Glossary by Subject

This glossary is organized by subject:

• Telephone Industry Terminology
• Data Networking Terminology
• Internet Specific Data Terminology
• Internet Service Provider Terminology
• Internet Related Organizations and Associated Terminology
• Internet Business Model Terminology

Telephone Industry Terminology

IXC

Inter Exchange Carrier is the post divestiture (1984) generic name for long distance phone companies in the United States'. AT&T is the largest, controlling more than 60% of the market. MCI and Sprint are the second and third largest IXC's. AT&T MCI, and Sprint are also international in scope. Many more small IXC's exist.

RBOC

The 1984 divestiture of AT&T left local telephone service under the control of seven Regional Bell Operating Companies (RBOCs), also sometimes referred to as RHCs (Regional Holding Companies). Each RBOC in turn is composed of several Local Exchange Carriers (LECs). The RBOCs and LECs operate under the same regulatory structures.

LEC

The Local Exchange Carrier is the local telephone company for a given geographic area. In return for being given a monopoly over residential connections to the telephone network, the LEC, which is most likely one of the more than 20 former Bell pre-divestiture operating companies, has been subject to strict regulation of the services it offers and rates it may charge for those services. IXC's pay LECs a fee for termination of phone calls at the businesses and residences served by the LEC

POTS

Plain Old Telephone Service refers to basic voice service available in residences throughout the United States for between 10 and 20 dollars a month.

MFJ

Modified Final Judgement is the name given Judge Green's decision outlining the rules of the 1984 divestiture of AT&T. Under the MFJ the RBOCs have been banned from manufacturing. Although allowed several years ago to provide information services, the RBOCs are still banned by the MFJ from delivery of inter-LATA telephone or data service.

LATA

The Local Access Transport Area was created by the 1984 divestiture. It defines the geographic area over which the Local Exchange Carrier may provide toll calls. The area is often smaller than that covered by a long distance area code. Even though ten or twenty LATAs are normally to be found within the territory of a Local Exchange Carrier, the LEC may not provide calls that cross LATA boundaries. Such inter-lata traffic is the exclusive domain of the Inter Exchange Carrier (IXC).

LDIP

Long Distance Internet Provider is the term coined to describe the alliance forced by the MFJ on RBOCs or LECs that wish to provide Internet service. Such companies must partner with an existing Internet Service Provider (ISP) which provides inter LATA backbone service to the local phone company points of presence (POPs).

Profit Cap Regulation

Before 1995 this was the predominant form of regulation applied to local phone companies in exchange for the monopoly of local phone service granted them by each state. Regulators looked at the total profit earned and, if it exceeded a 12 to 14% range, might force the phone company to give back excess profits with a rate reduction. In this world, the larger a company's gross revenues, the larger would be the base on which profits could be figured. Incentives to adopt new technologies and pare down the number of employees were not great.

Price Cap Regulation

By the end of 1995 a large number of the LECs had moved to Price Cap regulation where they promised not to raise rates for some specified period of time. They were now perfectly fee to earn larger profits and able to do so by adopting advanced digital technologies that allowed them to perform the same or improved services with far fewer employees. All five of Ameritech's LEC's were under this form of regulation by the end of 1995 and Ameritech profits were pushing into the 30% range.

Local loop

The local loop is often referred to as the last mile or last several miles from the IXC's lines to the customer's phones or modems. Operation of the local loop is the responsibility of the Local Exchange Carrier.

PSTN

The Public Switched Telephone Network (PSTN) refers to the combined infrastructure of the regulated IXC (AT&T) and the RBOCs and their respective Local Exchange Carriers. Universal telephone service embodied as the goal of the 1934 Communications Act is provided by access to the PSTN.

VAN

A Value Added Network is data network devoted to a specific application. Whereas the PSTN has been regulated since 1934, VANs are considered to be exempt from regulation.

Data Networking Terminology

Internet

The Internet is a worldwide network of TCP/IP networks reaching into well over 100 nations. Electronic mail can be gatewayed via the internet into more than another additional 60 nations.

Protocol

A protocol is the language that a network or network application "speaks." It is to networking what a programming language is to programming.

