Showing papers on "Virtual routing and forwarding published in 2007"

On designing incentive-compatible routing and forwarding protocols in wireless ad-hoc networks: an integrated approach using game theoretic and cryptographic techniques

Abstract: In many applications, wireless ad-hoc networks are formed by devices belonging to independent users. Therefore, a challenging problem is how to provide incentives to stimulate cooperation. In this paper, we study ad-hoc games--the routing and packet forwarding games in wireless ad-hoc networks. Unlike previous work which focuses either on routing or on forwarding, this paper investigates both routing and forwarding. We first uncover an impossibility result--there does not exist a protocol such that following the protocol to always forward others' traffic is a dominant action. Then we define a novel solution concept called cooperation-optimal protocols. We present Corsac, a cooperation-optimal protocol which consists of a routing protocol and a forwarding protocol. The routing protocol of Corsac integrates VCG with a novel cryptographic technique to address the challenge in wireless ad-hoc networks that a link's cost (i.e., its type) is determined by two nodes together. Corsac also applies efficient cryptographic techniques to design a forwarding protocol to enforce the routing decision, such that fulfilling the routing decision is the optimal action of each node in the sense that it brings the maximum utility to the node. We evaluate our protocols using simulations. Our evaluations demonstrate that our protocols provide incentives for nodes to forward packets. Additionally, we discuss the challenging issues in designing incentive-compatible protocols in ad hoc networks.

Dynamic system and method for virtual private network (VPN) packet level routing using dual-NAT method

Abstract: A system and method for virtual private network (VPN) packet level routing using a Dual-NAT architecture to provide a bi-directional secure connection between applications, hosts, or networks at any two end sites without exposing each other's actual IP addresses and network topologies. The method includes providing a client a list of available resources on a remote network; initiating a request by the client for at least one resource from the list of available remote resources as though the at least one resource is local to the client; NATting the source and destination IP addresses to a pair of client and resource Dynamic VPN (DVPN) addresses; routing the request to the remote network; NATting the client and resource DVPN addresses to local IP addresses on the remote network; issuing the request to the at least resource; and NATting/routing the response using the reverse process.

Cluster-Based Forwarding for Reliable End-to-End Delivery in Wireless Sensor Networks

Abstract: Providing efficient and reliable communication in wireless sensor networks is a challenging problem. To recover from corrupted packets, previous approaches have tried to use retransmissions and FEC mechanisms. The energy efficiency of these mechanisms, however, is very sensitive to unreliable links. In this paper, we present cluster-based forwarding, where each node forms a cluster such that any node in the next-hop's cluster can take forwarding responsibility. This architecture, designed specifically for wireless sensor networks, achieves better energy-efficiency by reducing retransmissions. Cluster-based forwarding is not a routing protocol. Rather, it is designed as an extension layer that can augment existing routing protocols. Using simulations, we demonstrate that cluster-based forwarding is effective in improving both end-to-end energy efficiency and latency of current routing protocols.

Evaluation of IP Fast Reroute Proposals

Abstract: With the increasing demand for low-latency applications in the Internet, the slow convergence of the existing routing protocols is a growing concern. A number of IP fast reroute mechanisms have been developed by the IETF to address the issue. The goal of the IPFRR mechanisms is to activate alternate routing paths which avoid micro loops under node or link failures. In this paper we present a comprehensive analysis of these proposals by evaluating their coverage for a variety of inferred and synthetic ISP topologies.

Evaluating Xen for Router Virtualization

Abstract: In this paper, we evaluate the performance of a software IP router forwarding plane inside the Xen virtual machine monitor environment with a view to identifying (some) design issues in Virtual Routers. To this end, we evaluate and compare the forwarding performance of two identical Linux software router configurations, run either above the Xen hypervisor or within vanilla Linux. Even with minimal sized packets, we show that the Xen DomO privileged domain offers near native forwarding performance at the condition that the sollicitation to unpriviledged domains stay minimal, whereas Xen unprivileged domains offer very poor performance in every cases. This shows that an important design principle for virtual router platforms must be to handle all forwarding, for all virtual routers, onto the same forwarding engine, in order to avoid much detrimental per-packet context switching.

