Hi, Consider the following scenario: - Customer A is a customer of SP A - SP A is a customer of SP B - SP B has a traffic engineering community implementation With regards to using BGP communities for TE: - Does SP A write their own community implementation that maps to (some portion of) the community implementation of SP B? - Does SP A write their own community implementation that has no mappings at all to the community implementation of SP B; any TE that is required to be pushed to SP B is done by some dialog and coordination between Customer A and SP A? - Does SP A allow Customer A to announce prefixes tagged with SP B’s communities[1][2] - Is this sort of thing really complicated today, but one of the goals of draft-heitz-idr-large-community? [1] Customer A has knowledge of SP A’s upstream SP B [2] This opens up a can of worms where SP A or SP B implements some communities prefixed with reserved ASes, so we’ll assume that SP A implements some method of allowing communities prefixed with ASes of SP A and SP B only. Thanks!