Efficient IPv6 Neighbor Discovery in Wireless Environment

As the address space of IPv4 is being depleted with the development of IoT (Internet Of Things), there is an increasing need for permanent transition to the IPv6 protocol as soon as possible. Nowadays, many 3GPP (3rd Generation Partnership Project) Networks have implemented or will implement IPv6 in the near future for Internet access. These networks will also use NDP (Neighbor Discovery Protocol), which is the IPv6 tailored version of ARP (Address Resolution Protocol). The protocol is responsible for address auto-configuration, maintaining lists of all neighbors connected to a network, verifying if they are still reachable, managing prefixes and duplicate address detection. The protocol is defined in RFC 4861 and although it works fine for wired connected devices, it has been proven highly inefficient in terms of battery lifetime saving, when wireless networks came to the market and its use increased tremendously. This thesis work is a continuation of a previous master thesis and complements the work done previously by showing how the solutions suggested in the new draft can be implemented at the router and host side and practically confirms the previous results of the theoretical analysis through simulation scenarios of sleep and wake-up of the nodes, performed in OMNeT++. Subsequently, the scalability of the system as a whole was analyzed with a simulation model containing a range of hosts from 1 to 100, and shows it can operate efficiently on a larger scale, reducing multicast messaging by almost 100%, presumably saving their battery power.The introduction and rise of Internet of Things (IoT), and the use of more and more wireless devices in the communication between users, has depleted the available addresses of IPv4. The introduction of the new IPv6 protocol solves the address depletion problem, but on the other hand, many of the existing protocols have to be redesigned. This thesis is based on RFC 4861’s NDP (Neighbor Discovery Protocol for IPv6 Networks, the equivalent protocol of ARP (Address Resolution Protocol) for IPv4 Networks. Like ARP, NDP is used in all Networks, wired or wireless, and it’s main feature is to check and update periodically the state of the Network, provide L2 addresses to hosts in the same Network and verify their reachability. While wired devices experience no issues regarding power supply, as they are constantly hooked to a power source and rarely experience network failures, wireless devices have limited power, as they rely on battery lifetime. This is also the case of machines running NDP - the protocol relies on periodic exchange of multicast ICMPv6 (Internet Control Message Protocol version 6) control messages, creating unnecessary traffic overhead in the Network, as all hosts in a Network would receive those messages, regardless if they are meant for them or not. As a general working mode of a battery operated device, one enters predefined sleeping cycles (stand-by), which are designed by each manufacturer in different ways. Therefore, multicast signaling inside Networks disrupt those sleeping cycles, causing increased battery consumption, as a result of more required processing power and more consumed bandwidth. RFC 6775, together with [3], propose updates to NDP, which would solve the problems mentioned above. The major update is that each host can update the router about its state, by sending unicast messages, without involving the other hosts in the Network. The router, instead of sending periodic control messages to every host, it sends control messages to each host separately in specific time intervals. Only when a major change occurs in the Network, for instance an addition of a new host, or when a host leaves the Network, multicast messages are sent to every host to update their state. Together with the establishment of unicast signaling, a new method of address registration is introduced in the documents cited above, called Address Registration Option. This registration method is fully compatible with the two standard mechanism which provide the L3 addresses to hosts - Stateless Address Autoconfiguration (SLAAC) and Dynamic Host Configuration Protocol (DHCP). The previous thesis work took the first steps in implementing the proposed protocol changes, by investigating functions inside RADVD - the Router Advertisement Daemon, run on all routers and responsible for sending the multicast periodic control messages to the hosts (Router Advertisements). A full implementation of the proposed changes require covering both sides of the Network, i.e Host and Router. While RADVD is handling the Router side, the implementation at the Host side needs to be done inside the Linux Kernel. In this thesis work, the RADVD implementation was completed and possible implementation methods were shown inside the Linux Kernel. Due to the overall complexity of the Linux Kernel, while the proposed code could cover most aspects from RFC 6775, it wasn’t possible to test it, in order to conclude how much workload is left. Simulations took place to compare the two protocols and verify, in what extend these proposed changes can potentially improve battery lifetime. So, sleep and wake up scenario was tested in same time intervals in order to observe Network traffic. The goal was to have a decrease in control messages in the case where the suggested changes were applied. Different number of hosts were selected to see if these changes can be applied to larger network. In both cases, the best case scenario was tested and parameters which would normally hinder network performance were neglected. This decision was made to reduce the complexity of the Network as well. The results of the simulations indicated that there could be a decrease in control messages and the Network seems stable and scalable as number of host increases

