Topologieänderung für RF nötig ??

[S. De Bruyne]

Gaston, kannst du das vielleicht etwas ausführen. Ich versteh's nicht und es passt auch nicht zur Aussage von Klaus.

[pbuechel]

this page intentially left blank ?

[S. De Bruyne]

...I was always wondering how IEC and espceially ISO could accept this specification wherfe ambiguity between terms are given (same Name "Line" as physical or logical entity). I was used to especially the ISO to be very strict on such ambiguities.

That is possible if the intended scope is clear from the context. Otherwise, the clear term "Logical Line" or "Physcial Line" has to be used.

The specifications specify in point 1.3.2 in the TP part, that "Bridges are used to combine physical Segments to a Line in order to achieve longer distances and to allow up to 255 devices (Figure 25) on a Line with TP1-64 devices."

That should then indeed better state "Logical Line".

The drawing joined to this shows a bnride in the backbone line. Also all subsequent figures show bridges in all types of lines. There is however abiguity again between backbone and main lines in figure 26. The best ist that lines markes as "Lines" actually are "Main Lines".

Indeed. I see. Thank you for reporting. I'll see if I can change it.

Now the argument one could throw in to say that the drawings are wrong because point 1.3.2 speaks about logical lines (while it doies not explicitely state it does). Don't know how the ISO works topday, but this would have been a reason for the ISO to throw over and invalidate the whole specification in the past as it clearly shows the ambiguity.

Likely because, in the Physical Layer specification, people assume the context of the Physical Line.

However here comes the glossary to help which specifies the bridge/repeater in the physical and not the logical line. So it is well the only place without ambiguity and it clearly includes the brige/repeater. And yes the main line is a physical line....

Sorry for interrupting here: the Glossary says that a TP1 Repeater or Bridge may be in a Physical Line. It does not exclude on other possible conditions. If these devices would have been allowed in any possible type of Logical Line, then it would have stated "One or more Bridges shall be possible on a Line."
But this is also some bad will interpretation: Bridges and Repeaters are only mentioned in the definition of the Line, not in the definition of the Main Line or Backbone Line.

...I can't see any reason to forbid the presence of bridges/repeaters in main/area line provided the specification that states "Not more than 6 Couplers (i.e. Bridges or Routers) shall be between any of two devices".

I cannot think or know of any technical reason right now either. It is more a matter of definition and what is allowed in an installation and what not. That does not always have to do with technical reasons, but also with clear rules and keeping things simple.