Cisco Fax Wiki

[Michael Hanes]

• Cisco Fax Wiki
• General FoIP Information
• General Fax Tech Tips and FAQ's
• Passthrough
• Relay
• T.37 Store-and-Forward Fax
• Fax Servers
• FoIP Training Material

Cisco Fax Wiki

Welcome to the Cisco Fax Wiki

A repository and one-stop location for everything related to Fax over IP (FoIP) and Cisco voice products

Getting fax communications to work successfully and reliably in IP environments can be more challenging than VoIP. Fax is modulated data and is therefore markedly different than voice. These differences must be taken into account and FoIP should not be treated like VoIP. From QoS to the underlying transport protocols to switchover mechanisms, dealing with FoIP is full of pitfalls and gotchas. The aim of this wiki page is to demystify fax communications in IP networks and provide a comprehensive reference page for anything related to FoIP."

General FoIP Information

Fax, Modem, and Text for IP Telephony The Definitive Resource for Understanding, Designing, Configuring, and Troubleshooting Fax, Modem, and Text in Today's IP Networks

General Fax Technical Documentation

• Listing of 12.4T IOS Fax Configuration Guides on CCO
• Cisco AVVID Gateway Support for Fax Relay and Fax Pass-Through (CCO)

Miscellaneous Fax and FoIP Links

• Fax on Wikipedia
• IEC Fax Technology Article
• Facsimile Theory
• T.38 Protocol Information
• Faxing over IP networks (discusses FoIP and its problems)

General Fax Tech Tips and FAQ's

• Listing of RTP Payload Types Used by Cisco Products
• Common NSE Event Types Used by Cisco Products
• Common Modulations Used in G3 Fax Calls
• Comparison of MH, MR, and MMR Fax Page Encodings
• T.30 Message Format
• Comprehensive Listing of Fax T.30 Messages
• G3 Fax Call Analysis
• Comparison of SG3 and G3
• Super G3 Fax Call Analysis
• Important G3 Timers
• Understanding Error Correction Mode (ECM)
• ECM Call Analysis

Passthrough

Passthrough simply involves the transport of fax information over a low compression codec, such as G.711. In most respects it is like a typical voice call.

• Passthrough and Pass-through - there is a difference!

Fax/Modem Passthrough (NSE-based)

• Everything you need to know about NSE-based fax passthrough
• Faxing over IP Using Catalyst 6608 and VG248 (CCO)
• Fax Configuration on a Cisco WS-X6624 with an H.323 Gateway (CCO)
• Clarification on RFC 2198 passthrough redundancy and its RTP payload type

Cisco ATA

At this time the Cisco ATA only officially supports NSE-based passthrough. On IOS voice gateways, you must use the "modem passthrough" configuration command to successfully send faxes to the ATA.

• Configuring and Troubleshooting the Cisco ATA 186 with Fax (CCO)

Fax Pass-through (protocol-based)

• Everything you need to know about protocol-based pass-through

Relay

Relay demodulates fax communications and passes the fax data across the IP network using special relay protocols. Cisco voice gateways generally support two types of fax relay, standards-based T.38 fax relay and the pre-standard, propriatary Cisco fax relay.

• Fax Relay Troubleshooting Guide (CCO)
• Working Examples of T.30 Debugs for Fax Relay (CCO)

T.38 Fax Relay

• Configuring T.38 Fax Relay (CCO)
• VTSP Debugging for T.38 (CCO)

Cisco Fax Relay

• Configuring Cisco Fax Relay (CCO)
• Faxing over IP Using Catalyst 6608 and VG248 (CCO)
• Fax Configuration on a Cisco WS-X6624 with an H.323 Gateway (CCO)

T.37 Store-and-Forward Fax

• Configuring T.37 Store-and-Forward Fax (CCO)
• Fax over IP T.37 Store and Forward Fax (CCO)
• T.37 OffRamp Faxing (CCO)
• T.37 Onramp Faxing (CCO)
• T.37 Fax over IP Configuration Guide for Voice Gateways (older CCO Doc but comprehensive)

Unity Integration

A Cisco voice gateway running T.37 onramp and/or offramp can be integrated directly with Unity.

• Cisco Unity IP Fax Configuration Wizard (download and supporting documentation)
• Unity IP Fax Inbound Gateway Configuration Example (CCO)
• Unity IP Fax Outbound Gateway Configuration Example (CCO)
• Unity IP Fax Outbound Troubleshooting (CCO)

Fax Servers

Cisco Fax Server

The Cisco fax server is simply an OEM of the Captaris RightFax product with a Dialogic fax engine (made up of a hardware-based fax board or the software-based SR140 solution). Integrating via T.38 with Cisco voice gateways and Unified CM, the Cisco fax server handles the faxing piece of a Unified Communications solution.

• Cisco Fax Server Product Overview (CCO)
• Cisco Fax Server Support Documents (CCO)

FoIP Training Material

 

• Deploying and Integrating Fax, Modem, and Text in Today's Enterprise Networks Presented at the Cisco Live/Networkers 2008 conference in Orlando, this preso discusses protocol fundamentals, QoS considerations, design best practices, troubleshooting tips, and includes an introduction to fax servers

• Cisco T.38 Fax Design Presented at the 2008 Captaris International Partner Conference, this preso covers T.38 design aspects for integrating with fax servers. The Cisco fax server is an OEM of the Captaris RightFax product so this presentation has a focus towards the Cisco fax server but the principles covered are applicable to just about any fax integration with Cisco products.
• Cisco T.38 Fax Troubleshooting Presented at the 2008 Captaris International Partner Conference, this preso covers T.38 troubleshooting techniques with a focus on fax server environments.