Protocol Stack

The protocol stack usually refers to the seven layer OSI protocol stack where TCP/IP occupies layers three and four and protocols, like x.25. Frame Relay and SMDS, level 2.

OSI

Open Systems Interconnection is set of data network architectural standards developed by ISO - the International Organization for Standardization. In the late 1970s and early 1980s it was thought that OSI standards would dominate data networking. However with the successful de-facto rise of the commercial Internet in the 1990s TCP/IP and associated IETF standards have become dominant.

ISO

International Organization for Standardization is the developer of the OSI standards.

GOSIP

Government OSI Profiles - a US government backed subset of the OSI standards.

TCP/IP

Transport Control Protocol/Internet Protocol (TCP/IP) has become, in a very short period, a world wide public domain standard for connecting computers by all vendors over wide area networks. It operates at level 3 and 4 of the 7 level protocol stack. Hence it can be transported by frame relay or SMDS which functions at level 2 of the stack.

SMTP

Simple Mail Transfer Protocol is the electronic mail or message transport protocol for the TCP/IP world and hence the Internet.

x.25

X.25 was the transport protocol for the earliest commercial packet data networks starting in the late 1970s. Speeds peaked at 56,000 bits per second

x.400

x.400 is the electronic mail protocol for OSI.

x.500

X.500 is the directory naming service protocol for OSI.

SNA

Systems Network Architecture is IBM's proprietary networking protocol used to enable its mainframes to communicate with each other. Before the development of multi-protocol routers, IBM could and did demand $80,000 to $300,000 for front end processors used in linking the mainframes. During the early nineties, many large companies abandoned these processors in favor of multi-protocol routers costing about $5,000 to 15,000 each and capable of encapsulating SNA traffic in TCP/IP packets.

DECnet

DECnet is Digital Equipment's proprietary networking protocol. It is facing the same problems that SNA is with customers desiring to use TCP/IP for networking all their equipment rather than having to run different dedicated networks for each different proprietary protocol.

EDI

Electronic Data Interchange is a set of standards that allows corporations to order from and send invoices to other corporations, all electronically by means of data networks.

Frame Relay

Frame relay is a level 2 fast packet switching service that takes up where the old x.25 networks left off (56 KBS) and goes to 45 megabits per second. The IXCs now have their own frame relay offerings which they will can to bring to businesses by means of virtual private networks (VPNs) that bypass the LECs entirely

Gateway

A gateway is an intersection between two networks running different protocols. A gateway router strips incoming packets of the protocol of the incoming network and encapsulates them in "envelopes" of the protocol of the outgoing network.

SMDS

Switched Multi-megabit Digital Service is a fast packet switching service. It can carry the TCP/IP protocol. The LECs however are at a disadvantage in that they will require a partnership with an IXC to carry SMDS data across LATA boundaries. . SMDS provides packet switched bandwidth, on demand, in increments up to 45 megabits.

ISDN

Integrated Services Digital Network technology has been available for more than a decade. Lack of equipment standardization and expensive modification for local computers have slowed down its deployment. In the last two years it has become widely available but, because most LECs insist on a per minute rather than flat charge, its growth in usage has been small. It can give a user up to 56 kilobits of data bandwidth on a phone line that is also used for voice or up to 128,000 bits per second if the user forgoes voice use of the ISDN line.

Asynchronous Transfer Mode or ATM

ATM has come into widespread use during 1995. It is composed of 53 byte "cells" having 5 byte headers and 48 byte payloads. It is a high speed network protocol into which the phone companies have invested billions. Because of its short packet length, it is good for real time voice and video. Devotees of data networking scorn it because it wastes about 10 % of all it bandwidth in the overhead of the 5 byte cell headers.

Connection Oriented

The telephone network is connection oriented. This means that, for the duration of a telephone call, a small segment of the network is solely dedicated to the traffic of that one call. In other words no other calls can use that portion of the network.

Connectionless

Most computer data networks are connectionless. Data is encapsulated in "envelopes" called packets. The packets from a user's session may be sent by network routers along different routes to their destination as traffic conditions on the network change from moment to moment.

