On Fri, Dec 18, 2009 at 10:09:32PM -0600, James Hess wrote:
On Fri, Dec 18, 2009 at 1:24 PM, Jonny Martin <jonny@pch.net> wrote: ..
modified if need be - to achieve this. ?Mixing billing with the reachability information signalled through BGP just doesn't seem like a good idea.
Indeed not.. but it might offer one advantage, if it was mandatory for any such tarrif/cost to be advertised there to be valid, and in the form of an ancillary BGP route attribute, rather than buried in some 500,000 page treaty that forces all ISPs to decipher it and try to figure out what their liabilities are.
Mainly because it makes any tarrif very visible, and easily understood. and offers an easy ability to automatically make decisions like discard reachability information that has any billing labels or "strings" attached to it, or has a cost greater than $X per million packets listed for 'source'... and easily allows an ISP to replace the next hop with null when a tarrif option has been listed, or use only a route not subject to tarrif.
I concur. Such visibility is efficient and drives simplification and automation from a data mining perspective, when analyzing accounting information. In such context, some care is required. Reachability information is destination based. Mixing accounting (ie. NetFlow) and reachability (ie. BGP) information is of good value for traffic delivered out of a routing domain but not for traffic received, ie. reverse reachability lookups can be a way although they are not truly deterministic due to routing asymmetries; a mix of ingress measurements, lookup maps and an export protocol supporting L2 information (ie. for same interface, multiple peers scenarios) give way a better chance to resolve which neighboring party is pulling which traffic into the observed domain. Cheers, Paolo