Modelling of Babel Routing Protocol

Tato práce se zabývá simulováním směrovacího protokolu Babel. Cílem je vytvoření implementace simulačního modelu pro prostředí OMNeT++. Součástí textu práce je popis tohoto protokolu a základních principů simulace počítačových sítí v prostředí OMNeT++ s použitím knihovny INET. Dále jsou v práci diskutovány již existující implementace a je předložen návrh simulačního modelu, následovaný popisem jeho implementace. Nakonec je provedeno ověření správnosti vytvořeného modelu.This thesis deals with the simulation of a Babel routing protocol. The goal is to create implementation of simulation model for OMNeT++ simulator. The text includes a description of the protocol and basic principles of computer network simulation in OMNeT++ environment using an INET library. Furthermore, the text discussed existing implementations and submits a proposal of a simulation model, followed by description of its implementation. Finally, the correctness of created model is verified.

How efficient is Efficient NDP?

In the following years we will experience a transition towards Internet Protocol version 6 (IPv6). The reason is the depletion of IPv4 address space due to the rapid increasing numbers of Internet of Things (IoT) devices connection. This transition however poses a problem, since the majority of these devices mostly are mobile and not connected to power source. Neighbor Discovery Protocol (NDP) defined in RFC 4861 is used in IPv6 networks, to manage the address configuration as well as the network prefix and maintain lists of all the neighbors connected to that network. However, this protocol does not work as good in wireless connected devices as in wired. The messages exchange in the network disrupts the sleep mode of the nodes resulting in lower battery time. Hence the energy efficiency of these devices is now something we should consider. To solve this problem, the Efficient NDP draft was introduced as one of the optimized methods. This thesis takes the previous theses of analysis and simulations of IPv6 Neighbor Discovery for wireless networks further, to explore the ND protocol in RFC 4861 (legacy NDP), and compare it to the Efficient NDP draft in terms of energy efficiency for the devices mentioned above. Several dynamic network cases are taken into analysis, and simulation scenarios for these cases are tested in OMNeT++. These simulation models follow the implementation process introduced in the protocols with consideration of network scalability, and present the result that the Efficient NDP has large improvement in saving multicast messages in ND process.In the real world, people need addresses to identify their locations. Similar to this, devices also need to have network labels which called IP addresses for identification and locating when they connect to the Internet. Internet Protocol version 4 (IPv4) is a protocol which introduces a 32-bits IP address format and popularly used in today’s networks. However, the increased number of devices connecting to the Internet has led to the depletion of available IPv4 addresses. IPv6 was introduced with more address space to solve IPv4 address exhaustion problem. But on the other hand, many existing protocols used in IPv4 have to be extended or redesigned to fit IPv6 networks. A network always contains many nodes (routers and hosts). A node recognizes other nodes in its located network as its neighbors. Discovering neighbor locations, gathering neighbor information and defining the communication methods between neighbors are the contents in IPv6 Neighbor Discovery Protocol (NDP). The legacy NDP was announced 10 years ago in RFC 4861. It relies on periodical multicast Internet Control Message Protocol version 6 (ICMPv6) control messages to maintain relationship between neighbors. Which means that these control messages are sent to all the members in a group. Although these messages are only relevant to a specific member in this group at most of time, other members also have to receive and process them. As we known, receiving and processing messages require power consumption. It is inefficient for nodes to handle these unnecessary messages frequently, especially for wireless devices. As wireless devices are always not connected to power supplies, power saving becomes an important point for their battery life. To solve the high power consumption problem in legacy NDP, a more efficient protocol the Efficient NDP was announced. This protocol introduces a registration mechanism for hosts with a router. In this mechanism, the router does not need to send periodical control messages to the hosts for asking their updates, but give a registration timer to each host. A host only has to wake up and send messages to the router when the timer is reached, and can keep in sleep mode for a long time. This can significantly reduce the power consumption. On the other hand, as the router functions as a registration point in the network, it has the knowledge of each node address information, so it can help hosts for handling address related issues with their neighbors. From analysis, we have already known that the Efficient NDP provides a good solution in power saving, comparing with the legacy NDP. But how efficient it can achieve? To answer this question, an evaluation is required. As today’s networks are always dynamic networks, nodes are able to enter, leave and change their locations in networks at any time, it is worth for us to analyze the performance of these two protocols in this environments. However, as implementing a real dynamic network environment is too complex, simulation becomes an ideal method for evaluation. Two scenarios were taken into analysis and simulations in this thesis, one is nodes entering and leaving a network scenario, and another is nodes losing connection to a network case in movement scenario. As network scalability is an important parameter for evaluation, simulation models were designed with different network sizes. The obtained results indicate that in both of these scenarios, the Efficient NDP can achieve very high messages saving percentages in large networks. On the other word, it provides a great power saving solution

