Glossary of Terms
Source for definitions - http://www.whatis.com
ABILENE: Abilene is an Internet 2 high-speed advances backbone research network that connects regional network aggregation points to support the work of over 180 Internet2 universities in developing advanced Internet applications.
ANJ: Access New Jersey. An ATM network funded and operated by Verizon with a goal to provide connectivity to every K-12 school in NJ. ANJ operates a video portal using this statewide network (Scheduled to be phased out 9/30/2011).
ARIN: The American Registry of Internet Numbers (ARIN) is the organization in the U.S. that manages IP address numbers for the U.S. and assigned territories. Because Internet addresses must be unique and because address space on the Internet is limited, there is a need for some organization to control and allocate address number blocks. IP number management was formerly a responsibility of the Internet Assigned Numbers Authority (IANA), which contracted with Network Solutions Inc. for the actual services. In December 1997, IANA turned this responsibility over to ARIN, which, along with Reseaux IP Europeens (RIPE) and Asia Pacific Network Information Center (APNIC), now manages the world's Internet address assignment and allocation. Domain name management is still the separate responsibility of Network Solutions and a number of other registrars accredited by the Internet Corporation for Assigned Names and Numbers (ICANN).
AS: Autonomous System. On the Internet, an autonomous system (AS) is the unit of router policy, either a single network or a group of network that is controlled by a common network administrator (or group of administrators) on behalf of a single administrative entity (such as a university, a business enterprise, or a business division). An autonomous system is also sometimes referred to as a routing domain. An autonomous system is assigned a globally unique number, sometimes called an Autonomous System Number (ASN).
Networks within an autonomous system communicate routing information to each other using an Interior Gateway Protocol (Interior Gateway Protocol). An autonomous system shares routing information with other autonomous systems using the Border Gateway Protocol (Border Gateway Protocol). Previously, the Exterior Gateway Protocol (Exterior Gateway Protocol) was used. The Internet's protocol guideline for autonomous systems, after offering a definition similar to the one above, provides a more technical definition as follows:
An AS is a connected group of one or more Internet Protocol prefixes run by one or more network operators which has a SINGLE and CLEARLY DEFINED routing policy.
ATM: ATM (asynchronous transfer mode) is a dedicated-connection switching technology that organizes digital data into 53-byte cell units and transmits them over a physical medium using digital signal technology. Individually, a cell is processed asynchronously relative to other related cells and is queued before being multiplexed over the transmission path.
Because ATM is designed to be easily implemented by hardware (rather than software), faster processing and switch speeds are possible. The prespecified bit rates are either 155.520 Mbps or 622.080 Mbps. Speeds on ATM networks can reach 10 Gbps. Along with Synchronous Optical Network (SONET) and several other technologies, ATM is a key component of broadband ISDN (BISDN).
BGP4: BGP (Border Gateway Protocol) is a protocol for exchanging routing information between gateway hosts (each with its own router) in a network of autonomous systems. BGP is often the protocol used between gateway hosts on the Internet. The routing table contains a list of known routers, the addresses they can reach, and a cost metric associated with the path to each router so that the best available route is chosen.
Hosts using BGP communicate using the Transmission Control Protocol (TCP) and send updated router table information only when one host has detected a change. Only the affected part of the routing table is sent. BGP-4, the latest version, lets adminstrators configure cost metrics based on policy statements. (BGP-4 is sometimes called BGP4, without the hyphen.)
BGP communicates with autonomous (local) networks using Internal BGP (IBGP) since it doesn't work well with IGP. The routers inside the autonomous network thus maintain two routing tables: one for the interior gateway protocol and one for IBGP.
BGP-4 makes it easy to use Classless Inter-Domain Routing (CIDR), which is a way to have more addresses within the network than with the current IP address assignment scheme.
BGP is a more recent protocol than the Exterior Gateway Protocol (EGP).
DNS: The domain name system (DNS) is the way that Internet domain names are located and translated into Internet Protocol addresses. A domain name is a meaningful and easy-to-remember "handle" for an Internet address.
Because maintaining a central list of domain name/IP address correspondences would be impractical, the lists of domain names and IP addresses are distributed throughout the Internet in a hierarchy of authority. There is probably a DNS server within close geographic proximity to your access provider that maps the domain names in your Internet requests or forwards them to other servers in the Internet.
DS1 1.544 Megs
DS3 Fractional 10 Megs
DS3 20 Megs
DS3 45 Megs
OC3 155 Megs
GATEKEEPER: The gatekeeper is the most powerful management tool available for an H.323 multimedia network. As the brain of the H.323 network, this application performs essential control, administrative, and managerial functions required to maintain the integrity of networks in both enterprise and carrier environments.
This component of the network provides bandwidth managements and quality of service for H.323
IGP: An IGP Interior Gateway Protocol) is a protocol for exchanging routing information between gateway (hosts with routers) within an autonomous network (for example, a system of corporate local area networks). The routing information can then be used by the Internet Protocol or other network protocols to specify how to route transmissions.
There are two commonly used IGPs: the Routing Information Protocol(RIP) and
the Open Shortest Path First (OSPF)protocol.
INTERNET: The Internet is a worldwide system of computer networks - a network of networks in which users at any one computer can, if they have permission, get information from any other computer (and sometimes talk directly to users at other computers).
INTERNET2: Internet2 is a consortium being led by over 180 universities working in partnership with industry and government to develop and deploy advanced network applications and technologies, accelerating the creation of tomorrow's Internet. Internet2 is recreating the partnership among academia, industry and government that fostered today’s Internet in its infancy. The primary goals of Internet2 are to:
1. Create a leading edge network capability for the national research community
2. Enable revolutionary Internet applications
3. Ensure the rapid transfer of new network services and applications to the broader Internet community.
ISDN: ISDN (Integrated Services Digital Network) is a set of CCITT/ITU standards for digital transmission over ordinary telephone copper wire as well as over other media. Home and business users who install an ISDN adapter (in place of a modem) can see highly-graphic Web pages arriving very quickly (up to 128 Kbps). ISDN requires adapters at both ends of the transmission so your access provider also needs an ISDN adapter.
There are two levels of service: the Basic Rate Interface (BRI), intended for the home and small enterprise, and the Primary Rate Interface (PRI), for larger users. Both rates include a number of B-channels and a D-channels. Each B-channel carries data, voice, and other services. Each D-channel carries control and signaling information.
The Basic Rate Interface consists of two 64 Kbps B-channels and one 16 Kbps D- channel. Thus, a Basic Rate user can have up to 128 Kbps service. The Primary Rate consists of 23 B-channels and one 64 Kpbs D-channel in the United States or 30 B-channels and 1 D-channel in Europe. Integrated Services Digital Network in concept is the integration of both analog or voice data together with digital data over the same network.
LATA: Local Access and Transport Area is a term in the U.S. for a geographic area covered by one or more local telephone companies, which are legally referred to as local exchange carriers (LECs). A connection between two local exchanges within the LATA is referred to as intraLATA. A connection between a carrier in one LATA to a carrier in another LATA is referred to as interLATA. InterLATA is long-distance service. The current rules for permitting a company to provide intraLATA or interLATA service (or both) are based on the Telecommunications Act of 1996.
MCU: Multipoint Control Unit. It is a unit that supports video conferencing with multiple users at the same time. It also acts as a gateway between the H.323 and the ISDN voice conference. The NJEDge.Net’s MCU will also provide a video portal to the Access New Jersey network.
MEMBER-to-MEMBER: Communications traffic over the NJEDge.Net network that goes from one member to another via the private virtual circuits of NJEDge.Net.
MPLS: stands for "Multiprotocol Label Switching". In an MPLS network, incoming packets are assigned a "label" by a "label edge router (LER)". Packets are forwarded along a "label switch path (LSP)" where each "label switch router (LSR)" makes forwarding decisions based solely on the contents of the label. At each hop, the LSR strips off the existing label and applies a new label which tells the next hop how to forward the packet.
Label Switch Paths (LSPs) are established by network operators for a variety of purposes, such as to guarantee a certain level of performance, to route around network congestion, or to create IP tunnels for network-based virtual private networks. In many ways, LSPs are no different than circuit-switched paths in ATM or Frame Relay networks, except that they are not dependent on a particular Layer 2 technology.
An LSP can be established that crosses multiple Layer 2 transports such as ATM, Frame Relay or Ethernet. Thus, one of the true promises of MPLS is the ability to create end-to-end circuits, with specific performance characteristics, across any type of transport medium, eliminating the need for overlay networks or Layer 2 only control mechanisms.
MPEG: MPEG (pronounced EHM-pehg), the Moving Picture Experts Group, develops standards for digital video and digital audio compression. It operates under the auspices of the International Organization for Standardization (ISO). The MPEG standards are an evolving series, each designed for a different purpose.
To use MPEG video files, you need a personal computer with sufficient processor speed, internal memory, and hard disk space to handle and play the typically large MPEG file (which has a file name suffix of .mpg). You also need an MPEG viewer or client software that plays MPEG files. (Note that .mp3 file suffixes indicate MP3 (MPEG-1 audio layer-3) files, not MPEG-3 standard files.) You can download shareware or commercial MPEG players from a number of sites on the Web.
MULTI-HOMING: Having multiple points of connection to the Internet. Multiple connections, known as multi-homing, reduces the chance of loss of Internet access if one of the connections fails. In addition to maintaining a reliable connection, multi-homing allows an organization to perform load-balancing by managing the traffic flow connecting to the Internet through any single connection. Distributing the load through multiple connections optimizes performance.Multi-homed networks are often connected to several different ISPs (Internet Service Providers). Networks that are multi-homed to the Internet require a public Autonomous System Number (ASN) from ARIN. Routers use BGP (Border Gateway Protocol), a part of the TCP/IP protocol suite, to route between networks using different protocols. In a multi-homed network, the router utilizes IBGP (Internal Border Gateway Protocol) on the stub domain side, and EBGP (External Border Gateway Protocol) to communicate with other routers.
NAT: NAT (Network Address Translation) is the translation of an Internet Protocol address (IP address) used within one network to a different IP address known within another network. One network is designated the inside network and the other is the outside. Typically, a company maps its local inside network addresses to one or more global outside IP addresses and unmaps the global IP addresses on incoming packets back into local IP addresses. This helps ensure security since each outgoing or incoming request must go through a translation process that also offers the opportunity to qualify or authenticate the request or match it to a previous request. NAT also conserves on the number of global IP addresses that a company needs and it lets the company use a single IP address in its communication with the world.
NAT is included as part of a router and is often part of a corporate firewall. Network administrators create a NAT table that does the global-to-local and local-to-global IP address mapping. NAT can also be used in conjunction with policy routing. NAT can be statically defined or it can be set up to dynamically translate from and to a pool of IP addresses. Cisco's version of NAT lets an administrator create tables that map:
A local IP address to one global IP address statically
A local IP address to any of a rotating pool of global IP addresses that a company may have
A local IP address plus a particular TCP port to a global IP address or one in a pool of them
A global IP address to any of a pool of local IP addresses on a round-robin basis
NAT is described in general terms in RFC 1631. which discusses NAT's relationship to Classless Interdomain Routing (CIDR) as a way to reduce the IP address depletion problem. NAT reduces the need for a large amount of publicly known IP addresses by creating a separation between publicly known and privately known IP addresses. CIDR aggregates publicly known IP addresses into blocks so that fewer IP addresses are wasted. In the end, both extend the use of IPv4 IP addresses for a few more years before IPv6 is generally supported.
PAT: Port Address Translation. A function provided by some routers which allows hosts on a LAN to communicate with the rest of a network (such as the Internet) without revealing their own private IP address. All outbound packets have their IP address translated to the routers external IP address. Replies come back to the router which then translates them back into the private IP address of the original host for final delivery.
PVC: A permanent virtual circuit (PVC) is a software-defined logical connection in a network such as a frame relay network. A feature of frame relay that makes it a highly flexible network technology is that users (companies or clients of network providers) can define logical connections and required bandwidth between end points and let the frame relay network technology worry about how the physical network is used to achieve the defined connections and manage the traffic. In frame relay, the end points and a stated bandwidth called a Committed Information Rate (CIR) constitute a PVC, which is defined to the frame relay network devices. The bandwidth may not exceed the possible physical bandwidth. Typically, multiple PVCs share the same physical paths at the same time. To manage the variation in bandwidth requirements expressed in the CIRs, the frame relay devices use a technique called statistical multiplexing.
QoS: On the Internet and in other networks, QoS (Quality of Service) is the idea that transmission rates, error rates, and other characteristics can be measured, improved, and, to some extent, guaranteed in advance. QoS is of particular concern for the continuous transmission of high-bandwidth video and multimedia information. Transmitting this kind of content dependably is difficult in public networks using ordinary "best effort" protocols.
RFC: A Request for Comments (RFC) is a formal document from the Internet Engineering Task Force (IETF) that is the result of committee drafting and subsequent review by interested parties. Some RFCs are informational in nature. Of those that are intended to become Internet standards, the final version of the RFC becomes the standard and no further comments or changes are permitted. Change can occur, however, through subsequent RFCs that supersede or elaborate on all or parts of previous RFCs
SVC: In a network, a switched virtual circuit (SVC) is a temporary virtual circuit that is established and maintained only for the duration of a data transfer session. A permanent virtual circuit (PVC) is a continuously dedicated virtual circuit. A virtual circuit is one that appears to be a discrete, physical circuit available only to the user but that is actually a shared pool of circuit resources used to support multiple users as they require the connections. Switched virtual circuits are part of an X.25 network. Conceptually, they can also be implemented as part of a frame relay network.
THE QUILT: Over 15 non-profit research and education network organizations, which provide network resources for thousands of U.S research and education institutions, have pooled resources to form the Quilt. The University Corporation for Advanced Internet Development (UCAID), a Washington, DC- based organization that promotes networking for education and research, is providing organizational support for The Quilt.
The Quilt’s initial objectives include: to provide a forum for best practices related to implementation of fiber-optic network infrastructure, to support improved end-to-end network performance through uniform standards to measure and assess performance, and to aggregate the Internet services buying power of The Quilt’s participants.
UBR: Unspecified Bit Rate A form of ATM transmission in which an information stream is supported on whatever bandwidth is available after other connection types have been satisfied. No congestion control is provided. UBR is commonly used to support information streams originating in LAN switches with ATM uplinks.
VBNS: The vBNS (very high-speed Backbone Network Service) is a network that interconnects a number of supercomputer centers in the United States and is reserved for science applications requiring the massive computing that supercomputers can provide. Scientists at the supercomputer centers and other locations apply for time on the supercomputers and use of the vBNS by describing their projects to a committee that apportions computer time and vBNS resources. The vBNS and the supercomputer centers were initiated and are maintained by the National Science Foundation (NSF). The vBNS has recently become part of the infrastructure of Internet2. A new NFS-funded initiative is developing an advanced network infrastructure referred to as the National Technology Grid.