Packet switched

A Packet Switched Network is another term for connectionless data network. Data are inserted in packets which are the equivalent of software envelopes with addresses on them. These addresses can be read by routers, which by reference to internally contained routing tables can decide what network path to send the data on to ensure that it gets to its destination. The paths chosen by the routers can vary from moment to moment as each router gets updated information on the condition of other routers and circuits in the network.

Envelope

Envelope is another term for the data packet within which is held information desired by a network's end users.

Switched

Frame relay is a switched technology where packet headers need be only 2 bytes long. The first bytes of the switched network's protocol headers are composed of the permanent virtual circuit numbers necessary to direct data from one network node to another, plus a few control bits. Switching takes place at layer 2, routing at layer 3 of the seven layer stack. Switching is a much less CPU intensive activity than routing.

PVC

A Permanent Virtual Circuit is a connection oriented circuit that may be set up by software between any two nodes of a switched network.

Circuit

Circuit refers to a logical stream of data set up to flow through two or more network nodes. A single physical link between these nodes may have several virtual circuits flowing through it.

Routed

Routed is sometimes used to describe a network where data is routed at level 3 rather than switched at level 2. Parts of the Internet fabric maybe switched but some part of the fabric (network topology) between user and sender must always be routed.

Router

A Router is the device that serves as a "traffic cop" in a connectionless network such as the Internet. Routers are specialized computers that take incoming packets and compare their destination addresses to internal routing tables and, depending on network conditions, send the packets out to the appropriate receiving router. This process may be repeated many times until the packets reach their intended destination. The market for multi-protocol routers that include TCP/IP is one of the fastest growing within the telecommunications industry.

Cisco

Cisco is the largest maker of TCP/IP routers in the world. On major Internet backbones, large Cisco routers are almost invariably used.

VPN

A Virtual Private Network describes a network set up solely for the users of a single company. Such a network might have a gateway to the public Internet.

Leased line

A leased line is the telephone circuit transmission channel reserved for the use of customer from point "a" to point "b" through phone company physical lines and switches. The line may be of different bandwidths of data carrying capacity. In data networking a bit pipe is a colloquial name for a leased line.

Bit Pipe

A bit pipe is the name given to a telephone circuit used for transmission of packets in a data network. A "dumb" bit pipe is a telephone circuit that provides only physical data layer transmission and no higher level applications.

Bandwidth

Bandwidth is the amount of data, measured usually in bits per second, that can be send through a dedicated (leased) transmission circuit.

Bit

A bit is the primary unit of digital data. Written in binary language as a "1" or a "0".

Byte

A byte is composed of 8 bits.

ASCII character set

The ASCII character set refers to a uniform way of encoding bits into bytes, so that 128 differently coded bytes will each stand for a different letter, number, or punctuation mark in the Latin alphabet

56 Kilobit Leased Line

A 56 kilobit (56,000 bits per second) leased line is currently the smallest bandwidth transmission data circuit useful in Internet applications. It is also roughly the bandwidth needed for a voice phone call.

T-1 circuit

A T-1 circuit or leased line equals 1,544,000 bits per second or 24 56 kbs leased lines.

E-1 circuit

An E-1 Circuit (2,000,000 bits per second) is the European equivalent (roughly speaking) of a T-1.

T-3

A T-3 Circuit (45,000,000 bits per second) is the backbone speed of all major national Internet service providers in the US.

OC-3

An OC-3 circuit (155,000,000 bits per second) is the backbone speed that major ISPs will need to be upgrading to some time in 1996-97.

OC-12

An OC-12 circuit (622,000,000 per second) is bandwidth that was experimented with in the Gigabit Testbeds of the early 1990s.

OC-48

An OC-48 circuit (2,400,000,000 bits or 2.4 gigabits per-second) is the typical speed for many aggregated telephone voice circuits on inter city fiber optic lines.

