG. 5 is a sequence diagram in such a case.

The sequence will be described with reference to FIGS. 1, 5 and 3. In FIG. 5, as in FIG.
Following the sequence of Bind Update 605 from 00, the route optimization of the signaling packet is started, and the session progress 607 is OK from Session Progress 607.
In the sequence of 615, resource negotiation is performed. After this, resources are secured until the sequence of OK626.
The GW 9 that has transmitted the MET message 616 transmits a dummy voice IP packet 619 to the MT 3. The dummy voice IP packet 619 is converted into a voice IP packet of 620 to 621 via the HA 6 and the FA 7 as an MT.
3 is sent.

Here, the HA 6 that has received the dummy voice IP packet 619 performs the route optimization of the voice IP packet, so that the HA 6 shown in FIG.
The te message 622 is transmitted to the GW 9. Bind
GW9 that received the Update message 622,
By encapsulating the voice IP packet for MT3 received thereafter and transmitting it to the FA 7 without going through the HA 6,
Route optimization 623 of the voice IP packet is performed. Thus, by transmitting the dummy voice IP packet 619,
Route optimization of voice IP packets can be performed when resources are secured, and route optimization of voice IP packets is performed immediately after the start of a call.

Embodiment 2 FIG. In the above embodiment, PS
Although the case where the call is activated from the CN connected to the TN has been described, the case where the call is activated from the MT will be described here. FIG. 6 shows the network model shown in FIG.
When MT3 makes a call to CN10, GW9
This is an operation sequence when a dummy voice IP packet is transmitted to the MT3 when an nvite message is received, so that a route optimization path for a voice IP packet is set before a call starts.

Next, the sequence will be described with reference to FIGS. 1, 6 and 3. First, MT3 transmits to CN10 and GW
9, an Invite message 700 is transmitted. In
The FA 7 having received the vite message 700 becomes the CA 8
Send an Invite message 701 to.
CA8 that has received the Invite message 701,
Send an Invite message to W9. In
vite message 702 is received by GW9,
The setup message 703 is transmitted to the CN 10. Here, the GW 9 receiving the Invite message 702
Is a dummy voice IP packet 704 from the address of MT3 in the Invite message to MT3.
Send The dummy voice IP packet 704 is
And after encapsulation, the dummy audio I
The P packet 705 is transmitted via the IP tunnel 11 to the FA
7 is transferred. The FA 7 that has received the dummy voice IP packet 705 performs decapsulation, and the dummy voice IP packet 706 is transmitted to the MT 3 via the BTS 4.

Here, the HA 6 receiving the dummy voice IP packet 704 follows the format of Mobile N according to the format of FIG. 3 in order to optimize the route of the voice IP packet.
The home address of MT3 is set in the mode Home Address 1200, and the Care-of Address is set.
After setting the address of FA7 in ss1201, Bin
The d Update message 707 is transmitted to the GW 9. The GW 9 that has received the Bind Update message 707 encapsulates the voice IP packet destined for the MT3 to be received thereafter and transmits the encapsulated voice IP packet to the FA 7 without passing through the HA 6, thereby starting the route optimization 708 of the voice IP packet. Then, route optimization is performed at the start 725 of the call. Thus, even when a mobile terminal makes a call,
When the GW receives the call setting message from the mobile terminal, the GW transmits the dummy voice packet and starts optimizing the route of the voice IP packet, so that the voice IP packet optimized route can be obtained immediately after the start of the call.

In the sequence of FIG. 6, the GW 9 transmits a dummy voice IP packet to the MT 3 upon receiving the Invite message from the MT 3.
May transmit a Ringing message to MT3 to transmit a dummy voice IP packet and start route optimization of the voice IP packet. FIG. 7 is a diagram showing a sequence in such a case.

