I wonder whether this conversation should happen in the intarea wg mailing list as the main draft was posted there in the first place. I don't know if cross posting is welcome but I take the risk.
Going back to the question, the transport changes are related to the request/reply semantic of the architecture. The two distinct forwarding paths described in the draft take care of forwarding requests or replies.This ends up in the transport layer as a unidirectional channel to recv data or snd data. The replies carry data originating from a transport end-point (snd buffer) that binds to an identifier which is location independent, an IPv6 number which is not a locator. The forwarding path of the requests is very close to unmodified IPv6 with the DST address carrying the identifier. If you check in the draft an hICN node does one additional lookup in a local cache though. But you can ignore that for now for sake of clarity. What is important is the address rewrite operation made on the SRC address of the request. A copy of the request is stored in the local cache and the locator of the output interface is written in the SRC address before transmission. This is used by an upstream hICN or the final end-point to know the locator that will be used to reply. Replies coming from the snd end-point are label swapped but not like MPLS. The label is the identifier itself that is stored in the SRC address of the reply, whereas the DST address is a locator. In this forwarding path a lookup is made in the local cache to find a request (one or many) and the associated locator (one or many) that matches the identifier. The DST addr field of the replies is rewritten with the locator(s) just obtained from the lookup. This is how the reply is forwarded to the end-points that issued requests for this identifier. For the replies there is no FIB lookup on the identifier (as it is in the SRC addr field). There can be a lookup in the FIB on the locator stored in the DST of the reply to reach back the previous hICN node or eventually the original end-point. On Wed, Jun 20, 2018 at 12:30 AM Tom Herbert <t...@quantonium.net> wrote: > On Tue, Jun 19, 2018 at 1:50 PM, Luca Muscariello > <luca.muscarie...@gmail.com> wrote: > > The paragraph you reported is from the draft that describes hICN to > enable > > several use cases. > > Mobility is one of those, not the only one. > > To clarify, the draft on hICN mobility deployment options focuses on the > 5G > > service based architecture. > > > > You may be asking > > 1) is it possible to get all the features provided by hICN w/o updates to > > the transport layer? > > 2) is changing the transport protocol unnecessary difficult to enable all > > the use cases mentioned in the draft? > > > Sorry, but I'm still missing something fundamental here. AFAICT, the > idea of hICN is to put routes in the local routing table and use > existing forwarding and routing to forward packets to mobile nodes. So > if a node changes location, then the routing tables need to be > updated. Effectively this is a bunch of host routes that need to be > maintained. At least this is what I gather from the draft: > > "hICN network layer is about using the IPv6 FIB to determine a next > hop router to forward requests or using a local packet cache to > determine if an incoming request can be satisfied locally." > > Is this correct? If it is, then I sort of understand how hICN could be > used for mobility or virtualization without network overlays, but then > I'm completely lost as to why this would require any changes in the > transport layer. > > Tom > > > > > > > IMO, the answers are no for both. > > > > Luca > > > > On Tue, Jun 19, 2018 at 9:26 PM Tom Herbert <t...@quantonium.net> wrote: > >> > >> On Tue, Jun 19, 2018 at 2:46 AM, Luca Muscariello > >> <luca.muscarie...@gmail.com> wrote: > >> > Hi all, > >> > > >> > the draft below has been posted and describes deployments options for > >> > anchorless mobility management by using > >> > the hicn network architecture that implements icn semantics in IPv6 > >> > networks. > >> > > >> > > >> > > https://datatracker.ietf.org/doc/draft-auge-dmm-hicn-mobility-deployment-options > >> > > >> > https://datatracker.ietf.org/doc/draft-muscariello-intarea-hicn/ > >> > > >> > A background document has been posted to the internet area WG and > >> > reported > >> > here for your convenience. > >> > The core principle behind hicn and mobility management is that data > >> > sources > >> > are named using location independent names > >> > encoded in IPv6 addresses. The transport service sitting on top of the > >> > hicn > >> > architecture is not based on usual TCP/UDP sockets > >> > but on a novel consumer/producer transport service that will be > >> > described in > >> > another draft. > >> > >> From the draft: "The transport end-point offers two kinds of services > >> to applications: a producer and a consumer service. The service is > >> instantiated in the application by opening communication sockets with > >> an API to perform basic transport service operations: allocation, > >> initialization, configuration, data transmission and reception." > >> > >> This seems like a pretty dramatic rethink of the transport layer just > >> for the purposes of mobility management. Will there be a way to use > >> hICN at the network layer with exsiting and unmodified transport > >> protocols (i.e. can this be done without boiling the ocean)? > >> > >> Thanks, > >> Tom > >> > >> > >> > >> > The current document and a companion document that will be posted soon > >> > describe the different deployment options > >> > with special care to the 5G service based architecture. > >> > Thanks for the comments already received that helped completing this > -00 > >> > draft. > >> > > >> > Luca > >> > > >> > > >> > > >> > > >> > > >> > > >> > _______________________________________________ > >> > dmm mailing list > >> > d...@ietf.org > >> > https://www.ietf.org/mailman/listinfo/dmm > >> > >
_______________________________________________ Int-area mailing list Int-area@ietf.org https://www.ietf.org/mailman/listinfo/int-area
