Subject: [GROW] Fwd: I-D Action:draft-van-beijnum-idr-iac-02.txt

From: Iljitsch van Beijnum <[email-masked]>
Date: Fri, 13 Mar 2009 12:12:54 +0100

Hi,

This is a draft that I presented at IDR earlier.

The idea is to add a new metric to BGP that allows for better traffic  
engineering for incoming traffic, reducing the need to deaggregate.

In the new version, the new IAC attribute is compared very late in the  
path selection algorithm: after the IGP cost, before the router ID  
comparison. This way, it doesn't influence what happens in large ASes  
where the IGP cost is a relevant metric and it also doesn't overrule  
the MED. But if all these are the same, which will be especially  
common in smaller ASes, this will first of all randomize the selection  
of the path based on the AS numbers involved, and secondly, allow both  
the source of the announcement and the local AS to apply push away or  
pull in additional traffic.

Feedback from the grow community would be much appreciated.

Begin forwarded message:

> 	Title           : A BGP Inter-AS Cost Attribute
> 	Author(s)       : I. van Beijnum, R. Winter
> 	Filename        : draft-van-beijnum-idr-iac-02.txt
> 	Pages           : 7
> 	Date            : 2009-03-09

> Although BGP implementations have extensive path selection
> algorithms, in practice operators have trouble performing
> satisfactory traffic engineering of incoming traffic based on BGP
> attributes that are taken into account in the path selection
> algorithm alone.  For this reason, many ASes deaggregate their
> address range(s) into smaller blocks and announce these blocks
> differently to different neighboring ASes in order to arrive at the
> desired traffic flow.  This practice contributes to the growth of the
> global routing table, which drives up capital expenditures for
> networks engaging in inter-domain routing.  This memo introduces a
> new inter-domain metric that supports finer-grained traffic
> engineering than current BGP attributes.

> A URL for this Internet-Draft is:
> http://www.ietf.org/internet-drafts/draft-van-beijnum-idr-iac-02.txt