Configuring Fax Detection (Single-Number Voice and Fax) with Cisco Unity Connection
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This article explains how to configure the Fax Detection (Single-Number Voice and Fax) feature with Cisco Unity Connection 7.1(1).
Fax Detection (Single-Number Voice and Fax) – An Overview
Fax detection is one of the interactive voice response (IVR) applications. Fax detection supports the use of a single E.164 number for both voice mail and fax mail by providing the capability to detect through an interactive voice response interface whether an incoming call is voice or fax. It is implemented using TCL script loaded on IOS gateway.
In an IP network, fax detection or the single-number voice and fax feature can be implemented by:
- Configuring Fax Detection on IOS Gateway
- Integrating Cisco Fax Server with IOS Gateway
- Integrating Cisco Fax Server with Cisco Unity Connection
Example Deployment Scenario
In this deployment scenario, incoming calls are directed to a Cisco gateway that can detect a CNG (fax) tone. When a CNG tone is detected, the gateway forwards the fax call to Cisco Fax Server. When no CNG tone is detected, the gateway forwards the voice call to Cisco Unity Connection.
Figure 1: Fax detection deployment scenario.
Call flow for an incoming fax
The following is the call flow for incoming fax calls:
- PSTN caller dials single number to send fax and voice calls.
- IOS Gateway with Fax Detect TCL script intercepts the call.
- Note: The above step depends on the mode of operation.
- If CNG tones are detected within 9 seconds, gateway falls back to T.38 and routes the fax call to Cisco Fax Server.
Call flow for an incoming voice call
The following is the call flow for incoming voice calls:
- PSTN caller dials single number to send fax and voice calls.
- IOS Gateway with Fax Detect TCL script intercepts the call.
- If CNG tones are not detected within 9 seconds, gateway connects the call to CUCM using H.323 or SIP.
- Voice call is answered by Auto Attendant in Cisco Unity Connection. Alternatively, calls can also be routed to an extension registered to Cisco Unified Communications Manager.
- Note: We recommend using listen-first mode when voice calls are routed to a phone.
Fax Detection on IOS Gateway
Fax detection can be configured to use the distinctive fax calling tones (CNG), a manually dialed digit, or both to distinguish fax calls from voice calls. Fax detection supports the following modes of operation:
- Connection-First
- Listen-First
- Default-Voice
- Default-Fax
Configuring Fax Detection on IOS Gateway
The following tasks configure the fax detection application on a network:
1. Load the fax detection application on the On-Ramp Gateway by loading the TCL script to the flash.
ABI-MWI-Relay#sh flash: CompactFlash directory: File Length Name/status 1 25214 app_fax_detect.2.1.2.x.tcl 2 59867460 c2800nm-adventerprisek9_ivs-mz.124-24.0.TTEST3 [60308704 bytes used, 68141852 available, 128450556 total] 125440K bytes of ATA CompactFlash (Read/Write)
2. Configure the fax detection application on the gateway.
Here is a configuration example:
application service faxdetect flash:app_fax_detect.2.1.2.x.tcl param prompt flash:en_listen_first.au param voice-dtmf 1 param fax-prefix 9 param fax-dtmf 2 param mode listen-first
3. Configure dial-peers on the gateway. Configure at least one inbound POTS dial peer, one VOIP dial peer for T.38 Fax Relay and one VOIP dial peer for voice calls.
Here is a configuration example:
{|border="0" cellspacing="2" width="100%"
|colspan = "3"|dial-peer voice 5002 pots
| Incoming POTS Dialpeer
|-
| service faxdetect
|
|Associates the fax detect application with dialpeer
|
|}
incoming called-number 2....
direct-inward-dial
port 0/0/1:23
{|border="0" cellspacing="2" width="100%"
|dial-peer voice 66669 voip
| Outbound VoIP dialpeer for T.38 Fax Relay to CFS
|}
destination-pattern 92....
session target ipv4:10.4.21.89
incoming called-number 55555
dtmf-relay h245-signal
codec g711ulaw
fax-relay ecm disable
fax rate 14400
fax protocol t38 ls-redundancy 0 hs-redundancy 0 fallback cisco
!