Comparison of Distance-Vector Routing Protocol

Táto práca sa zaoberá porovnaním Distance vector smerovacích protokolov. Presnejšie povedané EIGRP, RIP a Babel. Cieľom je získanie informácií pomocou simulačného nástroja OMNeT++, ale aj reálneho zapojenia. Súčasťou práce je detailný popis protokolov, princípov simulátoru OMNeT++ a jeho knižníc INET a ANSAINET. Následne sú zhrnuté výsledky experimentov a samotné porovnanie protokolov medzi sebou.This work deals with comparing the distance vector routing protocols. More accurately, protocols EIGRP, RIP and Babel. The aim is to compare information using the simulation OMNeT++, as well as the physical connection. Part of the work is a detailed description of the protocols, simulator OMNeT++ and the libraries INET and ANSAINET. Finally, we summarized the results of experiments and the comparison of protocols with each other.  

Advanced Signaling Support for IP-based Networks

This work develops a set of advanced signaling concepts for IP-based networks. It proposes a design for secure and authentic signaling and provides QoS signaling support for mobile users. Furthermore, this work develops methods which allow for scalable QoS signaling by realizing QoS-based group communication mechanisms and through aggregation of resource reservations

Tactical communication systems based on civil standards: Modeling in the MiXiM framework

In this paper, new work is presented belonging to an ongoing study, which evaluates civil communication standards as potential candidates for the future military Wide Band Waveforms (WBWFs). After an evaluation process of possible candidates presented in [2], the selection process in [1] showed that the IEEE 802.11n OFDM could be a possible military WBWF candidate, but it should be further investigated first in order to enhance or even replace critical modules. According to this, some critical modules of the physical layer has been further analyzed in [3] regarding the susceptibility of the OFDM signal under jammer influences. However, the critical modules of the MAC layer (e.g., probabilistic medium access CSMA/CA) have not been analysed. In fact, it was only suggested in [2] to replace this medium access by the better suited Unified Slot Allocation Protocol - Multiple Access (USAP-MA) [4]. In this regard, the present contribution describes the design paradigms of the new MAC layer and explains how the proposed WBWF candidate has been modelled within the MiXiM Framework of the OMNeT++ simulator.Comment: Published in: A. F\"orster, C. Sommer, T. Steinbach, M. W\"ahlisch (Eds.), Proc. of 1st OMNeT++ Community Summit, Hamburg, Germany, September 2, 2014, arXiv:1409.0093, 201

Modelling of EIGRP Routing Protocol

Simulace v oblasti počítačových sítí umožňuje analýzu chování sítě a nakonfigurovaných protokolů. Tato práce se zaměřuje na směrovací protokol EIGRP a jeho začlenění do simulačního nástroje OMNeT++. Součástí textu je detailní popis tohoto protokolu a jeho konfigurace na zařízení značky Cisco. Jsou zde shrnuty principy simulátoru OMNeT++ a~knihovny INET. Dále je nastíněn návrh rozšíření nástroje OMNeT++ o tento směrovací protokol. Následuje implementace protokolu podle provedených návrhů. Nakonec je implementované řešení porovnáno s výstupem reálných zařízení.The network simulation allows analysis of the computer networks behavior and configured protocols. This thesis focuses on the EIGRP routing protocol and its integration into the OMNeT++ simulation enviroment. The text includes a detailed description of the protocol and its configuration on Cisco devices. Furthermore, the text focuses on design of extension that supports routing protocol. The following describes implementation of the protocol according to design. Finally, the implemented solution is compared with the output of real devices.

