T.38 Fax Over IP (FoIP)

What is Fax over IP?

Fax over IP refers to the process of sending and/or receiving electronic faxes over a packet-switched (data) network. In order for fax over IP to function correctly, specific components and protocols must be implemented and enabled on both the FoIP server and the network to which it connects. The main protocols required for real-time fax over IP are T.38 and SIP or H323.

T.38 Real-Time Fax over IP

T.38 is the main protocol required for real-time fax over IP. T.38 is designed to preserve the traditional fax experience, and ensures that faxes are successfully sent and received. T.38 will make adjustments for jitter, latency, and packet loss, which are inherent in all IP networks.

What Do I Need For FoIP?

The Imecom FoIP server includes the Dialogic Brooktrout SR140 virtual fax board software which supports T.38, SIP, and H.323 protocols natively. In order for FoIP to function successfully, the Brooktrout SR140 “boardless” software needs to communicate with an IP-PBX or VoIP Gateway that also supports T.38 and SIP or H.323. SIP trunking services that support T.38 may also be used. The Imecom FoIP server is compatible with many popular IP-PBX, VoIP Gateway, and SIP trunking services – and the list is growing. Click here for a full interoperability list.

“Boardless” FoIP

The Imecom FoIP Server uses the Dialogic Brooktrout SR140 virtual fax board software. The Brooktrout SR140 can achieve the same high level of performance, reliability, and scalability as Brooktrout hardware-based fax boards. Brooktrout SR140 has been certified in SIP, H.323, and MGCP environments and has been tested and certified with IP-PBXs and VoIP gateways from leading vendors, including Cisco, Avaya, Nortel, Mitel, ShoreTel, and more.

Fax Server Virtualization

The Imecom FoIP Server is made up entirely of software – no fax board hardware is required. As a result, you can now deploy the Imecom FoIP Server on VMWare, Microsoft Hyper-V, and Citrix XenServer. Learn more about virtual fax servers.

Port Densities and Scalability

The Dialogic Brooktrout SR140 fax software supports is available in port densities ranging from 2-60 channels, and can reach 120 ports per Imecom FoIP Server. Additional ports can be installed by activating additional license keys via the Internet or over the phone.

Supports DID Fax Routing

Just like a traditional fax server, the Imecom FoIP Server supports automatic inbound fax routing based on DID/DNIS. Inbound faxes can be routed automatically to specific users, mailboxes, network folders, printers, workflows and document management applications. Learn more about inbound fax routing.

FoIP Through IP-PBX

In many deployments, the Imecom FoIP server will be configured to communicate directly with a T.38-compatible IP-PBX, such as Cisco CallManager, Avaya Communication Manager, etc. This configuration is ideal because the IP-PBX can handle all of the call routing. Click here for a full list of compatible IP-PBX systems.

Single-Site Deployment

In a single-site deployment, the Imecom FoIP server is configured to communicate with the IP-PBX. The IP-PBX handles all inbound and outbound call routing. Outbound faxes are passed to the IP-PBX via T.38. The IP-PBX then passes the call via T.38 to a VoIP gateway. The gateway then converts the call to T.30 and sends it over the telephone network to the receiving device. Inbound fax calls received via the VoIP gateway are routed through the IP-PBX to the Imecom FoIP Server where they are then forwarded on to the destination(s) of choice.

Multi-Site Deployment

Multi-site deployments take full advantage of the VoIP network. The Imecom FoIP server is configured to communicate with the IP-PBX. The IP-PBX handles all inbound and outbound call routing for all sites. Outbound faxes originating from anywhere on the WAN are passed through the Imecom FoIP Server to the IP-PBX via T.38. The IP-PBX then passes the call (via T.38) to the VoIP gateway closest to the destination. That gateway then converts the call to T.30 and sends it over the telephone network to the receiving device. Inbound calls received via any of the VoIP gateways are routed through the IP-PBX to the Imecom FoIP Server where they are then forwarded on to the destination(s) of choice.

