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Government Open Systems Interconnection Profile Users' Guide, Version 2
NIST Special Publication 500-192 [ Computer Systems Government Open Systems Technology Interconnection Profile Users' U.S. DEPARTMENT OF COMMERCE National Institute of Guide, Version 2 Standards and Technology Tim Boland Nisr NATL INST. OF STAND & TECH R.I.C, A111D3 71D7S1 NIST PUBLICATIONS --QC- 100 .U57 500-192 1991 C.2 NIST Special Publication 500-192 . 0)0 Government Open Systems Interconnection Profile Users' Guide, Version 2 Tim Boland Computer Systems Laboratory National Institute of Standards and Technology Gaithersburg, MD 20899 Supersedes NIST Special Publication 500-163 October 1991 U.S. DEPARTMENT OF COMMERCE Robert A. Mosbacher, Secretary NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY John W. Lyons, Director Reports on Computer Systems Technology The National Institute of Standards and Technology (NIST) has a unique responsibility for conriputer systems technology within the Federal government. NIST's Computer Systems Laboratory (CSL) devel- ops standards and guidelines, provides technical assistance, and conducts research for computers and related telecommunications systems to achieve more effective utilization of Federal information technol- ogy resources. CSL's responsibilities include development of technical, management, physical, and ad- ministrative standards and guidelines for the cost-effective security and privacy of sensitive unclassified information processed in Federal computers. CSL assists agencies in developing security plans and in improving computer security awareness training. This Special Publication 500 series reports CSL re- search and guidelines to Federal agencies as well as to organizations in industry, government, and academia. National Institute of Standards and Technology Special Publication 500-192 Natl. Inst. Stand. Technol. Spec. Publ. 500-192, 166 pages (Oct. 1991) CODEN: NSPUE2 U.S. -
ISSN: 2320-5407 Int. J. Adv. Res. 5(4), 422-426 RESEARCH ARTICLE
ISSN: 2320-5407 Int. J. Adv. Res. 5(4), 422-426 Journal Homepage: - www.journalijar.com Article DOI: 10.21474/IJAR01/3826 DOI URL: http://dx.doi.org/10.21474/IJAR01/3826 RESEARCH ARTICLE CHALLENGING ISSUES IN OSI AND TCP/IP MODEL. Dr. J. VijiPriya, Samina and Zahida. College of Computer Science and Engineering, University of Hail, Saudi Arabia. …………………………………………………………………………………………………….... Manuscript Info Abstract ……………………. ……………………………………………………………… Manuscript History A computer network is a connection of network devices to data communication. Multiple networks are connected together to form an Received: 06 February 2017 internetwork. The challenges of Internetworking is interoperating Final Accepted: 05 March 2017 between products from different manufacturers requires consistent Published: April 2017 standards. Network reference models were developed to address these challenges. Two useful reference models are Open System Key words:- Interconnection (OSI) and Transmission Control Protocol and Internet OSI, TCP/IP, Data Communication, Protocol (TCP/IP) serve as protocol architecture details the Protocols, Layers, and Encapsulation communication between applications on network devices. This paper depicts the OSI and TCP/IP models, their issues and comparison of them. Copy Right, IJAR, 2017,. All rights reserved. …………………………………………………………………………………………………….... Introduction:- Network reference models are called protocol architecture in which task of communication can be broken into sub tasks. These tasks are organized into layers representing network services and functions. The layered protocols are rules that govern end-to-end communication between devices. Protocols on each layer will interact with protocols on the above and below layers of it that form a protocol suite or stack. The most established TCP/IP suite was developed by Department of Defence's Project Research Agency DARPA based on OSI suite to the foundation of Internet architecture. -
Logical Link Control and Channel Scheduling for Multichannel Underwater Sensor Networks
