Improving ICE Service Selection in a P2P System using the Gradient Topology

GS

Gozar: NAT-friendly Peer Sampling with One-Hop Distributed NAT Traversal

Gossip-based peer sampling protocols have been widely used as a building block for many large-scale distributed applications. However, Network Address Translation gateways (NATs) cause most existing gossiping protocols to break down, as nodes cannot establish direct connections to nodes behind NATs (private nodes). In addition, most of the existing NAT traversal algorithms for establishing connectivity to private nodes rely on third party servers running at a well-known, public IP addresses. In this paper, we present Gozar, a gossip-based peer sampling service that: (i) provides uniform random samples in the presence of NATs, and (ii) enables direct connectivity to sampled nodes using a fully distributed NAT traversal service, where connection messages require only a single hop to connect to private nodes. We show in simulation that Gozar preserves the randomness properties of a gossip-based peer sampling service. We show the robustness of Gozar when a large fraction of nodes reside behind NATs and also in catastrophic failure scenarios. For example, if 80% of nodes are behind NATs, and 80% of the nodes fail, more than 92% of the remaining nodes stay connected. In addition, we compare Gozar with existing NAT-friendly gossip-based peer sampling services, Nylon and ARRG. We show that Gozar is the only system that supports one-hop NAT traversal, and its overhead is roughly half of Nylon’s

Mass Adoption of NATs: Survey and experiments on carrier-grade NATs

In recent times, the prevalence of home NATs and the widespread implementation of Carrier-Grade NATs have posed significant challenges to various applications, particularly those relying on Peer-to-Peer communication. This paper addresses these issues by conducting a thorough review of related literature and exploring potential techniques to mitigate the problems. The literature review focuses on the disruptive effects of home NATs and CGNATs on application performance. Additionally, the study examines existing approaches used to alleviate these disruptions. Furthermore, this paper presents a comprehensive guide on how to puncture a NAT and facilitate direct communication between two peers behind any type of NAT. The techniques outlined in the guide are rigorously tested using a simple application running the IPv8 network overlay, along with their built-in NAT penetration procedures. To evaluate the effectiveness of the proposed techniques, 5G communication is established between two phones using four different Dutch telephone carriers. The results indicate successful cross-connectivity with three out of the four carriers tested, showcasing the practical applicability of the suggested methods.Comment: 12 pages, 9 figure

Agent-based approach for cross-subnet communication

Projecte realitzat mitjançant programa de mobilitat. TECHNISCHE UNIVERSITÄT BERLIN. FAKULTÄT IV - ELEKTROTECHNIK UND INFORMATIKThe establishment of point-to-point connections between hosts behind NAT boxes have been always a problem due to the problem with the private IP addresses and NAT rewalls. To solve this problem, there are di erent techniques to make possible that hosts behind NAT boxes can establish a point-to-point connection rounding NAT rewalls and using solutions to exchange their IPs. The goal of this thesis is to present an implementation of a communication protocol which establishes a communication between agents that are behind NAT boxes avoiding all the problems that could occur during the communication, such as duplicated IP addresses or host unreachable errors and introduce to the reader some related work about NAT traversal. There is also in this thesis a little introduction to the existing techniques used to round a NAT rewall and the explanation of why we use NAT boxes even though they sometimes are a problem

An Experimental Study of Home Gateway Characteristics

Many residential and small business users connect to the Internet via home gateways, such as DSL and cable modems. The characteristics of these devices heavily influence the quality and performance of the Internet service that these users receive. Anecdotal evidence suggests that an extremely diverse set of behaviors exists in the deployed base, forcing application developers to design for the lowest common denominator. This paper experimentally analyzes some characteristics of a substantial number of different home gateways: binding timeouts, queuing delays, throughput, protocol support and others.Peer reviewe

DCCP Simultaneous-Open Technique to Facilitate NAT/Middlebox Traversal

https://datatracker.ietf.org/doc/rfc5595/Publisher PD

Evidences Behind Skype Outage

Skype is one of the most successful VoIP application in the current Internet spectrum. One of the most peculiar characteristics of Skype is that it relies on a P2P infrastructure for the exchange of signaling information amongst active peers. During August 2007, an unexpected outage hit the Skype overlay, yielding to a service blackout that lasted for more than two days: this paper aims at throwing light to this event. Leveraging on the use of an accurate Skype classification engine, we carry on an experimental study of Skype signaling during the outage. In particular, we focus on the signaling traffic before, during and after the outage, in the attempt to quantify interesting properties of the event. While it is very difficult to gather clear insights concerning the root causes of the breakdown itself, the collected measurement allow nevertheless to quantify several interesting aspects of the outage: for instance, measurements show that the outage caused, on average, a 3-fold increase of signaling traffic and a 10-fold increase of number of contacted peers, topping to more than 11 million connections for the most active node in our network - which immediately gives the feeling of the extent of the phenomeno

