Iljitsch van Beijnum's research while affiliated with University Carlos III de Madrid and other places

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.

It is clear that there is not enough time to upgrade existing Internet hosts to dual stack before the IPv4 address pool depletes. This implies that the IPv6 transition and co-existence must support interaction between IPv4 nodes and IPv6 nodes. In this article we describe NAT64 and DNS64, a tool suite that provides a way forward in the IPv4-to-IPv6 transition by allowing communication among unmodified IPv6 and IPv4 nodes.

Inter-domain traffic engineering is an important aspect of network operation both technically and economically. Traffic engineering the outbound direction 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, AS path prepending and systems based on BGP communities. These mechanisms have severe drawbacks such as an increase of the size of global routing table or providing only coarse-grained control. In this paper we propose and evaluate an alternative mechanism that 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 existing mechanisms that also do not add additional prefixes to the global routing table.

Although there are many reasons towards the adoption of a multi-path routing paradigm in the Internet, nowadays the required multi-path support is far from universal. It is mostly limited to some domains that rely on IGP features to improve load distribution in their internal infrastructure or some multi-homed parties that base their load balance on traffic engineering. This chapter explains the motivations for a multi-path routing Internet scheme, commenting the existing alternatives and detailing two new proposals. Part of this work has been done within the framework of the Trilogy research and development project, whose main objectives are also commented in the chapter. Part of this work has been done within the framework of the Trilogy research and development project. The different research partners of this project are: British Telecom, Deutsche Telekom, NEC Europe, Nokia, Roke Manor Research Limited, Athens University of Economics and Business, University Carlos III of Madrid, University College London, Universit Catholique de Louvain and Stanford University. European Community's Seventh Framework Program

The Shim6 architecture enables IPv6 multihoming without compromising the scalability of the global routing system by using provider aggregatable addresses. To do so, hosts use different addresses as locators for data packet transmission, but present the same source and destination identifier pair to transport and upper layers. The components of this architecture are the Shim6 entity, which maps and translates upper-layer identifiers and locators for remote hosts; the Shim6 protocol, which exchanges mapping information between two hosts that communicate; and the REAP protocol, which monitors the existing unidirectional paths and finds new valid locator combinations in case of failure. To protect against new vulnerabilities this architecture may introduce compared to IPv6, Shim6 hosts use either cryptographically generated addresses or hash-based addresses.

Normal TCP/IP operation is for the routing system to select a best path that remains stable for some time, and for TCP to adjust to the properties of this path to optimize throughput. By executing TCP's congestion control algorithms on multiple paths at the same time, a multipath TCP can shift its traffic to a less congested path, thus maximizing both the throughput for the multipath TCP user and leaving more capacity available for other traffic on more congested paths. And when a path fails, this can be detected and worked around by multipath TCP much more quickly than by waiting for the routing system to repair the failure. This paper proposes a one-ended multipath TCP that is implemented on the sending host only, without requiring modifications on the receiving host, for the purposes of maximizing performance in transmissions from multiply connected large servers towards singly connected end-users and recovering from failures more quickly.

The concurrent use of multiple paths through a communications network has the potential to provide many benefits, including better utilisation of the network and increased robustness. A key part of a multipath network architecture is the ability for routing protocols to install multiple routes over multiple paths in the routing table. In this paper we propose changes to local BGP processing that allow a BGP router to use multiple paths concurrently without compromising loop-freeness.