ICST Transactions on Mobile Communications and Applications Research Article Logical Link Control and Channel Scheduling for Multichannel Underwater Sensor Networks Jun Li ∗, Mylene` Toulgoat, Yifeng Zhou, and Louise Lamont Communications Research Centre Canada, 3701 Carling Avenue, Ottawa, ON. K2H 8S2 Canada Abstract With recent developments in terrestrial wireless networks and advances in acoustic communications, multichannel technologies have been proposed to be used in underwater networks to increase data transmission rate over bandwidth-limited underwater channels. Due to high bit error rates in underwater networks, an efficient error control technique is critical in the logical link control (LLC) sublayer to establish reliable data communications over intrinsically unreliable underwater channels. In this paper, we propose a novel protocol stack architecture featuring cross-layer design of LLC sublayer and more efficient packet- to-channel scheduling for multichannel underwater sensor networks. In the proposed stack architecture, a selective-repeat automatic repeat request (SR-ARQ) based error control protocol is combined with a dynamic channel scheduling policy at the LLC sublayer. The dynamic channel scheduling policy uses the channel state information provided via cross-layer design. It is demonstrated that the proposed protocol stack architecture leads to more efficient transmission of multiple packets over parallel channels. Simulation studies are conducted to evaluate the packet delay performance of the proposed cross-layer protocol stack architecture with two different scheduling policies: the proposed dynamic channel scheduling and a static channel scheduling. Simulation results show that the dynamic channel scheduling used in the cross-layer protocol stack outperforms the static channel scheduling. It is observed that, when the dynamic channel scheduling is used, the number of parallel channels has only an insignificant impact on the average packet delay. -
Physical Layer Overview
ELEC3030 (EL336) Computer Networks S Chen Physical Layer Overview • Physical layer forms the basis of all networks, and we will first revisit some of fundamental limits imposed on communication media by nature Recall a medium or physical channel has finite Spectrum bandwidth and is noisy, and this imposes a limit Channel bandwidth: on information rate over the channel → This H Hz is a fundamental consideration when designing f network speed or data rate 0 H Type of medium determines network technology → compare wireless network with optic network • Transmission media can be guided or unguided, and we will have a brief review of a variety of transmission media • Communication networks can be classified as switched and broadcast networks, and we will discuss a few examples • The term “physical layer protocol” as such is not used, but we will attempt to draw some common design considerations and exams a few “physical layer standards” 13 ELEC3030 (EL336) Computer Networks S Chen Rate Limit • A medium or channel is defined by its bandwidth H (Hz) and noise level which is specified by the signal-to-noise ratio S/N (dB) • Capability of a medium is determined by a physical quantity called channel capacity, defined as C = H log2(1 + S/N) bps • Network speed is usually given as data or information rate in bps, and every one wants a higher speed network: for example, with a 10 Mbps network, you may ask yourself why not 10 Gbps? • Given data rate fd (bps), the actual transmission or baud rate fb (Hz) over the medium is often different to fd • This is for -
User Datagram Protocol - Wikipedia, the Free Encyclopedia Página 1 De 6
User Datagram Protocol - Wikipedia, the free encyclopedia Página 1 de 6 User Datagram Protocol From Wikipedia, the free encyclopedia The five-layer TCP/IP model User Datagram Protocol (UDP) is one of the core 5. Application layer protocols of the Internet protocol suite. Using UDP, programs on networked computers can send short DHCP · DNS · FTP · Gopher · HTTP · messages sometimes known as datagrams (using IMAP4 · IRC · NNTP · XMPP · POP3 · Datagram Sockets) to one another. UDP is sometimes SIP · SMTP · SNMP · SSH · TELNET · called the Universal Datagram Protocol. RPC · RTCP · RTSP · TLS · SDP · UDP does not guarantee reliability or ordering in the SOAP · GTP · STUN · NTP · (more) way that TCP does. Datagrams may arrive out of order, 4. Transport layer appear duplicated, or go missing without notice. TCP · UDP · DCCP · SCTP · RTP · Avoiding the overhead of checking whether every RSVP · IGMP · (more) packet actually arrived makes UDP faster and more 3. Network/Internet layer efficient, at least for applications that do not need IP (IPv4 · IPv6) · OSPF · IS-IS · BGP · guaranteed delivery. Time-sensitive applications often IPsec · ARP · RARP · RIP · ICMP · use UDP because dropped packets are preferable to ICMPv6 · (more) delayed packets. UDP's stateless nature is also useful 2. Data link layer for servers that answer small queries from huge 802.11 · 802.16 · Wi-Fi · WiMAX · numbers of clients. Unlike TCP, UDP supports packet ATM · DTM · Token ring · Ethernet · broadcast (sending to all on local network) and FDDI · Frame Relay · GPRS · EVDO · multicasting (send to all subscribers). HSPA · HDLC · PPP · PPTP · L2TP · ISDN · (more) Common network applications that use UDP include 1. -