The sequence will be described with reference to FIGS. 1, 7 and 3. In FIG. 7, similarly to FIG. 6, Invite messages 800 to 802 are transmitted from MT3 to GW9. The GW 9 that has received the Invite message 802 transmits a Setup message 803 to the CN 10. Alert message 8 from CN10 to GW9
04 is transmitted and the GW 9 receives the Ringing message 8
05 to the MT3. This is further transmitted as a Ringing message 805 to 808 from the GW 9 to the HA.
6, transmitted to MT3 via FA7. Ringi
GW 9 that transmitted ng message 805 to MT 3
A dummy voice IP packet 809 is transmitted to T3. Dummy voice IP packet 809 includes HA6, FA7
, And as a dummy voice IP packet 811, the MT
3 is sent.

Here, the HA 6 that has received the dummy voice IP packet 809 performs the same setting of FIG. 3 as described above in order to optimize the route of the voice IP packet.
A dUpdate message 812 is transmitted to the GW 9. The GW 9 that has received the Bind Update message 812 encapsulates the voice IP packet for the MT3 to be received thereafter and transmits the encapsulated voice IP packet to the FA 7 without passing through the HA 6, thereby starting the route optimization 813 of the voice IP packet and starting the call. It is completed by the start 824. Thus, immediately after the start of the call, an optimized route for the voice IP packet is obtained.

In the sequence of FIG. 7, the GW 9 transmits a dummy voice IP packet to the MT 3 upon transmission of a Ringing message from the GW 9, but the GW 9
9 may transmit a dummy voice IP packet when the OK message is transmitted to the MT3, and start route optimization of the voice IP packet. FIG. 8 is a diagram showing a sequence in this case.

The sequence will be described with reference to FIGS. 1, 8, and 3. In FIG. 8, as in FIG. 7, Invite messages 900 to 902 are transmitted from MT3 to GW9. The GW 9 that has received the Invite message 902 transmits a Setup message 903 to the CN 10. Alert message 9 from CN10 to GW9
04 is transmitted, and the GW 9 receives the Ringing message 9
05 to the MT3. Ringing messages 905 to 908 are transmitted from GW 9 to MT 3 via HA 6 and FA 7. Here, the description of the sequence operation description of FIG. 7 is omitted, but the HA 6 that has received the Ringing message 906 transmits a BindUpdate message 909 based on the format of FIG. Send. The CA 8 that has received the Bind Update message 909 encapsulates the signaling packet for the MT3 that is received thereafter, and does not pass through the HA 6,
7, the route optimization 910 of the signaling packet is performed.

The GW 9 that has received the Connect message 911 transmits an OK message 912 to the CA 8. The OK message is transmitted from the GW 9 to the MT 3 via the HA 6 and the FA 7. OK message 912 to M
GW9 transmitted to T3 transmits a dummy voice I to MT3.
The P packet 915 is transmitted. The dummy voice IP packet 915 is sent from 916 to 91 via HA 6 and FA 7.
7 is transmitted to MT3 as a dummy voice IP packet. Here, the HA 6 that has received the dummy voice IP packet 915 performs route optimization of the voice IP packet,
As before, based on the format of FIG.
A Bind Update message 918 is transmitted to the GW 9. Upon receiving the Bind Update message 918, the GW 9 receives the audio I for the MT3 received thereafter.
Encapsulates P packet and does not go through HA6, FA7
To optimize the route of voice IP packets 9
19 is started. Immediately after the call starts,
An optimized route for P packets is obtained.

Embodiment 3 In addition to securing an optimized route for voice IP packets from the start of communication, a method of holding the optimized route even when a silent state continues will be described. That is, in the present embodiment, the route optimization of the voice IP packet is performed in advance, and even after the communication state is set, the dummy voice IP packet is periodically transmitted from the GW 9 to the MT3 to transmit the voice IP packet. Maintain the route optimization state. FIG. 9 is a diagram showing a sequence according to the present embodiment.

The sequence will be described with reference to FIGS. 1 and 2, FIGS. 9 and 3. At call start 1000 in FIG. 9,
In the first and second embodiments, it is assumed that voice IP packet route optimization has been performed in advance, and a call state is established. Thereafter, the voice IP packet is transmitted from 1001 to 100
Communication is performed via the optimization route as in the sequence of No. 3. Here, in the GW 9, the voice IP packet 100
If the voice IP packet has not been transmitted to the MT3 for a while after transmitting 2, the GW 9 transmits the dummy voice IP packet 1006 to the MT3 by the timer 1004 when the voice IP packet is not transmitted to the MT3. Dummy voice IP
Packet 1006 is transmitted via HA 6 and FA 7
MT as dummy voice IP packet from 07 to 1008
3 is sent.

