It’s been announced that the i3 Forum and SIP Forum (News - Alert) Task Groups have completed their Phase II test program in order to develop guidelines and recommendations for the global carrier community (the i3 Forum membership). This exploration is intended to significantly improve the international FoIP calls’ success rates, which was found to have been achieved only by routing calls that will most likely prove to be fax calls, (as in the caller is a fax server) over FoIP-tested and qualified routes.
In an excerpt from the Phase II test report, which will soon appear on each organization’s website, the opening acknowledgment states, “The guidelines and conclusions as well as target solution proposal were developed in close cooperation between the i3 Forum and SIP Forum FoIP Task Groups. Two testing sessions, carried out by i3 Forum carriers were possible thanks to Copia International and Commetrex (News - Alert) who delivered (free of charge) their software CopiaFacts and BladeWare to the testing participants.”
It’s inevitable that all carriers and service providers find problems with fax over IP (FoIP) at one point or another, mainly regarding international calls – which were the focus of this particular testing. Voice-over-IP (VoIP) connections usually aren’t problematic when setting up, yet still, fax connections can often fail or are prematurely disconnected, which poses a dilemma.
A number of problems were identified after two testing sessions conducted in 2011 and 2012, but it was not possible to clarify all of these problems and their causes due to the opacity of the multiple carrier networks often involved in international calls. Nonetheless, the document contains several components intended to provide guidelines to deliver reliable FoIP call setup.
The first is the specification of basic prerequisites for successful setup of fax calls over an IP link, redundancy level and required network QoS, echo control, protocol stack, and necessary gateway resources. It will also offer practical guidelines for testing, determining, and resolving problems in a new interconnection link.
The document will furthermore provide a description of i3 Forum and SIP Forum testing campaign, which was executed in peer-to-peer configurations through the open Internet and private-network configurations. Identified failures will be elaborated upon along with a hypothetical explanation of their causes, and as a result of the latest testing campaign, it will also display traces of FoIP calls on both ends (ie. between FoIP fax server and call handling functions, between the fax server and media gateway). Even if it is not possible to track an entire route, it will be able to build the hypothesis of its cause of failure.
In another section, the requirements for the “successful” route of fax calls originated in TDM and VoIP networks is proposed, as well as provided definitions for routing requirements. It also is predicted that the proper (“intelligent”) routing of FoIP calls should significantly increase its success rate.
Proposed methods of fax call identification and methods of intelligent routing will be presented, as based on earlier fax identification, and last, a review of the impact of related standard changes on FoIP interconnection problems.
Edited by Juliana Kenny