{|border="0" cellspacing="2" width="100%"
|dial-peer voice 66668 voip
| Outbound VoIP dialpeer for voice calls to CUCM
|}
destination-pattern 2....
session target ipv4:10.4.21.13
dtmf-relay h245-alphanumeric
codec g711ulaw
Integrating Cisco Fax Server with IOS Gateway
This section describes the configuration steps to integrate Cisco Fax Server with IOS gateway.
Use the Brooktrout Board Configuration Tool to configure Brooktrout Board to accept incoming calls using H.323 or SIP protocols.
Protocol Configuration under ‘IP Call Control Modules’ configuration should match with the configured dial peer on IOS gateway. If IOS gateway is configured for H.323 then the Call Control Module in Brooktrout Board should also be configured for H.323 protocol.
Note: Cisco Fax Server integration steps are same for Single Number Fax or not.
Configuring Brooktrout SR140 Board in Fax Server
In the DocTransport Configuration dialog box in Cisco Fax Server, configure Brooktrout Board to accept incoming calls using H.323 or SIP protocols.
Figure 2: DocTransport Configuration Dialog Box.
The following tasks configure Brooktrout Board to accept incoming calls using H.323/SIP protocols:
- Set the Fax ID for all channels.
- Set the capability for all channels. Alternatively, capability for each channel can also be configured separately.
- Configure the digits to be used for routing. Set the DID settings to the appropriate value to route incoming messages to Unity Connection subscribers.
- Click the Configure Brooktrout button to open the Brooktrout Configuration Tool for configuring Brooktrout-related board settings.
Configuring SR140 Call Control Parameters and Modules
After you have configured DocTransport, you need to configure Brooktrout-related board settings using the Brooktrout Configuration Tool provided by Brooktrout.
The following tasks configure call control parameters and modules:
1. Set the IP Call Control Module to H.323 or SIP and select the appropriate IP interface if there are multiple interfaces.
Figure 3: Call Control Parameters Tab.
2. Configure the IP address of the gateway along with the local IP address that was mentioned earlier.
Figure 4: IP Call Control Modules Tab.
Integrating Cisco Unity Connection with Cisco Fax Server
Cisco Unity Connection supports integration with Cisco Fax Server version 9.0 or later, which allows users to receive faxes that are sent to their fax extension, forward faxes that they receive to a fax machine for printing, and forward faxes that they receive to another user.
Cisco Fax Server relays the received fax to Cisco Unity Connection using SMTP. The steps to integrate Cisco Fax Server with Cisco Unity Connection are the same irrespective of the whether Single-Number Fax feature is being deployed or not. If Single-Number Fax feature is not deployed, the integration can be used to receive, print or forward faxes.
To integrate Cisco Unity Connection with Cisco Fax Server, you need to perform the following tasks:
- Configuring Email Gateway
- Configuring Fax Server on Unity Connection
- Configuring Users
Email Gateway Configuration
Cisco Fax Server also routes the incoming SMTP message to a fax machine when Unity Connection subscriber chooses to print the fax. Cisco Unity Connection interfaces with the Cisco Fax Server using the Cisco Fax Server Email Gateway. Incoming faxes are routed to Cisco Fax Server Email Gateway to be delivered to subscribers in Cisco Unity Connection.
To configure the POP3 Mailbox on the Cisco Fax Server:
1. Access RightFax Email Gateway from Control Panel or double-click on the RightFax Email Gateway Module in the Services pane of Enterprise Fax Manager.
Figure 5: Email Gateway Configuration.
2. Create users in RightFax for each Unity Connection subscriber who will be receiving fax.
3. Ensure that the Email address and Routing Info field matches the SMTP address of the Unity Connection subscriber.
Configuring Fax Server on Unity Connection
Fax Server can be configured on Cisco Unity Connection Administration > System Settings > Fax Server.
Figure 6: Fax Server Configuration.
- In the Fax Server Name field, enter a descriptive name for the Cisco Fax Server.
- In the SMTP Address field, enter the fully qualified SMTP address of the SMTP server on the Cisco Fax Server.
- Note: SMTP address mentioned in the Unity Connection needs to match the POP3 mailbox name in Cisco Fax Server.
