CN101018216B - Voice, Modem and Fax full control method - Google Patents

Abstract

The disclosed full control method for all of speech, Modem and Fax comprises: the calling user builds speech carrying channel; the first media gateway notifies the first soft exchange for the detected Fax or Modem affair; the latter indicates the first media gateway to switch into fax or modem state; the first soft exchange initiates the negotiation and building request for the fax media flow to the second soft exchange; the latter receives message and indicates the second media gateway to switch into fax or modem state; then the second soft exchange matches the fax or modem capacity with the initiator through signaling message; finally, the calling builds fax or modem channel with the called.

Description

Voice, Modem and Fax full control method

technical field

The invention relates to a next generation network (NGN) technology, in particular to a voice, Modem and Fax full control method.

Background technique

In a traditional TDM network, Modem and Fax services are realized through capability negotiation between terminal devices after the voice bearer channel is established between the calling party and the called party. The network device does not participate in the capability negotiation process of the terminal device, and the signaling is transparently transmitted through the bearer channel to realize the capability negotiation process between the calling device and the called device.

The gateway equipment of the NGN network has become a relatively mature technology for Modem and Fax signal detection, which provides the basis for the Modem and Fax full control technology of the NGN network. NGN takes softswitch as the core and can provide voice, video, data and other multimedia integrated services. It adopts an open and standard system structure and can provide a next-generation network with rich services. NGN network puts forward new requirements for Modem and Fax services, requiring core network equipment to be able to perceive the service implementation process of terminal equipment in order to provide better services for users and operators, which requires core network equipment to participate in the entire business of equipment in process.

Chinese application number 200310120016 discloses a method for implementing fax in the next generation network. When the media gateways at both ends communicate, one of the media gateways detects the fax start signal and notifies the media gateway controller; Fax codec, and at the same time send a codec modification command to the media gateways of both parties in parallel; if the codec is modified, the ports of the media gateways at both ends If the port at the local end changes, the media gateway controller sends a modification command to the media gateway at the opposite end to modify the properties of the remote end of the real-time transport protocol, and starts faxing after modification. Before the media gateway detects the fax start signal, it negotiates the fax codec while negotiating the voice codec. The disadvantage of this negotiation method is the same as the negotiation process of the MODEM and FAX terminals in the TDM network. The media gateway self-negotiation does not go through the softswitch, and the media gateway negotiates independently.

After the softswitch control mode detects the Modem signal, the media gateway reports the Modem event to the softswitch, and the softswitch controls the service capability of the called terminal. However, this technology does not solve the processing situation that the calling party and the called party are in different softswitch control domains. Since there is no signaling negotiation mechanism defined between the control devices, if two intercommunicating control devices use different negotiation mechanisms, these services cannot be realized.

Contents of the invention

The technical problem solved by the present invention is to provide a kind of voice, Modem, Fax full control method, be beneficial to NGN network control equipment to realize unified Modem, FAX service flow, have solved the equipment such as Modem, FAX under different softswitch control equipment Interoperability issues.

The technical solution is as follows:

Voice, Modem and Fax full control method, the steps are as follows:

(1) The calling user calls the called user to establish a voice bearer channel;

(2) The first media gateway notifies the first softswitch of the detected fax event or MODEM event;

(3) the first softswitch instructs the first media gateway to switch to the fax state or the MODEM state;

(4) The first softswitch initiates a negotiation and establishment request of the facsimile media flow to the second softswitch through a signaling message;

(5) After the second softswitch receives the signaling message, it instructs the second media gateway to switch to the fax state or the MODEM state;

(6) When the second media gateway switches to the fax state or the MODEM state, the second softswitch completes the negotiation and matching of the fax capability or the MODEM capability with the initiator through the signaling message; the media capabilities of the device;

(7) The calling device and the called device establish a fax channel or a modem channel.

Further, the first media gateway and the second media gateway are gateway access devices, used to access terminal devices, and accept the control of the softswitch device.

Further, the first softswitch and the second softswitch are core control devices of the NGN network, deployed on the IP network, and realize communication through the IP protocol.

Step (7) further includes returning to the original call state when the Modem call fails to be established.

Further, the step of returning to the original call state described in step (7) includes:

A. When the first media gateway detects the fax end event, it notifies the first softswitch;

B. The first softswitch requires the first media gateway to switch to the voice call state;

C. The first softswitch initiates a request to change to the voice call state through the re-INVITE message of SIP to the second softswitch;

D. After receiving the re-INVITE, the second softswitch instructs the second media gateway to switch to the voice call state;

E. The second softswitch sends the SDP information of the second media gateway to the first softswitch;

F. The first softswitch notifies the first media gateway of the SDP information of the second media gateway;

G. The calling user and the called user resume the established voice call.

Further, when the call ends, the calling device and the called device release resources.