Here, the dummy voice IP packet 1006
The HA 6 that has received the message “Mobile” follows the format of FIG. 3 in order to optimize the route of the voice IP packet.
MT3 on Node Home Address 1200
Set the home address of Care-of Addr
After setting the address of FA7 in ess1201, Bi
Send the nd Update message 1009 to the GW 9. The GW 9 that has received the Bind Update message 1009 performs the route optimization 1010 of the voice IP packet again, and holds the route optimization state. In the present embodiment, the timer is started after the last packet before the silence state is transmitted, but a periodical timer that is not related to these silence states is set,
Route optimization may be achieved by transmitting a dummy voice IP packet to MT3.

Embodiment 4 In each of the above embodiments, the method of transmitting the dummy voice IP packet to obtain the optimized route has been described. In the present embodiment, a method for obtaining an optimized route without transmitting a dummy voice IP packet to the MT will be described. That is, the address information of the FA that is the care-of address of the MT is added to the signaling message of the VoIP, and the GW is generated based on the address information.
Start the route optimization of voice IP packets before the start of the call. FIG. 10 is a diagram showing a sequence in this case. FIG. 11 shows a correspondence table between the MT and the FA address, which is the care-of address of the MT, held by the CA 8 in order to add the address information of the FA, which is the care-of address of the MT, to the VoIP signaling message.
Here, in 1300, “133.141.6
The MT having the home address of “5.43” is currently “16.
3.171.95.73 ". In this embodiment, it is assumed that the MT3 has the home address of “133.141.65.43”.

The sequence will be described with reference to FIGS. 1, 10, 3 and 11. In FIG. 10, as in the sequence of FIG.
Following the sequence of the pdate 1005, route optimization of the signaling packet is performed. Where Bin
CA8 that received the d Update message 1005
Is the home address “1” of the MT3 as shown in FIG.
33.141.65.43 "and the address of FA7 which is the care-of address of MT3," 163.171.95.7. "
The corresponding information of "3" is held in 1107.

Thereafter, the Ringing message 110
9 are transmitted from the MT 3 to the GW 9 via the FA 7. GW that received Ringing message 1109
9 is R from the correspondence information between MT3 and FA7 shown in FIG.
The address information of the FA 7 that is the care-of address of the MT 3 is added to the inging message, and the ringing message 1111 is transmitted to the GW 9. Ring
The GW 9 that has received the ing message 1111 becomes the CN 1
0 sends an Alert message 1112,
From the address information of FA7 added to the Ringing message, the voice IP packet addressed to MT3 is
By acquiring route optimization information for tunneling to A7, encapsulating a voice IP packet for MT3 to be received thereafter, and transmitting the encapsulated voice IP packet to FA7 without going through HA6, route optimization 1113 of voice IP packet is performed. Be started. In this way, even if the FA address information is added to the VoIP message and transmitted to the GW, the optimized route of the voice IP packet can be obtained immediately after the start of the call.

Embodiment 5 FIG. In each of the above embodiments, one of the contacts is a CN connected to the PSTN. However, the present invention is also applicable when two MTs communicate. FIG. 12 is a network configuration diagram illustrating an embodiment of a voice packet routing optimization method according to the present invention. In the figure, 23 is CN / M
T, 24 is BTS, 25 is RNC, 26 is CN / MT2
HA of 3 is in RNC 25 and CN / MT23
It is FA for Here, CN / MT23
The above describes the route optimization of the voice IP packet from the MT3 to the MT3, but it is needless to say that the present invention can also be applied to the route optimization of the voice IP packet from the MT3 to the CN / MT23.