Centrally controlled routing with tagged packet forwarding in a wireless mesh network

Abstract: Embodiments of the present invention include a method, an apparatus, and logic encoded in one or more computer-readable tangible medium to carry out a method. One method includes tagging packets and forwarding packets in a wireless mesh network using stored forwarding information for the tag, wherein the forwarding information is according to a centrally determined routing method and tag distribution method.

Post-Failure Routing Performance with Multiple Routing Configurations

Abstract: The slow convergence of IGP routing protocols after a topology change has led to several proposals for proactive recovery schemes in IP networks. These proposals are limited to guaranteeing loop-free connectivity after a link or node failure, and do not take into account the resulting load distribution in the network. This can lead to congestion and packet drops. In this work, we show how a good load distribution can be achieved in pure IP networks immediately after a link failure, when multiple routing configurations (MRC) is used as a fast recovery mechanism. This paper is the first attempt to improve the load balancing when a proactive recovery scheme is used. Unlike load balancing methods used with normal IP rerouting, our method does not compromise on the routing performance in the failure free case. Our method is evaluated using simulations on several real and synthetically generated network topologies. The evaluation shows that our method yields good routing performance, making it feasible to use MRC to handle transient network failures.

Selection of a Forwarding Area for Contention-Based Geographic Forwarding in Wireless Multi-Hop Networks

Abstract: Contention-based geographic forwarding (CGF) is a state-free forwarding technique. In this paper, we develop a general analytical framework to evaluate the performance of CGF with different forwarding areas in wireless multi-hop networks. In particular, we compare the performance of CGF for three typical forwarding areas, analytically and by extensive simulations. We further investigate the impact of several important assumptions on our analytical results. Our study provides guidelines regarding the selection of a specific forwarding area during the design phase of a CGF protocol. It also serves as a general performance evaluation framework for CGF protocols as well as traditional geographic forwarding protocols.

Communication network routing apparatus and techniques using logical communication links

Abstract: Communication network routing apparatus and techniques using logical communication links are disclosed. A routing apparatus identifies a logical communication link that it is capable of being used to establish a virtual connection with another routing apparatus within a virtual connection operational domain, which includes multiple sub-domains, of an underlying communication system. A destination that is associated with the routing apparatus and is reachable through the virtual connection is also identified. Information that is indicative of the identified logical communication link and of the identified destination is provided for distribution from a sub-domain of the routing apparatus in the virtual connection operational domain to another sub-domain within the virtual connection operational domain. This distribution of information enables a routing apparatus in one sub-domain to dynamically route a virtual connection toward a destination in a different sub-domain. Data structures for distributing the information are also disclosed.

IP fast reroute with failure inferencing

Abstract: Five nines availability is being expected from IP networks due to the growing popularity of IP telephony and the increasing usage of the Internet for mission-critical applications. This necessitates enhancing the resiliency of IP networks against transient failures that are observed to happen relatively frequently even in well-managed networks. Towards that end, we proposed failure inferencing based fast rerouting (FIFR) approach that exploits the existence of a forwarding table per line-card, for lookup efficiency in current routers, to provide fast rerouting similar to MPLS, while adhering to the destination-based forwarding paradigm. Earlier, we have shown that FIFR can deal with either single link or single node failures in a network consisting of point-to-point links with symmetric link weights. In this paper, we generalize FIFR to handle both link and node failures in networks with asymmetric link weights and multi-access links too. Furthermore, we apply FIFR for protecting against inter-AS failures also. With these extensions, we argue that FIFR elevates the resiliency of any IP network with minimal changes to the forwarding and routing planes.

