- With regular expression based subscription, it's hard to know that the above property is met for the universe of addresses.
- Unlike DFC, originating and terminating addresses are not natively 'comparable'.
Application D issues a reverse with address, r
Two cases.
- r subscribes to D in the other region. Compute route set of r, RS(r). D is in RS(r). Take RSR(r) = Suffix(RS(r), D) which is the list of applications higher in priority than D. [What about applications that have no ordering relationship with D? - They are arbitrarily included or not included?]
- r does not subscribe to D in other region. Compute route set of r, RS(r). D is not in RS(r). Let RRS(r) = RS(r). No fanciness trying to determine a suffix of RS(r) based on inferred order of D within RS(r) - too complex.