External Data Representation Standard: Protocol Specification 1. Status of This Standard Note: This Chapter Specifies a Protocol
External Data Representation Standard: Protocol Specification 1. Status of this Standard Note: This chapter specifies a protocol that Sun Microsystems, Inc., and others are using. It has been desig- nated RFC1014 by the ARPA Network Information Center. 2. Introduction XDR is a standard for the description and encoding of data. It is useful for transferring data between differ- ent computer architectures, and has been used to communicate data between such diverse machines as the Sun Workstation, VAX, IBM-PC, and Cray. XDR fits into the ISO presentation layer, and is roughly analo- gous in purpose to X.409, ISO Abstract Syntax Notation. The major difference between these two is that XDR uses implicit typing, while X.409 uses explicit typing. XDR uses a language to describe data formats. The language can only be used only to describe data; it is not a programming language. This language allows one to describe intricate data formats in a concise man- ner. The alternative of using graphical representations (itself an informal language) quickly becomes incomprehensible when faced with complexity. The XDR language itself is similar to the C language [1], just as Courier [4] is similar to Mesa. Protocols such as Sun RPC (Remote Procedure Call) and the NFS (Network File System) use XDR to describe the format of their data. The XDR standard makes the following assumption: that bytes (or octets) are portable, where a byte is defined to be 8 bits of data. A giv enhardware device should encode the bytes onto the various media in such a way that other hardware devices may decode the bytes without loss of meaning. -
Telematics Chapter 3: Physical Layer
Telematics User Server watching with video Chapter 3: Physical Layer video clip clips Application Layer Application Layer Presentation Layer Presentation Layer Session Layer Session Layer Transport Layer Transport Layer Network Layer Network Layer Network Layer Data Link Layer Data Link Layer Data Link Layer Physical Layer Physical Layer Physical Layer Univ.-Prof. Dr.-Ing. Jochen H. Schiller Computer Systems and Telematics (CST) Institute of Computer Science Freie Universität Berlin http://cst.mi.fu-berlin.de Contents ● Design Issues ● Theoretical Basis for Data Communication ● Analog Data and Digital Signals ● Data Encoding ● Transmission Media ● Guided Transmission Media ● Wireless Transmission (see Mobile Communications) ● The Last Mile Problem ● Multiplexing ● Integrated Services Digital Network (ISDN) ● Digital Subscriber Line (DSL) ● Mobile Telephone System Univ.-Prof. Dr.-Ing. Jochen H. Schiller ▪ cst.mi.fu-berlin.de ▪ Telematics ▪ Chapter 3: Physical Layer 3.2 Design Issues Univ.-Prof. Dr.-Ing. Jochen H. Schiller ▪ cst.mi.fu-berlin.de ▪ Telematics ▪ Chapter 3: Physical Layer 3.3 Design Issues ● Connection parameters ● mechanical OSI Reference Model ● electric and electronic Application Layer ● functional and procedural Presentation Layer ● More detailed ● Physical transmission medium (copper cable, Session Layer optical fiber, radio, ...) ● Pin usage in network connectors Transport Layer ● Representation of raw bits (code, voltage,…) Network Layer ● Data rate ● Control of bit flow: Data Link Layer ● serial or parallel transmission of bits Physical Layer ● synchronous or asynchronous transmission ● simplex, half-duplex, or full-duplex transmission mode Univ.-Prof. Dr.-Ing. Jochen H. Schiller ▪ cst.mi.fu-berlin.de ▪ Telematics ▪ Chapter 3: Physical Layer 3.4 Design Issues Transmitter Receiver Source Transmission System Destination NIC NIC Input Abcdef djasdja dak jd ashda kshd akjsd asdkjhasjd as kdjh askjda Univ.-Prof. -
RT-ROS: a Real-Time ROS Architecture on Multi-Core Processors
