In this paper, we propose a ring-based P2P-VPN (Peer-to-Peer Virtual Private Network) that provides a secure and reliable network to a large number of virtual organizations. The ring-based P2P-VPN establishes VPN by logically connecting nodes that operate autonomously in a ring topology. The ring-based P2P-VPN has an advantage of a high scalability in terms of the number of VPNs accommodated. I...

In our previous work, we have proposed a new VPN architecture for enabling user-based multiply associated VPNs [1]. Almost all existing VPN technologies assume that users never simultaneously access more than a single VPN. Thus, for realizing a new VPN service allowing users to simultaneously join multiple VPNs, several fundamental mechanisms, such as dynamically changing user’s VPN association...

Recognizing TimeML events and identifying their attributes, are important tasks in natural language processing (NLP). Several NLP applications like question answering, information retrieval, summarization, and temporal information extraction need to have some knowledge about events of the input documents. Existing methods developed for this task are restricted to limited number of languages, an...

In this study, Four Wave Mixing (FWM) characteristics in photonic crystal fibers are investigated. The effect of channel spacing, phase mismatching, and fiber length on FWM efficiency have been studied. The variation of idler frequency which obtained by this technique with pumping and signal wavelengths has been discussed. The effect of fiber dispersion has been taken into account; we obtain th...

يمومع باي تيعقوم متسيس كي تقد 3 رد متسيس وردوخ يربوان ياه يم ريثأت يفلتخم لماوع زا زا تـسا مزلا لـيلد نيمه هب و دريذپ شور دومن هدافتسا وردوخ هدش نييعت تيعقوم رد تقد شيازفا تهج هشقن قيبطت ياه . متسيس رد هشقن قيبطت وردوـخ يربواـن ياـه دراد هدهع رب ار رهش هشقن يوررب وردوخ يلعف تيعقوم نييعت هفيظو . رد هـشقن قيبطت هلأسم لح يارب يبيكرت متيروگلا كي هلاقم نيا متسيس رد يم داهنشيپ وردوخ يربوان يا...

ةصلاخلا بكرملل ةدیدج تاقتشم ریضحت ىلا ثحبلا يمری 4,3,1 ةیتلاا تلاعافتلا ءارجا للاخ نم لوزایادایاث : ًلاوأ : ب كرملل فیش ةدعاق ریضحت ) 2 و نیما 5 و تبكرم 4,3,1 لوزا یادایاث ( يلیفو یلكوینلا ضیو عتلا ءارجاو ةدعاقلل يرتسلاا ب كرملا نیو كت ى لا يدؤ یل مویدو صلا دیسكوثیا دو جوب ل ثیلاا تاتیسا ومورب عم ) 3 ( ، يذ لا یازاردیھلا عم ھتلعافم تمت ن 99 % د یازاردیھلا قتشم ریضحتل ) 4 ( فیش دعاوق نم د یدع...

VPN services has been around for decades but it did not get wide-spread usage until recently. A combination of new VPN technologies, network technologies and business communication requirements are the driving force behind the VPN services. This survey gives an overview of the recent approaches of VPN solutions and compare their scalability and flexibility aspects. The survey also categorises V...

A virtual private network (VPN) is simply secure network connectivity over a shared public network—basically, a private network on a public network infrastructure (the Internet). Figure 1 (next page) shows an example of a network layer VPN (adapted from Paul Ferguson and Geoff Huston, “What is a VPN? Part I,”The Internet Protocol J., June 1998,pp.2-19).Corporation X’s subnetworks (which belong ...

We describe an efficient cross-protocol attack, which enables an attacker to learn the VPN session key shared between a victim client and a VPN endpoint. The attack recovers the key which is used to encrypt and authenticate VPN traffic. It leverages a weakness of the RADIUS protocol executed between VPN endpoint and RADIUS server, and allows an “insider” attacker to read the VPN traffic of othe...

In recent years, IP-VPN (IP-based Virtual Private Network) that realizes a virtual dedicated line on the existing IP network has been capturing the spotlight. However, in the conventional IP-VPN, there is a problem that the fairness among IP-VPN customers is not guaranteed. In this paper, we therefore propose an IP-VPN fairness control mechanism called I2VFC (Interand Intra-VPN Fairness Control...