Topology Aggregating Routing Architecture (TARA)

TARA (Topology Aggregating Routing Architecture) is a novel architecture which allows to generate a map of the Internet. TARA allows to maintain and compute a precise topology of the near surrounding and lesser zoomed topologies the more remote they are. In the context of TARA, nodes are identified with “locators” which are derived from longitude/latitude degrees/minutes/seconds. TARA is designed to satisfy advanced traffic engineering such as computing QoS-inferred paths or non congested paths. TARA achieves these goals without requiring an increase of RIBs and FIBs. TARA solves also the issues of dynamic update churn as currently experienced in BGP-based Internet. TARA is also designed with mobility requirements in mind. Indeed, Mobility is supported without requiring dependency on home agents or care-of-address servers. Note, the Time-To-Live mechanism is neither needed nor used in TARA-forwarding. TARA supports various multicast, broadcast, MP2P (multipoint-to-point), anycast and MP2MP (multipoint-to-multipoint) communication schemes. In particular a stateless concept for multicast is outlined; this concept may serve as a pattern for anycast and MP2MP applications. TARA is fully prepared to cope with the IPv4-unicast address depletion issue.

A Hierarchical Approach to Reduce Power Consumption in Core and Edge Networks

With unicast, the metric is used to determine a low-power path between sources and destinations. The source and destination entities could be attached to Autonomous Systems (ASes) or to routing areas within the Autonomous System. Determining a low-power path within an Autonomous System provides a unique challenge as the topology of the constituent areas may not be known. To that end, we propose the use of a selective leak technique for disclosing low-power paths. Additionally, the proposed method can also be used to determine disjoint or redundant paths for load-balancing or fault tolerance. With multicast, the metric serves the twin purpose of finding low-power multicast paths as well as multicast replication points. Once low-power paths in either the unicast or the multicast cases are identified, then currently available traffic engineering techniques could be used to route the data packets.

Routing Architecture of Next-Generation Internet (RANGI)

This chapter describes a new Identifier/Locator split architecture, referred to as Routing Architecture for the Next Generation Internet (RANGI), which aims to deal with the routing scalability issues. Similar to the Host Identity Protocol (HIP) architecture, RANGI also introduces a host identifier (ID) layer between the IPv6 network layer and the transport layer and hence the transport-layer associations (e.g., TCP connections) are no longer bound to IP addresses, but to the host IDs. The major difference from the HIP architecture is that RANGI adopts hierarchical and cryptographic host IDs which have delegation-oriented structure. The corresponding ID to locator mapping system in RANGI is designed to preserve a “reasonable” business model and clear trust boundaries. In addition, RANGI uses special IPv4-embeded IPv6 addresses as locators and hence site-controllable traffic-engineering and simplified renumbering can be easily achieved while the deployment cost of such new architecture is reduced greatly.

Issues with Current Internet Architecture

Internet actors should work on an action plan to mitigate the increase of Routing Information Base (RIB) and Forwarding Information Base (FIB) table sizes and the load induced by routing updates churn (BGP Instability Report, n.d.).

Waveband Switching

In this chapter, the authors describe and review some of the recent research on WBS, including Multi-Granular optical cross-connect (MG-OXC) architectures that can switch traffic at different granularities. The authors focus on the dynamic online WBS problem, and describe and analyze two reconfigurable MG-OXC architectures in terms of their port count and blocking probabilities. Based on the analyses, the authors then propose a novel dynamic graph-based waveband assignment algorithm in conjunction with adaptive routing. The proposed algorithm employs ant optimization techniques to reduce ports and blocking probability in the network with online traffic in a distributed manner. The authors use simulation experiments to evaluate the effectiveness of the authors’ approach under various parameters such as varying number of ants, varying the number of routes and the wavelength assignment algorithm. The authors’ simulation results show that their graph-based waveband assignment algorithm combined with adaptive routing can achieve a superior performance when compared to other schemes. Furthermore, the authors’ studies shows that even with limited resources, WBS can achieve a low blocking probability and port savings.

On the Aggregatability of Router Forwarding Tables

In this book chapter, the authors first present Optimal Routing Table Constructor (ORTC), an optimal one-time FIB aggregation algorithm that preserves strong forwarding correctness. The authors then present four-level FIB aggregation algorithm(s) that can handle dynamic routing updates while maintaining forwarding correctness. Afterwards, the authors evaluate our algorithms using routing tables from RouteViews, and compare the algorithms with ORTC using routing tables from a Tier-1 ISP. The authors found that ORTC’s aggregation ratio is better than the Level 1, Level 2 and Level 3 algorithms, but the Level 4 algorithm has better aggregation ratio than ORTC as they relax the requirement of forwarding correctness. Finally, the authors evaluate the potential impact of introducing extra routable space in the Level 4 algorithm and discuss how to limit such negative impact.

Routing Optimization for Inter-Domain Traffic Engineering Under Identifier Network

Based on Identifier Network, we propose a solution for traffic engineering, which can be divided into two distinct parts: End-to-End traffic engineering and Neighbor-to-Neighbor traffic engineering. For each scenario, we develop a routing decision method for both routers and other network entities, such as IDMS (Identifier Mapping Server in Identifier Network). To analyze the feasibility of the solution, we collect Routeviews data set and the results show that the scheme proposed could reduce the burden of the core routing table.

Inter-Domain Traffic Engineering using the Origin Preference Attribute

Inter-domain Traffic Engineering (TE) is an important aspect of network operation both technically and economically. Outbound Traffic Engineering is less problematic as routers under the control of the network operator are responsible for the way traffic leaves the network. The inbound direction is considerably harder as the way traffic enters a network is based on routing decisions in other networks. There are very few mechanisms available today that facilitate inter-domain inbound traffic engineering, such as prefix deaggregation (i.e., advertise more specific prefixes), AS path prepending and systems based on BGP communities. These mechanisms have severe drawbacks such as exacerbating the increase of the size of global routing table or providing only coarse-grained control. In this chapter, an alternative mechanism is described and evaluated. The proposed solution does not increase the size of the global routing table, is easy to configure through a simple numeric value and provides a finer-grained control compared to currently used mechanisms that also do not add additional prefixes to the global routing table.

The Map-and-Encap Locator/Identifier Separation Paradigm

The chapter does not overview the merits of the Locator/Identifier separation paradigm. Rather, the aim is to provide a thorough analysis of the security aspects, assessing the security level of the architecture and providing recommendations on possible practices to improve it.

APT

The global routing system has seen a rapid increase in table size and routing changes in recent years, mostly driven by the growth of edge networks. This growth reflects two major limitations in the current architecture: (a) the conflict between provider-based addressing and edge networks’ need for multihoming, and (b) flat routing’s inability to provide isolation from edge dynamics. In order to address these limitations, we propose A Practical Tunneling Architecture (APT), a routing architecture that enables the Internet routing system to scale independently from edge growth. APT partitions the Internet address space in two, one for the transit core and one for edge networks, allowing edge addresses to be removed from the routing table in the transit core. Packets between edge networks are tunneled through the transit core. In order to automatically tunnel the packets, APT provides a mapping service between edge addresses and the addresses of their transit-core attachment points. We conducted an extensive performance evaluation of APT using trace data collected from routers at two major service providers. Our results show that APT can tunnel packets through the transit core by incurring extra delay on up to 0.8% of all packets at the cost of introducing only one or a few new or repurposed devices per AS.