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
General Fax Technical Documentation
Miscellaneous Fax and FoIP Links
General Fax Tech Tips and FAQ's
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.
Fax/Modem Passthrough (NSE-based)
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.
Fax Pass-through (protocol-based)
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.
T.38 Fax Relay
Cisco Fax Relay
T.37 Store-and-Forward Fax
Unity Integration
A Cisco voice gateway running T.37 onramp and/or offramp can be integrated directly with Unity.
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.
FoIP Training Material
- 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.