Fax

Fax transmission

It’s possible to send faxes from XiVO using the fax Xlet in the XiVO client.

../../_images/xivoclient-fax.png

The fax Xlet in the XiVO Client

The file to send must be in PDF format.

Fax reception

Adding a fax reception DID

If you want to receive faxes from XiVO, you need to add incoming calls definition with the Application destination and the FaxToMail application for every DID you want to receive faxes from.

This applies even if you want the action to be different from sending an email, like putting it on a FTP server. You’ll still need to enter an email address in these cases even though it won’t be used.

Note that, as usual when adding incoming call definitions, you must first define the incoming call range in the used context.

../../_images/Fax_recv_adding.png

Changing the email body

You can change the body of the email sent upon fax reception by editing /etc/xivo/mail.txt.

The following variable can be included in the mail body:

  • %(dstnum)s: the DID that received the fax

If you want to include a regular percent character, i.e. %, you must write it as %% in mail.txt or an error will occur when trying to do the variables substitution.

The agid service must be restarted to apply changes:

service xivo-agid restart

Changing the email subject

You can change the subject of the email sent upon fax reception by editing /etc/xivo/asterisk/xivo_fax.conf.

Look for the [mail] section, and in this section, modify the value of the subject option.

The available variable substitution are the same as for the email body.

The agid service must be restarted to apply changes:

service xivo-agid restart

Changing the email from

You can change the from of the email sent upon fax reception by editing /etc/xivo/asterisk/xivo_fax.conf.

Look for the [mail] section, and in this section, modify the value of the email_from option.

The agid service must be restarted to apply changes:

service xivo-agid restart

Changing the email realname

You can change the realname of the email sent upon fax reception by editing /etc/xivo/asterisk/xivo_fax.conf.

Look for the [mail] section, and in this section, modify the value of the email_realname option.

The agid service must be restarted to apply changes:

service xivo-agid restart

Using the advanced features

The following features are only available via the /etc/xivo/asterisk/xivo_fax.conf configuration file. They are not available from the web-interface.

The configuration file has documentation embedded in it in the form of comments, so we recommend you reading them before editing the configuration file.

The way it works is the following:

  • you first declare some backends, i.e. actions to be taken when a fax is received. A backend name looks like mail, ftp_example_org or printer_office.
  • once your backends are defined, you can use them in your destination numbers. For example, when someone calls the DID 100, you might want the ftp_example_org and mail backend to be run, but otherwise, you only want the mail backend to be run.

Here’s an example of a valid /etc/xivo/asterisk/xivo_fax.conf configuration file:

[general]
tiff2pdf = /usr/bin/tiff2pdf
mutt = /usr/bin/mutt
lp = /usr/bin/lp

[mail]
subject = FAX reception to %(dstnum)s
content_file = /etc/xivo/mail.txt
email_from = no-reply+fax@xivo.io
email_realname = Service Fax

[ftp_example_org]
host = example.org
username = foo
password = bar
directory = /foobar

[dstnum_default]
dest = mail

[dstnum_100]
dest = mail, ftp_example_org

The section named dstnum_default will be used only if no DID-specific actions are defined.

After editing /etc/xivo/asterisk/xivo_fax.conf, you need to restart the agid server for the changes to be applied:

service xivo-agid restart

Using the FTP backend

The FTP backend is used to send a PDF version of the received fax to an FTP server.

An FTP backend is always defined in a section beginning with the ftp prefix. Here’s an example for a backend named ftp_example_org:

[ftp_example_org]
host = example.org
port = 2121
username = foo
password = bar
directory = /foobar
convert_to_pdf = 0

The port option is optional and defaults to 21.

The directory option is optional and if not specified, the document will be put in the user’s root directory.

The convert_to_pdf option is optional and defaults to 1. If it is set to 0, the TIFF file will not be converted to PDF before being sent to the FTP server.

The uploaded file are named like ${XIVO_SRCNUM}-${EPOCH}.pdf.

Using the printer backend

To use the printer backend, you must have the cups-client package installed on your XiVO:

$ apt-get install cups-client

The printer backend uses the lp command to print faxes.

