Computer Networking and Internet Protocols
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TCP Over Wireless Multi-Hop Protocols: Simulation and Experiments
TCP over Wireless Multi-hop Protocols: Simulation and Experiments Mario Gerla, Rajive Bagrodia, Lixia Zhang, Ken Tang, Lan Wang {gerla, rajive, lixia, ktang, lanw}@cs.ucla.edu Wireless Adaptive Mobility Laboratory Computer Science Department University of California, Los Angeles Los Angeles, CA 90095 http://www.cs.ucla.edu/NRL/wireless Abstract include mobility, unpredictable wireless channel such as fading, interference and obstacles, broadcast medium shared In this study we investigate the interaction between TCP and by multiple users and very large number of heterogeneous MAC layer in a wireless multi-hop network. This type of nodes (e.g., thousands of sensors). network has traditionally found applications in the military To these challenging physical characteristics of the ad-hoc (automated battlefield), law enforcement (search and rescue) network, we must add the extremely demanding requirements and disaster recovery (flood, earthquake), where there is no posed on the network by the typical applications. These fixed wired infrastructure. More recently, wireless "ad-hoc" include multimedia support, multicast and multi-hop multi-hop networks have been proposed for nomadic computing communications. Multimedia (voice, video and image) is a applications. Key requirements in all the above applications are reliable data transfer and congestion control, features that are must when several individuals are collaborating in critical generally supported by TCP. Unfortunately, TCP performs on applications with real time constraints. Multicasting is a wireless in a much less predictable way than on wired protocols. natural extension of the multimedia requirement. Multi- Using simulation, we provide new insight into two critical hopping is justified (among other things) by the limited problems of TCP over wireless multi-hop. -
MPLS-Based Metro Ethernet Networks a Tutorial • Paresh Khatri • 2018
MPLS-based Metro Ethernet Networks A tutorial • Paresh Khatri • 2018 1 © Nokia 2017 Public Agenda 1. Introduction 2. Introduction to Metro Ethernet Services 3. Traditional Metro Ethernet networks 4. Delivering Ethernet over MPLS 5. Summary 6. Questions 2 © Nokia 2017 Public introduction 3 © Nokia 2017 Public Introduction • Paresh Khatri ([email protected]) - Chief Architect – IP Routing & Transport APAC, Alcatel-Lucent • Key focus areas: - End-to-end network architectures - SDN/NFV - Large-scale IP/MPLS networks - L2/L3 VPNs - Carrier Ethernet - Next-generation mobile backhaul networks • Acknowledgements: - Some figures and text are provided courtesy of the Metro Ethernet Forum (MEF) 4 © Nokia 2017 Public introduction to metro ethernet services 5 © Nokia 2017 Public AGenda 2. Introduction to Metro Ethernet Services a) Why Metro Ethernet ? b) Attributes of Carrier Ethernet c) Carrier Ethernet Services defined by the MEF 6 © Nokia 2017 Public 2.1 Why Metro Ethernet ? 7 © Nokia 2017 Public Introduction to Metro Ethernet Services What is Metro Ethernet ? “… generally defined as the network that bridges or connects geographically separated enterprise LANs while also connecting across the WAN or backbone networks that are generally owned by service providers. The Metro Ethernet Networks provide connectivity services across Metro geography utilising Ethernet as the core protocol and enabling broadband applications” from “Metro Ethernet Networks – A Technical Overview” from the Metro Ethernet Forum 8 © Nokia 2017 Public Introduction to Metro -
Configuring Ipv6 First Hop Security
Configuring IPv6 First Hop Security This chapter describes how to configure First Hop Security (FHS) features on Cisco NX-OS devices. This chapter includes the following sections: • About First-Hop Security, on page 1 • About vPC First-Hop Security Configuration, on page 3 • RA Guard, on page 6 • DHCPv6 Guard, on page 7 • IPv6 Snooping, on page 8 • How to Configure IPv6 FHS, on page 9 • Configuration Examples, on page 17 • Additional References for IPv6 First-Hop Security, on page 18 About First-Hop Security The Layer 2 and Layer 3 switches operate in the Layer 2 domains with technologies such as server virtualization, Overlay Transport Virtualization (OTV), and Layer 2 mobility. These devices are sometimes referred to as "first hops", specifically when they are facing end nodes. The First-Hop Security feature provides end node protection and optimizes link operations on IPv6 or dual-stack networks. First-Hop Security (FHS) is a set of features to optimize IPv6 link operation, and help with scale in large L2 domains. These features provide protection from a wide host of rogue or mis-configured users. You can use extended FHS features for different deployment scenarios, or attack vectors. The following FHS features are supported: • IPv6 RA Guard • DHCPv6 Guard • IPv6 Snooping Note See Guidelines and Limitations of First-Hop Security, on page 2 for information about enabling this feature. Configuring IPv6 First Hop Security 1 Configuring IPv6 First Hop Security IPv6 Global Policies Note Use the feature dhcp command to enable the FHS features on a switch. IPv6 Global Policies IPv6 global policies provide storage and access policy database services. -
