Abstract: A method for interconnecting P-NAP customers with P-NAP providers and symmetrically routing packets between a P-NAP customer and a destination within a P-NAP provider's backbone across the P-NAP and that provider's backbone or symmetrically routing packets between a P-NAP customer and a destination not currently within a P-NAP provider's backbone across the P-NAP and a pre-defined P-NAP provider's backbone known as the default backbone. The method comprises creating a list of all P-NAP provider AS numbers and a list of all AS numbers which peer at public NAPs but which are not associated with P-NAP providers. For each P-NAP provider, take the union of all provider AS numbers and AS numbers associated with public NAPs and subtracting out AS numbers associated with the current provider.