Host Identity Protocol-based Network Address Translator traversal in peer-to-peer environments

Osoitteenmuuntajat aiheuttavat ongelmia vertaisverkkojen yhteyksien luomiselle. Myös koneen identiteetti protokolla (HIP) kärsii osoitteenmuuntajien aiheuttamista ongelmista, mutta sopivilla laajennuksilla sitä voidaan käyttää yleisenä osoitteenmuuntajien läpäisymenetelmänä. Interaktiivinen yhteyden luominen (ICE) on tehokas osoitteenmuuntajien läpäisymenetelmä, joka toimii monissa erilaisissa tilanteissa. Tämän diplomityön tavoitteena on mahdollistaa HIP-pohjainen osoitteenmuuntajien läpäisy käyttämällä ICE-menetelmää, ja arvioida menetelmän toimivuutta implementoinnin ja mittausten avulla. Implementoimme ICE-prototyypin ja testasimme sitä eri tyyppisten osoitteenmuuntajien kanssa. Käytimme mittauksissa verkkoa, jossa kaksi isäntäkonetta olivat eri aliverkoissa, ja suoritimme ICE-yhteystestejä näiden koneiden välillä. Mittasimme testeissä lähetettyjen viestien ja tavujen määrän sekä käytetyn ajan. Mittaustulosten perusteella laskimme myös arvion ICE:n ja HIP:in aiheuttamalle ylimääräisten viestien ja ajankäytön määrälle. ICE onnistui luomaan yhteyden kaikissa testaamissamme tilanteissa, mutta käytti välillä enemmän viestejä ja aikaa kuin olisi tarpeen. Selvitimme työssä syyt ylimääräisille viesteille ja esitimme keinoja viestien määrän vähentämiselle. Saimme myös selville, että suuressa osassa tilanteista 4-5 yhteystestiviestiä riittää yhteyden luomiseksi, mutta tietynlaista osoitteenmuunnosta käyttävät osoitteenmuuntajat voivat helposti tuplata viestien määrän. Joka tapauksessa, yhteystestien luomat liikennemäärät ovat vähäisiä, ja käyttämällä lyhyempiä ajastinaikoja kuin mitä ICE spesifikaatio ehdottaa, voidaan ICE:n tehokkuutta kasvattaa merkittävästi. Käyttämällä HIP:iä ICE:n kanssa vertaisverkko-ohjelmat voivat saada käyttöönsä tehokkaan osoitteenmuuntajien läpäisymenetelmän, joka tukee myös yhteyden turvaominaisuuksia, mobiliteettia, sekä useita yhtäaikaisia verkkoliitäntöjä.Network Address Translators (NATs) cause problems when peer-to-peer (P2P) connections are created between hosts. Also the Host Identity Protocol (HIP) has problems traversing NATs but, with suitable extensions, it can be used as a generic NAT traversal solution. The Interactive Connectivity Establishment (ICE) is a robust NAT traversal mechanism that can enable connectivity in various NAT scenarios. The goal of this thesis is to enable HIP-based NAT traversal using ICE and to evaluate the applicability of the approach by implementation and measurements. We implemented an ICE prototype and tested it with different types of NATs. We used a network where two hosts were in different subnets and run ICE connectivity checks between them. The amount of messages and bytes sent during the process, and also how long the process took, was measured and analyzed. Based on the measurements, we calculated the overhead of using HIP with ICE for NAT traversal. ICE was able to create a connection in all the scenarios, but sometimes using more messages and longer time than expected or necessary. We found reasons why too many messages are exchanged and presented solutions on how some of these redundant messages could be avoided. We also found out that while 4-5 connectivity check messages are enough in many scenarios, NATs with specific address mapping behavior can easily double the amount of needed checks. Still, the generated traffic bitrate is modest, and using shorter timeout values than what the ICE specification suggests can have a significant positive impact on performance. By using HIP with ICE, P2P programs can get an efficient NAT traversal solution that additionally supports security, mobility and multihoming