Lecture 10: Switching & Internetworking
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802.11 BSS Bridging
802.11 BSS Bridging Contributed by Philippe Klein, PhD Broadcom IEEE 8021/802.11 Study Group, Aug 2012 new-phkl-11-bbs-bridging-0812-v2 The issue • 802.11 STA devices are end devices that do not bridge to external networks. This: – limit the topology of 802.11 BSS to “stub networks” – do not allow a (STA-)AP-STA wireless link to be used as a connecting path (backbone) between other networks • Partial solutions exist to overcome this lack of bridging functionality but these solutions are: – proprietary only – limited to certain type of traffic – or/and based on Layer 3 (such IP Multicast to MAC Multicast translation, NAT - Network Address Translation) IEEE 8021/802.11 Study Group - Aug 2012 2 Coordinated Shared Network (CSN) CSN CSN Network CSN Node 1 Node 2 Shared medium Logical unicast links CSN CSN Node 3 Node 4 • Contention-free, time-division multiplexed-access, network of devices sharing a common medium and supporting reserved bandwidth based on priority or flow (QoS). – one of the nodes of the CSN acts as the network coordinator, granting transmission opportunities to the other nodes of the network. • Physically a shared medium, in that a CSN node has a single physical port connected to the half-duplex medium, but logically a fully-connected one-hop mesh network, in that every node can transmit frames to every other node over the shared medium. • Supports two types of transmission: – unicast transmission for point-to-point (node-to-node) – transmission and multicast/broadcast transmission for point-to-multipoint (node-to-other/all-nodes) transmission. -
ISDN LAN Bridging Bhi
ISDN LAN Bridging BHi Tim Boland U.S. DEPARTMENT OF COMMERCE Technology Administration National Institute of Standards and Technology Gaithersburg, MD 20899 QC 100 NIST .U56 NO. 5532 199it NISTIR 5532 ISDN LAN Bridging Tim Boland U.S. DEPARTMENT OF COMMERCE Technology Administration National Institute of Standards and Technology Gaithersburg, MD 20899 November 1994 U.S. DEPARTMENT OF COMMERCE Ronald H. Brown, Secretary TECHNOLOGY ADMINISTRATION Mary L. Good, Under Secretary for Technology NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY Arati Prabhakar, Director DATE DUE - ^'' / 4 4 ' / : .f : r / Demco, Inc. 38-293 . ISDN LAN BRIDGING 1.0 Introduction This paper will provide guidance which will enable users to properly assimilate Integrated Services Digital Network (ISDN) local area network (LAN) bridging products into the workplace. This technology is expected to yield economic, functional and performance benefits to users. Section 1 (this section) provides some introductory information. Section 2 describes the environment to which this paper applies. Section 3 provides history and status information. Section 4 describes service features of some typical product offerings. Section 5 explains the decisions that users have to make and the factors that should influence their decisions. Section 6 deals with current ISDN LAN bridge interoperability activities. Section 7 gives a high-level summary and future direction. 2.0 ISDN LAN Bridging Environment 2 . 1 User Environment ISDN LAN bridge usage should be considered by users who have a need to access a LAN or specific device across a distance of greater than a few kilometers, or by users who are on a LAN and need to access a specific device or another network remotely, and, for both situations, have or are considering ISDN use to accomplish this access. -
Bridging Strategies for LAN Internets Previous Screen Nathan J
51-20-36 Bridging Strategies for LAN Internets Previous screen Nathan J. Muller Payoff As corporations continue to move away from centralized computing to distributed, peer-to- peer arrangements, the need to share files and access resources across heterogeneous networks becomes all the more necessary. The need to interconnect dissimilar host systems and LANs may arise from normal business operations or as the result of a corporate merger or acquisition. Whatever the justification, internetworking is becoming ever more important, and the interconnection device industry will grow for the rest of the decade. Introduction The devices that facilitate the interconnection of host systems and LANs fall into the categories of repeaters , bridges, routers, and gateways. Repeaters are the simplest devices and are used to extend the range of LANs and other network facilities by boosting signal strength and reshaping distorted signals. Gateways are the most complex devices; they provide interoperability between applications by performing processing-intensive protocol conversions. In the middle of this “complexity spectrum” are bridges and routers. At the risk of oversimplification, traditional bridges implement basic data-level links between LANs that use identical protocols; traditional routers can be programmed for multiple network protocols, thereby supporting diverse types of LANs and host systems over the same WAN facility. However, in many situations the use of routers is overkill and needlessly expensive; routers cost as much as $75,000 for a full-featured, multiport unit, compared with $6,000 to $30,000 for most bridges. The price difference is attributable to the number of protocols supported, the speed of the Central Processing Unit, port configurations, WAN interfaces, and network management features. -
Wifi Direct Internetworking