Junos® OS Protocol-Independent Routing Properties User Guide Copyright © 2021 Juniper Networks, Inc
Junos® OS Protocol-Independent Routing Properties User Guide Published 2021-09-22 ii Juniper Networks, Inc. 1133 Innovation Way Sunnyvale, California 94089 USA 408-745-2000 www.juniper.net Juniper Networks, the Juniper Networks logo, Juniper, and Junos are registered trademarks of Juniper Networks, Inc. in the United States and other countries. All other trademarks, service marks, registered marks, or registered service marks are the property of their respective owners. Juniper Networks assumes no responsibility for any inaccuracies in this document. Juniper Networks reserves the right to change, modify, transfer, or otherwise revise this publication without notice. Junos® OS Protocol-Independent Routing Properties User Guide Copyright © 2021 Juniper Networks, Inc. All rights reserved. The information in this document is current as of the date on the title page. YEAR 2000 NOTICE Juniper Networks hardware and software products are Year 2000 compliant. Junos OS has no known time-related limitations through the year 2038. However, the NTP application is known to have some difficulty in the year 2036. END USER LICENSE AGREEMENT The Juniper Networks product that is the subject of this technical documentation consists of (or is intended for use with) Juniper Networks software. Use of such software is subject to the terms and conditions of the End User License Agreement ("EULA") posted at https://support.juniper.net/support/eula/. By downloading, installing or using such software, you agree to the terms and conditions of that EULA. iii Table -
Generating Synthetic Voip Traffic for Analyzing Redundant Openbsd
UNIVERSITY OF OSLO Department of Informatics Generating Synthetic VoIP Traffic for Analyzing Redundant OpenBSD-Firewalls Master Thesis Maurice David Woernhard May 23, 2006 Generating Synthetic VoIP Traffic for Analyzing Redundant OpenBSD-Firewalls Maurice David Woernhard May 23, 2006 Abstract Voice over IP, short VoIP, is among the fastest growing broadband technologies in the private and commercial sector. Compared to the Plain Old Telephone System (POTS), Internet telephony has reduced availability, measured in uptime guarantees per a given time period. This thesis makes a contribution towards proper quantitative statements about network availability when using two redun- dant, state synchronized computers, acting as firewalls between the Internet (WAN) and the local area network (LAN). First, methods for generating adequate VoIP traffic volumes for loading a Gigabit Ethernet link are examined, with the goal of using a minimal set of hardware, namely one regular desktop computer. pktgen, the Linux kernel UDP packet generator, was chosen for generating synthetic/artificial traffic, reflecting the common VoIP packet characteristics packet size, changing sender and receiver address, as well as typical UDP-port usage. pktgen’s three main parameters influencing the generation rate are fixed inter-packet delay, packet size and total packet count. It was sought to relate these to more user-friendly val- ues of amount of simultaneous calls, voice codec employed and call duration. The proposed method fails to model VoIP traffic accurately, mostly due to the cur- rently unstable nature of pktgen. However, it is suited for generating enough packets for testing the firewalls. Second, the traffic forwarding limit and failover behavior of the redun- dant, state-synchronized firewalls was examined. -
Don't Trust Traceroute (Completely)