SONET

SONET or Synchronous Optical Network is a Bellcore-developed, CCITT, international standard for high speed communication over fiber-optic networks. SONET functions as a carrier for ATM fixed length packets (53 bytes). TCP/IP can ride on top of SONET and ATM. All major IXCs are completing the installation of SONET and ATM on their backbones at speeds ranging up to OC48 (2.4 gigabits per second). OC-3, etc refers to the measurements for SONET based circuit speed.

Clear Channel Transmission

Clear Channel Transmission defines the amount of data occupied by a single user's network application. Al Gore's ideas about the need for an NREN not withstanding, clear channel gigabit TCP/IP transmission over a wide area network is not yet a proven technology let alone economically viable.

Aggregate Transmission

Aggregate Transmission refers to multiplexing or mixing together of the applications of thousands of users across a backbone. Such aggregate traffic can reach gigabit speeds with present technology and with acceptable dollar cost.

Twisted Pair

Twisted Pair refers to the standard two strands of copper that, with the appropriate insulation, have made up ordinary physical telephone lines for most of the 20th century. The data capacity of twisted pair is about 56 kilobits per second. However with special equipment and within a very few miles of phone company central offices speeds in excessive of several megabits per send data transmission have been achieved.

COAX

Coaxial cable is most often used in the home to attach to the back of a TV set to bring incoming cable TV signals to the set. The data capacity of coax can exceed 10 megabits per second.

Fiber

Fiber, or fiber optic, refers to cable containing often about two dozen threads of pure glass. Lasers attached to the end of such cable can send digital patterns of light pulses at hitherto unimaginable speeds. Compared to copper the carrying capacity of fiber for telecommunications signaling is almost unlimited.

Network topology

Network topology is a diagrammatic representation of the physical layout of the network. It includes a description of the hardware at the nodes and the structure adobted that will enable those links talk to each other.

Backbone

The backbone of a network is its means of linking its major nodes so that all its leaf nodes feed into backbone nodes with a high speed uninterrupted flow.

Node

A Node on a network is formed usually by the presence of a router and user access equipment - dial up, leased line or both. Often several leased lines are joined together at a network node. If a network topology is visualized as a road map, the leased lines are the roads and the nodes are the towns of which many roads travel. A POP is normally a network node, but a network node need not also be a POP.

Leaf

A leaf refers to a node found at the end of a network branch. There is only one connection between the leaf and the rest of the network.

Mesh

A mesh refers to one possible topology for a network backbone. For redundancy in the case of a circuit outage, a backbone is usually connected in a circular fashion so that if data can't get to the next node because of a line cut, it can get there by flowing in the opposite direction. A mesh architecture is formed by adding lines that go directly from one node to a second node three or four nodes around the "circle" from the first node.

Star

A star architecture would be formed by branches that would be connected to the network only at a central machine rather than connected to each other.

LAN

A Local Area Network (LAN) most often uses Ethernet as its protocol and generally extends through out a building or extends over several buildings over a radius of up to a couple of miles

MAN

A Metropolitan Area Network (MAN) refers to the high speed linking of hosts in buildings through out a city.

WAN

A Wide Area Network (WAN) refers to a network with a backbone that can link computers over distances of hundreds or even thousands of miles. T-3 or 45 megabits per-second has become a fairly typical WAN backbone capacity. Some WANs still have only T-1 backbones.

CAP

A Competitive Access Provider is a venture that may compete with LECs and IXCs in offering a set of tailored data or voice services. A CAP will often be more regional that nation wide - although MFS is somewhat of an exception to this rule.

MFS

Metropolitan Fiber Systems is a major CAP that began in the late 80s by offering high speed Metropolitan Area Network service between clumps of strategically located buildings in roughly 20 cities across the US. During 1993 MFS established powerful backbone of its own. It then became a purveyor of bandwidth on a national scale when it used TCP/IP to link its MAN services together into a national Wide Area Network (WAN).

Ethernet

Ethernet is a local area network transport protocol that first appeared in the 1970s. It offers a 10 megabit per second speed for data throughput. However, because hosts on an ethernet may transmit at random times, without any technology to deter data collision, the actual data throughput, depending on how heavily the ethernet is being used in a given situation, may be much closer to the three to six megabit per-second range. To complicate things still more100 megabit per second Ethernet technology has been recently introduced.

