att_abstract={To accommodate the increasing demands for bandwidth,
Internet Service Providers (ISPs) have deployed higherspeed
links and reconfigurable optical add drop multiplexers
(ROADMs) in their backbone networks. To address the reliability
challenges due to failures and planned outages, ISPs typically
use two backbone routers at each central office in a dualhome
configuration. Thus at the IP layer, redundant backbone
routers as well as redundant transport equipment to interconnect
them are deployed to provide reliability through node and path
diversity. However, adding such redundant resources increases
the overall cost of the network. Hence, a fundamental redesign
of the backbone network which avoids such redundant resources
by leveraging the capabilities of an intelligent optical transport
network is a highly desirable objective. It is clear that such a
redesign must lower costs without compromising on the reliability
achieved by today�s backbone networks. Modeling the costs and
reliability of the network at all layers is an important step in
achieving this objective. In this paper, we undertake an in-depth
investigation of the cost and reliability considerations involved
in designing the next-generation backbone network. Our work
includes a detailed analysis of the operation, cost and reliability
of the network at the IP layer and the multiple layers below it.
We discuss alternative backbone network designs which use only
a single router at each central office but use the optical transport
layer to carry traffic to routers at other offices in order to survive
failures or outages of the single local router. We discuss trade-offs
involved in using these designs.},
	att_authors={rs5419, kr2812},
	att_copyright_notice={This version of the work is reprinted here with permission of IEEE for your personal use. Not for redistribution. The definitive version was published in International Conference on Computer Communication Networks (IEEE ICCCN 2011). {{, 2011-07-31}}{{, http://icccn.org/icccn11/}}
	att_tags={network design,  architecture,  multi-layer restoration},
	author={Byrav Ramamurthy AND Kadangode Ramakrishnan AND Rakesh Sinha},
	institution={{International Conference on Computer Communication Networks
(IEEE ICCCN 2011)}},
	title={{Cost and Reliability Considerations in Designing the
Next-Generation IP over WDM Backbone Networks}},