Don’t Trust Traceroute (Completely) Pietro Marchetta, Valerio Persico, Ethan Katz-Bassett Antonio Pescapé University of Southern California, CA, USA University of Napoli Federico II, Italy [email protected] {pietro.marchetta,valerio.persico,pescape}@unina.it ABSTRACT In this work, we propose a methodology based on the alias resolu- tion process to demonstrate that the IP level view of the route pro- vided by traceroute may be a poor representation of the real router- level route followed by the traffic. More precisely, we show how the traceroute output can lead one to (i) inaccurately reconstruct the route by overestimating the load balancers along the paths toward the destination and (ii) erroneously infer routing changes. Categories and Subject Descriptors C.2.1 [Computer-communication networks]: Network Architec- ture and Design—Network topology (a) Traceroute reports two addresses at the 8-th hop. The common interpretation is that the 7-th hop is splitting the traffic along two Keywords different forwarding paths (case 1); another explanation is that the 8- th hop is an RFC compliant router using multiple interfaces to reply Internet topology; Traceroute; IP alias resolution; IP to Router to the source (case 2). mapping 1 1. INTRODUCTION 0.8 Operators and researchers rely on traceroute to measure routes and they assume that, if traceroute returns different IPs at a given 0.6 hop, it indicates different paths. However, this is not always the case. Although state-of-the-art implementations of traceroute al- 0.4 low to trace all the paths -
Navigating Network Migration Challenges: Upgrade Your 1GE
Navigating Network Migration Challenges: Upgrade Your 1GE Metro Ethernet Access Network to 10GE A White Paper from Telco Systems Upgrade Your 1GE Metro Ethernet Access Network to 10GE | 2 Intoduction Many businesses and service providers are migrating from • Service providers are finding it more difficult to live up to 1GE to 10GE networks as they attempt to avoid the obstacles their customers’ service level agreements (SLA) to presented by heavy bandwidth, while leveraging the benefits provide multiple services, which require more bandwidth that 10GE networking has to offer. The requirement for • Generating more revenue within the current limits of a more bandwidth has become a constant battle. As internet 1Gig network usage continues to increase with the popularity of data and streaming services, so does the demand for more bandwidth. As the gap between service revenues and the demand for From education (homework, e-learning, campus networks), higher bandwidth grows, providers are looking for ways to finance (online banking, stock trading, bill pay), and business better control their expenses while offering higher bandwidth purposes (company intranets, remote workers), to social media and more services to more customers. With the increasing (Facebook, Instagram, Twitter, Snapchat), political (campaigns demand for more bandwidth with OTT (over-the-top) and outreach) and personal purposes, data requirements applications like video streaming, Hulu, Netflix, and Amazon continue to rise – quicker than service providers can react. Prime becoming more popular, 1GE networks aren’t going to cut it anymore. In support of these activities, service providers are being driven to enhance their network capacities in their business Ethernet, To conquer these challenges, enterprises and service mobile backhaul, E-Rate, cloud networking, and SDN & NFV providers are migrating their 1GE networks to 10GE. -
Routing Loop Attacks Using Ipv6 Tunnels
Routing Loop Attacks using IPv6 Tunnels Gabi Nakibly Michael Arov National EW Research & Simulation Center Rafael – Advanced Defense Systems Haifa, Israel {gabin,marov}@rafael.co.il Abstract—IPv6 is the future network layer protocol for A tunnel in which the end points’ routing tables need the Internet. Since it is not compatible with its prede- to be explicitly configured is called a configured tunnel. cessor, some interoperability mechanisms were designed. Tunnels of this type do not scale well, since every end An important category of these mechanisms is automatic tunnels, which enable IPv6 communication over an IPv4 point must be reconfigured as peers join or leave the tun- network without prior configuration. This category includes nel. To alleviate this scalability problem, another type of ISATAP, 6to4 and Teredo. We present a novel class of tunnels was introduced – automatic tunnels. In automatic attacks that exploit vulnerabilities in these tunnels. These tunnels the egress entity’s IPv4 address is computationally attacks take advantage of inconsistencies between a tunnel’s derived from the destination IPv6 address. This feature overlay IPv6 routing state and the native IPv6 routing state. The attacks form routing loops which can be abused as a eliminates the need to keep an explicit routing table at vehicle for traffic amplification to facilitate DoS attacks. the tunnel’s end points. In particular, the end points do We exhibit five attacks of this class. One of the presented not have to be updated as peers join and leave the tunnel. attacks can DoS a Teredo server using a single packet. The In fact, the end points of an automatic tunnel do not exploited vulnerabilities are embedded in the design of the know which other end points are currently part of the tunnels; hence any implementation of these tunnels may be vulnerable. -
Is QUIC a Better Choice Than TCP in the 5G Core Network Service Based Architecture?
