For a long time now, funding agencies around the world have been promoting the research towards the so-called future Internet. Clean-slate design has been a buzz term for networking project proposals.
Today’s use of the Internet arises well known limitations in terms of mobility, security, address space exhaustion, routing and content delivery efficiency. Continuously patching the Internet with ad-hoc protocol extensions and overlay solutions (overlays, CDN, P2P, DPIs, NAT-aware protocols, MIP) is a complex and costly solution for the long term.
Research to circumvent current Internet limitations can be divided into those advocating a completely new architecture (clean-slate), and those defending an evolutionary approach due to incremental deployability concerns. From a research perspective, clean-slate design does not presume clean-slate deployment and aims at innovation through questioning fundamentals [Slide 3 of PSIRP public presentation].
A key question is to what extent a new paradigm thinking ‘out-of-the-TCP/IP-box’ for the future network is really necessary, e.g., as packet switching was to circuit switching in the 70’s. The reasoning is based on the large scale use of the Internet for dissemination of data [Jac06]. Tons of connected devices are generating and consuming content, without caring about the actual data source as long as integrity and authenticity are assured [DONA].
The Internet has shifted from being a simple host connectivity infrastructure to a platform enabling massive content production and content delivery, transforming the way information is generated and consumed. From its original design, the Internet carries datagrams inserted by sending hosts in a best effort manner, agnostic to the semantics and purpose of the data transport. There is a sense that the network could do more and better given that today’s use of the network is about retrieval of named pieces of data (e.g., URL, service, user identity) rather than specific destination host connections. TCP/IP is inherently unfair and inefficient for data dissemination purposes (e.g., multiple flows of P2P applications, redundant information over the wires, etc.). With this in mind, the enhancements of new internetworking layer should not be limited to QoS or routing efficiency: data persistence, availability and authentication of the data itself are beneficial in-network capabilities to be embraced from design [DONA].
Last decade’s efforts towards a next generation Internet, whether clean slate or evolutionary, have mainly focused on end-host reachability, with novel concepts (e.g., id/loc split) addressing the ’classic’ end-to-end security, mobility and routing issues. The common denominator of these proposals is host-centrism.
Research in a new generation Internet has prompted architectural proposals (e.g., FARA, Plutarch, UIP, IPNL, TRIAD, ROFL, NodeID) that mainly aimed at solving the “old” host connectivity and point-to-point communication problems. At the core of these new architectures are more flexible, expressive, and comprehensive naming and addressing frameworks than the Internet hierarchical IP address space.
However, this trend is changing, and senior researchers that have participated in the Internet development since its beginning, have advised to tackle the future Internet problem from an information interconnection perspective.
Van Jacobsen provides a vision [Google video talk] to understand the motivation for a networking revolution; while the first networking generation was about wiring (telephony) and the second generation was about interconnecting wires (TCP/IP), the next generation should be about interconnecting information at large (Content-centric networking) [JAC06]. This shift in the orientation of network architecture design implies rethinking many fundamentals by handling information as a first-class object.
We can also observe this shift toward information-centric networking in the momentum of service oriented architectures (SOA) and infrastructures (SOI), XML routers, deep packet inspection (DPI), content delivery networks (CDN) and P2P overlay technologies. A common issue is the necessity to manage a huge quantity of data items, which is a quite different task than reaching a particular host. In today’s Internet, forwarding decisions are made not only by IP routers, but also by middleboxes, VLAN switches, MPLS routers, DPIs, load balancers, mesh routing nodes and other cross-layer approaches. Moving down data-centric functions to the lower networking layers could be in tune with the trend in access and backbone technologies represented by the coupling of the dominant Ethernet access protocol and label switched all optical transport networks.
Only time will tell whether revolutionary networking concepts get commercially deployed. History has shown that economics and not purely technological arguments is what ultimately turns prototypes into reality. Recent concerning events (and more to come) may potentially promote and accelerate the adoption of new internetworking paradigms.
Our days economy is Internet-sensitive, service outages due to DDoS attacks or due to limitations of BGP insecure routing (remember Pakistan Telecom Youtube shut-down?) carry important worries and expenses: Internet reports claim potential costs of $31.000 per minute for Amazon’s two hour outage in June 2008.
Furthermore, end-users suffer from threats coming from the network such as evolving phishing methods and new forms of SPAM such as SPIT (over IP telephony) or SPIM (over instant messaging), that may end up frustrating the up today so successful Internet-based communication’s experience.
A recent move towards information-centric can be observed in projects addressing the future internetworking mod such as Trilogy, 4ward, EIFFEL, PSIRP, ICT’s FIRE and other activities in the frameworks of EU FP7 and NSF FIND. Similar in spirit, data-centric architectural proposals up today include the DOA, i3, DONA, Haggle and RTFM, in addition to ’peer-to-peer’, ’content-delivery’, ’sensor’ and ’delay-tolerant’ networks.
More than an endless discussion [Darwin] around clean-slate design and actual network (r)evolution deployment, what we really need for the future Internetworking is 1) ‘clean-slate thinking’ beyond the TCP/IP heritage to foster innovation through questioning paradigms; and 2) feasibility work on an information-oriented infrastructure capable of supporting the actual and future demands over the network of networks.
This post is the motivation and background of my current research work [SPSWITCH], now in cooperation with Ericsson Research and the EU FP7 PSIRP project.
References
[JAC06] V. Jacobson. If a clean slate is the solution what was the problem? Stanford ”Clean Slate” Seminar., Feb 2006. [Google video talk]
[RTFM] M. Särelä, T. Rinta-aho, and T. Tarkoma. RTFM: Publish/subscribe internetworking architecture. ICT Mobile Summit, Stockholm., June 2008.
[PSIRP] http://psirp.org
[Darwin] What would Darwin Think about Clean-Slate Architectures?
[DONA] T. Koponen, M. Chawla, B.-G. Chun, A. Ermolinskiy, K. H. Kim, S. Shenker, and I. Stoica. A data-oriented (and beyond) network architecture. SIGCOMM Comput. Commun. Rev., 37(4):181–192, 2007.
[SPSWITCH] C. Esteve Rothenberg, Fabio Verdi and Mauricio Magalhaes. “Towards a new generation of information-oriented internetworking architectures” ACM CoNext, First Workshop on Re-Architecting the Internet (Re-Arch08). Dec. 2008, Madrid, Spain. [PPT] [PDF] [bibtex]
Internet, I have started to delve into the world of “network coding”, a recent field of study (Ahlswede, 2000) that aims at solving an “information flow problem”
