Short version: One of the most important benefits of the "LISP" architecture (or any other CES architecture) is that it does *not* involve hosts using "Locator / Identifier Separation".
I suggest renaming the "LISP" architecture - to avoid the confusion caused by its current name. Hi Scott, Thanks for your reply, in which you wrote: >> An EID address is not an Identifier and an RLOC >> address is not a Locator. Both kinds of address >> are like any IP address - they play the roles of >> both Identifier and Locator. ITRs use a different >> algorithm for EID destination addresses. All >> other routers and all hosts make no distinction >> between EID and RLOC addresses. > > Give up on the names and look at how things are used. As to whether > something "is" an identifier or not, the main question is NOT whether it > is sometimes used by forwarding functions (forwarders already use > anything and everything they want to make forwarding decisions), but > whether its association with a particular endpoint (at some layer) is > independent of changes in topology. Both EID and RLOC addresses function as Identifiers - I am not suggesting that an EID address doesn't. I am suggesting that an EID address in the destination field also acts as a routing Locator, since it is used in exactly the same way as any other kind of address by all hosts and routers except ITRs. ITRs use it as a routing locator too, but with a second algorithm which uses the mapping system and tunneling. I explained this in the original message: http://www.ietf.org/mail-archive/web/rrg/current/msg06190.html I previously noted (msg06202) that the first sentence above should have been: An EID address is not only an Identifier and an RLOC address is not only a Locator. > In the case of LISP the answer is not clear because it depends on use. > Potentially it can be topology-independent, but it is expected to be > used by forwarding in some site deployments, and a site might renumber > endpoints within an EID prefix if they move within that site. > > But really, the thing to focus on is expected usage and real world usage. "Locator / Identifier Separation" is an enormously important architectural concept which pre-dates "LISP". It concerns hosts dealing with other hosts by two separate types of object: Identifiers to uniquely identify a host (though a host could have more than one Identifier) and Locators to control how a packet gets to the destination host. It affects packet addressing structures, host stacks and typically applications. (Loc/ID Separation architectures which attempt to support un-modified applications are pretty dodgy, I think, since the applications make assumptions about the IP addresses they use which are hard to support with the Loc/ID Separation stack and network.) Your architecture does not implement "Locator / Identifier Separation" at a host level - which is what the term has always referred to. You could argue that this concept is at work in the ITR's algorithm, but that is unimportant to hosts - and hosts are the most important things in the Net. I think this field has suffered considerable confusion due to your architecture being named after "Locator / Identifier Separation" - and due to continued claims that it really does support this Loc/ID Separation naming model. I suggest you rename your proposal. This would save a great deal of confusion when people try to understand it. Your architecture is completely different from the Locator / Identifier Separation architectures such as HIP, GSE, ILNP, Name-Based Sockets, RANGI and GLI-Split. Your architecture is a Core-Edge Separation architecture, which is a very good thing. One of the most important benefits of your architecture (or any other CES architecture) is that it does *not* involve hosts using "Locator / Identifier Separation". - Robin _______________________________________________ rrg mailing list rrg@irtf.org http://www.irtf.org/mailman/listinfo/rrg