FoIP Through VoIP Gateway

If you currently do not have a T.38-compatible IP-PBX, it is still possible to deploy FoIP using a VoIP gateway. Fax traffic is routed via T.38 between Imecom FoIP server and the VoIP gateway. The VoIP gateway communicates with the telephone network via T.30 using standard analog or digital telephony. Imecom supplies Dialogic VoIP media gateways with these types of solutions, however you may opt to use another T.38 compatible VoIP gateway if desired. Click here for a full list of compatible gateways.

FoIP Through SIP Trunking Service

SIP trunking service typically used for VoIP calling may also be used for fax over IP. The main requirement of the SIP trunking service and equipment is support for the T.38 protocol. Imecom FoIP solutions currently support several SIP Trunking service providers and we are continuing to expand support for more services. Click here for a full list of compatible SIP trunking services.

PLEASE NOTE: T.38 is required for successful FoIP deployment. In many instances, you will need to enable support for T.38 on IP-PBX and VoIP gateway equipment manually as it is generally not enabled by default. Other VoIP-side configurations may be required as well. Customers are advised to access to technical resources capable of performing such VoIP-side configurations in order to assist Imecom with your FoIP deployment.

T.38 FoIP Interoperability

The following is a list of all IP telephony equipment and SIP trunking services that have been tested for interoperability with the Imecom FoIP solution. If you have a product that supports T.38, but is not listed here, please contact Imecom Sales for information on establishing compatibility.

