On 8/16/23 16:16, michael brooks - ESC wrote:

Perhaps (probably) naively, it seems to me that DPA would have been a useful BGP attribute. Can anyone shed light on why this RFC never moved beyond draft status? I cannot find much information on this other than IETF's data tracker (https://datatracker.ietf.org/doc/draft-ietf-idr-bgp-dpa/) and RFC6938 (which implies DPA was in use, but then was deprecated).

I've never heard of this draft until now, but reading it, I can see why it would likely not be adopted today (not sure what the consensus would have been back in the '90's). DPA looks like MED on drugs. Not sure operators want remote downstream ISP's arbitrarily choosing which of their peering interconnects (and backbone links) carry traffic from source to them. BGP is a poor communicator of bandwidth and shilling cost, in general. Those kinds of decisions tend to be locally made, and permitting outside influence could be a rather hard sell. It reminds me of how router vendors implemented GMPLS in the hopes that optical operators would allow their customers to build and control circuits in the optical domain in some fantastic fashion. Or how router vendors built Sync-E and PTP into their routers hoping that they could sell timing as a service to mobile network operators as part of a RAN backhaul service. Some things just tend to be sacred. Mark.