WiFi Direct Internetworking António Teólo∗† Hervé Paulino João M. Lourenço ADEETC, Instituto Superior de NOVA LINCS, DI, NOVA LINCS, DI, Engenharia de Lisboa, Faculdade de Ciências e Tecnologia, Faculdade de Ciências e Tecnologia, Instituto Politécnico de Lisboa Universidade NOVA de Lisboa Universidade NOVA de Lisboa Portugal Portugal Portugal [email protected] [email protected] [email protected] ABSTRACT will enable WiFi communication range and speed even in cases of: We propose to interconnect mobile devices using WiFi-Direct. Hav- network infrastructure congestion, which may happen in highly ing that, it will be possible to interconnect multiple o-the-shelf crowded venues (such as sports and cultural events); or temporary, mobile devices, via WiFi, but without any supportive infrastructure. or permanent, absence of infrastructure, as may happen in remote This will pave the way for mobile autonomous collaborative sys- locations or disaster situations. tems that can operate in any conditions, like in disaster situations, WFD allows devices to form groups, with one of them, called in very crowded scenarios or in isolated areas. This work is relevant Group Owner (GO), acting as a soft access point for remaining since the WiFi-Direct specication, that works on groups of devices, group members. WFD oers node discovery, authentication, group does not tackle inter-group communication and existing research formation and message routing between nodes in the same group. solutions have strong limitations. However, WFD communication is very constrained, current imple- We have a two phase work plan. Our rst goal is to achieve mentations restrict group size 9 devices and none of these devices inter-group communication, i.e., enable the ecient interconnec- may be a member of more than one WFD group. -
Bridging Internetwork Operating System Release 10.2
Internetwork Operating System Release 10.2 cisc EM Bridging Software Release O2 September 1994 Corporate Headquarters 170 West Tasman Drive San Jose CA 95134-1706 USA Phone 408 526-4000 Fax 408 526-4100 Customer Order Number TRN-IRSC-1O.2 Text Part Number 2O91O1 The and and other technical information the products specifications configurations regarding products contained in this manual are subject to change without notice Alt statements technical information and recommendations contained in this manual are believed to be accurate and reliable but are without of and must take full for their presented warranty any kind express or implied users responsibility application of any products specified in this manual This radiate radio if not installed and used in equipment generates uses and can frequency energy and accordance with the instruction manual for this device may cause interference to radio communications This equipment has been tested and found to comply with the limits for Class computing device which reasonable pursuant to Subpart of Part 15 of FCC Rules are designed to provide protection against such interference when operated in commercial environment of this in residential is in which their Operation equipment area likely to cause interference case users at own expense will be required to take whatever measures may be required to correct the interference will The following third-party software may be included with your product and be subject to the software license agreement The Cisco implementation of TCP header compression -
Understanding Linux Internetworking
White Paper by David Davis, ActualTech Media Understanding Linux Internetworking In this Paper Introduction Layer 2 vs. Layer 3 Internetworking................ 2 The Internet: the largest internetwork ever created. In fact, the Layer 2 Internetworking on term Internet (with a capital I) is just a shortened version of the Linux Systems ............................................... 3 term internetwork, which means multiple networks connected Bridging ......................................................... 3 together. Most companies create some form of internetwork when they connect their local-area network (LAN) to a wide area Spanning Tree ............................................... 4 network (WAN). For IP packets to be delivered from one Layer 3 Internetworking View on network to another network, IP routing is used — typically in Linux Systems ............................................... 5 conjunction with dynamic routing protocols such as OSPF or BGP. You c an e as i l y use Linux as an internetworking device and Neighbor Table .............................................. 5 connect hosts together on local networks and connect local IP Routing ..................................................... 6 networks together and to the Internet. Virtual LANs (VLANs) ..................................... 7 Here’s what you’ll learn in this paper: Overlay Networks with VXLAN ....................... 9 • The differences between layer 2 and layer 3 internetworking In Summary ................................................. 10 • How to configure IP routing and bridging in Linux Appendix A: The Basics of TCP/IP Addresses ....................................... 11 • How to configure advanced Linux internetworking, such as VLANs, VXLAN, and network packet filtering Appendix B: The OSI Model......................... 12 To create an internetwork, you need to understand layer 2 and layer 3 internetworking, MAC addresses, bridging, routing, ACLs, VLANs, and VXLAN. We’ve got a lot to cover, so let’s get started! Understanding Linux Internetworking 1 Layer 2 vs. -