A Scalable Routing System Design for Future Internet

Abstract: Internet routing is at an important crossroad. The current global routing table, which is largely based on IPv4 addresses, has been growing at an alarming rate over the last few years, despite the constraints by the shortage of IPv4 addresses. IPv6 removes the address shortage problem, however its deployment may potentially further exacerbate the routing scalability challenges facing us today. In this paper, we first examine and describe the root causes of the routing scalability problem and then discuss a promising direction towards an effective solution. The explosive growth of the Internet over the last decade made it no longer feasible to perform global routing based on all end user IP address prefixes. Yet at the same time, we must preserve the end-to-end model of the Internet architecture. We sketch out a basic approach to an effective solution which is to separate globally routable addresses (GRA) from globally deliverable addresses (GDA). This separation of address space can simultaneously achieve the goals of improved routing scalability, ease of site-multihoming without using multiple addresses, and elimination of the need for user renumbering when changing providers. An interesting aspect of this approach is that it both facilitates the deployment of IPv6 at edge sites and also does not require immediate changes at large IPv4 deployed bases.

Routing and quality decision in mobile ip networks

Abstract: The invention relates to a method for routing streams of traffic in IP networks, particularly in mobile IP networks. The invention involves a plurality of streams of traffic to be transmitted being routed such that they are transmitted in a carrier/context (7). The plurality of streams of traffic at different destination networks (5; 6) and/or demands on transmission quality for the respective stream of traffic are merged and are transmitted from a terminal (3) via one carrier/context (7) to a network access node (4) in the IP network and are routed from there to the respective destination networks and devices.

Integrated Cost-Based MAC and Routing Techniques for Hop Count Forwarding in Wireless Sensor Networks

Abstract: This paper presents integrated MAC/routing solutions for wireless sensor networks. At the MAC layer, every node accesses the channel according to its own cost by means of properly defined cost-dependent access probabilities. Costs are used to capture the suitability of a node to act as the relay and may depend on several factors such as residual energies, link conditions, queue state, etc. Our cost-aware MAC discriminates nodes right in the channel access phase by therefore assisting the forwarding decisions to be made at the routing level. In fact, nodes with high costs are ruled out from channel contention and are not considered when making routing decisions. This provides the routing layer with better relay candidates and, at the same time, decreases the number of in-range devices contending for the channel, thereby reducing interference. The proposed MAC scheme is coupled with routing over hop count (HC) coordinates. To this end, we introduce a set of rules designed to perform HC routing by exploiting first and second order neighborhood information. These are then integrated with our MAC scheme according to a cross-layer approach and their effectiveness is demonstrated by means of analysis and simulation

Automatically identifying dynamic Internet protocol addresses

Abstract: Dynamic IP addresses may be automatically identified and their dynamics patterns may be analyzed. Multi-user IP address blocks are determined as candidates for further analysis. An entropy score is determined for each IP address in every candidate block to distinguish between a dynamic IP and a static IP shared by multiple users. IP addresses with high entropy scores are grouped, and then analyzed, and may be used in various applications, such as spam filtering.

L-Chord: Routing Model for Chord Based on Layer-Dividing

Abstract: Chord is a kind of structured P2P networkbut the routing table in Chord suffers serious information redundancy and it is not very efficient. Therefore, a routing model and algorithm implementation for Chord based on layer-dividing(L-Chord) is proposed. Simulation experiments show that L-Chord compress- es the routing table length of most nodes into only one so as to eliminate repetitious entries and reduce the average lookup path length.L-Chord coordinates loo- kup efficiency and routing table length well.

Apparatus and method for packet forwarding in layer 2 network

Abstract: A packet forwarding apparatus with a function of registering packet forwarding control information for each user terminal into a user management table during PPPoE connection and authentication phases in which the apparatus carries out predetermined communication procedures with each user terminal. During DHCP and IP forwarding phases following the authentication phase, the packet forwarding apparatus controls packet forwarding based on the user management table. Packets are forwarded in the form of PPPoE frame until the authentication phase is completed and packets are forwarded in the form of Ethernet frame in the DHCP and IP forwarding phases.

