[address-policy-wg] comments on 2008-05 Anycasting Tier 0/1 ENUM

I am broadly supportive of the principle behind this proposal. However  
the detail needs some refinement IMO.
It's not clear what is meant by "Tier-0/1" or even "ENUM". This needs  
to be clarified. I think we all know what we mean by these terms. But  
the proposal does not define them or incorporate a definition by  
reference.

My worry here is that if "ENUM" in particular is not defined, the  
proposal as written opens up a pandora's box. Does it apply  
*exclusively* to the public e164.arpa tree? If not, which other  
flavours of ENUM does the proposal cover? I'm thinking here of  
potential implementations of Infrastructure ENUM which could be done  
either on the public Internet or behind closed doors between telcos:  
should these be entitled to a /24 for anycasting too? Let's say two  
telcos implement some form of Infrastructure ENUM for cross-operator  
routing. Will this proposal mean they will both be entitled to a /24  
for their respective ENUM trees? Since telcos tend to use bi-lateral  
agreements, there is the prospect here of forests of ENUM trees. Each  
telco could well have a tree for each telco it has a bi-liateral  
agreement for Infrastructure ENUM and each of these trees could be  
entitled to a /24 for anycasting.