Jarno Rajahalme

Naming in content-oriented architectures

There have been several recent proposals for content-oriented network architectures whose underlying mechanisms are surprisingly similar in spirit, but which differ in many details. In this paper we step back from the mechanistic details and focus only on the area where the these approaches have a fundamental difference: naming. In particular, some designs adopt a hierarchical, human-readable names, whereas others use self-certifying names. When discussing a network architecture, three of the most important requirements are security, scalability, and flexibility. In this paper we examine the two different naming approaches in terms of these three basic goals.

A Node Identity Internetworking Architecture

The Internet consists of independent networks that belong to different administrative domains and vary in scope from personal area networks, private home networks, corporate networks to ISP and global operator networks. These networks may employ different technologies, communications mediums, addressing realms and may have widely different capabilities. The coming years will add a significant level of dynamic behavior, such as mobile nodes and moving networks, which the Internet must support. At the same time, there is a need to address the increasing levels of harmful traffic and denial-of-service attacks. The existing Internet architecture does not support dynamic behavior or secure communication to a sufficient degree. This paper outlines a node-identity-based internetworking architecture that allows heterogeneous networks to work together without loss of functionality. Some of techniques employed in this architecture include reliance on cryptographic node identifiers, identity routers and localized addressing realms.

On name-based inter-domain routing

Locating objects with topology-independent identifiers has emerged as a key functionality in recent content networking approaches. Numerous designs have been proposed to address the obvious scalability and efficiency challenges such systems face in Internet-scale deployments. These designs have often been based on implicit assumptions of full deployment and a homogeneous autonomous system structure. Considering incremental deployment in a heterogeneous inter-domain setting, however, reveals both new scalability challenges and deployment and operation related disincentives. In this paper, we propose an inter-domain rendezvous design that combines policy-based name routing between adjacent networks with hierarchical interconnection overlays for scalable global connectivity. This hybrid design enables partial deployment and explicitly addresses the different operational incentives and policies of network service providers and enterprise networks. Extensive domain-level simulations show good performance for our solution in terms of overlay-induced latency, inter-domain path stretch and routing load distribution.

Incentive-compatible caching and peering in data-oriented networks

Several new, data-oriented internetworking architectures have been proposed recently. However, the practical deployability of such designs is an open question. In this paper, we consider data-oriented network designs in the light of the policy and incentive structures of the present internetworking economy. A main observation of our work is that none of the present proposals is both policy-compliant and incentive-compatible with the current internetworking market, which makes their deployment very challenging if not impossible. This difficulty stems from the unfounded implicit assumption that data-oriented routing policies directly reflect the underlying packet-level inter-domain policies. We find that to enable the more effective network utilization promised by data-oriented networking, essential caching incentives need to exist, and that data-oriented peering needs be considered separately from peering for packet forwarding.

Names, addresses and identities in ambient networks

Ambient Networks interconnect independent realms that may use different local network technologies and may belong to different administrative or legal entities. At the core of these advanced internetworking concepts is a flexible naming architecture based on dynamic indirections between names, addresses and identities. This paper gives an overview of the connectivity abstractions of Ambient Networks and then describes its naming architecture in detail, comparing and contrasting them to other related next-generation network architectures.

Incentive-Informed Inter-Domain Multicast

IP multicast enables reduced link loads for multiple recipients with overlapping data paths. In inter-domain settings, however, the costs and benefits of multicast redundancy elimination fall on different economic entities. Hence, in the absence of multicast specific inter-domain contracts and compensation, IP multicast has remained mostly an intra-domain endeavor. We propose incentive-informed inter-domain multicast, with which domains base multicast operation solely on their local unicast- derived incentives. Multicast forking will be provided only by domains that find it locally beneficial. Multicast traffic will pass through other domains using unicast paths. We find that, overall, up to 95% of the optimal IP multicast link load reduction can be attained, varying by the multicast group size. Link loads near the multicast sources can still remain high, mostly due to the considerable uphill diversity in the Internet topology. However, causal dynamics seem to exist for top tier transit providers to offer multicast as a service, significantly reducing the effective uphill diversity, thus enabling highly reduced link loads also on uphill paths. In this case the overall efficiency is also better than with optimal IP multicast.

Wireless and mobility issues in IP telephony

IP telephony has seen a tremendous surge in interest in the last couple of years. Several equipment vendors, application developers and service provides are entering into this emerging market. Regional as well as international standardization organizations have been involved in developing standards in the area, while several other forums have been actively promoting the industry as a whole. However, until recently, mobility and wireless issues have not been considered in detail with the scope of IP telephony, and the focus has been on fixed IP telephony systems. In this paper, we discuss some of the issues that need to be considered when mobility and wireless transport is introduced within IP telephony.