Asterisk 11 T.38 Fax Gateway Configuration
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). 2
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 3
Packages Manager Review: Server>Packages Manager>Versions Information
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 5
Navigate to Telephony>Configuration>Channels>IAX Channel Enable Jitter Buffer? : No Save 6
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. 7
Navigate to: Telephony>Virtual Fax Click Add a new Modem 8
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 9
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 10
Virtual Fax: Modems>Identification Enter custom values in each text field This example shows default values and subsequent prefixes Click Add when done 11
Virtual Fax: Fax Routing Click on the Fax Routing tab Click Add a new Route 12
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 13
Virtual Fax: Authentication Click on Add a new Authentication 14
Virtual Fax: Authentication Enter a Username Enter a secure Password Click on the Contact tab 15
Virtual Fax: Authentication Enter custom info into the required fields Click on the Options tab 16
Virtual Fax: Options Use the mouse to highlight each Virtual Modem Use the mouse to highlight each DNIS/DID (Routing) Click Add 17
Incoming Lines Example 1: Incoming Line Dedicated to Virtual Fax Modem Lines Manager Incoming Lines>General Example: 9055551234 Type = Extension (DNIS) Extension (DNIS) = 9055551234 Trunk = 9055551234
Incoming Lines Example 1: 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
Incoming Lines Example 1: 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
Incoming Lines Example 2: Incoming Line Shared between Voice and Fax Lines Manager Incoming Lines>General Example: 9055551234 Type = Extension (DNIS) Extension (DNIS) = 9055551234 Trunk = 9055551234
Incoming Lines Example 2: Incoming Line Shared between Voice and Fax Lines Manager Incoming Lines>Destination Destination: use the drop down list selector for your default destination
Incoming Lines Example 2: 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
Incoming Lines Example 2: 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 Outgoing Lines: 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]
Telephony General Services Check HylaFAX (Virtual Fax): [x] Check IAXmodem (Virtual Modem): [x] Click Apply Change 26
Telephony General Services Commit Start IAXmodem (Virtual Modem) Restart HylaFAX (Virtual Fax) 27
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