FDDI

FDDI or Fiber Distributed Data Interface is a 100 megabit per second transport protocol used over fiber in local area networks and based on token ring technology where data collisions are avoided by allowing hosts to transmit only when each host can grab the token or network equivalent of a green light for transmission.

Gigaswitch

A device used for high speed routing interchange at MAE -East to allow those with heaviest traffic to do their data exchanges before sending the remainder to the FDDI ring. At a NAP, when a FDDI ring becomes too crowded, the addition of a gigaswitch is generally necessary.

Internet Specific Data Terminology

IP number

An IP number (also referred to as Internet address number) in the Internet world is like a telephone number in the telephony world. IP numbers are the addresses of hosts or other intelligent devices on the Internet. The IP number of the desktop MAC/Internet host on which this glossary is written is 205.164.155.3

DNS

Domain Name Service offers a means of mapping a written name to an IP number. Thus one can write the easier to remember cookreport.com in place of the long IP number.

Top Level Domain

Com (commercial) is a top level domain. Gov, net, edu, org (Government, network, education, organization) are the other top level domains that uniquely identify Internet addresses worldwide. Some domain name addressing is done on a geographic basis. For example cnri.reston.va.us refers to the Corporation for National Research Initiatives, Reston, Virginia, United States.

InterNIC

InterNIC stands for Internet Network Information Center. The most important part of the InterNIC is run by Network Solutions INC which is responsible for the assignment of domain names and IP numbers. On September 14, 1995 withe concurrence of the National Science Foundation, NSI announced a $50 charge per year per domain name.

Class C Network

A class C Network in the IP addressing scheme of things can accommodate 256 hosts. A Class A network holds 16 million hosts and a Class B network 65,000 hosts. Under IPv4 only 128 Class A address can exist - of which only 64 have been used. Class C addresses were to small for many organizations, which opted for Class B instead. When available Class B address began to be seriously depleted in the early 90s, CIDR (Classless Inter Domain Routing) was created to enable groups of class c address to be used together.

ASN

Autonomous System Number (ASN) Autonomous System has meant one of two things: (a) a set of systems sharing a common routing protocol under common administration, or (b) the domain of a routing protocol. RFC 1009 probably has the earliest formal definition: 1.1.3. Autonomous Systems -- For technical, managerial, and sometimes political reasons, the gateways of the Internet system are grouped into collections called "autonomous systems" [35]. The gateways included in a single autonomous system (AS) are expected to: Be under the control of a single operations and maintenance (O&M) organization; and Employ common routing protocols among themselves, to maintain their routing data-bases dynamically. A number of different dynamic routing protocols have been developed (see Section 4.1); the particular choice of routing protocol within a single AS is generically called an interior gateway protocol or IGP. An IP datagram may have to traverse the gateways of two or more ASs to reach its destination, and the ASs must provide each other with topology information to allow such forwarding. The Exterior Gateway Protocol (EGP) is used for this purpose, between gateways of different autonomous systems. [Our thanks to Fred Baker of Cisco for this material.] In short an autonomous system number is the unique identifier for each autonomous system announced in the Routing Arbiter Database and in the route peering process in general.

CIDR

Classless Inter Domain Routing is described in a series of Internet RFC's (Requests for Comment). It was established in the 1992-93 time frame in order to allocate IP addresses more efficiently as the Internet began to grow dramatically. It is now the driving mechanism for the use of routing in the Internet as providers are straining to keep up with dramatic growth. Those wanting a detailed look at this extremely important subject should check the CIDR FAQ Sheet

Network Prefixes

Are used to aggregate class C networks. A network number with a prefix of 8 identifies a Class A, 16 a Class B, 24 a Class C, and 32 a single host. For example 207.8.160.0/19 would indicate the ability to serve 8,192 hosts beginning at address 207.8.160.0. As the prefix number grows smaller, the host ip numbers capable of being assigned from the CIDR block double with each decrease in prefix number. Thus 24, as a prefix, contains 256 host numbers, 23 holds 512, 22 holds 1024, 21 holds 2048, 20 holds 4096, 19 holds 8,192, and so on