Modelling of Distance-Vector Routing Protocols

Tato diplomová práce se zabývá implementací směrovacího protokolu RIPng v prostředí OMNeT++/INET. K tomu popisuje samotný RIPng protokol a jeho specifika na zařízeních Cisco. Dále ujasňuje významné pojmy jako IPv6 a distance-vektor směrovací protokoly. Práce také popisuje prostředí OMNeT++ a jeho rozšíření INET, u kterého se zaměřuje na současný stav implementace komponent nutných pro integraci protokolu RIPng.This master thesis deals with the implementation of the RIPng routing protocol in the OMNeT++/INET environment. It describes the RIPng protocol and its specifics on the Cisco devices. It clarifies important concepts such as IPv6 and distance-vector routing protocols. The thesis also describes the OMNeT++ environment and the INET Framework, where it focuses on the current status of implementation of the components required for the RIPng protocol integration.

Προσομοιώσεις mpls δικτύων με χρήση του omnet++

Στην παρούσα Διπλωματική Εργασία επιχειρείται μία εκτενής παρουσίαση και ανάλυση όλων των πτυχών της τεχνολογίας Multiprotocol Label Switching (MPLS). Μετά από μία εισαγωγή στις τεχνολογίες πριν το MPLS και μία συνοπτική αναφορά των πλεονεκτημάτων του, εξετάζονται η αρχιτεκτονική και τα βασικά στοιχεία του MPLS. Ειδική αναφορά γίνεται στο πρωτόκολλο διανομής ετικετών LDP. Στη συνέχεια εξηγείται ο τρόπος με τον οποίο προωθούνται τα πακέτα στο MPLS δίκτυο, καθώς και ο ρόλος που παίζουν οι ετικέτες στην προώθηση. Κατόπιν, δίνεται ιδιαίτερη έμφαση στην παρουσίαση των δύο βασικότερων εφαρμογών του MPLS: του Virtual Private Network (VPN) και του Traffic Engineering. Εξετάζονται επίσης δύο διαφορετικά μοντέλα Quality of Service για το MPLS, καθώς και οι προτεινόμενοι τρόποι μεταφοράς IPv6 πακέτων μέσω MPLS δικτύων. Τέλος, αναλύονται οι τομείς στους οποίους αναμένεται να επικεντρωθούν οι προσπάθειες για την εξέλιξη του MPLS. Όσον αφορά την πρακτική επαλήθευση της γνώσης που αποκομίσθηκε από την εργασία, πραγματοποιήθηκαν με χρήση του εργαλείου προσομοιώσεων OMNeT++ case studies MPLS δικτύων. Σε πρώτη φάση μελετώνται δύο υπάρχουσες προσομοιώσεις που παρέχονται στη βιβλιοθήκη INET και αφορούν α) τον τρόπο λειτουργίας και προώθησης πακέτων σε ένα MPLS δίκτυο και β) τη λειτουργία του πρωτοκόλλου LDP για την κατανομή των ετικετών. Στη συνέχεια, δημιουργούνται και παρουσιάζονται δύο νέες προσομοιώσεις για τις βασικές εφαρμογές του MPLS. Η πρώτη προσομοίωση αφορά τη λειτουργία ενός MPLS VPN δικτύου και η δεύτερη προσομοίωση αφορά το Traffic Engineering στο MPLS. Ο κώδικας των προσομοιώσεων παρατίθεται στα Παραρτήματα Ι και ΙΙ.In this Master Thesis a detailed presentation and analysis of all aspects of the Multiprotocol Label Switching (MPLS) technology is provided. After an introduction in the pre-MPLS technologies and a brief report of its advantages, the MPLS architecture and basic network elements are being examined. There is a specific mention on the Label Distribution Protocol (LDP). Subsequently, we explain the packet forwarding in MPLS networks and the role played by the labels. Afterwards, particular emphasis is given in the presentation of the two fundamentals MPLS applications: Virtual Private Network (VPN) and Traffic Engineering. We also examine two different Quality of Service models for MPLS, as well as the suggested ways of carrying IPv6 packets across the MPLS backbone. Finally, we analyze the areas expected to be the main focus of the efforts regarding the development of MPLS. Finally, for the practical verification of the knowledge reflected in our analysis, some case studies of MPLS networks were made using the OMNeT++ simulation tool. Firstly, we study two existing simulations of the INET framework concerning a) the operation and forwarding of packets in MPLS networks and b) the function of the LDP for label distribution. After that, we create and present two new simulations about MPLS basic applications. The first simulation is about the operation of an MPLS VPN network and the second one, about the MPLS Traffic Engineering. The code of the simulations is given in the Annexes I and II