Send Fax Module Documentation

Table of Contents

1. Navigation & Access
2. Screenshots & Visual Interface
3. Module Overview (Technical)
4. Module Overview (Commercial/Business)
5. Module Overview (End User/Administrator)
6. Sending Process
7. Supported Formats
8. Common Scenarios & Examples
9. Limitations & Important Notes
10. Model Context Protocol (MCP) AI Integration
11. Troubleshooting Tips
12. Glossary

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Navigation & Access

To access the Fax Sending interface:

1. Log in to the Ring2All Web Portal (https://<domain-or-ip>/login).
2. In the left navigation sidebar, expand PBX Engine.
3. Under Virtual Faxes, click Fax Sending (/pbx/virtual-faxes/sending).
4. Select the sending device, enter the recipient fax number, attach your document (PDF or TIFF), and click Send Fax.

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Screenshots & Visual Interface

Web Fax Transmission Console

Modern outbound fax dispatch dashboard with integrated file upload dropzone, sending endpoint selector, resolution quality options, and real-time transmission feedback.

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1. Module Overview (Technical)

What Is Send Fax?

Send Fax is a web-based fax transmission interface that allows users to send documents as faxes through configured fax devices. Documents are uploaded, converted if necessary, and transmitted via Telephony Server’s fax engine.

Architecture

┌─────────────────────────────────────────────────────────────────┐
│                   Send Fax Architecture                         │
├─────────────────────────────────────────────────────────────────┤
│                                                                 │
│  Admin Panel                                                    │
│  ┌──────────────────────────────────────────────────────────┐   │
│  │        FaxSendingPage.tsx                                │   │
│  │                                                          │   │
│  │  1. Select fax device                                    │   │
│  │  2. Enter destination number                             │   │
│  │  3. Upload PDF/TIFF document                             │   │
│  │  4. Click "Send Fax"                                     │   │
│  │                                                          │   │
│  └──────────────────────────────────────────────────────────┘   │
│       │                                                         │
│       ▼ API Call                                                │
│  ┌──────────────────────────────────────────────────────────┐   │
│  │        Backend Fax API                                   │   │
│  │                                                          │   │
│  │  1. Validate file and device                             │   │
│  │  2. Store document temporarily                           │   │
│  │  3. Convert PDF to TIFF if needed                        │   │
│  │  4. Originate call via Telephony Server                        │   │
│  │                                                          │   │
│  └──────────────────────────────────────────────────────────┘   │
│       │                                                         │
│       ▼ Telephony Server Originate                                    │
│  ┌──────────────────────────────────────────────────────────┐   │
│  │        fax/fax_send.lua                                  │   │
│  │                                                          │   │
│  │  1. Load fax device config from public.fax_devices       │   │
│  │  2. Configure T.38 / ECM settings                        │   │
│  │  3. Connect to destination                               │   │
│  │  4. Transmit fax (txfax)                                 │   │
│  │  5. Send email notification                              │   │
│  │  6. Log to public.fax_logs                               │   │
│  │                                                          │   │
│  └──────────────────────────────────────────────────────────┘   │
│       │                                                         │
│       ▼                                                         │
│  Remote Fax Machine                                             │
│                                                                 │
└─────────────────────────────────────────────────────────────────┘

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2. Module Overview (Commercial/Business)

Business Value

Send Fax provides web-based fax transmission:

Without Send Fax	With Send Fax
Physical fax machine	Web interface
Print documents	Upload PDF
Manual dialing	Click to send
No status tracking	Email notifications

Use Cases

1. Document Transmission

   • Send contracts and agreements
   • Transmit signed documents

2. Business Communications

   • Send invoices to vendors
   • Transmit purchase orders

3. Healthcare/Legal

   • HIPAA-compliant fax
   • Court document filing

4. Remote Work

   • Fax from anywhere
   • No physical equipment

Feature Highlights

Feature	Benefit
PDF Support	No conversion needed
TIFF Support	Native fax format
T.38 Protocol	Reliable FoIP
Auto-Retry	Handle busy lines
Notifications	Email on success/fail
Logging	Full audit trail

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3. Module Overview (End User/Administrator)

What Can You Do?

