On Sun, Nov 25, 2012 at 7:30 AM, Ammar Salih <ammar.sa...@auis.edu.iq> wrote: > 2- Layer 7 will not be detected by layer 3 devices (routers) .. so > location-based service on layer-3 will not be possible.
Geographic-based layer 3 routing has been thoroughly discussed on the IRTF RRG and just as thoroughly rejected. It's wholly inadequate as an approximation for topographic locality within the network graph. Uses of geolocation information at layer 3 are similar to uses of the "evil bit." On Sun, Nov 25, 2012 at 1:28 AM, Jimmy Hess <mysi...@gmail.com> wrote: > On 11/24/12, John Adams <j...@retina.net> wrote: >> Don't conflate layer 5-7 needs with basic communication requirements. IP is >> not the place for this sort of header. > > IP is the logical place for this kind of header, as this information > is node dependent, not application dependent. As is the user's legal name and social security number. If it isn't processed by the layer 3 protocols, if they don't use it for next hop selection, then it doesn't belong at layer 3. > For example, in the case of an anycasted service, the source IP > address does not uniquely identify where the source came from. Given appropriate construction of the layer 4 protocol, nothing stops an anycasted service from responding with a unicast IP address and using the unicast address during subsequent communication. An anycast service has far better mechanisms available to identify the responding server than stuffing a GPS header in the layer 3 packet. Regards, Bill Herrin -- William D. Herrin ................ her...@dirtside.com b...@herrin.us 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004