Future Generation Computer Systems 56 (2016) 171–178 Contents lists available at ScienceDirect Future Generation Computer Systems journal homepage: www.elsevier.com/locate/fgcs RT-ROS: A real-time ROS architecture on multi-core processors Hongxing Wei a,1, Zhenzhou Shao b, Zhen Huang a, Renhai Chen d, Yong Guan b, Jindong Tan c,1, Zili Shao d,∗,1 a School of Mechanical Engineering and Automation, Beihang University, Beijing, 100191, PR China b College of Information Engineering, Capital Normal University, Beijing, 100048, PR China c Department of Mechanical, Aerospace, and Biomedical Engineering, The University of Tennessee, Knoxville, TN, 37996-2110, USA d Department of Computing, The Hong Kong Polytechnic University, Hong Kong, China article info a b s t r a c t Article history: ROS, an open-source robot operating system, is widely used and rapidly developed in the robotics Received 6 February 2015 community. However, running on Linux, ROS does not provide real-time guarantees, while real-time tasks Received in revised form are required in many robot applications such as robot motion control. This paper for the first time presents 20 April 2015 a real-time ROS architecture called RT-RTOS on multi-core processors. RT-ROS provides an integrated Accepted 12 May 2015 real-time/non-real-time task execution environment so real-time and non-real-time ROS nodes can be Available online 9 June 2015 separately run on a real-time OS and Linux, respectively, with different processor cores. In such a way, real-time tasks can be supported by real-time ROS nodes on a real-time OS, while non-real-time ROS nodes Keywords: Real-time operating systems on Linux can provide other functions of ROS. -
OSI Model and Network Protocols
CHAPTER4 FOUR OSI Model and Network Protocols Objectives 1.1 Explain the function of common networking protocols . TCP . FTP . UDP . TCP/IP suite . DHCP . TFTP . DNS . HTTP(S) . ARP . SIP (VoIP) . RTP (VoIP) . SSH . POP3 . NTP . IMAP4 . Telnet . SMTP . SNMP2/3 . ICMP . IGMP . TLS 134 Chapter 4: OSI Model and Network Protocols 4.1 Explain the function of each layer of the OSI model . Layer 1 – physical . Layer 2 – data link . Layer 3 – network . Layer 4 – transport . Layer 5 – session . Layer 6 – presentation . Layer 7 – application What You Need To Know . Identify the seven layers of the OSI model. Identify the function of each layer of the OSI model. Identify the layer at which networking devices function. Identify the function of various networking protocols. Introduction One of the most important networking concepts to understand is the Open Systems Interconnect (OSI) reference model. This conceptual model, created by the International Organization for Standardization (ISO) in 1978 and revised in 1984, describes a network architecture that allows data to be passed between computer systems. This chapter looks at the OSI model and describes how it relates to real-world networking. It also examines how common network devices relate to the OSI model. Even though the OSI model is conceptual, an appreciation of its purpose and function can help you better understand how protocol suites and network architectures work in practical applications. The OSI Seven-Layer Model As shown in Figure 4.1, the OSI reference model is built, bottom to top, in the following order: physical, data link, network, transport, session, presentation, and application. -
OSI Model: the 7 Layers of Network Architecture
OSI Model: The 7 Layers of Network Architecture The Open Systems Interconnection (OSI) Reference Model is a conceptual framework that describes functions of the networking or telecommunication system independently from the underlying technology infrastructure. It divides data communication into seven abstraction layers and standardizes protocols into appropriate groups of networking functionality to ensure interoperability within the communication system regardless of the technology type, vendor, and model. The OSI model was originally developed to facilitate interoperability between vendors and to define clear standards for network communication. However, the olderTCP/IP model remains the ubiquitous reference framework for Internet communications today. The 7 layers of the OSI model This image illustrates the seven layers of the OSI model. Below, we’ll briefly describe each layer, from bottom to top. 1. Physical The lowest layer of the OSI model is concerned with data communication in the form of electrical, optic, or electromagnetic signals physically transmitting information between networking devices and infrastructure. The physical layer is responsible for the communication of unstructured raw data streams over a physical medium. It defines a range of aspects, including: Electrical, mechanical, and physical systems and networking devices that include specifications such as cable size, signal frequency, voltages, etc. Topologies such as Bus, Star, Ring, and Mesh Communication modes such as Simplex, Half Duplex, and Full Duplex Data transmission performance, such as Bit Rate and Bit Synchronization Modulation, switching, and interfacing with the physical transmission medium Common protocols including Wi-Fi, Ethernet, and others Hardware including networking devices, antennas, cables, modem, and intermediate devices such as repeaters and hubs 2. -
Protocol Specification for OSI *
167 Protocol Specification for OSI * Gregor v. BOCHMANN 1. Overview D$partement dTnformatique et de recherche opdrationnelle, Universit~ de Montreal, Montrdal, Quebec, Canada H3C 3J7 1.1. Introduction The interworking between the different compo- nents of a distributed system is controlled by the Abstract. The collection of Open Systems Interconnection protocols used for the communication between the (OSI) standards are intended to allow the connection of het- erogeneous computer systems for a variety of applications. In different system components. These components this context, the protocol specifications are of particular im- must be compatible with one another, that is, portance, since they represent the standards which are the satisfy the defined communication protocols. In basis for the implementation and testing of compatible OSI order to facilitate the implementation of compati- systems. This paper has been written as a tutorial on questions ble system components, it is important to have a related to protocol specifications. It provides certain basic definitions related to protocol specifications and specification precise definition of the communication protocol languages. Special attention is given to the specification for- to be used. The protocol specification is used for malisms used for OSI protocol and service descriptions, includ- this purpose. ing semi-formal languages such as state tables, ASN.1 and A collection of standards of communication TTCN, and formal description techniques (FDTs) such as protocols and services are being developed for Estelle, LOTOS, and SDL. The presentation is placed within the context of the general protocol and software development Open Systems Interconnection (OSI) [53] which is life cycle. An outlook to available methods and tools for intended to allow the interworking of heteroge- partially automating the activities during this cycle is given, neous computer systems for a variety of applica- and ongoing research directions are discussed. -
Connecting to the Internet Date
Connecting to the Internet Dial-up Connection: Computers that are serving only as clients need not be connected to the internet permanently. Computers connected to the internet via a dial- up connection usually are assigned a dynamic IP address by their ISP (Internet Service Provider). Leased Line Connection: Servers must always be connected to the internet. No dial- up connection via modem is used, but a leased line. Costs vary depending on bandwidth, distance and supplementary services. Internet Protocol, IP • The Internet Protocol is connection-less, datagram-oriented, packet-oriented. Packets in IP may be sent several times, lost, and reordered. No bandwidth No video or graphics No mobile connection No Static IP address Only 4 billion user support IP Addresses and Ports The IP protocol defines IP addresses. An IP address specifies a single computer. A computer can have several IP addresses, depending on its network connection (modem, network card, multiple network cards, …). • An IP address is 32 bit long and usually written as 4 8 bit numbers separated by periods. (Example: 134.28.70.1). A port is an endpoint to a logical connection on a computer. Ports are used by applications to transfer information through the logical connection. Every computer has 65536 (216) ports. Some well-known port numbers are associated with well-known services (such as FTP, HTTP) that use specific higher-level protocols. Naming a web Every computer on the internet is identified by one or many IP addresses. Computers can be identified using their IP address, e.g., 134.28.70.1. Easier and more convenient are domain names.