Bridging Principles
Bridging Principles 1 By the end of this session you will be able to... n Define bridging modes – Source Routing – Transparent – Source Route Transparent (SRT) n Describe how Spanning Tree functions Token Ring Bridging 2 2 Flexible Frame Forwarding Choice of Techniques Source Route Source Route Transparent Transparent Bridging Bridging Bridging n Transparent u Ethernet and Token Ring u simple to implement u not easy to manage in a complex network n Source Routing u Token Ring u requires management effort to implement u trouble shooting is simplified n SRT u short term combination solution Token Ring Bridging 3 Bridging Techniques Transparent Can be used on both Token Ring and Ethernet networks Nothing is identified so implementation is simple Nothing is identified so locating problems can be difficult on complex networks Source Route Bridging Designed for Token Ring networks Requires each ring and bridge to be identified Locating potential and actual trouble spots is simplified SRT Useful when combing transparent and source routing networks, e.g. when adding a department using ‘the other method’ to a company network. Allows bridges/switches to forward both source routed and transparent frames appropriately. Also allows the bridges/switches to communicate with each other. A short term solution, ultimately MAKE UP YOUR MIND; use source routing OR transparent for the whole network. 3 What is the purpose of a Bridge ? 2 4 1 Ring A Ring B 6 3 5 n Connects two physical rings n Forwards or Filters Frames n Single logical network n Keeps local traffic local Token Ring Bridging 4 Bridges are used to physically connect two rings. -
Internetworking and Layered Models
1 Internetworking and Layered Models The Internet today is a widespread information infrastructure, but it is inherently an insecure channel for sending messages. When a message (or packet) is sent from one Website to another, the data contained in the message are routed through a number of intermediate sites before reaching its destination. The Internet was designed to accom- modate heterogeneous platforms so that people who are using different computers and operating systems can communicate. The history of the Internet is complex and involves many aspects – technological, organisational and community. The Internet concept has been a big step along the path towards electronic commerce, information acquisition and community operations. Early ARPANET researchers accomplished the initial demonstrations of packet- switching technology. In the late 1970s, the growth of the Internet was recognised and subsequently a growth in the size of the interested research community was accompanied by an increased need for a coordination mechanism. The Defense Advanced Research Projects Agency (DARPA) then formed an International Cooperation Board (ICB) to coordinate activities with some European countries centered on packet satellite research, while the Internet Configuration Control Board (ICCB) assisted DARPA in managing Internet activity. In 1983, DARPA recognised that the continuing growth of the Internet community demanded a restructuring of coordination mechanisms. The ICCB was dis- banded and in its place the Internet Activities Board (IAB) was formed from the chairs of the Task Forces. The IAB revitalised the Internet Engineering Task Force (IETF) as a member of the IAB. By 1985, there was a tremendous growth in the more practical engineering side of the Internet. -
Guidelines for the Secure Deployment of Ipv6
Special Publication 800-119 Guidelines for the Secure Deployment of IPv6 Recommendations of the National Institute of Standards and Technology Sheila Frankel Richard Graveman John Pearce Mark Rooks NIST Special Publication 800-119 Guidelines for the Secure Deployment of IPv6 Recommendations of the National Institute of Standards and Technology Sheila Frankel Richard Graveman John Pearce Mark Rooks C O M P U T E R S E C U R I T Y Computer Security Division Information Technology Laboratory National Institute of Standards and Technology Gaithersburg, MD 20899-8930 December 2010 U.S. Department of Commerce Gary Locke, Secretary National Institute of Standards and Technology Dr. Patrick D. Gallagher, Director GUIDELINES FOR THE SECURE DEPLOYMENT OF IPV6 Reports on Computer Systems Technology The Information Technology Laboratory (ITL) at the National Institute of Standards and Technology (NIST) promotes the U.S. economy and public welfare by providing technical leadership for the nation’s measurement and standards infrastructure. ITL develops tests, test methods, reference data, proof of concept implementations, and technical analysis to advance the development and productive use of information technology. ITL’s responsibilities include the development of technical, physical, administrative, and management standards and guidelines for the cost-effective security and privacy of sensitive unclassified information in Federal computer systems. This Special Publication 800-series reports on ITL’s research, guidance, and outreach efforts in computer security and its collaborative activities with industry, government, and academic organizations. National Institute of Standards and Technology Special Publication 800-119 Natl. Inst. Stand. Technol. Spec. Publ. 800-119, 188 pages (Dec. 2010) Certain commercial entities, equipment, or materials may be identified in this document in order to describe an experimental procedure or concept adequately. -