DEGREE PROJECT IN INFORMATION AND COMMUNICATION TECHNOLOGY, SECOND CYCLE, 30 CREDITS STOCKHOLM, SWEDEN 2020 Is QUIC a Better Choice than TCP in the 5G Core Network Service Based Architecture? PETHRUS GÄRDBORN KTH ROYAL INSTITUTE OF TECHNOLOGY SCHOOL OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE Is QUIC a Better Choice than TCP in the 5G Core Network Service Based Architecture? PETHRUS GÄRDBORN Master in Communication Systems Date: November 22, 2020 Supervisor at KTH: Marco Chiesa Supervisor at Ericsson: Zaheduzzaman Sarker Examiner: Peter Sjödin School of Electrical Engineering and Computer Science Host company: Ericsson AB Swedish title: Är QUIC ett bättre val än TCP i 5G Core Network Service Based Architecture? iii Abstract The development of the 5G Cellular Network required a new 5G Core Network and has put higher requirements on its protocol stack. For decades, TCP has been the transport protocol of choice on the Internet. In recent years, major Internet players such as Google, Facebook and CloudFlare have opted to use the new QUIC transport protocol. The design assumptions of the Internet (best-effort delivery) differs from those of the Core Network. The aim of this study is to investigate whether QUIC’s benefits on the Internet will translate to the 5G Core Network Service Based Architecture. A testbed was set up to emulate traffic patterns between Network Functions. The results show that QUIC reduces average request latency to half of that of TCP, for a majority of cases, and doubles the throughput even under optimal network conditions with no packet loss and low (20 ms) RTT. Additionally, by measuring request start and end times “on the wire”, without taking into account QUIC’s shorter connection establishment, we believe the results indicate QUIC’s suitability also under the long-lived (standing) connection model. -
Internet Protocol Suite
InternetInternet ProtocolProtocol SuiteSuite Srinidhi Varadarajan InternetInternet ProtocolProtocol Suite:Suite: TransportTransport • TCP: Transmission Control Protocol • Byte stream transfer • Reliable, connection-oriented service • Point-to-point (one-to-one) service only • UDP: User Datagram Protocol • Unreliable (“best effort”) datagram service • Point-to-point, multicast (one-to-many), and • broadcast (one-to-all) InternetInternet ProtocolProtocol Suite:Suite: NetworkNetwork z IP: Internet Protocol – Unreliable service – Performs routing – Supported by routing protocols, • e.g. RIP, IS-IS, • OSPF, IGP, and BGP z ICMP: Internet Control Message Protocol – Used by IP (primarily) to exchange error and control messages with other nodes z IGMP: Internet Group Management Protocol – Used for controlling multicast (one-to-many transmission) for UDP datagrams InternetInternet ProtocolProtocol Suite:Suite: DataData LinkLink z ARP: Address Resolution Protocol – Translates from an IP (network) address to a network interface (hardware) address, e.g. IP address-to-Ethernet address or IP address-to- FDDI address z RARP: Reverse Address Resolution Protocol – Translates from a network interface (hardware) address to an IP (network) address AddressAddress ResolutionResolution ProtocolProtocol (ARP)(ARP) ARP Query What is the Ethernet Address of 130.245.20.2 Ethernet ARP Response IP Source 0A:03:23:65:09:FB IP Destination IP: 130.245.20.1 IP: 130.245.20.2 Ethernet: 0A:03:21:60:09:FA Ethernet: 0A:03:23:65:09:FB z Maps IP addresses to Ethernet Addresses -
The Internet Protocol, Version 4 (Ipv4)