Separating routing and forwarding: A clean-slate network layer design

Abstract: We present a ”clean-slate” design for a network-layer routing and forwarding system intended to address short-comings of the current Internet Protocol. Our design separates routing from both forwarding and topology discovery; requires only a flat, topology-independent namespace; and allows for policies of both users and service providers to be supported. Channels serve as the primary abstraction, allowing the network topology to be viewed at multiple levels of abstraction using the same identifiers. In this paper we present the basic design, which is based on loose source routing. Our routing and forwarding scheme is part of a larger project to produce a “clean-slate” network layer design.

Routing operations using sensor data

Abstract: In one embodiment, a method comprises an Internet Protocol (IP) router receiving sensor data from at least one of a second IP router or an attached host sensor node, the sensor data distinct from link data of a network link; the IP router generating sensor information based on storing the sensor data with metadata describing reception of the sensor data by the IP router in a routing information base; and the IP router executing a routing operation based on the sensor information stored in the routing information base.

A novel loop-free IP fast reroute algorithm

Abstract: Although providing reliable network services is getting more and more important, currently used methods in IP networks are typically reactive and error correcting can take a long time. One of the most interesting solutions is interface based fast rerouting, where not only the destination address but also the incoming interface is taken into account during the forwarding. Unfortunately, current methods can not handle all the possible situations as they are prone to form loops and make parts of the network with no failure unavailable. In this paper we propose a new interface based routing method, which always avoids loops for the price of a bit longer paths. We also present extensive simulation results to compare current and proposed algorithms.

Communicating packets between forwarding contexts using virtual interfaces

Abstract: Packets are communicated between forwarding contexts (e.g., virtual routers, logical routers, and/or private networks) using virtual interfaces in communications and computing systems, especially routers, packet switching systems, and other devices. A virtual interface refers to the interface infrastructure (e.g., buffers, memory locations, other data structures), but does not connect to an external cable or other communications mechanism such as is a physical interface. Packets are moved between forwarding contexts by automatically moving a packet placed in a first virtual interface associated with a first forwarding context to a second virtual interface associated with a second forwarding context (assuming the packet is not dropped by a feature applied to the packet at the first virtual interface).

Route once and cross-connect many

Abstract: The present invention relates generally to high-speed packet forwarding (switching/routing) system such as the present IP (Internet Protocol). More particularly, the invention encompasses a protocol that includes having the capabilities of high-speed IP packet forwarding to over come network delays. The invention further includes a protocol that allows for an easy and transparent implementation on current IP networks or any packet switching system/device so that one can route once (at a certain level) and cross-connect many (at a lower layer) (ROACM).

Modeling the communication costs of content-based routing: the case of subscription forwarding

Abstract: Content-based routing (CBR) provides the core distribution support of several middleware paradigms, most notably content-based publish-subscribe. Despite its popularity, however, the performance of CBR protocols is typically evaluated through simulation, and analytical models are extremely rare in the literature. Analytical models capture formally the characteristic of the analyzed system, and are therefore worth pursuing on their own. However, they also provide very practical advantages in that they allow one to evaluate tradeoffs extensively (i.e., across many parameter combinations and across all the interesting values) without the lengthy computation times required by simulations. These benefits are particularly welcome when large-scale networks are considered.In this paper, we provide an analytical model for subscription forwarding [4], arguably the most common CBR protocol in use today and one that is often used as a baseline against which to compare new approaches. We provide closed analytical expressions for the overall network traffic required to disseminate subscriptions and propagate notifications, as well as for the message forwarding load on individual nodes. The analytical model we present is validated through simulation for networks with more than 100,000 nodes and against several combinations of the relevant parameters. Results show that our model remains within 3% of the simulated traffic (and in most scenarios well below 1%), therefore indicating that our model can effectively replace simulations. The paper is completed by some examples of how our analytical model can be used in practice, including a precise characterization of the tradeoffs between subscription forwarding and event forwarding.

