dear SG16 colleagues,

In the discussion on SUDs, I would like to state that we should specify the capabilities that are supported in the various devices. To my understanding, we are now in the early phase of defining SUDs for the black phone, secure black phone and the text telephone. I think the concept of SUDs is very powerful since the market is asking for this. Therefore, I also believe that this is just the beginning of a long list of single use devices. In order to prevent interoperability problems between two SUDs, or between an H.323 compliant device and a SUD, I propose to specify capabilities that are supported in these devices, in terms of Venn diagrams. For instance, a black phone is a subset of a secure blackphone, and does not contain any extra features, and both lay within the scope of all H.323 capabilities, as does the text telephone. This text phone however, has got some properties in common with the blackphone, but not all.

I'm sure that this will be helpful in the future in case discussions rise on how to define more SUDs than just these three. I hope this will also help us now in specifying how we provide interoperablility.

bye for now, Jeroen de Muijnck KPN Research The Netherlands