FIG. 13 is a diagram showing a route optimization sequence when the CN / MT 23 transmits to the MT 3 in the network configuration diagram shown in FIG.
That is, when the VoIP message is received by the FA 7 and the FA 27, a dummy voice IP packet is transmitted to the MT 3 and the CN / MT 23, and the MT 3
To CN / MT23 and CN / MT23 to M
The setting of the route optimization path of the voice IP packet in the direction to T3 is started.

This sequence will be described with reference to FIGS. 12, 13 and 3. The CN / MT 23 sends an Invite message 1500 to the MT3, and an Invite message 1504 is sent to the MT3 via CA and FA. H that has received the Invite message 1502
The mobile node A6 follows the format of FIG. 3 to optimize the route of the signaling packet.
e) Set the home address of MT3 in Home Address 1200, and perform Care-of Address.
After setting the address of FA7 in 1201, Bind
An Update message 1505 is transmitted to CA8.
The CA 8 that has received the Bind Update message 1505 encapsulates the signaling packet for the MT3 that is received thereafter and transmits the encapsulated signaling packet to the FA 7 without passing through the HA 6, thereby optimizing the route of the signaling packet 1
506 is performed.

Further, the FA 7 having received the Invite message 1503 transmits a dummy voice IP packet 1507 to the CN / MT 23 from the address of the CN / MT 23 in the Invite message. The dummy voice IP packet 1507 is transmitted to the CN / MT 23 via the HA 26 and the FA 27. Here, the HA 26 that has received the dummy voice IP packet 1507 performs setting as described in the previous embodiment based on the format of FIG. 3 to perform route optimization of the voice IP packet, and sets the Bind Update message. 1511
Is transmitted to the FA 7. The FA 7 that has received the Bind Update message 1511 transmits the CN 7 that is received thereafter.
/ MT23 is encapsulated in a voice IP packet, and H
By transmitting to FA27 without passing through A26,
Route optimization 1512 of the P packet is started.

In response to Invite 1504, MT3
From the Ringing messages 1513 to 151
7 is transmitted to CN / MT23. Also Ring
The HA 26 that has received the ing message 1515 transmits a Bind Update message 1518 whose address is set in the format of FIG. 3 to the CA 8 in order to optimize the route of the signaling packet. Bind U
The CA 8 having received the update message 1518 encapsulates the signaling packet for the CN / MT 23 received thereafter and transmits the encapsulated signaling packet to the FA 27 without passing through the HA 26, thereby optimizing the route of the signaling packet 1
519 is started.

Further, the FA 27 that has received the Ringing message 1516 transmits a dummy voice IP packet 1520 to the CN / MT 23 from the address of the MT3 included in the Ringing message. The dummy voice IP packet 1520 is transmitted to the MT 3 via the HA 6 and the FA 7. Here, the HA 6 that has received the dummy voice IP packet 1520 performs a route update of the voice IP packet, and the Bind Update message 1523 whose address is set in the format of FIG.
Is transmitted to the FA 27. The FA 27 that has received the Bind Update message 1523 encapsulates the voice IP packet for MT3 that is received thereafter, and
By transmitting the voice IP packet to the FA 7 without passing through, the route optimization 1524 of the voice IP packet is started.

Next, an OK message 152 is sent from the MT3.
5 to 1528 are transmitted to CN / MT23. At this time, route optimization of the signaling message is performed, and the OK message is transmitted without passing through the HA. Similarly, from CN / MT23, in the sequence of 1529 to 1532, the ACK message
Is also being routed for the signaling message. And CN / MT23 and MT3
Changes to the call state 1533, and changes from CN / MT23 to MT3.
The voice IP packet sent to
The route is optimized and transmitted to the MT 3 without passing through the HA 6. Also, the voice IP packet transmitted from the MT 3 to the CN / MT 23 is route-optimized immediately after the start of the call, and without passing through the HA 26, the CN / MT 2
3 is sent. As described above, in this embodiment, even when the correspondent terminal CN of the MT communication is the mobile terminal MT, the dummy voice IP is issued by the FA and the optimization is started. An optimized route for voice IP packets is obtained. Note that the FA in this embodiment may be an RNC.