Ethernet switching and forwarding method, system and apparatus

Abstract: An Ethernet switching and forwarding method, and at least one Ethernet forwarding mode of standard Ethernet forwarding, multiplex Ethernet forwarding, layer-3 routing and forwarding, across-VLAN multicast forwarding plane, point-to-point VLAN forwarding, or point-to-point double VLAN forwarding. The method includes: an Ethernet message entering a user side port or a network side port; processing, by the port, the message to provide the message with a VLAN tag allocated uniformly by the port; determining, by the port, a forwarding mode for the message and sending the message to a corresponding forwarding plane; determining, by the forwarding plane, an egress port of the message and processing the specific Ethernet control message in accordance with a control message capturing policy table; and forwarding the message to the egress port and encapsulating the message in accordance with an attribute table of the egress port.

Destination-Region-Based Local Minimum Aware Geometric Routing

Abstract: Geometric routing in mobile ad-hoc networks (MANETs) is comprised of two forwarding modes: greedy forwarding and face forwarding. It is known that face forwarding is inefficient and fails frequently in practical situations. A previous work, NEAR [2], avoids switching to face forwarding by predicting local minima and not forwarding messages to them. However, NEAR predicts excessive local minima, which results in subop- timal routing performance. Also, it is not fully localized due to its bridge detection scheme. Aiming to further improve the performance, we propose a destination- region-based Local minimum AwaRe GEometric Routing (LARGER) algorithm which improves the accuracy of the local minima prediction by dividing the network into a number of regions and predicting local minima based on the region where the destination is located. Simulation results show that LARGER substantially improves the prediction accuracy and the routing performance of NEAR and that of the other state-of-the-art geometric routing algorithms in terms of route length.

Optimal forwarding probability for real-time routing in wireless sensor network

Abstract: In Wireless Sensor Network (WSN), sensors gather information about the physical world and the base station makes decision and then performs appropriate actions upon the environment. This technology enables a user to effectively sense and monitor from a distance in real-time. WSN uses real-time forwarding which means messages in the network are delivered according to their end-to-end deadlines (packet lifetime). This paper proposes optimal forwarding probability for real-time routing protocol with load distribution (RTLD) that provides efficient power consumption, high packet delivery ratio and minimum control packet overhead in WSN. It combines packet reception rate (PRR), maximum packet velocity and the remaining power to achieve real-time routing in WSN. RTLD almost avoid routing holes problem by using the remaining power as a parameter of forwarding to distribute the forwarding load to all forwarding candidates.

Network Simulation and Analysis using Operational Forwarding Data

Abstract: A hybrid approach to populating forwarding tables in a virtual network obtains forwarding data both by simulating routing protocol behavior in the virtual network to build forwarding tables, and by importing operational forwarding data from corresponding physical nodes in a physical network. The use of operational forwarding data improves the fidelity of the simulation by closely conforming forwarding behavior in the simulation to that which occurs in the physical network.

Methods, systems, and computer program products for source-aware ip routing at a media gateway

Abstract: The subject matter described herein includes methods, systems, and computer program products for source-aware IP routing at a media gateway. According to one aspect, a method for source-aware IP routing at a media gateway is provided. The method includes providing a packet including a layer 3 source address and a layer 3 destination address at a media gateway having a source-aware routing table. Using the destination address included in the packet, at least one entry corresponding to the destination address is located in the source-aware routing table, where the located entry contains at least a portion of a source IP address, at least a portion of a destination IP address and routing information including an interface identifier and a next hop identifier. From among the at least one located entry corresponding to the destination IP address information, at least one entry corresponding to the source IP address included in the packet is located. Based on the routing information located in the routing table, the packet is routed to the destination.