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Lightweight Directory Access Protocol

Lightweight Directory Access Protocol

In computer networking, the Lightweight Directory Access Protocol, or LDAP, is a standardized networking protocol designed for querying and modifying directory services.

Origin and influences

LDAP defines a protocol for updating and searching directories running over TCP/IP. It was created as an alternative to the much more cumbersome Directory Access Protocol (DAP) for browsing X.500 directories. The protocol was originally authored by Tim Howes of the University of Michigan, Steve Kille of ISODE and Wengyik Yeong of Performance Systems International. LDAP has influenced subsequent Internet protocols, including later versions of X.500, Directory Services Markup Language (DSML), Service Provisioning Markup Language (SPML) and the Service Location Protocol.

LDAP directories

The common term "LDAP directory" can be misleading. No specific type of directory is an "LDAP directory". One could reasonably use the term to describe any directory accessible using LDAP and which can identify objects in the directory with X.500 identifiers. Directories such as OpenLDAP and its predecessors from the University of Michigan, though primarily designed as native repositories optimized for access by LDAP rather than as a gateway to X.500 protocols as was provided in ISODE, are nevertheless no more "LDAP directories" than any other directory accessible by the LDAP protocol. An LDAP directory entry consists of a collection of attributes and is referenced unambiguously with a name, called a distinguished name (DN). For example, a DN might be the value "cn=John Doe,ou=people,dc=wikipedia,dc=org". Each of the entry's attributes are defined as part of an object class and are grouped together into schemas; those schemas for representing individual people within organizations are termed white pages schema. Each entry in the database is associated with one or more of these object classes, which define whether an attribute is optional or mandatory, and what type of information it stores. The attribute names are typically mnemonic strings, like "cn" for common name, or "mail" for e-mail address. The values depend on the type, and most non-binary values in LDAPv3 use UTF-8 string syntax. For example, a mail attribute might contain the value "user@example.com". A jpegPhoto attribute would contain a photograph in binary JPEG/JFIF format. LDAP directory entries feature a hierarchical structure that reflects political, geographic, and/or organizational boundaries. In the original X.500 model, entries representing countries appear at the top of the tree; below them come entries representing states or national organizations. Typical LDAP deployments use DNS names for structuring the top levels of the hierarchy. Further below might appear entries representing people, organizational units, printers, documents, or just about anything else...

Supporting vendors

LDAP has gained wide support from vendors such as:
- Apache (through Apache Directory Server)
- Apple (through Open Directory/OpenLDAP)
- AT&T
- Banyan
- eB2Bcom (through View500)
- Fedora Directory Server
- Hewlett-Packard
- Identyx
- IBM/Lotus
- ISODE (through M-Vault server)
- Microsoft (through Active Directory)
- Netscape (now in Sun Microsystems and Red Hat products)
- Novell (through eDirectory)
- OctetString (through VDE server)
- Oracle (through Oracle Internet Directory)
- Radiant Logic (through RadiantOne Virtual Directory Server)
- [http://www.redhat.com/en_us/USA/home/solutions/directoryserver/ Red Hat Directory Server ]
- Siemens AG (through DirX server)
- SGI and
- Sun (through the iPlanet and Sun ONE directory servers)
- Symlabs (through Directory Extender) as well as in open source/free software implementations such as OpenLDAP and Fedora Directory Server. Also the Apache HTTP Server used as a proxy (by the module mod_proxy) supports LDAP.

RFCs

LDAP is defined by a series of Request for comments documents:
- RFC 1777 - LDAPv2
- RFC 1778 - LDAPv2 String Representation of Standard Attribute Syntaxes
- RFC 2254 - String Representation of LDAP Search Filters
- RFC 1823 - LDAP API (in C)
- RFC 2247 - Use of DNS domains in distinguished names
- RFC 2251 - LDAPv3: The specification of the LDAP on-the-wire protocol
- RFC 2252 - LDAPv3: Attribute Syntax Definitions
- RFC 2253 - LDAPv3: UTF-8 String Representation of Distinguished Names
- RFC 2254 - LDAPv3: The String Representation of LDAP Search Filters
- RFC 2255 - LDAPv3: The LDAP URL Format
- RFC 2256 - LDAPv3: A Summary of the X.500(96) User Schema for use with LDAPv3
- RFC 2829 - LDAPv3: Authentication Methods for LDAP
- RFC 2830 - LDAPv3: Extension for Transport Layer Security
- RFC 3377 - LDAPv3: Technical Specification
- RFC 2307 - Using LDAP as a Network Information Service

References

LDAP Implementations

- [http://directory.apache.org Apache Directory Server]
- [http://directory.fedora.redhat.com Fedora Directory Server]
- [http://www.redhat.com/software/rha/directory/ Red Hat Directory Server]
- OpenLDAP
- [http://www.novell.com/products/edirectory/ Novell eDirectory]
- [http://www.sun.com/software/products/directory_srvr/home_directory.xml Sun Directory Server]
- IBM SecureWay Directory
- IBM Tivoli Directory Server (formerly IBM Directory Server)
- [http://www.microsoft.com/windowsserver2003/technologies/directory/activedirectory/default.mspx Windows Server 2003 Active Directory]
- [http://www.view500.com View500]

External links

- LDAP Software
- [http://edsadmin.sourceforge.net/ EDS Admin tool]
- [http://www.softerra.com/products/ldapbrowser.php Freeware Win32 LDAP Client]
- [http://www.jxplorer.org JXplorer java OSS LDAP Client]
- GQ ([http://sourceforge.net/projects/gqclient Homepage])
- Luma ([http://luma.sourceforge.net/ Homepage])
- [http://www.perldap.org PerLDAP], an interface to the C SDK API, and a set of Object Oriented Perl classes
- [http://www.tldp.org/HOWTO/LDAP-HOWTO/ Linux LDAP HOWTO]
- [http://www.bind9.net/ldap/ LDAP Articles, Links, Whitepapers]
- [http://www.bind9.net/ldap-tools LDAP Software, Tools & Utilities]
- [http://www.ietf.org/html.charters/ldapbis-charter.html LDAP (v3) Revision (ldapbis) Working Group]
- [http://twistedmatrix.com/users/tv/ldap-intro/ldap-intro.html Nice Neat Introduction To LDAP with examples ]
- [http://www.metaconsultancy.com/whitepapers/ldap.htm Using OpenLDAP - Installing OpenLDAP under Debian GNU/Linux]
- [http://www.metaconsultancy.com/whitepapers/ldap-linux.htm LDAP Authentication for Linux - Integrating LDAP into PAM]
- [http://forge.novell.com/modules/xfmod/project/showfiles.php?group_id=1318 LDAP Libraries for C#].
- [http://www.zytrax.com/books/ldap/ LDAP for Rocket Scientists]
- [http://www.freesoftwaremagazine.com/free_issues/issue_03/ldap/ The importance of LDAP] A commentary by Tom Jackiewicz about LDAP
- [http://nermus.its.ac.id/show/main.php?track0=3&track1=0&&howto=central-auth&xml=no HOWTO on LDAP + SASL + KERBEROS Master/Slave Central Authentication] A Complex Howto By Danang Wijanarko Category:Internet standards Category:Internet protocols ja:Lightweight Directory Access Protocol

Computer networking

A computer network is a system for communication between computers. These networks may be fixed (cabled, permanent) or temporary (as via modems or null modems). Carrying instructions between calculation machines and early computers was done by human users. In September, 1940 George Stibitz used a teletype machine to send instructions for a problem set from his Model K at Dartmouth College in New Hampshire to his Complex Number Calculator in New York and received results back by the same means. Linking output systems like teletypes to computers was an interest at the Advanced Research Projects Agency ARPA when, in 1962, J.C.R. Licklider was hired and developed a working group he called the 'Intergalactic Network' a precursor to the ARPANet. In 1964 researchers at Dartmouth developed a time sharing system for distributed users of large computer systems. The same year, at MIT, a research group supported by General Electric and Bell Labs used a computer (DEC's PDP-8) to route and manage telephone connections. in 1968 Paul Baran proposed a network system consisting of datagrams or packets that could be used in a packet switching network between computer systems. In 1969 the University of California at Los Angeles, SRI (in Stanford), University of California at Santa Barbara, and the University of Utah were connected as the beginning of the ARPANet network using 50 kbit/s circuits. Networks, and the technologies needed to connect and communicate through and between them, continue to drive computer hardware, software, and peripherals industries. This expansion is mirrored by growth in the numbers and types of users of networks from researchers and businesses to families and individuals in everyday use.

Categorizing

- Local area network (LAN)
- HomePNA
- Power line communication (HomePlug)
- Metropolitan area network (MAN)
- Wide area network (WAN)

Protocol stacks

Computer networks may be implemented using a variety of protocol stack architectures, computer buses or combinations of media and protocol layers, incorporating one or more of:
- ARCNET
- AppleTalk
- ATM
- Bluetooth
- DECnet
- Ethernet
- FDDI
- Frame relay
- HIPPI
- IEEE 1394 aka FireWire, iLink
- IEEE 802.11
- IEEE-488
- IP
- IPX
- Myrinet
- QsNet
- RS-232
- SPX
- System Network Architecture
- Token Ring
- TCP
- TCP Tuning for discussion of improving performance of same
- USB
- UDP
- X.25 For a list of more see Network protocols. For standards see IEEE 802.

References

- Andrew S. Tanenbaum, "Computer Networks" (ISBN 0133499456).
- Important publications in computer networks

External links

- [http://www.ericdigests.org/pre-921/networking.htm Networking and Microcomputers]
- [http://www.elook.org/computing/network.htm Network – eLook Computing Reference] – defines what a network is and provides leading links
- [http://www.ericdigests.org/1993/k-12.htm Networking: K-12]
- [http://www.pcnineoneone.com/howto/hmnetwk1.html How to set up a home network]
- [http://www.techbooksforfree.com/networking.shtml Open source and non-copyrighted books on networking available for free download]
- Prof. Rahul Banerjee's [http://discovery.bits-pilani.ac.in/rahul/PDFversions/Complete-InetBook-PHI-2003-Secure.pdf free e-book on Internetworking Technologies] deals with the foundations of major internetworking architectures (chapters 4–9)
- [http://www.netfilter.org/documentation/HOWTO//networking-concepts-HOWTO.html Easy Network Concepts] (Linux kernel specific) Category:Information technology Category:Networks zh-min-nan:Tiān-náu bāng-lō· ja:コンピュータ・ネットワーク nb:Datanett simple:Computer network th:เครือข่ายคอมพิวเตอร์

Networking protocol

Hello! This article concerns communication between pairs of electronic devices. For the specific topic of computing protocols, see Protocol (computing). For protocols on two-way voice communications, see voice procedure. For the original and other meanings of the word protocol, see the disambiguation page for protocol. In the field of telecommunications, a communications protocol is the set of standard rules for data representation, signalling, authentication, and error detection required to send information over a communications channel. An example of a simple communications protocol adapted to voice communication is the case of a radio dispatcher talking to mobile stations. The communication protocols for digital computer network communication have many features intended to ensure reliable interchange of data over an imperfect communication channel.

Network protocol design principles

Systems engineering principles have been applied to create a set of common network protocol design principles. These principles include effectiveness, reliability, and resiliency.

Effectiveness

For a protocol to be effective it needs to be specified in such a way, that engineers, designers, and in some cases software developers can implement and/or use it. In human-machine systems, its design needs to facilitate routine usage by humans. Protocol layering accomplishes these objectives by dividing the protocol design into a number of smaller parts, each of which performs closely related sub-tasks, and interacts with other layers of the protocol only in a small number of well-defined ways. Protocol layering allows the parts of a protocol to be designed and tested without a combinatorial explosion of cases, keeping each design relatively simple. The implementation of a sub-task on one layer can make assumptions about the behavior and services offered by the layers beneath it. Thus, layering enables a "mix-and-match" of protocols that permit familiar protocols to be adapted to unusual circumstances. In the realm of computing, an email protocol like Simple Mail Transfer Protocol (SMTP) can be adapted to send messages to a system that follows SMTP.It can be an Aircraft having a SMTP Server to receive SMTP protocol based messages. An SMTP Client can build SMTP messages. and an SMTP Server handles the connection and interacts with client as defined through the SMTP protocol specification. RFC2821 specifies the protocol details. This paragraph informally provides some examples of layers, some required functionalities, and some protocols that implement them, all from the realm of computing protocols. A layer in charge of presentation might describe how to encode text (ie: ASCII or Unicode). A protocol like SMTP, may (among other things) describe how to inquire about electronic mail messages. A sub-task of error detection and either message correction or retransmission may be performed by the Transmission control protocol (TCP), while the related sub-task of addressing implemented by the Internet Protocol(IP) will pair up these two protocols giving rise to the familiar acronym TCP/IP. These examples may assume some point-to-point connectivity offered by point-to-point protocol (PPP) implemented in the lower-level Data link layer. At the lowest level is the sub-task involving the electrical encoding/decoding of bits into/from voltages performed in the Physical layer. These examples motivate the need to specify some software architecture or reference model that systematically places each subtask into its proper context. The reference model usually used for protocol layering is the OSI seven layer model, which can be applied to any protocol, not just the OSI protocols initially sanctioned by the International Organization for Standardization (ISO). In particular, the Internet Protocol can be analysed using the OSI model.

Reliability

Assuring reliability of data transmission involves error detection and correction, or some means of requesting retransmission. It is a truism that communication media are always faulty. The conventional measure of quality is the number of failed bits per bits transmitted. This has the wonderful feature of being a dimensionless figure of merit that can be compared across any speed or type of communication media. In telephony, links with bit error rates of 10^-4 or more are regarded as faulty (they interfere with telephone conversations), while links with a BER of 10^-5 or more should be dealt with by routine maintenance (they can be heard). Communication systems correct errors by selectively resending bad parts of a message. For example, in TCP (the internet's Transmission Control Protocol), messages are divided into packets, each of which has a checksum. When a checksum is bad, the packet is discarded. When a packet is lost, the receiver acknowledges all of the packets up to, but not including the failed packet. Eventually, the sender sees that too much time has elapsed without an acknowledgement, so it resends all of the packets that have not been acknowledged. At the same time, the sender backs off its rate of sending, in case the packet loss was caused by saturation of the path between sender and receiver. (Note: this is an over-simplification: see TCP and congestion collapse for more detail) In general, the performance of TCP is severely degraded in conditions of high packet loss (more than 0.1%), due to the need to resend packets repeatedly. For this reason, TCP/IP connections are typically either run on highly reliable fiber networks, or over a lower-level protocol with added error-detection and correction features (such as modem links with ARQ). These connections typically have uncorrected bit error rates of 10^-9 to 10^-12, ensuring high TCP/IP performance.

Resiliency

Resiliency addresses a form of network failure known as topological failure in which a communications link is cut, or degrades below usable quality. Most modern communication protocols periodically send messages to test a link. In phones, a framing bit is sent every 24 bits on T1 lines. In phone systems, when "sync is lost", fail-safe mechanisms reroute the signals around the failing equipment. In packet switched networks, the equivalent functions are performed using router update messages to detect loss of connectivity.

Standards organisations

Most recent protocols are assigned by the IETF for Internet communications, and the IEEE, or the ISO organizations for other types. The ITU-T handles telecommunications protocols and formats for the public switched telephone network (PSTN). The ITU-R handles protocols and formats for radio communications. As the PSTN. radio systems, and Internet converge, the different sets of standards are also being driven towards technological convergence.

Protocol families

A number of major protocol stacks or families exist, including the following: Proprietary standards:
- AppleTalk
- DECnet
- IPX/SPX
- SMB
- Systems Network Architecture (SNA)
- Distributed Systems Architecture (DSA) Open standards:
- Open Systems Interconnect (OSI)
- Internet protocol suite

References

- Radia Perlman: Interconnections: Bridges, Routers, Switches, and Internetworking Protocols. 2nd Edition. Addison-Wesley 1999, ISBN 0201634481. In particular Ch. 18 on "network design folklore".
- Gerard J. Holzmann: Design and Validation of Computer Protocols. Prentice Hall, 1991, ISBN 0-13-539925-4. Also available online at http://spinroot.com/spin/Doc/Book91.html

External links

- [http://www.javvin.com/protocolsuite.html Javvin's Protocol Dictionary]
- ja:通信プロトコル th:เกณฑ์วิธีการสื่อสาร

Internet protocol suite

The Internet protocol suite is the set of communications protocols that implement the protocol stack on which the Internet runs. It is sometimes called the TCP/IP protocol suite, after the two most important protocols in it: the Transmission Control Protocol (TCP) and the Internet Protocol (IP), which were also the first two defined. The Internet protocol suite can be described by analogy with the OSI model, which describes the layers of a protocol stack, not all of which correspond well with internet practice. In a protocol stack, each layer solves a set of problems involving the transmission of data, and provides a well-defined service to the higher layers. Higher layers are logically closer to the user and deal with more abstract data, relying on lower layers to translate data into forms that can eventually be physically manipulated. The Internet model was produced as the solution to a practical engineering problem. The OSI model, on the other hand, was a more theoretical approach. Therefore, some consider the OSI model as easier to understand, and the TCP/IP model as the one that fits with actual use. Some consider it helpful to have an understanding of the OSI model before learning TCP/IP, as the same principles apply, but are easier to understand in the OSI model.

Layers in the TCP/IP stack

There is some discussion about how to map the TCP/IP model onto the OSI model. Since the TCP/IP and OSI protocol suites do not match precisely, there is no one correct answer. In addition, the OSI model is not really rich enough at the lower layers to capture the true layering; there needs to be an extra layer (the Internetworking layer) between the Transport and Network layers. Protocols specific to a particular network type, but which are run on top of the basic hardware framing, ought to be at the Network layer. Examples of such protocols are ARP and the Spanning Tree Protocol (used to keep redundant bridges idle until they are needed). However, they are local protocols and operate beneath the internetwork functionality. Admittedly, placing both groups (not to mention protocols which are logically part of the internetwork layer, but run on top of the internetwork protocol, such as ICMP) all at the same layer can be confusing, but the OSI model is not complex enough to do a better job. The following diagram attempts to show where various TCP/IP and other protocols would reside in the original OSI model: Commonly, the top three layers of the OSI model (Application, Presentation and Session) are considered as a single Application Layer in the TCP/IP suite. Because the TCP/IP suite has a comparatively lightweight session layer, consisting of opening and closing connections under TCP and RTP and providing different port numbers for different applications under TCP and UDP, these functions may be augmented by individual applications. Similarly, IP is designed around the idea of treating the network below it as a black box so it can be considered as a single layer for the purposes of discussing TCP/IP.

The link layer

The Link layer is not really part of the Internet protocol suite, but is the method used to pass packets from the Internet layer of one device to the Internet layer of another. This process can be controlled both in the software device driver for the network card, as well as on firmware or specialist chipsets. These will perform data link functions such as adding a packet header to prepare it for transmission, then actually transmit the frame over a physical medium. On the other end, the link layer will receive data frames, strip off the packet headers, and hand the received packets to the Internet layer. However, the link layer is not always so simple. It may also be a Virtual private network (VPN) or tunnel, where packets from the Internet layer, instead of being sent over a physical interface, are sent using a tunneling protocol and another (or the same) protocol suite. The VPN or tunnel is usually established ahead of time, and has special characteristics that direct transmission out a physical interface does not (for example, it may encrypt the data going over it). This recursive use of the protocol suite can be confusing since the link "layer" is now an entire network. But it is an elegant method for implementing often complex functions. (though care is needed to prevent a packet that is wrapped and sent through a tunnel being repeatedly re-wrapped and sent down the tunnel again).

The Internetwork layer

As originally defined, the Network layer solves the problem of getting packets across a single network. Examples of such protocols are X.25, and the ARPANET's Host/IMP Protocol. With the advent of the concept of internetworking, additional functionality was added to this layer, namely getting data from the source network to the destination network. This generally involves routing the packet across a network of networks, known as an internet. In the internet protocol suite, IP performs the basic task of getting packets of data from source to destination. IP can carry data for a number of different higher level protocols; these protocols are each identified by a unique IP Protocol Number. ICMP and IGMP are protocols 1 and 2, respectively. Some of the protocols carried by IP, such as ICMP (used to transmit diagnostic information about IP transmission) and IGMP (used to manage multicast data) are layered on top of IP but perform internetwork layer functions, illustrating an incompatibility between the internet and OSI models. All routing protocols, such as BGP, OSPF, and RIP are also really part of the internetwork layer, although they might seem to belong higher in the stack.

The transport layer

The protocols at the Transport layer can solve problems like reliability ("did the data reach the destination?") and ensure that data arrives in the correct order. In the TCP/IP protocol suite, transport protocols also determine which application any given data is intended for. The dynamic routing protocols which technically fit at this layer in the TCP/IP Protocol Suite (since they run over IP) are generally considered to be part of the Network layer; an example is OSPF (IP protocol number 89). TCP (IP protocol number 6) is a "reliable", connection-oriented, transport mechanism providing a reliable byte stream, which makes sure data arrives complete, undamaged, and in order. TCP tries to continuously measure how loaded the network is and throttles its sending rate in order to avoid overloading the network. Furthermore, TCP will attempt to deliver all data correctly in the specified sequence. These are its main differences from UDP, and can become disadvantageous in real-time streaming or routing applications with high internetwork layer loss rates. The newer SCTP is also a "reliable", connection-oriented, transport mechanism. It is record rather than byte oriented, and provides multiple sub-streams multiplexed over a single connection. It also provides multi-homing support, in which a connection end can be represented by multiple IP addresses (representing multiple physical interfaces), such that if one fails the connection is not interrupted. It was developed initially for telephony applications (to transport SS7 over IP), but can also be used for other applications. UDP (IP protocol number 17) is a connectionless datagram protocol. It is a "best effort" or "unreliable" protocol - not because it is particularly unreliable, but because it does not verify that packets have reached their destination, and gives no guarantee that they will arrive in order. If an Application requires these characteristics, it must provide them itself, or use TCP. UDP is typically used for applications such as streaming media (audio and video, etc) where on-time arrival is more important than reliability, or for simple query/response applications like DNS lookups, where the overhead of setting up a reliable connection is disproportionately large. DCCP is currently under development by IETF. It provides TCP's flow control semantics, while keeping UDP's datagram service model visible to the user. Both TCP and UDP are used to carry a number of higher-level applications. The applications at any given network address are distinguished by their TCP or UDP port number. By convention certain well known ports are associated with specific applications. RTP is a datagram protocol that is designed for real-time data such as streaming audio and video. RTP is a session layer that uses the UDP packet format as a basis yet is said to sit within the transport layer of the Internet protocol stack.

The application layer

The Application layer is the layer that most common network-aware programs use in order to communicate across a network with other programs. Processes that occur in this layer are application specific; data is passed from the network-aware program, in the format used internally by this application, and is encoded into a standard protocol. Some specific programs are considered to run in this layer. They provide services that directly support user applications. These programs and their corresponding protocols include HTTP (The World Wide Web), FTP (File transport), SMTP (Email), SSH (Secure remote login), DNS (Name <-> IP Address lookups) and many others. Once the data from an application has been encoded into a standard application layer protocol it will be passed down to the next layer of the IP stack. At the Transport Layer, applications will most commonly make use of TCP or UDP, and server applications are often associated with a well-known port number. Ports for server applications are officially allocated by the Internet Assigned Numbers Authority (IANA) but developers of new protocols today often choose the port numbers themselves. As it is rare to have more than a few server applications on the same system, problems with port conflicts are rare. Application software also generally allows users to specify arbitrary port numbers as runtime parameters. Client applications connecting out generally use a random port number assigned by the operating system. Applications that listen on a port and then send that port to another copy of the application via a server to set up a peer-peer link (e.g. dcc file transfers on IRC). may also use a random port but the applications usually allow specification of a specific port range to allow the ports to be mapped inwards through a router that implements network address translation.

Development

The Internet protocol suite came from work done by DARPA in the early 1970s. After doing the pioneering ARPANET, DARPA started work on a number of other data transmission technologies, including packet radio, and satellite links. Wanting to be able to communicate across them, Robert E. Kahn of DARPA recruited Vint Cerf of Stanford University to work with him on the problems of connecting multiple networks, using different access protocols. By the summer of 1973, they had soon worked out a fundamental reformulation, where the differences between network protocols were hidden by using a common internetwork protocol, and instead of the network being responsible for reliability, as in the ARPANET, the hosts became responsible. (Cerf credits Hubert Zimmerman and Louis Pouzin (designer of the CYCLADES network) with important influences on this design.) With the role of the network reduced to the bare minimum, it became possible to join almost any networks together, no matter what their characteristics were, thereby solving Kahn's initial problem. (One popular saying has it that TCP/IP, the eventual product of Cerf and Kahn's work, will run over "two tin cans and a string".) A computer called a gateway (later changed to router to avoid confusion with other types of gateway) is provided with an interface to each network, and forwards packets back and forth between them. The idea was worked out in more detailed form by Cerf's networking research group at Stanford in the 1973–74 period. (The early networking work at Xerox PARC, which produced the PARC Universal Packet protocol suite, much of which was contemporaneous, was also a significant technical influence; people moved between the two.) DARPA agreed to fund development of prototype software, and after several years of work, the first somewhat crude demonstration of what had by then become TCP/IP occurred in July 1977. On 9 November 2005 Kahn and Cerf were presented with the Presidential Medal of Freedom for their contribution to American culture. [http://news.bbc.co.uk/1/hi/technology/4415326.stm]

Implementation

- KA9Q PPJ

External links

- [http://www.showip.org/ Show your IP address]
- [http://www.itprc.com/tcpipfaq/ TCP/IP FAQ]
- [http://www.columbia.edu/~rh120/other/tcpdigest_paper.txt A Study of the ARPANET TCP/IP Digest]
- [http://www.eventhelix.com/RealtimeMantra/Networking/ TCP/IP Sequence Diagrams]
- [http://cng.ateneo.edu/cng/wyu/classes/cs197/ Ateneo Network Research Group] TCP/IP research at the Ateneo de Manila University Internet protocol suite ja:TCP/IP

X.500

X.500 is a series of computer networking standards covering electronic directory services. The X.500 series was developed by ITU-T, formerly known as CCITT. The directory services were developed in order to support the requirements of X.400 electronic mail exchange and name lookup. ISO was a partner in developing the standards, incorporating them into the Open Systems Interconnect suite of protocols. ISO/IEC 9594 is the corresponding ISO identification. The protocols defined by X.500 include:
- DAP (Directory Access Protocol)
- DSP (Directory System Protocol)
- DISP (Directory Information Shadowing Protocol)
- DOP (Directory Operational Bindings Management Protocol) X.509, the portion of the standard providing for an authentication framework, is now also widely used outside of the X.500 directory protocols. It specifies a standard format for public-key certificates. Because of the complexity of the protocols, a simplified alternative, known as Lightweight Directory Access Protocol (LDAP), was developed implementing only a subset of the protocols.

List of X.500 series standards

External links

University of Michigan

:This article is about the University of Michigan in Ann Arbor. You may be looking for University of Michigan-Dearborn or University of Michigan-Flint The University of Michigan, Ann Arbor (U-M or "U of M") is a public coeducational university in Michigan, United States. The flagship and oldest campus of the University of Michigan is consistently ranked as one of the top academic institutions in the world, and is considered as a "Public Ivy." Spread over three major campuses in Ann Arbor, the university's professional graduate schools in the fields of information science, law, medicine, business, engineering, public policy, and education are consistently ranked by US News & World Report in the top 10 in the country. The U-M has one of the largest research expenditures of any university in the United States. It is a major contributor to advances in medicine, computer science, and engineering. It was the site of the announcement of the success of the scientific trials that led to the Salk polio vaccine (1955). The university has one of the largest numbers of living alumni of any American university. It is also known for athletic prowess—notably in football and hockey—and has a history of student activism. U-M was the site of the nation's first faculty led anti-Vietnam War "teach in" and the anti-war group SDS was founded by then U-M students, including Tom Hayden. The university was the first in America to employ the seminar method of study, as well as where President John F. Kennedy first proposed the concept of what became the Peace Corps. President Lyndon B. Johnson first announced his domestic poverty program known as the Great Society at U-M. More recently, the university successfully affirmed before the United States Supreme Court the principle that race may be considered as a factor in college admissions.

History

The University of Michigan was one of the nation's first public universities that was established in 1817 by the Michigan Territorial legislature on 1,920 acres (776 hectares) ceded through the Treaty of Fort Meigs by the Chippewa, Ottawa, and Potawatomi peoples. The university moved from Detroit to Ann Arbor in 1837. Hoping to be chosen as the site for the new state capital, Ann Arbor had set aside 40 acres (16 hectares) that it subsequently offered to the university when Lansing was instead chosen as the state capital. The ceded land in Detroit was sold and the proceeds remain in the U-M's permanent endowment. The original 40 acres (16 hectares) in Ann Arbor became part of the current Central Campus. The first classes were held in 1841, comprising six freshmen and a sophomore, taught by two professors. Eleven men graduated in the first commencement ceremony in 1845. By 1865–66, the enrollment had increased to 1,205 students, of whom many were veterans of the Civil War. Women were first admitted in 1870. James B. Angell, who served as the university's president from 1871 to 1909, aggressively expanded U-M's curriculum to include professional studies in dentistry, architecture, engineering, government, and medicine. The first two decades of the 20th century saw a construction boom on campus that included facilities to house the dental and pharmacy programs, a chemistry building, a building for the study of natural sciences, Hill Auditorium, large hospital and library complexes, and two residential halls. The university's reputation for research gained momentum in 1920 with a formal reorganization of the College of Engineering and the formation of an advisory committee of 100 industrialists to guide academic research initiatives. During World War II, U-M's research output grew significantly, and included major initiatives on behalf of the U.S. Navy, in particular, breakthroughs in the development of weapons such as the proximity fuze, depth bomb, the PT boat, and radar jammer. By 1950, enrollment had reached 21,000, of whom 7,700 were veterans supported by the G.I. Bill. G.I. Bill As the Cold War and the Space Race took hold in the second half of the 20th century, U-M became a major recipient of government grants for strategic research, and was on the cutting edge of the development of peacetime uses for atomic power. In a 1966 survey of American universities by the American Council on Education, U-M was rated either first or second in graduate teaching in all 28 disciplines surveyed. On March 24, 1964, a group of academic staff members and 2,500 students held the nation's first "teach-in" to protest against American policy in Southeast Asia. In response to a series of sit-ins in 1966 by Voice—the campus political party of Students for a Democratic Society—the U-M's administration banned sit-ins, a move which in turn led 1,500 students to conduct a further one-hour sit-in in the administration building. During the 1970s, severe budget constraints hindered the university's physical development and academic standing, but the 1980s saw a surge in funds devoted to research in the social and physical sciences. Nevertheless, campus controversy arose over involvement in the anti-missile Strategic Defense Initiative and investments in South Africa. During the 1980s and 1990s, the university devoted substantial resources to renovating its massive hospital complex and improving the academic facilities on the North Campus. The university also emphasized the development of computer and information technology throughout the campus. In 2003, two lawsuits involving U-M's affirmative action admissions policy reached the U.S. Supreme Court (Grutter v. Bollinger and Gratz v. Bollinger). President George W. Bush took the unusual step of publicly opposing the policy before the court issued a ruling, though the eventual ruling was mixed. In the first case, the court upheld the Law School admissions policy, while in the second it ruled against the university's undergraduate admissions policy. In the early 2000s, the U-M also faced declining state funding as a percentage of its funding due to state budget shortfalls. At the same time, U-M has attempted to maintain its high academic standing while keeping tuition costs affordable. There were also disputes between U-M's administration and labor unions, notably with the Lecturers' Employees Organization (LEO) and the Graduate Employees Organization (GEO), the union representing graduate student employees. These conflicts have led to a series of one-day walkouts by the unions and their supporters.

Academic profile

2000s The university has about 24,800 undergraduate and 14,900 graduate students in 600 academic programs; each cohort numbers about 6,250 students, although the university admits fewer than 50% of applicants. Students come from all 50 U.S. states and more than 100 countries. 98% of applicants have achieved a high school GPA of more than 3.0. The upper quartile of each U-M class is two to three times the size of the average interquartile class of the Ivy League institutions; with a minimum SAT score of around 1400, that quartile is academically competitive with the Ivy League average of 1430. As a result, the university's student body includes weaker students as well as those who are competitive with, and as proportionately large as those of the other Ivy League institutions. 15% of newly enrolled undergraduates are members of ethnic minority groups. About 65% of undergraduate students are enrolled in the College of Literature, Science, and the Arts (LS&A). The university has a top ranking engineering school, which takes in about 20% of undergraduate students. Fewer than 3% of undergraduate students are enrolled in the highly selective Ross School of Business. The rest of the undergraduate students are enrolled in the smaller schools, including the School of Music, the School of Nursing, and the School of Art and Design. Most graduate students are enrolled in the LS&A, the College of Engineering, the Law School, the Ross School of Business, and the Medical School. The Medical School is partnered with one of the largest health care complexes in the world, the University of Michigan Health System. There are just over 5,000 faculty members, 73 of whom are members of the National Academy. The university consistently leads the nation in the number of Fulbright Scholars and has several Rhodes Scholars—its academic departments are consistently placed towards the top of college rankings. In one recent rankings summary, more than 70% of U-M's 200 major programs, departments, and schools were ranked in the top 10 nationally, and more than 90% of programs and departments were ranked in the top 20 nationally. In the areas of intellectual breadth and quality, the Philosophical Gourmet ranks U-M fourth. Similarly, in 2005 U-M was rated among the top 10 colleges in America in the annual rankings by the Washington Monthly. The School of Social Work has been ranked first by the US News and World Report every year since 1994. One concern about academics at the U-M is that many courses, including upper-level courses, are taught by Graduate Student Instructors — a problem facing many public and private universities in America. The Princeton Review ranked U-M seventh worst in the category of "teaching assistants teach too many upper-level courses." Another concern is the high level of educational expenses, especially for out-of-state undergraduate students, who pay about $27,000 annually for tuition alone. On the other hand, in-state undergraduate students pay about $8,500.

Research

The university has one of the largest annual research expenditures of any public university in the United States, totaling roughly $750 million in 2004. The Medical School has the largest research expenditures at nearly $300 million, while the College of Engineering, at more than $135 million, is second. U-M was at the center of the development of one of the first university computer networks and has made major contributions to the mathematics of information theory, notably through Claude Shannon. Other major contributions include the construction of the precursor to the National Science Foundation computer networking backbone, the virtual memory model, and computer databases. The university is also a major contributor to the medical field with the EKG, gastroscope, Jonas Salk's polio vaccine, and the extracorporal membrane oxygenation system. The National Election Studies and one of the nation's most watched economic indices, the University of Michigan's Consumer Confidence Index, are based at U-M. The university is also home to major research centers in optics, reconfigurable manufacturing systems, wireless integrated microsystems, and social sciences. The University of Michigan Transportation Research Institute is located at the university, and huge support was recently given to the life sciences with the establishment of the Life Sciences Institute and the construction of associated facilities. Undergraduate students are able to participate in various research projects through the Undergraduate Research Opportunity Program (UROP) as well as the UROP/Creative-Programs. These programs are currently first in the national ranking.

Libraries and museums

Undergraduate Research Opportunity Program The U-M library system is one of the largest in the United States. It comprises 19 individual libraries with 24 separate collections—roughly 7.96 million volumes, growing at the rate of 150,000 volumes a year. U-M was the original home of the JSTOR database, which contains about 750,000 digitized pages from the entire pre-1990 backfile of ten journals of history and economics. The University recently initiated an innovative book digitization program in collaboration with Google. Two prominent libraries, the Harlan Hatcher Graduate Library and the Shapiro Undergraduate Library (also called the UGLi, which is officially an acronym but was used by students as a reference to the building's uninspired appearance prior to its recent renovation), are on Central Campus and are connected by a skywalk. The Duderstadt Center on North Campus houses books on art, architecture, and engineering. The Duderstadt Center also contains multiple computer labs, video editing studios, and a 3D virtual reality room. North Campus is the location of the Gerald R. Ford Presidential Library. Gerald R. Ford Presidential Library The University of Michigan is home to a number of museums, whose focuses include archeology, anthropology, paleontology, zoology, dentistry, and art. The natural history public collections are housed at the University of Michigan Exhibit Museum of Natural History, which displays items from the collections of the paleontology, zoology, and anthropology museums. The Exhibit Museum also holds the largest display of dinosaur specimens in Michigan as well a specimen of the state fossil, the mastodon. One of the better-known museums is the University of Michigan Museum of Art, with a permanent collection of European, American, Middle Eastern, Asian, and African items, and temporary exhibits on a wide variety of subjects.

Campus

mastodon The Ann Arbor campus is divided into three main areas: the North, Central and South Campuses. The physical infrastructure includes more than 300 major buildings, with a combined area of more than 29 million square feet (3 km²). The campus also consists of buildings scattered throughout the city, many occupied by organizations affiliated with the University of Michigan Health System. The university also has an office building called Wolverine Tower in southern Ann Arbor near Briarwood Mall. All three campus areas are connected by free bus services, the majority of which connect the North and Central Campuses. There is a shuttle service connecting the University Hospital, which lies between North and Central Campuses, with other medical facilities throughout northeastern Ann Arbor.

Central Campus

Central Campus was the original location of U-M when it moved to Ann Arbor in 1841. It originally had a school and dormitory building (where Mason Hall now stands) and several houses for professors on land bounded by North University Avenue, South University Avenue, East University Avenue, and State Street. Because Ann Arbor and Central Campus developed simultaneously, there is no distinct boundary between them, and some areas contain a mixture of private and university buildings. Central Campus is the location of the College of Literature, Science and the Arts and the medical campus. Most of the graduate and professional schools, including the Ross School of Business and the Law School, are on Central Campus. Ten of the buildings on Central Campus were designed by Detroit-based architect Albert Kahn between 1904 and 1936. The most notable of the Kahn-designed buildings are the Burton Memorial Tower and nearby Hill Auditorium.

North Campus

Hill Auditorium North Campus is the most contiguous campus, built independently from the city on a large plot of land the university bought in 1952. It is newer than Central Campus, and thus has more modern architecture, while most Central Campus buildings are classical or gothic in style. The architect Eero Saarinen, based in Birmingham, Michigan, created one of the early master plans for North Campus and designed several of its buildings in the 1950s, including the Earl V Moore School of Music Building. North and Central Campuses each have unique bell towers reflecting the predominant architectural style of their surrounding architectural styles. The College of Engineering, the Schools of Music and Art and Design, the Taubman College of Architecture and Urban Planning, and an annex of the School of Information are located on North Campus.

South Campus

South Campus is the site for the athletic programs, including major sports facilities, such as Michigan Stadium, Crisler Arena, and Yost Ice Arena. South Campus is also the site of the Buhr library storage facility (the collections of which are undergoing digitization by Google), the Institute for Continuing Legal Education, and the Student Theatre Arts Complex, which provides shop and rehearsal space for student theatre groups. The university's department of public safety and transportation services offices are located on South Campus.

Athletics

Yost Ice Arena The University of Michigan's sports teams are called the Wolverines, after the state's nickname. They participate in the NCAA's Division I-A and in the Big Ten Conference in all sports except ice hockey, which competes in the Central Collegiate Hockey Association. In seven of the past ten years, U-M has finished in the top five of the NACDA Director's Cup, a list compiled by the National Association of Collegiate Directors of Athletics, which charts the success of universities in competitive sport. NACDA Director's Cup The U-M football team won the first Rose Bowl game in 1902, and has won an NCAA-record 842 games through the 2004 season. The football team is the NCAA's all-time winningest program—in both total wins and winning percentage. The program is a model of consistency, because it is one of only two teams to have been ranked in the final "Top 25" poll every year since 1989. Since that time, the Wolverines have won outright or shared seven Big Ten titles and won a national championship. U-M football has won eleven national championships overall, the most recent in 1997, and has produced three Heisman trophy winners. Michigan Stadium ("The Big House"), is the largest college football-only stadium in the world, with a capacity of 107,501 and attendance typically exceeding 110,000. The NCAA's record-breaking attendance has become commonplace at Michigan Stadium, especially since the arrival of Bo Schembechler in 1969. U-M has fierce rivalries with many teams, including Michigan State and Notre Dame; however, its football rivalry with Ohio State is widely considered to be the fiercest in all of college athletics and has been referred to as the greatest rivalry of all time by ESPN. The men's basketball team, which plays at Crisler Arena, and the ice hockey team, which plays at Yost Ice Arena, are highly popular teams. A Harris Survey in 2003 found the U-M men's basketball program to be the second most popular in the nation and the women's program the third most popular in the nation. The men's ice hockey has won nine national championships, the most of any American university or college. The men's basketball team won the national championship in 1989, though during the 1990s the team was involved in a scandal involving payments from a booster, which led to the program's later relinquishing several championship titles won during that decade. The University of Michigan remains the only school in NCAA history to win at least one national championship in all four major sports: football, basketball, hockey, and baseball.

Student life

Residential life

Yost Ice Arena The University of Michigan has the sixth largest campus accommodation system in the U.S. and the third largest family housing operation, catering for up to 12,562 people. The residence halls are organized into three distinct groups: Central Campus, Hill Area (between Central Campus and the University of Michigan Medical Center) and North Campus. Family housing is located on North Campus and mainly serves graduate students. The largest residence hall has a capacity of 1277 students, while the smallest accommodates 31 residents. A majority of upper-class and graduate students live in off-campus apartments, houses, and cooperatives, with the largest concentrations in the Central and South Campus areas. The residential system has a number of "living-learning communities" where academic activities and residential life are combined. These communities focus on areas such as research, medical sciences, community service and the German language. The Residential College (RC), a living-learning community that is a division of the College of Literature, Science and the Arts, has its principal instructional space in the East Quadrangle of the residence hall system. East Quadrangle is located on Central Campus.

Groups and activities

There are more than 900 student clubs and organizations at the university. With a history of student activism, some of the most visible groups include those dedicated to causes such as civil rights and labor rights. Although the student body generally leans to the left, there is a sizeable conservative and religious community. Fraternities and sororities, many of which are located east of Central Campus, play a major role in the university's social life. Intramural sports are popular, and there are three major campus recreation facilities, one for each of the three campuses. There are also several engineering projects teams, including the University of Michigan Solar Car Team, which placed first in the American Solar Challenge four times and third in the World Solar Challenge three times. The Michigan Union and Michigan League are student activity centers located on Central Campus while Pierpont Commons is on North Campus. The Michigan Union in particular houses a majority of student bodies including the student government. The William Monroe Trotter House, located east of Central Campus, is a multicultural student center operated by the university's Office of Multi-Ethnic Student Affairs. Michigan Union The Michigan Daily is the student-run daily newspaper. Other student publications include the conservative The Michigan Review, the progressive Michigan Independent, and the humorous publications The Michigan Every Three Weekly and Gargoyle. WCBN (88.3 FM) is a freeform radio station; WOLV-TV is a student-run television station that is primarily shown on the university's cable television system.

Student government

Housed within the Michigan Union, the Michigan Student Assembly (MSA) is the central student government of the University. With representatives from each of the University's colleges and schools, the MSA represents the voice of students and manages student funds on the campus. The Michigan Student Assembly is a member of the statewide Association of Michigan Universities. In recent years MSA has organized a shuttle bus to Detroit Metropolitan Wayne County Airport and brought musical acts such as Guster and Ludacris to campus. The current MSA president is Jesse Levine. There are student governance bodies in each college and school. The two largest colleges at the University of Michigan are the College of Literature, Science, and the Arts (LS&A) and the College of Engineering. Students in the LS&A are represented by the LS&A Student Government. The University of Michigan Engineering Council manages student government affairs for the College of Engineering.

Michigan "fight song"

The University of Michigan's "fight song" is The Victors, written by student Louis Elbel in 1898, following a last-minute victory over the University of Chicago that clinched a league championship. The song was declared by John Philip Sousa as "the greatest college fight song ever written." It includes a reference to the university being the "champions of the West." At the time Michigan was part of the "Western Conference," which would later become the Big Ten Conference. The alma mater song is The Yellow and Blue. A common rally cry is "Let's Go Blue!", written by former student Joseph Carl, a tuba player and drum major. Although mainly used at sporting events, the fight song can be heard at other competitive events that U-M wins. The fight song is sung during graduation commencement ceremonies.

Famous alumni

There are more than 425,000 living alumni, among the largest number of living alumni of any American university. Campus tour guides and orientation meetings commonly report that the university is the only one with an alumni association represented on the moon, due to the U-M flag being one of only two placed there (the other being the U.S. flag), along with a charter for the U-M Alumni Association moon chapter. The items were placed there by the Apollo 15 crew. Famous alumni include former President Gerald R. Ford, playwright Arthur Miller, Sun Microsystems co-founder Bill Joy, Google co-founder Larry E. Page, actor James Earl Jones, actress Lucy Liu, TV journalist Mike Wallace, former House Minority Leader Dick Gephardt, humanitarian Raoul Wallenberg, actress Ruth Hussey, Super Bowl MVP Tom Brady, Mayo clinic co-founder William James Mayo, Nobel Prize-winner (Physics) Samuel Ting, Nobel Prize-winner (Medicine) Marshall Nirenberg, screenwriter Judith Guest, Scopes trial attorney Clarence Darrow, authors Charles Major and Sandra Steingraber, and filmmaker Lawrence Kasdan. Several astronauts are U-M alumni, including the all-UM crews of Gemini 4 and Apollo 15.

Notes

#[http://ed.sjtu.edu.cn/rank/2005/ARWU2005_Top100.htm Top 500 World Universities (2005)]. Institute of Higher Education, Shanghai Jiao Tong University. Accessed October 1, 2005. #Calculated with data from [http://thecenter.ufl.edu/research2004.html The Top American Research Universities (2004)]. TheCenter. Accessed October 1, 2005. #[http://www.umich.edu/%7Eoapainfo/TABLES/PDF/EnrollmentFA00toFA04.pdf Enrollment by Degree Type and School/College (2004)]. UM News Service. Accessed October 2, 2005. #[http://thecenter.ufl.edu/research2004.pdf The Top American Research Universities (December 2004)]. TheCenter. Accessed October 2, 2005. #[http://www.umich.edu/%7Eoapainfo/TABLES/PDF/UMAA_Rankings.pdf University of Michigan Rankings (7-13-2005). UMich.edu]. #[http://www.usnews.com/usnews/edu/grad/rankings/hea/brief/sow_brief.php America's Best Graduate Schools 2006 - Health: Social Work (Master's)]. US News and World Report. #[http://www.philosophicalgourmet.com/topresearch.htm Rankings: The Philosophical Gourmet Copyright 2004: by Brian Leiter]. #[http://sitemaker.umich.edu/obpinfo/files/umaa_tuitfee_rates.pdf Academic Year Tuition and Fees for Full-Time Students (8-18-2005)]. University of Michigan Office of Budget & Planning. Accessed October 7, 2005. #[http://www.research.umich.edu/research_guide/annual_reports/FY04/04regentsreport.html Ulaby, Fawwaz T. Annual Report on Research, Scholarship and Creative Activity at the University of Michigan FY2004]. (February 17, 2005). UM Research. #[http://www.umich.edu/%7Eoapainfo/TABLES/PDF/UM_Research.pdf University of Michigan - Research (3-21-2005)]. U of M Office of Budget and Planning - Electronic Fact Pages. Accessed September 15, 2005. #[http://www.lsa.umich.edu/lsa/detail/0,2034,5377%255Farticle%255F7354,00.html UROP is First (2005)]. LSAMagazine. #[http://www.umich.edu/%7Eoapainfo/TABLES/PDF/Libraries.pdf University of Michigan Libraries (1-11-2005)]. U of M News Service. Accessed September 19, 2005. #Carter, Brian (2000). [http://www.tcaup.umich.edu/publications/dimensions/dimfourteen.html Eero Saarinen-Operational Thoroughness A Way of Working]. Dimensions Volume Fourteen. #[http://sportsillustrated.cnn.com/2003/football/ncaa/specials/preview/2003/powerful.teams/ Top 10 Most Power Programs]. SI.com (8-18-2003). #[http://www.umich.edu/~bhl/athdept/football/misc/natchamp.htm University of Michigan Football - National Championships]. University of Michigan Athletics History (2002). #[http://www.mgoblue.com/document_display.cfm?document_id=13326 Michigan in the Heisman Trophy Voting]. MGoBlue.com (2005). #[http://espn.go.com/endofcentury/s/other/bestrivalries.html The 10 greatest rivalries (1-3-2005)]. ESPN.com #[http://www.harrisinteractive.com/harris_poll/index.asp?PID=363 The Harris Poll - College Basketball]. HarrisInteractive. #[http://www.housing.umich.edu/general/factsheet.html Housing Fact Sheet]. UM Housing (2005). #[http://www.umich.edu/~newsinfo/Profile/umprofil.html University of Michigan System Profile]. July 2001. #[http://alumni.umich.edu/info/um/famous_alumni_abc.php About the Association - Famous U-M Alumni (2005)]. UMAlumni.com.

References

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External links

- [http://www.umich.edu/ Unversity of Michigan Home Page]
- [http://alumni.umich.edu/ UM Alumni Association]
- [http://www.mgoblue.com/ University of Michigan Athletics Site]
- [http://www.photos.ns.umich.edu/Public/Standard/RecordView.jsp Various images of the campus]
- [http://www.johnwcooper.com/annarbor-michigan.htm College Students' Guide to University of Michigan's Campus]
- [http://www.umich.edu/~info/maize.html The Yellow and Blue lyrics]
- [http://www.everythreeweekly.com/ The Every Three Weekly, student-run parody newspaper]
- [http://www.wolv.org/ WOLV-TV, the University of Michigan's student-run television station] Category:Association of American Universities Michigan Category:Universities and colleges in Michigan
- Category:Space-grant universities ja:ミシガン大学

ISODE

The ISODE software, originally perhaps intended to be an ISO Development Environment, was an implementation of the OSI upper layer protocols, from transport layer to application layer, which was widely used in the Internet research community to experiment with implementation and deployment of OSI during the late 1980s and early 1990s. While the ISODE implementation could be configured to use one of several X.25 (CONS) or connectionless lower layer protocols, many ISODE deployments were based on [RFC 1006], the implementation of OSI transport protocol TP0 as a layer atop TCP, in order to use IP-based networks which were becoming increasingly common. ISODE formed the basis for popular implementations of X.400 (PP) and X.500 (QUIPU), and the approaches for providing a simplified directory lookup protocol that was easier to implement in a client than X.500's Directory Access Protocol led to the development of the Lightweight Directory Access Protocol. Implementations of FTAM and VT were included in ISODE, and implementations of X.400 P7 (PPMS), TMN (OSIMIS) and other OSI protocols were also made atop ISODE. [http://www.isode.com Isode] is also the name of the company founded by Steve Kille, one of the LDAP protocol authors to produce and market LDAP/X.500 directory servers and messaging systems based on the X.400 protocol. Category:System software

X.500

List of X.500 series standards

External links

SPML

SPML (Service Provisioning Markup Language) is an XML-based framework, being developed by OASIS, for exchanging user, resource and service provisioning information between cooperating organizations.

SPML Protocol

The Service Provisioning Markup language is the open standard protocol for the integration and interoperation of service provisioning requests. SPML version 1.0 is an OASIS standard, approved in October 2003.

What is Service Provisioning?

Service provisioning refers to the "preparation beforehand" of IT systems' materials or supplies required to carry out a specific activity. It goes beyond the initial "contingency" of providing resources, to encompass the entire lifecycle management of these resources. This includes the provisioning of digital services such as user accounts and access privileges on systems, networks and applications, as well as the provisioning of non-digital or "physical" resources such as cell phones and credit cards. "Provisioning is the automation of all the steps required to manage (setup, amend and revoke) user or system access entitlements or data relative to electronically published services". (this information was copied from http://www.openspml.org/spml_faq.html)

Goal of SPML

The goal of SPML is to allow organizations to securely and quickly set up user interfaces for Web services and applications, by letting enterprise platforms such as Web portals, application servers, and service centers generate provisioning requests within and across organizations. This can lead to automation of user or system access and entitlement rights to electronic services across diverse IT infrastructures, so that customers are not locked into proprietary solutions. For example, a supply partner (Company A) goes to its partner's (Company B) supply chain portal and requests access to its inventory data, which is stored in a back-office system. In response, Company B initiates a request using SPML to communicate with SPML-enabled identity management software. After automatically acquiring the appropriate permissions, Company B grants the appropriate access levels to Company A to gain access to the data it needs. This process takes place without the need for the portal environment to have an intimate understanding of the back-office environment. In other words, it's all automatic. The prototype encompasses all of the provisions of the proposed SPML standard while also leveraging the benefits of the Security Assertion Markup Language (SAML). (this info copied from http://www.nwfusion.com/details/5623.html)

External links

- http://www.oasis-open.org
- http://www.openspml.org Category:XML-based standards

OpenLDAP

OpenLDAP is a free, open source implementation of the Lightweight Directory Access Protocol (LDAP). It is released under its own OpenLDAP license. While it is a platform-independent protocol, several common Linux distributions include OpenLDAP, and the software [http://www.openldap.org/faq/data/cache/1142.html allegedly] runs on BSD-variants, AIX, HP-UX, Mac OS X, Solaris, Microsoft Windows (2000, XP) and z/OS. OpenLDAP has four main components:
- slapd - stand-alone LDAP daemon
- slurpd - stand-alone LDAP update replication daemon
- libraries implementing the LDAP protocol
- utilities, tools, and sample clients.

External links

- [http://openldap.org OpenLDAP.org]
- [http://www.openldap.org/doc/admin22/license.html OpenLDAP license]
- [http://lucas.bergmans.us/hacks/openldap/ Lucas Bergman's hacks: Windows OpenLDAP] Category:Identity management systems

Lightweight Directory Access Protocol

Origin and influences

LDAP directories

Supporting vendors

RFCs

References

See also

LDAP Implementations

External links

Computer networking

Categorizing

By functional relationship

By network topology

By specialized function

Protocol stacks

Suggested topics

Layers

Data transmission

Wired transmission

Wireless transmission

Other

See also

References

External links

Networking protocol

Network protocol design principles

Effectiveness

Reliability

Resiliency

Standards organisations

Protocol families

See also

References

External links

Internet protocol suite

Layers in the TCP/IP stack

The link layer

The Internetwork layer

The transport layer

The application layer

Development

Implementation

See also

External links

X.500

List of X.500 series standards

External links

University of Michigan

History

Academic profile

Research

Libraries and museums

Campus

Central Campus

North Campus

South Campus

Athletics

Student life

Residential life

Groups and activities

Student government

Michigan "fight song"

Famous alumni

Notes

References

External links

ISODE

X.500

List of X.500 series standards

External links

SPML

SPML Protocol

What is Service Provisioning?

Goal of SPML

External links

OpenLDAP

External links

University of Michigan

History

Academic profile