In the network configuration of FIG. 12, a case has been described in which communication is performed between the MT and the CN / MT. The present invention is also applicable to a configuration in which one of the communications is an Internet terminal (CN / IP). FIG. 14 is a network configuration diagram in this case. In the figure, 22 is CN /
IP. Here, an outline of route optimization of a voice IP packet from the CN / IP 22 to the MT 3 is shown. FIG. 15 shows the network configuration shown in FIG.
FIG. 7 is a diagram showing a route optimization sequence when the CN / IP 22 sends a message to the MT3. That is, CN / IP22
Sends a dummy voice IP packet to MT3 upon receiving the Ringing message, and starts setting a route optimization path for voice IP packets from CN / IP 22 to MT3 before starting a call.

This sequence will be described with reference to FIGS. 14, 15 and 3. Invite from CN / IP22
Messages 1700 to 1704 are sent to MT3. The HA 6 that has received the Invite message 1702 converts the Bind Update message 1705 in which the address is set according to the format of FIG.
Send to A8. Bind Update message 1
The CA 8 that has received 705 encapsulates the signaling packet for MT3 that is received thereafter, and transmits it to the FA 7 without passing through the HA 6, thereby performing the route optimization 1706 of the signaling packet.

In response to Invite, MT3 sends R
inging messages 1707 to 1710 are CN
/ IP22. Upon receiving the Ringing message 1709, the CN / IP 22
From the address of MT3 in the ng message, MT2
3, a dummy voice IP packet 1711 is transmitted. Dummy voice IP packet 1711 is stored in HA6, FA
7 to the MT3. Here, the HA 6 receiving the dummy voice IP packet 1711 transmits the voice IP
In order to optimize the route of a packet, a Bind Update in which an address is set according to the format shown in FIG.
A message 1714 is sent to the CN / IP 22. B
C that has received the ind Update message 1714
N / IP 22 is a voice IP for MT3 to be received thereafter.
By encapsulating the packet and transmitting it to the FA 7 without going through the HA 6, the route optimization of the voice IP packet 17
15 is performed. As described above, even when the communication partner terminal of the MT is the terminal CN / IP connected to the IP network, the CN / IP transmits a dummy voice packet, so that the voice IP packet An optimized route is obtained.

[0055]

According to the present invention, when a call is transmitted from the CN to the MT or from the MT to the CN, the ringing is performed.
When receiving a message, etc., the MT
By transmitting the dummy voice IP packet to the router, the route optimization of the voice IP packet is performed, and the optimized route of the voice IP packet is obtained immediately after the start of the call, the delay time is reduced, and the packet discard is avoided. Has the effect.

Furthermore, since a timer triggered by a silent state is provided, an optimized route is always secured during a call, so that there is an effect that packet delay and discard can be avoided.

Further, since a dummy voice IP packet is transmitted to the FA prior to the start of a call even for a call between mobile terminals, an optimized route can be obtained immediately after the start of the call.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a first embodiment to a fourth embodiment of the present invention;
FIG. 1 is a network configuration diagram illustrating route optimization of a voice IP packet from a CN to an MT in FIG.

FIG. 2 shows a route optimization sequence of a voice IP packet according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a Bind according to each embodiment of the present invention;
It is an Update message format figure.

FIG. 4 is a route optimization sequence diagram of another IP packet according to the first embodiment of the present invention.

FIG. 5 shows another voice I according to the first embodiment of the present invention.
It is a route optimization sequence diagram of a P packet.

FIG. 6 is a route optimization sequence diagram of a voice IP packet according to the second embodiment of the present invention.

FIG. 7 shows another voice I according to the second embodiment of the present invention.
It is a route optimization sequence diagram of a P packet.

FIG. 8 shows another voice I according to the second embodiment of the present invention.
It is a route optimization sequence diagram of a P packet.

FIG. 9 is a diagram illustrating a sequence of holding a route optimization path of a voice IP packet according to the third embodiment of the present invention.

FIG. 10 shows a voice IP according to Embodiment 4 of the present invention.
It is a route optimization sequence diagram of a packet.

