SCOPTEL IP PBX Software - Asterisk 11 T.38 Fax Gateway Configuration

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SCOPTEL Asterisk 11 T.38 Fax Gateway

Source: https://wiki.asterisk.org/wiki/display/AST/T.38+Fax+Gateway Full T.38 Capabilities

Initial support for handling of T.38 sessions was merged into the Asterisk 1.4 codebase. Inside of Asterisk 1.4, it is possible to perform what is referred to as T.38 passthrough. T.38 Passthrough allows Asterisk to carry T.38 UDPTL from one T.38-speaking endpoint to another T.38-speaking endpoint. Asterisk does not modify the media. Asterisk 1.6, in addition to its T.38 passthrough capabilities, introduced T.38 termination support, such that T.38 fax sessions could be initiated from locally stored TIFF files (SendFax) or that T.38 fax sessions could be terminated into locally stored TIFF files (ReceiveFax). The basic faxing capabilities of Asterisk 1.8 remained the same as 1.6. The limitation of these versions of Asterisk is that while 1.6 - 1.8 are fully capable of passing through or terminating T.38 sessions, there is no capability for T.38 gateway. Older versions of Asterisk cannot directly pass a fax from the PSTN or a non-T.38 endpoint to a T.38 endpoint. Instead, older versions of Asterisk require that two separate calls be established - e.g. one to receive the Fax into a TIFF file (ReceiveFax), and an entirely separate call to send the Fax from a TIFF file to a fax machine (SendFax), or vice versa.

SCOPTEL Asterisk 11 overcomes this limitation and provides full T.38 Fax Gateway support. T.38 Gateway provides a number of advantages over the older, two-step store-and-forward method (generally referred to as T.37). Advantages include: end-to-end confirmation of receipt (with two separate calls the callee doesn’t necessarily know the caller was trying to send them a fax), reduced time to fax (not receiving and then sending separately cuts the time in half), and increased reliability (no concerns about the reliability of local file storage or the TIFF interpreters).

SCOPTEL Background and Pre-requisites

  • You must already be using a currently supported version of asterisk11.SCOPSERV.rpm

  • Refer to version switcher documentation and use the version switcher to deploy Asterisk 11 if you have not done so already

  • You must be using minimum SCOPSERV-server version 2.4.1

  • You must be using minimum SCOPSERV-telephony version 5.1.0.0.20131114

  • You must be using minimum SCOPSERV-core version 3.5.27

  • Package hylafax must be installed

  • Package avantfax must be installed

  • Package iaxmodem must be installed

  • Package sendmail or postfix must be installed

  • Valid VoIP Account

  • Use the Packages Manager>Versions Information tab to install any missing or non-compliant packages

Packages Manager Review

Server>Packages Manager>Versions Information

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  • Navigate to Telephony>Configuration>Telephony Modules and click Edit

  • Check the option for SIP Channels: Yes

  • Check the option for Virtual Fax: Yes

  • Disable T.38 Fax (UDPTL) Passthrough

  • Save

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  • Navigate to Telephony>Configuration>Channels>IAX Channel

  • Enable Jitter Buffer ? : No

  • Save

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Navigate to: * Telephony>Interfaces * Edit an existing or new SIP VoIP Account * Click on the Options tab * Check the option for Enable Fax T.38 Gateway: [x] * Save

NOTE

This will enable T.38 Gateway support on all incoming calls to this interface. You will still need to set a destination(s) for incoming faxes. And you will need to configure DNIS routing for each DID so the Virtual Fax Routing can set the proper destination.

Navigate to:

  • Telephony>Interfaces

  • Edit an existing or new SIP VoIP Account

  • Click on the Network tab

  • Check the option for Can Reinvite >[x]

  • Save

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Navigate to Telephony>Virtual Fax

  • Click Add a new Modem

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Virtual Fax: Modems>General

  • Mode: Virtual Modem from drop down list

  • Name: must be unique

  • Port ID: must be numerical and unique

  • Click on Options tab when finished

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Virtual Fax: Modems>Options

  • Choose the desire d Class of Services (Outgoing): object from the drop down list

  • Click on the Identification tab when done

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Virtual Fax: Modems>Identification

  • Enter custom values in each text field

  • This example shows default values and subsequent prefixes

  • Click Add when done

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Virtual Fax: Fax Routing

  • Click on the Fax Routing tab

  • Click Add a new Route

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Virtual Fax: Fax Routing

This is where the Incoming Lines info does a lookup for the destination email address