Today’s Lecture I. IPv4 Overview The Internet Protocol, II. IP Fragmentation and Reassembly Version 4 (IPv4) III. IP and Routing IV. IPv4 Options Internet Protocols CSC / ECE 573 Fall, 2005 N.C. State University copyright 2005 Douglas S. Reeves 1 copyright 2005 Douglas S. Reeves 2 Internet Protocol v4 (RFC791) Functions • A universal intermediate layer • Routing IPv4 Overview • Fragmentation and reassembly copyright 2005 Douglas S. Reeves 3 copyright 2005 Douglas S. Reeves 4 “IP over Everything, Everything Over IP” IP = Basic Delivery Service • Everything over IP • IP over everything • Connectionless delivery simplifies router design – TCP, UDP – Dialup and operation – Appletalk – ISDN – Netbios • Unreliable, best-effort delivery. Packets may be… – SCSI – X.25 – ATM – Ethernet – lost (discarded) – X.25 – Wi-Fi – duplicated – SNA – FDDI – reordered – Sonet – ATM – Fibre Channel – Sonet – and/or corrupted – Frame Relay… – … – Remote Direct Memory Access – Ethernet • Even IP over IP! copyright 2005 Douglas S. Reeves 5 copyright 2005 Douglas S. Reeves 6 1 IPv4 Datagram Format IPv4 Header Contents 0 4 8 16 31 •Version (4 bits) header type of service • Functions version total length (in bytes) length (x4) prec | D T R C 0 •Header Length x4 (4) flags identification fragment offset (x8) 1. universal 0 DF MF s •Type of Service (8) e time-to-live (next) protocol t intermediate layer header checksum y b (hop count) identifier •Total Length (16) 0 2 2. routing source IP address •Identification (16) 3. fragmentation and destination IP address reassembly •Flags (3) s •Fragment Offset ×8 (13) e t 4. Options y IP options (if any) b •Time-to-Live (8) 0 4 ≤ •Protocol Identifier (8) s e t •Header Checksum (16) y b payload 5 •Source IP Address (32) 1 5 5 6 •Destination IP Address (32) ≤ •IP Options (≤ 320) copyright 2005 Douglas S. -
T-Metro 200 Carrier Ethernet Multi-Service Ces Aggregation
T-Metro 200 carrier ethernet multi-service ces aggregation The T-Metro 200 is a feature-rich multiservice access device designed to increase service provider revenues and deliver a complete portfolio of voice, data and video services. The T-Metro family of products supports a wide variety of technologies including Ethernet, circuit emulation services (CES), MPLS, OAM (operations, administration and maintenance) tools and hierarchical quality of service (HQoS). This rich combination of technologies PRODUCT HIGHLIGHTS allows service providers to deliver an enhanced service offering while Enhanced Ethernet services, maintaining competitive pricing. features and capabilities The T-Metro 200 provides access to advanced data services such as virtual – 802.1ad provider bridges for Ethernet private LAN services (VPLS), virtual private wire services (VPWS) and IP virtual based L2VPN services private network (IP-VPN) services. In addition, the T-Metro product line enables – Super VLAN for traffic isolation service providers to carry native TDM traffic transparently across packet – Fast-Ring with sub 50ms recovery switched networks (PSN), using various circuit emulation techniques. The TDM traffic is encapsulated in Ethernet or IP frames to emulate the functionality of a – IEEE 802.3ad link aggregation TDM circuit, ensuring that all original feature-sets are preserved. Circuit Emulation Services deliver traditional voice or leased line Designed for Metro Ethernet Services services Convergence of voice, data and video services over a single Ethernet-based – Structured agnostic traffic over infrastructure is transforming the way enterprises and service providers packet (SAToP) conduct their businesses. The T-Metro 200’s versatility, advanced feature-set, – CES over packet switched networks wire speed performance and robust design makes it an ideal convergence (CESoPSN) platform for metro applications, either in a bridged metro Ethernet or MPLS – T1/E1; DS3/T3, OC-3/STM-1 environment.