OEM Cobranet Module Design Guide
CDK-8 OEM CobraNet Module Design Guide Date 8/29/2008 Revision 1.1 © Attero Tech, LLC 1315 Directors Row, Suite 107, Ft Wayne, IN 46808 Phone 260-496-9668 • Fax 260-496-9879 620-00001-01 CDK-8 Design Guide Contents 1 – Overview .....................................................................................................................................................................................................................................2 1.1 – Notes on Modules .................................................................................................................................................... 2 2 – Digital Audio Interface Connectivity...........................................................................................................................................................................3 2.1 – Pin Descriptions ....................................................................................................................................................... 3 2.1.1 - Audio clocks ..................................................................................................................................................... 3 2.1.2 – Digital audio..................................................................................................................................................... 3 2.1.3 – Serial bridge ..................................................................................................................................................... 4 2.1.4 – Control............................................................................................................................................................ -
Bridging Basics
CHAPTER 3 Bridging Basics Background Bridges became commercially available in the early 1980s. At the time of their introduction, bridges connected and enabled packet forwarding between homogeneous networks. More recently, bridging between different networks has also been defined and standardized. Several kinds of bridging have emerged as important. Transparent bridging is found primarily in Ethernet environments. Source-route bridging is found primarily in Token Ring environments. Translational bridging provides translation between the formats and transit principles of different media types (usually Ethernet and Token Ring). Source-route transparent bridging combines the algorithms of transparent bridging and source-route bridging to allow communication in mixed Ethernet/Token Ring environments. The diminishing price and the recent inclusion of bridging capability in many routers has taken substantial market share away from pure bridges. Those bridges that have survived include features such as sophisticated filtering, pseudo-intelligent path selection, and high throughput rates. Although an intense debate about the benefits of bridging versus routing raged in the late 1980s, most people now agree that each has its place and that both are often necessary in any comprehensive internetworking scheme. Internetworking Device Comparison Internetworking devices offer communication between local area network (LAN) segments. There are four primary types of internetworking devices: repeaters, bridges, routers, and gateways. These devices can be differentiated very generally by the Open System Interconnection (OSI) layer at which they establish the LAN-to-LAN connection. Repeaters connect LANs at OSI Layer 1; bridges connect LANs at Layer 2; routers connect LANs at Layer 3; and gateways connect LANs at Layers 4 through 7. -
Bridging (Networking)
Bridging (networking) A network bridge is a computer networking device that creates a single, aggregate network from multiple communication networks or network segments. This function is called network bridging.[1] Bridging is distinct from routing. Routing allows multiple networks to communicate independently and yet remain separate, whereas bridging connects two separate networks as if they were a single network.[2] In the OSI model, bridging is performed in the data link layer (layer 2).[3] If one or more segments of the bridged network are wireless, the device is known as a wireless bridge. A high-level overview of network bridging, using the ISO/OSI layers and terminology The main types of network bridging technologies are simple bridging, multiport bridging, and learning or transparent bridging.[4][5] Contents Transparent bridging Simple bridging Multiport bridging Implementation Forwarding Shortest Path Bridging See also References Transparent bridging Transparent bridging uses a table called the forwarding information base to control the forwarding of frames between network segments. The table starts empty and entries are added as the bridge receives frames. If a destination address entry is not found in the table, the frame is flooded to all other ports of the bridge, flooding the frame to all segments except the one from which it was received. By means of these flooded frames, a host on the destination network will respond and a forwarding database entry will be created. Both source and destination addresses are used in this process: source addresses are recorded in entries in the table, while destination addresses are looked up in the table and matched to the proper segment to send the frame to.