Further, the steps of releasing resources include:

i. The first media gateway detects an on-hook event and reports it to the first softswitch;

ii. The first softswitch requires the first media gateway to release resources;

iii. The first softswitch sends a BYE message to the second softswitch;

iv. The second softswitch requires the second media gateway to release resources.

Furthermore, when the calling device and the called device initiate a modem call at the same time, the first softswitch and the second softswitch have a co-op negotiation mechanism.

The invention solves the control ability of the NGN core network equipment to the terminal service, and provides more refined service for the operator and the user service. The Modem full control flow realized by the invention is beneficial to NGN network control equipment to realize unified Modem and FAX service flow, and solves the intercommunication problem of Modem, FAX and other equipment under different softswitch control equipment. Furthermore, through the full control process, functions such as service authentication and service charging for users are realized.

Description of drawings

Figure 1 and Figure 2 are structural diagrams of the IP access Modem/Fax call full control system;

Fig. 3 is the flowchart of Modem call establishment;

Fig. 4 is the flow chart of grabbing messages simultaneously initiated by the calling party and the called by the Modem;

Fig. 5 is the flow chart of Modem call termination;

Fig. 6 is the FAX call establishment process;

Fig. 7 is a flow chart of returning to the original call state after the fax finishes;

Fig. 8 is a flowchart of the end of fax;

FIG. 9 is a flow chart of simultaneous detection of the fax end event by the calling party and the called party.

Detailed ways

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

With reference to shown in Fig. 1, soft switch equipment comprises the first soft switch (Softswitch1) and the second soft switch (softswitch2), the first soft switch (Softswitch1) and the second soft switch (softswitch2) are the core control equipment of NGN network, deployment in an IP network. The communication between the two softswitches is realized through the IP protocol, such as the SIP protocol.

The gateway device includes a first media gateway and a second media gateway. The first media gateway and the second media gateway are gateway access devices for accessing terminal devices and accepting the control of the softswitch device. The communication between the gateway device and the softswitch device is realized through IP protocol, such as H.248, SIP and so on.

Modem terminal 1 and Modem terminal 2 are facsimile equipment with TDM circuit interface, and the communication with the gateway equipment is realized through TDM circuit.

Referring to Figure 2, Softswitch1 and softswitch2 are the core control devices of the NGN network and are deployed on the IP network. Communication between the first soft switch (soft switch 1) and the second soft switch (soft switch 2) is implemented through an IP protocol, such as the SIP protocol.

In order to distinguish the voice and fax in the G.711 mode, the attribute line of the media parameter is extended, and the attribute description a=fax is added to indicate that it is a fax service at this time. The specific format is as follows:

m=audio 8766RTP/AVP 0; a=Fax (newly expanded parameters, identifying fax services, case insensitive).

When the modem service is started across domains, the extended parameter a=modem indicates that it is currently a modem service. The specific format is as follows:

m=audio 8766RTP/AVP 0; a=modem (newly expanded parameters, identifying modem business, case insensitive).

Modem terminal 1 and Modem terminal 2 are facsimile devices with IP interface. Communication between fax equipment and softswitch equipment is realized through IP protocol, such as H.248, SIP, etc.

Shown in Fig. 3 with reference to, the specific steps of Modem call establishment process are as follows:

Step 1: The calling user calls the called user, and a voice bearer channel is established between the two.

Here, both the calling user and the called user can initiate a fax.

Step 2: If a user under Softswitch 1 initiates a fax request, Media Gateway 1 (trunk gateway, AG or IAD) notifies Softswitch 1 after detecting the fax event.

Step 3: Softswitch 1 requires media gateway 1 to switch to MODEM state.

Step 4: Softswitch 1 initiates a negotiation and establishment request of the fax media stream to Softswitch 2 through a SIP re-INVITE message. The re-INVITE message carries the SDPOffer described by the MODEM capability.