  • Match/Route: Choose DNIS

  • Enter a valid DNIS Pattern which must match an Incoming Line Pattern

  • Select the Format/Type: of the attachment from the list

  • Enter the Destination (Email): address

  • Click Add when done

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Virtual Fax: Authentication

  • Click on Add a new Authentication

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Virtual Fax: Authentication

  • Enter a Username

  • Enter a secure Password

  • Click on the Contact tab

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Virtual Fax: Authentication

Enter custom info into the required fields Click on the Options tab

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Virtual Fax: Options

Use the mouse to highlight each Virtual Modem Use the mouse to highlight each DNIS/DID (Routing) Click Add

Example 1

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Incoming Line Dedicated to Virtual Fax Modem Lines Manager Incoming Lines>General Example: 9055551234 Type = Extension (DNIS) Extension (DNIS) = 9055551234 Trunk = 9055551234

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Incoming Line Dedicated to Virtual Fax Modem Lines Manager Incoming Lines>Options Fax Extension (Routing): can be left blank. The default is to use the General tab’s DNIS value to Virtual Fax Route A custom DNIS value can be used to override the default incoming DNIS Examples: Telco sends DNIS 2234 and you want to send the fax to virtual fax route 9055551234 POTS lines do not support DNIS but you still want to send them to a virtual fax route You want to send many Incoming Lines to the same virtual fax route 9055551234 In any of these examples you could set the Fax Extension (Routing) : <DNIS> to a custom numerical value

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Incoming Line Dedicated to Virtual Fax Modem Lines Manager Incoming Lines>Destination Destination: use the drop down list selector to chose Virtual Fax After choosing the Virtual Fax Destination use the drop down list selector to select your Virtual Modem Port Add or Save your configuration

Example 2

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Incoming Line Shared between Voice and Fax Lines Manager Incoming Lines>General

Example: 9055551234 Type = Extension (DNIS) Extension (DNIS) = 9055551234 Trunk = 9055551234

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Incoming Line Shared between Voice and Fax Lines Manager Incoming Lines>Destination Destination: use the drop down list selector for your default destination

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Incoming Line Shared between Voice and Fax Lines Manager Incoming Lines>Options Fax Extension (Routing): can be left blank. The default is to use the General DNIS value to Virtual Fax Route A custom DNIS value can be used to override the default incoming DNIS Examples: Telco sends DNIS 2234 and you want to send the fax to virtual fax route 9055551234 POTS lines do not support DNIS but you still want to send them to a virtual fax route You want to send Incoming Lines to the same virtual fax route 9055551234 In any of these examples you could set the Fax Extension (Routing) : <DNIS> to a custom numerical value

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Incoming Line Shared between Voice and Fax Lines Manager Incoming Lines>Options You must check Enable Fax Detection ? [x] to share between voice and fax routing You should check Indicate Ringing during Fax Detection ? [x] to supply ring back to voice callers Add or Save your configuration

Outgoing Lines

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You must enable Fax T.38 Gateway :[x] to allow Asterisk to enable T.38 Gateway processing for outgoing faxes. Lines>Outgoing Lines>Dial Options>Advanced Options>Enable Fax T.38 Gateway :[x]

Virtual Fax>Email-to-Fax

How it works: The user sends a fax attachment using any email client or webmail service. Supported fax attachment types are PDF, TIFF The POP3 mail server account can be a shared account as in faxes@domain.com The user enters the external fax number in the subject line including any PBX prefix or long distance prefix The user must also enter any fax token in the subject line if the administrator has configured this feature to implement additional security.

Examples of subject line: 5551212 95551212 915555551212 With token = faxpassword 5551212 faxpassword 95551212 faxpassword 915555551212 faxpassword

The SCOPTEL server will attempt to login to the POP3 server and use the POP3 credentials specified in the POP3 Settings tab to download attachments. Once an attachment is downloaded the SCOPTEL server will use the subject line to select an outgoing Fax Modem port to dial and send the fax.

Virtual Fax>Email-to-Fax

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General Tab Give your Email-to-Fax account a name

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Options The server will use the Options settings to periodically connect to an external POP3 server

Virtual Fax>Email-to-Fax

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POP3 Settings This example shows how to configure a Gmail account for Email-to-Fax

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Destination Choose the desired settings for Outgoing Fax Modem Port, Cover Page

Telephony General Services

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Check HylaFAX (Virtual Fax): [x] Check IAXmodem (Virtual Modem): [x] Click Apply Change

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Commit Start IAXmodem (Virtual Modem) Restart HylaFAX (Virtual Fax)