[Nrg-l] Renata Texeira visit: Tuesday (8/24)

Mark Crovella crovella at cs.bu.edu
Sat Aug 21 09:31:16 EDT 2004


Dear NRGers: 

On Tuesday (8/24) we will host Renata Texeira of UCSD.  She will give a talk
in the NRG slot, and will be available beforehand to meet with us.   Please
let me know if you'd like to meet with her, either alone or in a group with
others.

Her talk abstract is below.

Mark

---------------------------

Title: Network Sensitivity to Intradomain Routing Changes

Abstract:

In a large transit IP network, hosts outside the network originate and
consume most of the traffic. This implies that the network performance and
robustness is determined by both intradomain and interdomain routing.
Despite the architecture separation between these two classes of routing
protocols in the Internet, intradomain protocols do influence the
path-selection process in the Border Gateway Protocol (BGP). When there are
multiple (equally good) BGP routes available for a given destination, BGP
selects the route associated with the closest egress point based upon
intradomain path costs. Under such hot-potato routing, BGP-level routes to
destinations that connect to the network in multiple points (such as
multi-homed customers and destinations learned from peers) may change
because of intradomain routing changes.

This talk looks at the unforeseen implications of the interaction between
intra and interdomain routing. First, I present the results of our analysis
of the influence of intradomain routing changes on BGP routing in a large
tier-1 ISP network.  We found that intradomain routing changes trigger a
significant number of BGP updates.  For example, we have measured some
instances in which more than half of a router's BGP table changed because of
a single intradomain routing event.  In addition, we discovered that BGP
routing changes triggered by intradomain events can take more than a minute
to converge, which may lead to transient forwarding instabilities.  We call
these abrupt swings of external routes "hot-potato disruptions".
Applications such as voice, streaming, and gaming are particularly sensitive
delays and losses caused by these disruptions.

As a result, there is a need for guidelines and tools to assist in the
design of networks that minimize hot-potato disruptions. However, developing
these tools is challenging due to the complex and subtle nature of the
interactions between exterior and interior routing. We address these
challenges using an analytic model of hot-potato routing that incorporates
metrics to evaluate network sensitivity to hot-potato disruptions.  After
describing this model, I demonstrate its utility by analyzing the
sensitivity of a large tier-1 ISP network.

More info on this work can be found at:
http://www-cse.ucsd.edu/~teixeira/p184-teixeira.pdf
http://www-cse.ucsd.edu/~teixeira/p347-teixeira.pdf

Renata Teixeira is a Ph.D. student at the University of California, San
Diego in the Department of Computer Science and Engineering. She received
her B.Sc. in Computer Science and M.Sc. in Electrical Engineering from
Universidade Federal do Rio de Janeiro, Brazil in 1997 and 1999,
respectively. Her research interests are in measurement and analysis of
routing protocols, and in management of large IP networks.




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