INVITE sip:tombeijing.com SIP/2.0

Via: SIP/2.0/UDP 10.10.10.10

From: lianwl<sip:lianwlzte.com.cn>; tag＝123456789

To: tom<sip:tombeijing.com>

Call-ID: 3863931310.10.10.10

CSeq: 2 INVITE

Supported: 100rel

Contact: <sip:lianwl10.10.10.10:5060>

Content-Type: application/sdp

Content-Length:...

v=0

o＝faxgw1 2890844526 2890842807 IN IP410.10.10.10

t=00

c=IN IP4 10.10.11.11

m=audio 8766 RTP/AVP 0

a = modem

Step 5: After receiving the re-INVITE, the soft switch 2 instructs the media gateway 2 to switch to the MODEM state.

Step 6: When the media gateway 2 switches to the MODEM state, the softswitch completes the negotiation of the MODEM capability with the initiator through the SDP (answer) content carried in the 200 message.

SIP/2.0 200OK

Via: SIP/2.0/UDP 1.1.1.1 (address of softswitch 1)

Via: SIP/2.0/UDP 10.10.10.10

From: lianwl<sip:lianwlzte.com.cn>; tag＝123456789

To: tom<sip:tombeijing.com>; tag＝987654321

Call-ID: 3863931310.10.10.10

CSeq: 2 INVITE

Contact: <sip:tom20.20.20.20:5060>

Content-Type: application/sdp

Content-Length:...

v=0

o＝faxgw228908445272890842808IN IP420.20.20.20

t=00

c=IN IP4 20.20.21.21

m=audio 8766RTP/AVP 0

a = modem

Step 7: Softswitch 1 informs Media Gateway 1 of the modem capability of Media Gateway 2 after receiving the SDP sent by Softswitch 2

Step 8: The calling device and the called device perform modem communication.

Referring to Figure 4, when the calling party and the called party of the Modem initiate a call at the same time, the steps of grabbing the message at the same time are as follows:

Step 1: The calling user calls the called user, and a voice channel is established between the two.

Here, both the calling user and the called user can initiate a fax.

Step 2: Assuming that a user under Softswitch 1 initiates a fax request, Media Gateway 1 (trunk gateway, AG or IAD) notifies Softswitch 1 after detecting the Modem event.

At the same time, after the media gateway 2 (trunk gateway, AG or IAD) detects the Modem event, it notifies the softswitch 2.

Step 3: The soft switch 1 requires the media gateway 1 to switch to the MODEM state; the soft switch 2 requires the media gateway 2 to switch to the MODEM state.

Step 4: Softswitch 1 initiates a negotiation and establishment request of the fax media stream to Softswitch 2 through a SIP re-INVITE message. The re-INVITE message carries the SDPOffer described by the MODEM capability.

Softswitch 2 initiates a negotiation and establishment request of the fax media stream to softswitch 1 through a SIP re-INVITE message. Among them, the SDP offer with MODEM capability description in the re-INVITE message.

Step 5: After receiving the re-INVITE, the softswitch 2 determines that the user initiates a Modem call.

After receiving the re-INVITE, softswitch 1 determines that the user has initiated a Modem call.

Step 6: Softswitch 1 sends a 491 message to Softswitch 2; Softswitch 2 sends a 491 message to Softswitch 1.

Step 7: Softswitch 1 starts the Reinvite timer for retransmission.

The calling side randomly sets a timer of 2.1 to 4 seconds, and the called side randomly sets a timer of 0 to 2 seconds, and the timer duration is adjustable.

In this embodiment, it is assumed that the softswitch 2 timer is timed at 0 to 2 seconds (10 ms unit).

Step 8: The timer of softswitch 2 arrives first, and a reinvite message will be sent to softswitch 1.

Step 9: After receiving the SDP sent by the soft switch 2, the soft switch 1 informs the media gateway 1 of the modem capability of the media gateway 2.

Step 10: The calling device and the called device perform modem communication.

The process of calling the calling party and the called party by Fax is the same as the above process, and only needs to change the corresponding Modem information to Fax information.

Shown in Fig. 5 with reference to, the concrete steps of Modem call end process are as follows:

Step 1: The calling and called users are in the MODEM state or restored to the voice state.

Step 2: Media Gateway 1 detects the on-hook event and reports it to Softswitch 1.

Step 3: Softswitch 1 requires Media Gateway 1 to release resources.

Step 4: Softswitch 1 sends a BYE message to Softswitch 2.

Step 5: Softswitch 2 requests media gateway 2 to release resources.

Referring to Figure 6, the specific steps of FAX call establishment are as follows:

The calling user calls the called user, and a voice channel is established between the two. Here, both the calling user and the called user can initiate a fax. In this embodiment, it is assumed that a user under softswitch 1 initiates a fax request.

