Philip, thanks for your email.
See my comments inside whether your understand does or does not comply with  
what I was writing.
Heiner
 
In einer eMail vom 09.11.2007 16:56:27 Westeuropäische Normalzeit schreibt  
[EMAIL PROTECTED]:

Heiner 
Thanks. re your first  para - personally I find it very useful to understand 
what a protocol is  trying to do at a high level and why - before reading all 
the  detail. 
Let me see if I  understand your approach: 
- A node’s address is  simply its geographic location [based on 
latitude/longitude].  
No. The geographical location is only an attribute. Within the same  
geographical area there are, in general, multiple routers which show up  at 
some more 
upper map. You might object, well, a single particularly  elected router shall 
represent let's say a fifth of all router's from  California. What if that 
one goes down?
Well, all other routers which are closer to this one than to any other  
representative router from California, would continue to "stick to it". 
Sometimes ugly situations like such one are helpful to demonstrate the  
bottom line:
If I am sending from Munich, Germany, a postal letter to someone in  
Sausolito, who however has moved to a different location, it is perfectly fine 
-  in 
my view - that this letter is first of all sent to some postal office in  
Sausolito rather. For me, it is acceptable that such a letter has to be sent  
back 
all the long way because I believe, it makes no sense, that if someone  
relocates, all postal offices in the world should be informed. Also, in that  
case 
we wouldn't have got the lovely Elvis song RETURN TO SENDER :-)
 


- The topology is  hierarchical & follows the addressing.  
The topology is  hierarchical and the way the hierarchy is "formed up" is 
according to  geograph. attributes. 
Geographic-based  routing is an interesting idea and there has been some 
study of it in the ad  hoc community I believe. Couple of questions: 
- Would any policy  control be possible?
 For sure, because as soon as some concept is established people  are smart 
enough to enhance it :-) 
Also: Imagine, that your OSPF routers would also have these geo-attributes!  
You may try to get closest to the destination inside your OSPF network,  e.g.

eg to route through a  particular higher level network that you have a 
commercial deal with. How  about TE & multihoming? 
How about multiple routes with even different   hierarchical  links towards 
the egress?!
 
All these things would seem to me to  make it more problematic to enforce ‘
topology must follow geography’. in the  context of a global network, would it 
mean there was only one  network?
 


- how would failures  be dealt with? Can you discover & swap to and 
alternative path? (this  would then mean that topology didn’t follow  geography)
Maybe it is better to put this law aside again, there is no extra value in  
following this or that. The proposed concept was not developed based on this  
law.

- could you handle  mobile nodes and networks? 
We can cross that bridge when we have arrived there.
 
Heiner
 
 
 




   

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