- In the IP Address field, enter the IP address of the Cisco Fax Server
- Optionally, SMTP messages can be routed through a smart host to Cisco Fax Server. Enable the Use SMTP Smart Host option.
- Note: Before enabling the Use SMTP Smart Host option, configure a SMTP Smart Host in the SMTP Configuration page.
Configuring Users
The Cisco Fax Server must have a subscriber for each Connection user that you are configuring. Subscriber can choose to print a received fax by pressing 8 or by saying Fax. The fax messages can also be accessed using Outlook or other IMAP clients. Fax cannot be printed or accessed from Cisco Personal Communications Assistant.
You can configure subscriber for connection users from Cisco Unity Connection Administration > Users.
To configure subscriber for connection users:
- On the Edit User Basics page, in the Outgoing Fax Number field, enter the number for the fax machine that users send faxes for printing.
- In the Outgoing Fax Server field, click the name of the Cisco Fax Server
- Note: Add file extension to Faxable File Type under advanced settings to render files.
Troubleshooting Single-Number Fax configuration
You can use the diagnostic trace files from Connection SMTP server and Connection Message Transfer Agent to assist you in troubleshooting issues with Single-Number Fax configuration. The SMTP server and MTA trace files are located in /var/log/active/cuc. The filename format is diag_SMTP_xxxxxxxx.uc and diag_MTA_xxxxxxxx.uc.
The trace files can be collected using RTMT > Trace and Log central. The trace files can also be viewed/collected using the CLI command:
file view activelog cuc/diag_SMTP_xxxxxxxx.uc
Troubleshooting a Fax Server Issue
If you are unable to receive fax messages from Cisco Fax Server, perform the following to troubleshoot the issue:
- Check the SMTP address configured on the Outgoing Fax Server. This SMTP address should match the POP3 account name configured on the Email Gateway on Cisco Fax Server.
- If the Use smart host option is enabled, make sure that Cisco Unity Connection is configured in the Smart Hosts page and SMTP messages can be received from the relay server.
- Ensure that the Routing Info field details in Inbound Routing Tab on Cisco Fax Server for users is the SMTP address of the subscriber in Unity Connection.
- Note: MTA traces can be helpful to debug the above issue.
Example MTA traces
Here are some MTA traces that can assist you in troubleshooting issues with fax configuration.
Troubleshooting routing information for SMTP address mismatch
Troubleshooting POP3 account name mismatch with configured SMTP address in Unity Connection.
Using RightFax FaxUtil for Troubleshooting
RightFax FaxUtil is a fax document management application that is installed as part of Cisco Fax Server. FaxUtil application can be used to send new fax messages to Unity Connection.
Figure 7: RightFax FaxUtil Application.
For end-to-end troubleshooting, perform the following:
- Send a test fax without the FaxDetect script on the IOS gateway.
- Using FaxUtil verify that the fax message is available in the Cisco Fax Server user mailbox.
Then use FaxUtil to send a test fax message to Unity Connection subscriber and perform the following:
- Verify that the fax message can be successfully sent to Unity Connection subscriber through the Email Gateway.
- Based on the error message collect the log files from the appropriate module.
- To collect logs for Email gateway, stop the service and issue the command:
smtpgateway -d -1 -sgateway n
- where n is the gateway number.
- Note: Execute the command from Rightfax Gateway.
Troubleshooting FaxDetect Application
The following are the steps to troubleshoot FaxDetect Application:
- Verify that a test fax message can be sent without the Fax Detect application.
- Verify that voice calls are successfully established without the Fax Detect application.
- Enable Fax Detect and make sure that the dial peer with service configured is used as the incoming dial peer by turning on debug voice dialpeer.
- Issue the command debug voip application script to display debug information from the fax detection script.
Sample debug VOIP application script output for a fax call
A sample debug VOIP application script output for fax.
Sample debug VOIP application script output for a voice call
A sample debug VOIP application script output for av oice call.
Related Information
Cisco Fax over IP Application Guide
Cisco Fax Server Administration Guide
http://cisco.com/en/US/docs/voice_ip_comm/fax_server/94/94ciscofaxag.pdf
System Administration Guide for Cisco Unity Connection Release 7.x