A printer backend is always defined in a section beginning with the printer prefix. Here’s an example for a backend named printer_office:

[printer_office]
name = office
convert_to_pdf = 1

When a fax will be received, the system command lp -d office <faxfile> will be executed.

The convert_to_pdf option is optional and defaults to 1. If it is set to 0, the TIFF file will not be converted to PDF before being printed.

Warning

You need a CUPS server set up somewhere on your network.

Using the mail backend

By default, a mail backend named mail is defined. You can define more mail backends if you want. Just look what the default mail backend looks like.

Using the log backend

There’s also a log backend available, which can be used to write a line to a file every time a fax is received.

Fax detection

XiVO does not currently support Fax Detection. A workaround is described in the Fax detection section.

Using analog gateways

XiVO is able to provision Cisco SPA122 and Linksys SPA2102, SPA3102 and SPA8000 analog gateways which can be used to connect fax equipments. This section describes the creation of custom template for SPA3102 which modifies several parameters.

Note

With SPA ATA plugins >= v0.8, you should not need to follow this section anymore since all of these parameters are now set in the base templates of all, except for Echo_Canc_Adapt_Enable, Echo_Supp_Enable, Echo_Canc_Enable.

Note

Be aware that most of the parameters are or could be country specific, i.e. :

  • Preferred Codec,
  • FAX Passthru Codec,
  • RTP Packet Size,
  • RTP-Start-Loopback Codec,
  • Ring Waveform,
  • Ring Frequency,
  • Ring Voltage,
  • FXS Port Impedance
  1. Create a custom template for the SPA3102 base template:

    cd /var/lib/xivo-provd/plugins/xivo-cisco-spa3102-5.1.10/var/templates/
    cp ../../templates/base.tpl .
    
  2. Add the following content before the </flat-profile> tag:

    <!-- CUSTOM TPL - for faxes - START -->
    
    {% for line_no, line in sip_lines.iteritems() %}
    <!-- Dial Plan: L{{ line_no }} -->
    <Dial_Plan_{{ line_no }}_ ua="na">([x*#].)</Dial_Plan_{{ line_no }}_>
    
    <Call_Waiting_Serv_{{ line_no }}_ ua="na">No</Call_Waiting_Serv_{{ line_no }}_>
    <Three_Way_Call_Serv_{{ line_no }}_ ua="na">No</Three_Way_Call_Serv_{{ line_no }}_>
    
    <Preferred_Codec_{{ line_no }}_ ua="na">G711a</Preferred_Codec_{{ line_no }}_>
    <Silence_Supp_Enable_{{ line_no }}_ ua="na">No</Silence_Supp_Enable_{{ line_no }}_>
    <Echo_Canc_Adapt_Enable_{{ line_no }}_ ua="na">No</Echo_Canc_Adapt_Enable_{{ line_no }}_>
    <Echo_Supp_Enable_{{ line_no }}_ ua="na">No</Echo_Supp_Enable_{{ line_no }}_>
    <Echo_Canc_Enable_{{ line_no }}_ ua="na">No</Echo_Canc_Enable_{{ line_no }}_>
    <Use_Pref_Codec_Only_{{ line_no }}_ ua="na">yes</Use_Pref_Codec_Only_{{ line_no }}_>
    <DTMF_Tx_Mode_{{ line_no }}_ ua="na">Normal</DTMF_Tx_Mode_{{ line_no }}_>
    
    <FAX_Enable_T38_{{ line_no }}_ ua="na">Yes</FAX_Enable_T38_{{ line_no }}_>
    <FAX_T38_Redundancy_{{ line_no }}_ ua="na">1</FAX_T38_Redundancy_{{ line_no }}_>
    <FAX_Passthru_Method_{{ line_no }}_ ua="na">ReINVITE</FAX_Passthru_Method_{{ line_no }}_>
    <FAX_Passthru_Codec_{{ line_no }}_ ua="na">G711a</FAX_Passthru_Codec_{{ line_no }}_>
    <FAX_Disable_ECAN_{{ line_no }}_ ua="na">yes</FAX_Disable_ECAN_{{ line_no }}_>
    <FAX_Tone_Detect_Mode_{{ line_no }}_ ua="na">caller or callee</FAX_Tone_Detect_Mode_{{ line_no }}_>
    