SIP Trunking Services

IP-PBX and VoIP Gateway Platforms

	Aastra Ericsson MX-ONE Telephony System SIP Release v3.2 SP1 or higher The MX-ONE Telephony System includes: Ericsson MX-ONE Manager Telephony System version 8.48.1 Ericsson MX-ONE Telephony Server version 12.45.6 Ericsson MX-ONE Media Gateway Classic version 1.4_5
	Alcatel Alcatel OmniPCX Enterprise SIP, H.323 Release 7.1 or higher Certified with Release 9.1 Alcatel OmniPCX Office (OXO) SIP Release 7.0 or higher
	AudioCodes AudioCodes Mediant SIP (using UDP) Software version 5.00A or higher AudioCodes MP-114 SIP (using UDP) Software version 5.60A or higher
	Avaya Avaya IP Office SIP IP Office 500 hardware with VCM 32 (T.38 support) with the third-party SIP endpoint license Release 6.0 or higher DevConnect certified on Release 7.0 Avaya Aura Communication Manager H.323, SIP (CM release 5.0 or greater) Release 3.01 (with update 628.6-11410) or higher Release 4.03 or higher within the 4.x codeline Release 5.0 or higher within the 5.x codeline DevConnect Certified, Release 6.0.1 Avaya Media Gateway Services (those capable of supporting T.38) H.323, SIP Firmware 26.31.0 or higher Note: Avaya Communication Manager does not presently support error correction for T.38 fax over IP.
	Broadsoft Achieved BroadSoft validation on BroadWorks Release 18.SP1 with Dialogic® Brooktrout® Fax Software SDK 6.5.2
	Cisco Cisco Unified Communication Manager (Cisco Unified CallManager) SIP, H323, and (MGCP via CallManager) Release 4.2.x or higher Cisco Integrated Services Router (IOS-based Gateways capable of supporting T.38) SIP, H.323, and (MGCP via CallManager) IOS version 12.3 or higher T.38 V.34 supported on IOS 15.1.1T or higher Cisco AS Universal Gateway Series (those capable of supporting T.38) SIP, H.323, and (MGCP via CallManager) IOS version 12.3 or higher Cisco High Performance Gatekeeper Series (H.323 IOS Gatekeepers) H.323 IOS version 12.3 or higher Cisco Unified Communications 500 Series for Small Business SIP, H.323 UC520 IOS version 12.4 or higher Cisco SPA2102-NA ATA SIP Software version 3.3.6 or later Note: at the time of testing the maximum T.38 protocol supported by the Cisco SPA2102 ATA was V.17 (14,400 bits/sec); Error Correction Mode (ECM) was not supported Cisco Unified Border Element (CUBE) with Cisco 2911 SIP CUBE version 9.x or later IOS version 15.2-3.T1 or later
	Dialogic Dialogic® DMG 1000 & 2000 Series SIP Release 5.1.118_5n or higher Dialogic® DMG 3000 & 4000 Series SIP SUI-1_8.51 or higher Dialogic IMG 1010 SIP, H.323 Release 10.3.2 or higher Dialogic BorderNet 500 Session Border Controller BN500IP SIP inGate SIParator Release 4.8.5 or higher Dialogic BorderNet 3000 Session Border Controller BN3000 SIP Release C2.9.4.12 or higher
	Grandstream Grandstream HT-502 ATA SIP V1.1C or later Grandstream GXW4024IP Analog Gateway SIP V0.4A or later
	Linksys Linksys SPA 8000 Gateway SIP Software version 5.1.10 or higher Hardware version 1.0.0 or higher
	Mitel Mitel 3300 MXe SIP Mitel 3300 MXe controller software version 9.0.3.15 or higher Prerequisites: The DSP II module, T.38 licenses, and SIP trunk licenses must be installed and enabled
	Multi-Tech MultiVoIP MVP210 SIP Multi-Tech MVP210 firmware version 6.11.27-07-Aug-09 or higher
	Nortel Nortel Communication Server 1000 Release 5.5 SIP Release 5.5 or higher
	Patton Patton 4960 PRI Gateway SIP Software version 5.1.10 or higher R5.4, 2009-07-20 or higher Patton 4554 BRI Gateway SIP Software version 5.1.10 or higher R5.3, 2009-05-20 or higher
	Quintum Quintum Tenor Series SIP, H.323 Release P104-12-10 or higher
	ShoreTel ShoreGear 220T1A Switch SIP Software Release 10, build 15.6.4207.0 (Controlled Release) Software Release 11.1, build 16.23.5609.0 Software Release 12.1, build 17.22.5240.0 Qualified using the maximum FoIP data rate supported by the gateway (V.29)
	Siemens Siemens HiPath 8000 SIP Release V3.0 R2 PS19.E05 or higher Siemens RG8702 Media Gateway SIP
	3Com 3Com VCX V7000 SIP Software version 9.0.7 or higher 3Com Media Gateway SIP Software version 4.40.211.387 or higher

Virtual FoIP Server

The Imecom FoIP Server is made up entirely of software and can be deployed on virtual server platforms like VMware, Microsoft Hyper-V, and Citrix. The following list contains information about supported server virtualization platforms. Learn more about Imecom’s Virtual Fax Server.

	VMware SR140 only. (TR1034 is not compatible with VMware at this time) ESX Server version 3.0.1 or higher within the 3.0.x product line ESXi Server version 4.0.0 or higher using Windows System Requirements: Windows Server 2008 Enterprise Edition Windows Server 2008 Standard Edition Windows Server 2003 Enterprise Edition, Service Pack 2 Windows Server 2003 Standard Edition, Service Pack 2 Windows 2000 Server, Service Pack 4 The VMware virtual environment created for SR140 must meet SR140 minimum requirements as well as the minimum processor emulated by VMware, which is the Xeon processor. Therefore, the minimum requirements of the virtual machine presented to SR140 are: Single Xeon – 2 GHz, 512 MB memory. This results in approximately 15% CPU utilization when running 120 simultaneous SR140 faxes.
	Microsoft Hyper-V SR140 only. (TR1034 is not compatible with Hyper-V at this time) Windows Server 2008 R2 Hyper-V version 6.1.7600.16385 running any supported Windows guest operating system
	Citrix XenServer SR140 only. (TR1034 is not compatible with Xen at this time) Citrix XenServer v5.5.0 running any supported Windows guest operating system