ERCIM News No.37 - April 1999

Networking Technologies

by Yves Devillers

The tremendous increase in the demand for and use of Internet, mobile communications and multimedia along with an improved or more exacting employment of existing facilities is creating new problems that call for innovative solutions. This special theme section on Networking Technologies discusses some of the ways in which ERCIM institutions are addressing these issues.

The basic technologies such as Synchronous Data Hierarchy, Wavelength Multiplexing and optical switching needed to deploy high speed networks running at gigabits per second as envisioned by initiatives such as Internet 2, Canary, NGI and STARTAP are marginal to ERCIM's scope of interest. Attention in the ERCIM institutions is focussed on deploying testbeds to tame such speeds, to experiment new applications and to understand the impact of speed on applications when the end to end throughput is in the order of hundreds of megabit per second. This question is treated in the first paper, by Wunderling and Hommes, on Gigabit Networking.

New architectures that include dedicated hardware and algorithms must be designed to handle routing and switching at such speeds since software alone is no longer sufficient. The unification of transport concepts will mean that one common architecture can handle several protocols (such as ATM, IP and PDH), see the papers from FORTH ('Wormhole IP over ATM', 'High-Performance ATM Switching: the ATLAS I Single Chip Switch') and VTT ('Integration of Multiple Switching Disciplines').

The widely requested and long awaited introduction of multimedia on the network cannot be achieved without Quality of Service enforcement. Several tracks are relevant to this field such as resource reservation, service differentiation, simplified and integrated routing techniques, or even over dimensioning of the bandwidth resource, with significant efforts in convergence toward one single protocol for the Internet. Cooper ('Multiservice Internet: Service Network or Ham Technology?') summarises the problems to be expected in terms of scaling and of resource allocation and reservation. Queueing theory allows the identification of undesirable behaviour when mixing real time and best effort traffic or flowing long-trailed traffic (see 'Resource Allocation in Integrated-Services Networks' by Borst); the invited paper by Matthias Grossglauser ('Control of Network Resources over Multiple Time-Scales') advocates monitoring traffic at different time scales in order to improve resource control mechanism.

In order to deploy simpler networks capable of handling high speeds and providing quality of service, emerging operators in North America usually rely upon IP absorbing ATM and SDH with the aim of running directly over wavelength multiplexing and optical switches at 10 to 40 Gbps around 2002. As of today, ATM is still the preferred operational protocol for Telcos to enforce QoS over long distance networks at 155 Mbps (TEN 155 in Europe) and 622 Mbps (vBNS in the USA) with a few extensions and testbeds at 2.5Gbps. Multi Protocol Label Switching (MLPS) - IP routing protocols controlling ATM switches to support IP flows labelled according to requested QoS - is one example of convergence between IP and ATM; Chatzaki and Sartzetakis ('Internet Enhancements - Coexistence with ATM') discuss this and related experiments, while Sartzetakis addresses multi-vendor ATM management ('Technology Interoperation in ATM Management ') and Todrova and Brandt warn about security issues raised by ‘ATM to the desk’ applications via public ATM networks ('ATM Security Aspects').

The ubiquitous Internet is now entering into our homes. Luckenbach ('HOT - Home and Office Technologies') and Elias ('Heterogeneous Inhouse Networking Environment') tell us more about technologies and protocols of potential interest for hooking up the home and gives research news on in-house networking topics (‘ATM QoS to the toaster’).

‘Everywhere’ is anyway reachable by wireless local loops either via mobile phones (GSM, DECT) for Personal Data Assistant or even portable laptops, or for immobile LANs (LMDS) in the suburbs and industrial areas. Mühlenbein ('ARNO: Algorithms for Radio Network Optimization') talks about antenna dimensioning and placement together with frequency assignment problems while Gregori and Luckenbach describe a laptop technology based on DECT with - an expectable - sub-optimal TCP performance over non error-free media ('AMC - ATM based Wireless Mobile Computing'). GSM wireless and IP telephony are the topic of the papers from VTT: Paananen discusses the integration of a GSM network with the corporate intranet ('Internet Telephony merges with the GSM Network') and Laakso talks about reliable file transfer over GSM to communicate with Finnish icebreakers ('SFT - Smart File Transfer'). Research news from SICS ('Activities at SICS's Computer and Network Architecture Laboratory') spans from network conscious applications to IP telephony and differentiated services.

Finally case studies tell us more about the monitoring and displaying of Web traffic (Markatos and Papathanasiou), about Web cache monitoring in Hungarnet and the day to day network management of this net (papers from SZTAKI), and reasons behind the not so evident choice by CNR for an ATM rather than a Gigabit Ethernet solution for its new Pisa campus ('The New CNR Research Area in Pisa chooses an ATM Local Area Network').

Please contact:

Yves Devillers - INRIA
Tel: +33 1 3963 5976

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