scope:

The present document addresses the analysis of the different requirements for reliable real-time modem and facsimile transmission over packet-based networks. The metrics for an evaluation of the overall MoIP and FoIP transmission quality are developed and proposed, and the various characteristics of the packet-based network, like network delay and its variation (jitter) and the effects of discarded packets (in the jitter buffer), with an emphasis on modem/facsimile transmission using different codecs are investigated in order to determine the margins of the network and media gateways and gateway parameters that enable a successful and reliable real-time modem/facsimile transfer over packet-based networks.

Emphasis is on the modem/facsimile transmission using different codecs and media gateways and gateways in order to determine the margins of the media gateways and gateway parameters that enable a successful and reliable real-time modem/facsimile transfer over packet-based networks.

In contrast to the original intention, a perceptual metrics could not be derived, since the results obtained indicate that there is not very much of a "grey zone" for the quality, but rather a "go / no-go" behaviour; the design of perceptual metrics can be considered as future work in this area.

The task of the STF 392 was separated in two steps; the first step was to define an extensive list of test conditions and the second step was to perform a selection of these test.

It is expected to have additional results available in a revision of the present document in the near future.

The material collected here can be used as a basis for future MoIP and FoIP tests.