It's interesting that when authors turn up at IETF to explain their work/resolve issues etc they use colored diagrams to do so - not ASCII art. Some of this is fashionable, but in many cases it is to clearly articulate a point in the very little time made available. I don't see why such powerful techniques shouldn't be applied to the specifications themselves to allow the reader to most grasp what is being said with the minimum effort. I am afraid that I don't subscribe to the hair shirt approach to drawings. I think that they should be exactly fit for purpose neither too complex, nor too simple, and that the need to work round the limits of 72 ASCII characters should not be a constraint that limits the clarity of expression. For example look at slides 5 and 6 in http://www3.ietf.org/proceedings/05nov/slides/pwe3-2.ppt and compare to figure1 in http://www.ietf.org/internet-drafts/draft-balus-bocci-martini-dyn-ms-pwe3-00.txt The latter shows the components of the system, but it is impossible to put the detail shown in the slides into the diagrams in the specification itself with our current tools. Look at the figures in http://www.ietf.org/internet-drafts/draft-bocci-bryant-pwe3-ms-pw-arch-01.txt particularly figure 8. We are at the limit of what we can describe in these diagrams. I can also find examples in the IP Fast Re-route work where we struggle to show network snippets in ASCII with the associated addressing and subsequent tunneling, and yet the operation is simple to show in ppt, pdf, etc etc, particularly with colour. Another example - many of the ideas that we talk about in the IETF start life as a few coloured lines on a large whiteboard - because that is the simplest way to visualise these ideas and to express them for the first time to our peers. That style of expression therefore seems to the specifications themselves and for exactly the same reason - clarity. Perhaps it is because the work that I do is mainly on overlay network techniques where it is necessary to describe how the virtual network maps onto the physical network that I find difficulty producing clear ASCII art, but I would be surprised if I were alone in that view. If we think that ASCII art is all that is needed, perhaps - as an experiment - we should forbid the use of anything other than ASCII art in presentations at the next IETF? - Stewart _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf