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A. Glossary

ACI (Access Control Information):
Access Control Information. Specified in the X.500 specification.
ACL (Access Control List):
Rules associated with a directory that defines the permissions that users, groups, processes, and devices have for accessing data stored in the directory.
Authentication:
Establishes a user's identity. Who are you?
Authorization:
Establishes a user's permissions. What are you allowed to do? Permission may be based on the identity you have established via authentication, or by other attributes associated with that identity such as "enrolled in BUS201" or "person who can be authenticated by UAB".
BIND:
An application establishes an association with an LDAP server (using that server's hostname and port number), and then performs an LDAP bind operation which accomplishes the following: (a) requests access and is returned appropriate authorization and (b) is returned a session handle that typically corresponds to a connection to a single server.
Call Server:
A protocol-specific signaling engine that routes video or voice calls on the network. In H.323 this entity is a gatekeeper. In SIP, this entity is a SIP Proxy Server. Note that not all signaling protocols use a call server.
Client:
a SIP client is a network device that initiates SIP requests and receives SIP responses on a network.
commObject:
An LDAP object class defined in ITU-T H.350 that represents generic multimedia conferencing endpoints.
commURI:
Labeled URI containing an LDAP URL identifying the directory containing the referenced commObject instance. Used to find the endpoint of the user in question.
DIT (Directory Information Tree):
The hierarchical data structure for LDAP information.
DN (Distinguished Name):
A globally unique name that can be used to access a specific LDAP entry.
Endpoint:
a logical device that provides video and/or voice media encoding/decoding, and signaling functions. Examples include:
  1. a group teleconferencing appliance that is located in a conference room
  2. an IP telephone.
  3. a software program that takes video and voice from a camera and microphone and encodes it and applies signaling using a host computer.
Enterprise Directory:
A canonical collection of information about users in an organization. Typically this information is collected from a variety of organizational units to create a whole. For example, Human Resources may provide name and address, Telecommunications may provide the telephone number, Information Technology may provide the email address, etc. For the purposes of this architecture, it is assumed that an enterprise directory is accessible via LDAP.
Gatekeeper:
The H.323 gatekeeper controls a particular set of videoconferencing resources (terminals, gateways, MCU's) and provides advanced services somewhat like a videoconferencing switchboard operator or traffic cop. In this role, the gatekeeper enables more scalable, reliable and secure H.323 conferencing.
Gateway:
A device that translates from one protocol to another. Often gateways translate between the IP network and the public switched voice network to allow integration of the two.
GDS (Global Dialing Scheme):
GDS is a numbering plan for the global video and voice over IP network test bed, developed by ViDeNet. It resembles the international telephone system numbering plan, with some exceptions. With the GDS, you can number each participating videoconferencing endpoint, MCU conference and gateway. GDS provides easy, uniform dialling throughout the world . Each basic number consists of four parts: <International Access Code><Country Code><Organizational Prefix><Endpoint Number>. More information on the GDS and the Numerical Addressing Space Management (NASM) working group overseeing its development can be found at: http://www.wvn.ac.uk/support/h323address.htm and http://www.vide.net/workgroups/nasm/index.shtml.
H.323:
A multimedia protocol for video, voice and data over IP as standardized by the International Telecommunication Union (ITU).
Internet2:
A consortium led by 200 universities working in partnership with industry and government to develop and deploy advanced network applications and technologies, accelerating the creation of tomorrow's Internet. See http://www.internet2.edu/.
LDAP (Lightweight Directory Access Protocol):
As defined in IETF RFC 1777.
LDIF (LDAP Data Interchange Format):
LDIF files are easily human readable (text) files representing LDAP entries. LDIF files are used to add, delete, or modify data in an LDAP directory, and to import or export that data. LDIF files provided in our cookbook create the H.350 object classes and attributes for you.
MCU (Multipoint Control Unit):
A device capable of mixing audio/video from multiple endpoints to create a virtual meeting space.
Middleware:
Middleware is software that connects two or more otherwise separate applications across the Internet. More specifically, the term refers to an evolving layer of services that resides between the network and more traditional applications for managing security, access and information exchange.
OID (Object_Identifier):
A unique number assigned to each LDAP schema attribute and object. While it is most common to perform LDAP lookups by object class or attribute name, it should also be possible to perform lookups by OID number.
Proxy Server (SIP Proxy):
A server that acts as both a client and a server to make requests on behalf of another user agent. The primary role of a proxy server is to ensure that a request generated by a UA is passed to another entity that is closer to the destination user.
Registrar:
a registrar is a server that accepts REGISTER requests and places the information it receives in those requests into the location service for the domain it handles.
Resource:
A non-human entity to which an endpoint is associated. For example, and endpoint may be associated with a conference room, classroom, office, or other physical or virtual location.
Schema:
Formal definition of data to be stored in an LDAP directory. The schema definition maintains consistency across implementations and establishes a means for interoperability. The schema defines the name, OID number, and date type for each attribute, and specifies whether attributes are required or optional. The schema also establishes how attributes are to be compared, and whether the attribute instance is expected to be unique or multi-valued.
SIP (Session Initiation Protocol):
As defined in IETF RFC 3261.
SIP URI:
A type of Uniform Resource Identifier that identifies a communication resource in SIP. A SIP URI usually contains a user name and a host name and is similar in format to an email address.
URI (Uniform Resource Identifier):
Syntax for the name and address of any object on the Internet. A URI consists of a scheme name (such as file, http, ftp, news, mailto, ldap) followed by a colon, followed by a path whose nature is determined by the scheme that precedes it (see RFC 1630).
URL (Uniform Resource Locator):
The World Wide Web address of a site on the Internet.
User Agent (UA):
a device that can function as both a user agent client and server in SIP.
ViDe (The Video Development Initiative):
Founded by representatives from universities and education networks, the Video Development Initiative (ViDe) promotes the deployment of digital video in research and higher education. Leveraging collective resources and expertise, ViDe advances digital video deployment through promotion and development of interoperable, standardized, and cost-effective technologies. See http://www.vide.net/.
ViDeNet:
ViDeNet is a project of ViDe that consists of a large scale, multi-institutional test bed of interconnected voice and video over IP networks in order to explore issues associated with global deployment of those technologies. See https://videnet.unc.edu/.
VidMid (The Video Middleware Working Group):
VidMid is a joint working group sponsored by Internet2 and ViDe. For more information, see http://middleware.internet2.edu/video.
White Pages:
An application that allows end users to look up the address of another user. This may be web-based or use some other user interface


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Next: B. Resources Up: VII. Appendices Previous: VII. Appendices

Video Middleware Cookbook
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