[e2e] Port numbers in the network layer?
jeanjour at comcast.net
Fri May 10 15:22:05 PDT 2013
At 8:27 AM -0700 5/10/13, Joe Touch wrote:
>On May 8, 2013, at 1:45 PM, John Day <jeanjour at comcast.net> wrote:
>> Application names are suppose to be location-independent. Except on
>> broken OSs, you don't need to know what medium a file is on.
>Agreed; this, however, is one of the key failures of the "slice"
>model of network virtualization. It binds network interfaces and to
>OS components (slivers), and maps slivers to virtual networks. That
>inherently inhibits gateways - devices (or slivers) that bridge
>traffic between different VNs.
Boy, you are right about that! It is *one* of the failures. ;-)
>> Addresses are suppose to be location-dependent, where given two
>> addresses you should be able to tell if they are "near" each other
>> for some definition of "near."
>You're conflating "address" with a knowledge of the topology of its
No, I am conflating address with the homeomorphism used to create the
>Location spaces need not be Euclidean or even continuous.
No one suggested they did. The peculiar thing about examples is
that they are *examples* and represent only a single point in what
could be a very large space. They don't necessarily have all the
properties of all the other examples from the same space. Very
>Consider street addresses in Tokyo; two addresses on the same street
>typically satisfy no spatial "nearness" metric (the numbers are
>sometimes assigned in the order they are built, so 'near' is a
>temporal metric, rather than spatial).
>And not all addresses support aggregation.
Actually, this is incorrect. All addresses support aggregation
(given the previous definitions I used). Although not all
aggregations are useful for finding routes or establishing "physical
>Finally, addresses *are* names. A "name" is just an identifier; once
>you assign meaning, it becomes something else - an endpoint
>identifier, a location identifier, etc.
Absolutely. An address is a type of name. Nothing new there. That
has been well accepted as long as I have been around.
More information about the end2end-interest