    <Network_Jitter_Level_{{ line_no }}_ ua="na">very high</Network_Jitter_Level_{{ line_no }}_>
    <Jitter_Buffer_Adjustment_{{ line_no }}_ ua="na">disable</Jitter_Buffer_Adjustment_{{ line_no }}_>
    {% endfor %}
    
    <!-- SIP Parameters -->
    <RTP_Packet_Size ua="na">0.020</RTP_Packet_Size>
    <RTP-Start-Loopback_Codec ua="na">G711a</RTP-Start-Loopback_Codec>
    
    <!-- Regional parameters -->
    <Ring_Waveform ua="rw">Sinusoid</Ring_Waveform> <!-- options: Sinusoid/Trapezoid -->
    <Ring_Frequency ua="rw">50</Ring_Frequency>
    <Ring_Voltage ua="rw">85</Ring_Voltage>
    
    <FXS_Port_Impedance ua="na">600+2.16uF</FXS_Port_Impedance>
    <Caller_ID_Method ua="na">Bellcore(N.Amer,China)</Caller_ID_Method>
    <Caller_ID_FSK_Standard ua="na">bell 202</Caller_ID_FSK_Standard>
    
    <!-- CUSTOM TPL - for faxes - END -->
    
  3. Reconfigure the devices with:

    xivo-provd-cli -c 'devices.using_plugin("xivo-cisco-spa3102-5.1.10").reconfigure()'
    
  4. Then reboot the devices:

    xivo-provd-cli -c 'devices.using_plugin("xivo-cisco-spa3102-5.1.10").synchronize()'
    

Most of this template can be copy/pasted for a SPA2102 or SPA8000.

Using a SIP Trunk

Fax transmission, to be successful, MUST use G.711 codec. Fax streams cannot be encoded with lossy compression codecs (like G.729a).

That said, you may want to establish a SIP trunk using G.729a for all other communications to save bandwith. Here’s a way to be able to receive a fax in this configuration.

Note

There are some prerequisites:

  • your SIP Trunk must offer both G.729a and G.711 codecs
  • your fax users must have a customized outgoing calleridnum (for the codec change is based on this variable)
  1. We assume that outgoing call rules and fax users with their DID are created

  2. Create the file /etc/asterisk/extensions_extra.d/fax.conf with the following content:

    ;; For faxes :
    ; The following subroutine forces inbound and outbound codec to alaw.
    ; For outbound codec selection we must set the variable with inheritance.
    ; Must be set on each Fax DID
    [pre-incall-fax]
    exten = s,1,NoOp(### Force alaw codec on both inbound (operator side) and outbound (analog gw side) when calling a Fax ###)
    exten = s,n,Set(SIP_CODEC_INBOUND=alaw)
    exten = s,n,Set(__SIP_CODEC_OUTBOUND=alaw)
    exten = s,n,Return()
    
    ; The following subroutine forces outbound codec to alaw based on outgoing callerid number
    ; For outbound codec selection we must set the variable with inheritance.
    ; Must be set on each outgoing call rule
    [pre-outcall-fax]
    exten = s,1,NoOp(### Force alaw codec if caller is a Fax ###)
    exten = s,n,GotoIf($["${CALLERID(num)}" = "0112697845"]?alaw:)
    exten = s,n,GotoIf($["${CALLERID(num)}" = "0112697846"]?alaw:end)
    exten = s,n(alaw),Set(__SIP_CODEC_OUTBOUND=alaw)
    exten = s,n(end),Return()
    
  3. For each Fax users’ DID add the following string in the Preprocess subroutine field:

    pre-incall-fax
    
  4. For each Outgoing call rule add the the following string in the Preprocess subroutine field:

    pre-outcall-fax