Step 1: Media gateway 1 (trunk gateway, AG or IAD) notifies softswitch 1 after detecting the fax event.

Step 2: Softswitch 1 requires MG1 to switch to the fax state.

Step 3: Softswitch 1 initiates a negotiation and establishment request of the fax media stream to Softswitch 2 through a SIP re-INVITE message.

The re-INVITE message contains the SDP offer describing the fax capability. In this embodiment, the media gateway 1 supports both T.38 and G.711 faxes.

INVITE sip:tombeijing.com SIP/2.0

Via: SIP/2.0/UDP10.10.10.10

From: lianwl<sip:lianwllianwl.zte.com>; tag＝123456789

To: tom<sip:tombeijing.com>

Call-ID: 3863931310.10.10.10

CSeq: 2 INVITE

Supported: 100rel

Contact: <sip:lianwl10.10.10.10:5060>

Content-Type: application/sdp

Content-Length:...

v=0

o＝faxgw12890844526 2890842807IN IP410.10.10.10

t=00

c=IN IP410.10.11.11

m=image 49170udptl t38

a=T38FaxRateManagement:transferredTCF

a=T38FaxUdpEC:t38UDPFEC

m=audio 8766RTP/AVP 0

a=fax

Step 4: After receiving the re-INVITE, the soft switch 2 instructs the media gateway 2 to switch to the fax state.

Step 5: When the media gateway 2 switches to the fax state, the softswitch completes the fax capability negotiation with the offerer through the SDP (answer) content carried in the 200 message.

In this embodiment, the recipient selects T.38 fax.

SIP/2.0 200OK

Via: SIP/2.0/UDP 1.1.1.1 (address of softswitch 1)

Via: SIP/2.0/UDP 10.10.10.10

From: lianwl<sip:lianwlzte.com.cn>; tag＝123456789

To: tom<sip:tombeijing.com>; tag＝987654321

Call-ID: 3863931310.10.10.10

CSeq: 2 INVITE

Contact: <sip:tom20.20.20.20:5060>

Content-Type: application/sdp

Content-Length:...

v=0

o＝faxgw2 2890844527 2890842808IN IP420.20.20.20

t=00

c=IN IP 420.20.21.21

m=image 49270 udptl t38

a=T38FaxRateManagement:transferredTCF

a=T38FaxUdpEC:t38UDPFEC

m=audio 0RTP/AVP 0

a=fax

Step 6: Softswitch 1 informs Media Gateway 1 of the fax capability of Media Gateway 2 after receiving the SDP sent by Softswitch 2;

Step 7: The calling party and the called party perform facsimile communication.

Referring to Figure 7, the specific steps for returning to the original calling state after faxing are as follows:

Step 1: The calling user calls the called user, and a voice channel is established between the two.

Here, both the calling user and the called user can initiate a fax. In this example, it is assumed that a user under softswitch 1 initiates a fax request.

Step 2: After fax negotiation, the user under softswitch 1 establishes a fax with the user under softswitch 2.

Step 3: Media gateway 1 detects the fax end event and notifies softswitch 1.

Step 4: Softswitch 1 requires Media Gateway 1 to switch to the voice call state.

Step 5: Softswitch 1 initiates a request to Softswitch 2 to change to the voice call state through a SIP re-INVITE message.

Step 6: After receiving the re-INVITE, the soft switch 2 instructs the media gateway 2 to switch to the voice call state.

Step 7: Softswitch 2 sends the SDP information of media gateway 2 to Softswitch 1.

Step 8: The softswitch 1 notifies the media gateway 1 of the SDP information of the media gateway 2.

Since softswitch 1 has recorded the local and remote SDP descriptions of successful voice negotiation, the voice switching in step 4 can switch the call to the voice SDP saved last time. If the original voice channel port of the opposite end has not changed, the soft switch 1 may not notify the media gateway 1 to modify the remote media.

Step 9: The calling user and the called user resume the previously established voice call.

Referring to Figure 8, the specific steps for releasing resources after the fax is over are as follows:

Step 1: The calling and called users are in the fax state or restored to the voice state.

Step 2: Media Gateway 1 detects the on-hook event and reports it to Softswitch 1.

Step 3: Softswitch 1 requires Media Gateway 1 to release resources.

Step 4: Softswitch 1 sends a BYE message to Softswitch 2.

Step 5: Softswitch 2 requests media gateway 2 to release resources.