FIG. 11 is a diagram showing a correspondence table of MNs and FA addresses of networks in which the MNs are stored, held by the CA.

FIG. 12 is a diagram showing a state in which CN / MT to MT according to the fifth embodiment is used.
FIG. 1 is a network configuration diagram illustrating route optimization of a voice IP packet to a network.

FIG. 13 shows audio IP according to Embodiment 5 of the present invention.
It is a route optimization sequence diagram of a packet.

FIG. 14 is a diagram illustrating a configuration in which CN / IP to MT according to the fifth embodiment are used.
FIG. 1 is a network configuration diagram illustrating route optimization of a voice IP packet to a network.

FIG. 15 is a diagram showing a route optimization sequence for voice IP packets according to the fifth embodiment.

FIG. 16 is a network configuration diagram illustrating conventional route optimization of a VoIP signaling message between CN and MT.

FIG. 17 is a network configuration diagram for explaining route optimization of a voice IP packet between the conventional CN and MT.

[Explanation of symbols]

1 IP network, 2 PSTN, 3 MT, 4,
24 BTS, 5,25 RNC, 6,26 HA,
7,27 FA, 8 CA, 9 GW, 10CN, 1
1 IP tunnel from HA6 to FA7, 12, 16
Route Optimized IP Tunnel to FA7, 22C
N / IP, 23 CN / MT, 411, 510, 61
9,704,809,915,1006,1507,1
520, 1711 Dummy voice IP packet transmission, 41
4,513,622,707,812,918,100
9, 1511, 1523, 1714 Bind Upd
ate transmission, 415, 514, 623, 708, 81
3,919,1010,1512,1524,1715
Voice IP packet route optimization, 1107 FA address storage, 1110 FA address addition, 1111
Ringing, 1113 voice IP packet route optimization.

Continued on the front page F-term (reference) 5K030 HB01 HC09 HC14 HD03 HD05 HD06 HD09 JL01 JT01 JT09 LB05 5K051 AA01 AA02 BB01 CC01 CC02 CC07 CC08 EE01 EE02 FF11 FF16 HH16 HH17 HH27 JJ04 JJ13 KK14 A0723 DD04A07 DD04 HH23 KK15

Claims (7)

[Claims] 1. In a network for optimizing a route between a general terminal and a mobile terminal via a gateway by a home agent and a call agent, a gateway through which the general terminal passes from the mobile terminal before starting a call Transmitting a dummy voice packet in response to the call or response to the call, and the home agent managing the mobile terminal receives the dummy voice packet and transmits a bind message including the address of the mobile terminal. And a route optimization method for voice packets, wherein the gateway starts route optimization upon receiving the bind message. 2. The voice packet communication channel optimizing method according to claim 1, wherein the gateway transmits a dummy voice packet as a response to the ringing from the mobile terminal. 3. The voice packet communication channel optimizing method according to claim 1, wherein the gateway transmits a dummy voice packet in response to a call from the mobile terminal. 4. A timer is provided in the gateway, and a silence state is triggered even after a call is started, and the timer is operated to transmit a dummy voice packet when silence continues for a predetermined time. Item 2. The communication path optimization method for voice packets according to Item 1. 5. A management agent provided in a network stores a management agent address of a mobile terminal in response to a call from a general terminal, adds the stored address to a response to the call from the mobile terminal, and adds the stored address to a gateway. Transmitting, transmitting a dummy voice packet;
2. The method according to claim 1, wherein, instead of transmitting the message, the gateway starts route optimization in response to the transmission from the management agent. . 6. An agent that manages a mobile terminal by making a call with another mobile terminal instead of a general terminal via a gateway, and manages an agent that manages the other mobile terminal instead of a gateway. 2. The voice packet communication channel optimizing method according to claim 1, further comprising a step of transmitting a dummy voice packet with an agent, and starting route optimization. 7. A method for making a call with an Internet terminal instead of a general terminal via a gateway, and the Internet terminal transmitting a dummy voice packet instead of a gateway, and starting route optimization. 2. The method for optimizing a communication path for voice packets according to claim 1, wherein: