As there is AFI=16387 Type 5, I would like to suggest an additional Type by
which the geographical coordinates wrt longitude and latitude are bijectively
mapped to {square degree#,square minute#, second row#, second column#} such
that the meridian (east/west) and equator ( north/south) dominated scheme is
transformed into a fast addressable (offsetting) scheme which starts at the
south pole and which only knows the directions to-east and to north as by the
following:
(1) Unicast:
Square degree#:
The globe may be conceived as 180 rings of sphericaltriangles/rectangles,
starting at the South pole with a ring of 360 sphericaltriangles, each of which
is limited by two longitudes and latitude 89° Southfrom the Equator. Towards
North there follow 178 rings of 360 sphericalrectangles, each of which is
limited by two consecutive longitudes andlatitudes. Finally there is a last
ring of 360 spherical triangles around theNorth pole.
Each spherical triangles/rectangles is assigned a square degree number from 1
to 64800, startingat the South Pole with that triangle which is limited by the
twolongitude degrees 0 and 1 East, the South Pole and latitude 89 South,
windingfrom there in eastbound direction, while forming a full circle such that
number360 is assigned to that triangle, which is limited by the two
longitudedegrees 1 West and 0,while number 361 is assigned to that spherical
rectangle,which is limited by the longitude degrees 0 and 1 East and the
latitudes 89South and 88 South. While winding in eastbound direction and while
windingtowards the North Pole, the last number 64800 is assigned to
thatspherical triangle which is limited by the longitudes 1 West and 0, the
latitude89 North and the North Pole.
Square minute# derived from given longitude minute x and latitude minute y.
if South of the Equator then minute row# = 60 –y else minute row# = y+1
if West of Greenwich then minute column# = 60- x else minute column# = x+1.
square minute# = (minute row# -1) times 60 + minute column#Square minute#
derived from given longitude minute x and latitude minute y.
second row# and second column# derived from given longitude second x and
latitude second y.
if South of the Equator then second row# = 60 –y else second row# = y+1
if West of Greenwich then second column# = 60- x else second column# = x+1.
(no second square# needs to be calculated)
The proposed enhancement would enable a next-hop determination by either one or
three table offsets in case of unicast forwarding
(2) Multicast
Multicast-Locator {square degree#; "multicast address"-number which is unique
per indicated square degree}
Well-known Multicast-Locator {square degree# =64801; standardized "Multicast
address" number for that well-known service}
The Multicast-Locator enables the retrieving of the proper entry from a new
Multicast-FIB entry (inside a participating node only) which enables multiple
concurrent next-hops eventually.
(3) Anycast
Anycast-Locator {square degree#; "anycast address"-number which is unique per
indicated square degree}
Well-known Anycast-Locator {square degree# =64802; standardized "Anycast
address" number for that well-known service}
The Anycast-Locator enables the retrieving of an entry of a new Anycast-FIB
(inside a participating node only) which enables just one next hop.
While (2) and (3) specify which one out of multipe Multicast/Anycast-services,
at a more general place of the LISP header there should be
some flags which indicate the fundamental forwarding type
0=unicast,1=multicast, 2= anycast, 3=.broadcast, 4=mp2p,.....)
H.H.
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