Single Number Voice/Fax Routing

When feature F-1450 is configured, using the same dialing number, the IMG will be able to switch the SIP call from a voice endpoint to a fax endpoint device. A SIP user first dials a number and the call comes into the IMG. The IMG then routes the call through an outgoing channel group to a configured voice endpoint such as a SIP voice gateway. Within this call, the user then sends a fax and the IMG detects the fax tone. The IMG then disconnects the outgoing side of the call from the initial voice external gateway and reconnects it to the fax external gateway. The call is now connected to the fax device, and the fax is thus sent to the proper destination. Because the call is always routed to a voice endpoint, the call remains at the voice endpoint if no fax tones are detected. The call doesn’t switch to the fax endpoint. For more information see below.

 

Call Flow Diagram

cf_f1450_voice_fax_routingb.png

 

Call Trace

To view a Call Trace displaying the feature see Single Number Voice/Fax Routing Call Trace.

 

Configuration

Below are instructions on how to configure the IMG to allow it to switch the outgoing call to a fax endpoint. In the procedure below the incoming side and outgoing side will be using the SIP protocol although the incoming side can be any protocol supported on the IMG (H.323, CAS, SS7, ISDN and SIP).

Logical Node

Physical Node

IP Network

IP Address (Configure Interface)

IP Bearer Spans

TDM Spans

Signaling - SIP

SIP SGP

 

Create a SIP gateway for the incoming side.

  1. Right Click on IMG EMS and select New External Network Elements. There is no configuration needed within this object. The External Network Elements object is a parent object for external network entities such as gateways, gatekeepers, DNS Servers, and any other external network entities. Refer to External Network Elements for more information on this object.
  2. Right Click on External Network elements just created and select New External Gateways. There is no configuration needed within this object. The External Gateways object is a parent object to the external gateway object. Multiple external gateway objects are configured under the External Gateways object. Refer to External Gateways for more information.
  3. Right Click on External Gateways object and select New External Gateway. Enter a Name, IP address, and change the Gateway Signaling Protocol to SIP. This is the gateway being created for the incoming side. Refer to External Gateway for more information on this object.

Note: The incoming side can be any protocol supported on the IMG. This procedure will use SIP as the incoming protocol

 

Create two outgoing SIP gateways. One for Fax and one for Voice.

  1. Right Click on External Gateways object again and select New External Gateway. Enter a Name for the Voice endpoint. In this procedure Voice_Gateway_Out was selected. Enter an IP address, and change the Gateway Signaling Protocol to SIP. This is the gateway being created for the voice endpoint on the outgoing side. Refer to External Gateway for more information on this object.
  2. Right Click on External Gateways object again and select New External Gateway. Enter a Name for the Fax endpoint. In this procedure Fax_Gateway_Out was selected. Enter an IP address, and change the Gateway Signaling Protocol to SIP. This is the gateway being created for the fax endpoint on the outgoing side. Refer to External Gateway for more information on this object.

 

Create IP Bearer Profile and configure Single Number Voice/Fax Routing

  1. Right click on the Profiles object and select New IP Bearer Profile. Enter a name in the IP Bearer Profile Name field that identifies the profile being created.
  2. In the Single-Number Fax field select Enable. By selecting Enable, a second field labeled Single-Number Fax Server can now be modified. Select from drop down menu the external gateway for the fax endpoint. See screen capture below.

sc_f1450_conf_ipbearer.png

 

  1. Within the Fax Mode field, select the Fax Mode to be used. This field has to be configured to something other than Disable.
  2. Within the Fax Bypass Codec field select the Bypass Codec to be used.
  3. Within the Modem Behavior field, select Disabled from drop down menu.
  4. Create a second IP Bearer Profile that will be associated with the incoming side. In this procedure it is labeled Gateway_Inc.

Refer to IP Bearer Profile for more information on this object.

 

Note: The new parameters are applicable only when the IP Bearer profile is used by an outgoing Channel Group. The GCEMS can allow the IP Bearer profile with these new parameters enabled to be associated to an incoming Channel Group. But these parameters wouldn’t be applicable.

 

Create Outgoing Channel Group

Create an outgoing channel group. The outgoing channel group has to be a SIP channel group.

  1. Right Click on IMG EMS and select New Routing Configuration. A Routing Configuration Pane will appear. See Routing Configuration for more information on this object.
  2. Right Click on Routing Configuration and select New Channel Groups. A Channel groups container object is created. This object will allow multiple channel groups to be created beneath it. See Channel Groups for more information on this object.
  3. Right Click on the Channel Groups Object and select New Channel Group. A Channel Group Object will appear. Enter a name for this channel group and set the Signaling Type to SIP. The outgoing channel group in this example will be a SIP Channel Group and be named ChannelGrp_Out.
  4. Set the Outgoing IP Profile field to the IP Bearer Profile created earlier with the Single Number Voice routing configured. See screen capture below.

sc_f1450_sel_ipbearer_inchangrp.png

See Channel Group for more information on configuring a channel group.

 

Create IP Network Element communicating with Outgoing Channel Group

  1. Right Click on the outgoing channel group created and select New IP Network Element. Select from drop down menu, the Gateway for the voice endpoint on the outgoing side. See Below

sc_f1450_select_outgoing_gateway.png

 

 

Create Incoming channel group

Create an incoming channel group. The channel group being created in this procedure is an SIP channel group. The incoming channel group can be any protocol supported on the IMG.

  1. Right Click on the Channel Groups Object again and select New Channel Group. A Channel Group Object will appear. Enter a name for this channel group. The Incoming Channel Group in this example will be a SIP Channel Group and be named ChannelGrp_Inc. See Channel Group for more information on configuring a channel group.

 

Create IP Network Element communicating with Incoming Channel Group

  1. Right Click on the incoming channel group created and select New IP Network Element. Select from drop down menu, the Gateway on the incoming side. See Below.

sc_f1450_sel_incoming_gateway.png

 

The feature is now configured.

 

Additional Information

The IMG will detect the fax tone from the A side and switch the endpoints on the B side.

If the IMG detects the fax tone from the B side, it will not perform the Single Number Voice/Fax functionality by switching the endpoints on the A side.

The IMG doesn’t differentiate between the fax tones (thus which side initiates the fax). If the endpoint on the B side initiates the fax (sending CNG), and the endpoint on the A side sends back the CED/V.21, the IMG will handle it as a usual and perform the Single Number Voice/Fax option. In this case, the IMG will disconnect and switch the endpoints on the B side (failing the fax). It is the user’s responsibility to have the setup properly for the feature.

When Fax Mode is set to Enable Relay (T.38), the IMG sends the RE-INVITE to the fax endpoint for a T.38 session.

When Fax Mode is set to Enable Bypass, the IMG sends the RE-INVITE to the fax endpoint for a G.711 session.

When Fax Mode is set to Relay Fallback to Bypass, the IMG sends the RE-INVITE to the fax endpoint for a T.38 session. And if the RE-INVITE is rejected, the IMG sends another RE-INVITE for a G.711 session.