• Select outbound fax device
• Enter destination number
• Upload PDF or TIFF document
• Send fax with one click
• Receive email notifications
• View transmission status

Send Fax Interface

┌─────────────────────────────────────────────────────────────────┐
│              Send Fax                                           │
├─────────────────────────────────────────────────────────────────┤
│                                                                 │
│  Section: Send Fax                                              │
│  ├─ Fax Device: [Main Office Fax ▼]                            │
│  │   Only devices with outbound capability shown                │
│  │                                                              │
│  └─ Destination Number: [+15551234567            ]             │
│      Include country code for international faxes               │
│                                                                 │
│  Section: Document Upload                                       │
│  ┌──────────────────────────────────────────────────────────┐   │
│  │                                                          │   │
│  │         📄 Drop your document here                       │   │
│  │              or click to browse                          │   │
│  │                                                          │   │
│  │         [Browse Files]                                   │   │
│  │                                                          │   │
│  │    Supported formats: PDF, TIFF (max 10 MB)             │   │
│  │                                                          │   │
│  └──────────────────────────────────────────────────────────┘   │
│                                                                 │
│  ℹ️ Important Information:                                      │
│  • Supported formats: PDF and TIFF                              │
│  • Maximum file size: 10 MB                                     │
│  • Email notifications based on device configuration            │
│  • T.38 protocol used if enabled and supported                  │
│                                                                 │
│  [Send Fax] [Cancel]                                            │
│                                                                 │
└─────────────────────────────────────────────────────────────────┘

Quick Tips

[!TIP] PDF Format: Upload PDFs directly - they’re converted automatically.

[!TIP] Country Code: Always include country code (e.g., +1) for reliable delivery.

[!CAUTION] File Size: Maximum 10 MB per document.

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4. Sending Process

Step-by-Step Flow

1. Select Device

   • Choose outbound-capable fax device
   • Device determines caller ID and settings

2. Enter Destination

   • Full phone number with country code
   • Example: +15551234567

3. Upload Document

   • Drag and drop or browse
   • PDF or TIFF format

4. Send

   • Click “Send Fax”
   • System queues transmission

5. Transmission

   • Telephony Server originates call
   • T.38 negotiation if enabled
   • Document transmitted

6. Notification

   • Email sent on success/failure
   • Log recorded in database

Retries

Setting	Default	Description
Max Retries	3	Total retry attempts
Retry Interval	300s	Seconds between retries

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5. Supported Formats

PDF Documents

Aspect	Details
Format	PDF 1.0 - 2.0
Conversion	Auto-converted to TIFF
Pages	Multi-page supported
Color	Converted to B&W

TIFF Documents

Aspect	Details
Format	TIFF (Group 3/4 fax)
Native	No conversion needed
Pages	Multi-page supported
Compression	G3/G4 fax compression

Size Limits

Limit	Value
Max File Size	10 MB
Max Pages	Depends on document

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6. Common Scenarios & Examples

Scenario 1: Send Contract

1. Select fax device: “Sales Fax”
2. Destination: +14155551234
3. Upload: contract.pdf
4. Click “Send Fax”
5. Receive success email

Scenario 2: International Fax

1. Select fax device: “International Fax”
2. Destination: +442071234567 (UK)
3. Upload: invoice.pdf
4. Send and wait for confirmation

Scenario 3: Multi-Page Document

1. Upload multi-page PDF
2. System converts all pages
3. Transmits as single fax
4. Pages sent sequentially

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7. Limitations & Important Notes

Technical Notes

[!NOTE] Outbound Only: This module is for sending only. See Fax Devices for receiving.

[!NOTE] Device Required: Must have fax device with outbound direction enabled.

[!WARNING] Carrier Support: Remote carrier must support fax protocol.

