Use of locator/identifier separation to improve the future internet routing system

The Internet evolved from its early days of being a small research network to become a critical infrastructure many organizations and individuals rely on. One dimension of this evolution is the continuous growth of the number of participants in the network, far beyond what the initial designers had in mind. While it does work today, it is widely believed that the current design of the global routing system cannot scale to accommodate future challenges. In 2006 an Internet Architecture Board (IAB) workshop was held to develop a shared understanding of the Internet routing system scalability issues faced by the large backbone operators. The participants documented in RFC 4984 their belief that "routing scalability is the most important problem facing the Internet today and must be solved." A potential solution to the routing scalability problem is ending the semantic overloading of Internet addresses, by separating node location from identity. Several proposals exist to apply this idea to current Internet addressing, among which the Locator/Identifier Separation Protocol (LISP) is the only one already being shipped in production routers. Separating locators from identifiers results in another level of indirection, and introduces a new problem: how to determine location, when the identity is known. The first part of our work analyzes existing proposals for systems that map identifiers to locators and proposes an alternative system, within the LISP ecosystem. We created a large-scale Internet topology simulator and used it to compare the performance of three mapping systems: LISP-DHT, LISP+ALT and the proposed LISP-TREE. We analyzed and contrasted their architectural properties as well. The monitoring projects that supplied Internet routing table growth data over a large timespan inspired us to create LISPmon, a monitoring platform aimed at collecting, storing and presenting data gathered from the LISP pilot network, early in the deployment of the LISP protocol. The project web site and collected data is publicly available and will assist researchers in studying the evolution of the LISP mapping system. We also document how the newly introduced LISP network elements fit into the current Internet, advantages and disadvantages of different deployment options, and how the proposed transition mechanism scenarios could affect the evolution of the global routing system. This work is currently available as an active Internet Engineering Task Force (IETF) Internet Draft. The second part looks at the problem of efficient one-to-many communications, assuming a routing system that implements the above mentioned locator/identifier split paradigm. We propose a network layer protocol for efficient live streaming. It is incrementally deployable, with changes required only in the same border routers that should be upgraded to support locator/identifier separation. Our proof-of-concept Linux kernel implementation shows the feasibility of the protocol, and our comparison to popular peer-to-peer live streaming systems indicates important savings in inter-domain traffic. We believe LISP has considerable potential of getting adopted, and an important aspect of this work is how it might contribute towards a better mapping system design, by showing the weaknesses of current favorites and proposing alternatives. The presented results are an important step forward in addressing the routing scalability problem described in RFC 4984, and improving the delivery of live streaming video over the Internet

LISP-TREE: A DNS Hierarchy to Support the LISP Mapping System

During the last years, some operators have expressed concerns about the continued growth of the BGP routing tables in the default-free zone. Several proposed solutions for this issue are centered around the idea of separating the network node’s identifier from its topological location. Among the existing proposals, the Locator/ID Separation Protocol (LISP) has seen important development and implementation effort. LISP relies on a mapping system to provide bindings between locators and identifiers. The mapping system is a critical protocol component, and its design is still an open issue. In this paper we present a new mapping system: LISP-TREE. It is based on DNS and has a similar hierarchical topology: blocks of identifiers are assigned to the levels of the hierarchy by following the current IP address allocation policies. We also present measurementdriven simulations of mapping systems’ performance, assuming a deployment of LISP in the current Internet

Effects of Anterior Thalamic Nucleus DBS on Interictal Heart Rate Variability in Patients with Refractory Epilepsy

Objective: Heart rate variability (HRV) changes were investigated by several studies after resective epilepsy surgery/vagus nerve stimulation. We examined anterior thalamic nucleus (ANT)-deep brain stimulation (DBS) effects on HRV parameters. Methods: We retrospectively analyzed 30 drug-resistant epilepsy patients’ medical record data and collected electrocardiographic epochs recorded during video- electroencephalography monitoring sessions while awake and during N1- or N2-stage sleep pre-DBS implantation surgery, post-surgery but prestimulation, and after stimulation began. Results: The mean square root of the mean squared differences between successive RR intervals and RR interval standard deviation values differed significantly (p < 0.05) among time-points, showing increased HRV post-surgery. High (0.15–0.4 Hz) and very low frequency (<0.04 Hz) increased, while low frequency (0.04–0.15 Hz) and the LF/HF ratio while awake decreased, suggesting improved autonomic regulation post-surgery. Change of effect size was larger in patients where both activated contacts were located in the ANT than in those where only one or none of the contacts hit the ANT. Conclusions: In patients with drug-resistant epilepsy, ANT-DBS might positively influence autonomic regulation, as reflected by increased HRV. Significance: To gain a more comprehensive outcome estimation after DBS implantation, we suggest including HRV measures with seizure count in the post-surgery follow-up protocol

Miscellanea. Levelek a szerkesztőhöz; Folyóirat-referátumok; Beszámolók; Könyvismertetések; Interjú = Miscellaneous

Levelek a szerkesztőhöz (pp. 2157-2159) 1. Zsír-szénhidrát anyagcsere-változások, gyulladásos és immunfolyamatok hatása az inzulinrezisztencia alakulására 2. Cytomegalovirus-fertőzés terhességben 3. A statinok hepatotoxicitása Folyóirat-referátumok (pp. 2160-2161) Alvásdiagnosztika: 1. P. I. Hair - P. L. McCormack - M. P. Curran: Reflektorfényben az eszopiclon, álmatlanság kezelésére = Spotlight on Eszopiclone in Insomnia Gasztroenterológia: 1. H. Sokol [et al.]: Thalidomid a befolyásolhatatlan idült granulomatosus colitis kezelésére = Thalidomide as a Treatment for Refractory CGD Colitis Infektológia: 1. M. Million [et al.]: Láz és eosinophilia a hazatérő utazón = Fever and Eosinophilia in a Returned Traveller Kardiológia: 1. S. J. Connolly [et al.]: Clopidogrel és acetilszalicilsav együttes adásának hatása pitvarremegésben = Effect of Clopidogrel Added to Aspirin in Patients with Atrial Fibrillation Beszámolók (pp. 2162-2163) 1. ESMO (European Society for Medical Oncology) és ECCO (European CanCer Organisation) kongresszus. Berlin, 2009. szeptember 19–24. 2. Jubileumi X. Sümegi Orvosi Napok. Sümeg, Hotel Kapitány, 2009. augusztus 27–29. 3. MSD–EGIS-együttműködés eredménye az új hatásmódú dipeptidilpeptidáz-4-gátló szitagliptin hazai forgalmazása Könyvismertetések (pp. 2164-2167) 1. Mózsik Gyula - Dömötör András - Past Tibor [et al.]: Capsaicinoids 2. Simon Singh - Edzard Ernst: Trick or Treatment? Alternative Medicine on Trial Interjú (pp. 2167) 1. Akarnoksággal nem lehet tekintélyt szerezni… : Interjú Dr. Cholnoky Péterre