Referring to Figure 9, the specific steps when the calling party and the called party detect the fax end event at the same time are as follows:

Step 1: The calling user calls the called user, and a voice channel is established between the two. Both the calling user and the called user can initiate a fax. In this example, it is assumed that a user under softswitch 1 initiates a fax request.

Step 2: After fax negotiation, the user under softswitch 1 establishes a fax with the user under softswitch 2.

Step 3: Media gateway 1 detects the fax end event and notifies softswitch 1.

Step 4: Softswitch 1 requires Media Gateway 1 to switch to the voice call state.

Step 5: Media gateway 2 also detects the fax end event and notifies softswitch 2.

Step 6: The soft switch 2 requires the media gateway 2 to switch to the voice communication state.

Step 7: Softswitch 1 initiates a request to Softswitch 2 to change to the voice call state through a SIP re-INVITE message.

Step 8: Softswitch 2 sends a request to Softswitch 1 to change to the voice call state through the SIP re-INVITE message.

Step 9: Softswitch 1 sends a 491 message to Softswitch 2.

Step 10: Softswitch 2 sends a 491 message to Softswitch 1.

Step 11: After receiving the 491 message, the softswitch 1 starts a resend re_INVITE timer.

At this time, the duration of the timer on the calling side is 2.1 to 4 seconds (in units of 10 ms).

Step 12: After receiving the 491 message, the softswitch 2 starts the resend re_INVITE timer at the same time.

The duration of the timer on the called side is 0 to 2 seconds (in units of 10ms).

Step 13: The timer of softswitch 2 expires first, and the re_INVITE message will be sent to softswitch 1 again.

Step 14: Softswitch 1 completes media switching according to the content in the re_INVITE message, and the calling and called parties switch to the voice state.

The flow process of the calling party and the called party detecting the Modem end event at the same time is processed in the same way as the flow process of Fax.

Claims (8)

1. A voice, Modem and Fax full control method, the steps are as follows: (1) The calling user calls the called user to establish a voice bearer channel; (2) The first media gateway notifies the first softswitch of the detected fax event or Modem event; (3) the first softswitch instructs the first media gateway to switch to the fax state or the Modem state; (4) The first softswitch initiates a negotiation and establishment request of the facsimile media flow to the second softswitch through a signaling message; (5) After the second softswitch receives the signaling message, it instructs the second media gateway to switch to the fax state or the Modem state; (6) When the second media gateway switches to the fax state or the Modem state, the second softswitch completes the negotiation and matching of the fax capability or the Modem capability with the initiator through a signaling message; the signaling message carries the called side device media capabilities; (7) The calling device and the called device establish a fax channel or a Modem channel. 2. The full control method of voice, Modem and Fax according to claim 1, characterized in that, the first media gateway and the second media gateway are gateway access equipment, used to access terminal equipment, and accept softswitch Device control. 3. voice according to claim 1, Modem and Fax full control method, it is characterized in that, described first soft switch and the second soft switch are the core control equipment of NGN network, are deployed in IP network, realize by IP protocol communication. 4. voice according to claim 1, Modem and Fax full control method, it is characterized in that, step (7) further comprises, when Modem calls and establishes failure, returns original calling state. 5. voice according to claim 4, Modem and Fax full control method, it is characterized in that, the step of returning original calling state described in the step (7) comprises: A. When the first media gateway detects the fax end event, it notifies the first softswitch; B. The first softswitch requires the first media gateway to switch to the voice call state; C. The first softswitch initiates a request to change to the voice call state through the re-INVITE message of SIP to the second softswitch; D. After receiving the re-INVITE, the second softswitch instructs the second media gateway to switch to the voice call state; E. The second softswitch sends the SDP information of the second media gateway to the first softswitch; F. The first softswitch notifies the first media gateway of the SDP information of the second media gateway; G. The calling user and the called user resume the established voice call. 6. The voice, Modem and Fax full control method according to claim 1, characterized in that, when the call ends, the calling device and the called device release resources. 7. voice according to claim 6, Modem and Fax full control method, it is characterized in that, the step of releasing resource comprises: i. The first media gateway detects an on-hook event and reports it to the first softswitch; ii. The first softswitch requires the first media gateway to release resources; iii. The first softswitch sends a BYE message to the second softswitch; iv. The second softswitch requires the second media gateway to release resources. 8. voice according to claim 1, Modem and Fax full control method, it is characterized in that, when calling equipment and called equipment initiate Modem call simultaneously, described first softswitch and second softswitch have the same consultation mechanism.

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