Best Practices

1. Use T.38: Enable on device for reliability
2. Include Country Code: Always use full E.164 format
3. Check File Size: Stay under 10 MB limit
4. Verify Device: Ensure device is enabled
5. Monitor Logs: Check fax viewer for status

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8. Model Context Protocol (MCP) AI Integration

The Ring2All Platform Copilot connects directly with the Fax Outbound Transmission engine via the Model Context Protocol (MCP), providing conversational document transmission, spooling, recipient normalization, and delivery status tracking.

Exposed MCP Tools

Tool Name	Operation	Primary Parameters	Description
send_virtual_fax	Outbound Spooling	fromFaxDevice (string), toNumber (string), documentPath (string, optional), callerIdNumber (string, optional)	Dispatches an outbound virtual fax job to a remote recipient phone number using an existing domain fax endpoint.
query_fax_history	Outbound Transmission Audit	direction (“outbound”), search (string, optional), limit (number)	Retrieves recent outbound fax delivery attempts, success flags, page counts, and transmission speeds.
list_fax_devices	Available Sending Gateways	search (string, optional)	Lists active fax endpoints available to originate outgoing faxes.

Transmission Safeguards & Formatting Validation

• E.164 Destination Sanitization: Recipient fax numbers are normalized automatically. Punctuation, dashes, and parentheses are stripped to avoid dialplan string injection (+1 (305) 555-0199 → +13055550199).
• Sender Verification: The originating device identifier (fromFaxDevice) is resolved against active domain fax devices. Disabled devices or devices with inbound-only direction cannot be used to dispatch faxes.
• Asynchronous Telephony Server Job Spooling: Outbound faxes are inserted into public.fax_logs and dispatched asynchronously via txfax so long transmission handshakes do not block Copilot responses.

Example MCP Payloads

1. Dispatching an Outbound Fax (send_virtual_fax)

{
  "fromFaxDevice": "Main Virtual Fax",
  "toNumber": "+13055550199",
  "callerIdNumber": "+17863643150",
  "documentPath": "/var/lib/ring2all/fax/invoices/INV-9021.pdf"
}

Response:

{
  "success": true,
  "data": {
    "message": "Outbound virtual fax transmission queued successfully to +13055550199!",
    "faxJobId": 412,
    "fromDevice": "Main Virtual Fax",
    "fromNumber": "2099",
    "toNumber": "+13055550199",
    "status": "queued"
  }
}

2. Querying Recent Outbound Fax Dispatches (query_fax_history)

{
  "direction": "outbound",
  "limit": 5
}

Copilot Natural Language Prompts

• “Send a fax to +13055550199 using the Accounting Virtual Fax.”
• “Check if our last outbound fax to +13055550199 went through successfully.”
• “Which fax devices in our domain are configured for outbound transmission?”
• “Show me all failed outbound faxes from today.”

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9. Troubleshooting Tips

Common Issues

Symptom	Possible Cause	Solution
No devices shown	No outbound devices	Create device with outbound direction
Send fails	File too large	Reduce file size
Invalid format	Wrong file type	Use PDF or TIFF
Transmission fails	Remote busy	Retries will occur
No notification	Email not configured	Set email_to on device

Validation Errors

Error	Meaning
deviceRequired	Select a fax device
destinationRequired	Enter destination number
fileRequired	Upload a document
invalidFileType	Only PDF/TIFF allowed
fileTooLarge	File exceeds 10 MB

Check Recent Transmissions

SELECT
  direction, remote_number, pages,
  success, result_text, created_at
FROM public.fax_logs
WHERE direction = 'outbound'
  AND domain_id = [domain_id]
ORDER BY created_at DESC
LIMIT 10;

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10. Glossary

Term	Definition
txfax	Telephony Server transmit fax
T.38	Fax over IP protocol
ECM	Error Correction Mode
TIFF	Tagged Image File Format
E.164	International phone format
Originate	Telephony Server call initiation

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Documentation last updated: January 2026