Routing tables

Routing tables are lists of paths or routes to get to IP addresses that are held in router memory. A small router may have a table that takes an aggregated address (IE - this is for a host contained within the 207.8.160.0/19 hierarchy). Once sent to the gateway router, the routing table in that router will tell the router how to send it to its final destination via other routers lower in the hierarchy than the gateway router. Routing tables that must be carried by backbone routers have grown to exceed 30,000 routes. The most powerful backbone routers made by Cisco can carry about 60,000 routes. Since the beginning of 1995 CIDR rules have been enforced much more vigorously both because the number of routes has been increasing faster than the growth of CPU and memory capability, and because a memory buffer is needed to allow routers to dampen route flaps.

Provider Based Routing

CIDR implementation has come to mean that routing has become largely provider based. An ISP get its IP numbers from its upstream provider's CIDR bloc and not from the InterNIC where only the larger providers can go. This operational necessity is causing power to gravitate into the hands of the larger players.

Geographic Based Routing

Dave Crocker, a prominent IETF member, has argued that the CIDR working group should have done more to enable geographic based routing where IP numbers would have been assigned according to geography rather than given by larger providers to smaller ones. Doing what he asks would be quite difficult. It would however lessen the ongoing concentration of power in the hands of the large providers.

Multiple Homing

When a small ISP begins to prosper, it often takes a leased line to a second (usually national) backbone provider. This is referred to as multiple homing. It requires the ISP to announce a second set of routes that cannot be CIDR aggregated and hence obviates the neat routing hierarchy that provider based routing tries to achieve.

Route Portability

Until 1995 if a customer of an Internet service provider wanted to move to another provider, that customer could take its IP numbers with it to the new provider. This however would "punch a hole" in the new provider's CIDR bloc and cause routes for the new customer to have to be announced all the way out to the backbone level. Consequently many providers began to say that they would not announce IP numbers that new customers brought with them. This meant that a customer would have to renumber, if it were going to change providers. Renumbering for a large customer is usually so expensive as to be prohibitive.

Route Aggregation

By assigning prefixes to old class C addresses and by apportioning their address (IP number) space carefully as well as encouraging customers to renumber and return unused addresses, ISPs can aggregate the announcement of many routes into the announcement of only one route.

Renumbering

In the future, renumbering of a customer's IP addresses will normally be imposed on a customer if that customer changes providers. If that customer is very large, the expense in changing IP numbers on dozens or even hundreds of hosts is likely to be vast. Also if the customer's applications are time critical, it will likely take the customer off the air for an unacceptable amount of time. Finally, some software applications actually require the IP number of the workstation on which they reside to be entered into the license. Change of IP number therefore could require a software license change.

Route Flap

When a network link (leased line) goes down, there will be routers which temporarily are unreachable by packets from the rest of the network. The network begins to route around the missing link and router. It does this by propagating from the point of the fault the information that the router is unreachable. Software in adjacent routers begins to redirect data and the need for data redirection is propagated, from router to router, throughout the network. This propagation spreads throughout Internet backbones like ripples from a rock cast into the middle of a pond eventually after a period of time reaching all the routers in the network. If however during this propagation time another link goes down else where, the changed routing data from that also propagates ripple like across the Internet pond. When the two sets of ripples intersect stress on router memory and CPU's becomes great and if network conditions are changing quickly enough the router software will exceed the ability of the hardware to cope. The router flaps or losses its ability to route. Such a flap can spread like falling dominoes across an entire network and, at a NAP, can threaten to cascade into the network of another provider. One reason for keeping the number of routes advertised well below the number the router can theoretically carry is that spare memory and CPU capacity are needed to enable a router to cope with chaotic conditions and avoid flapping.

NAP

On April 30 1995 the architecture of the American Internet underwent a major change from a single dominant NSFnet backbone to a series of commercial provider owned and operated coast-to-coast national backbones. Under these conditions, the backbones had to have some means of exchanging data. Four NAPs or Network Access Points were designated to serve as data interchange points for backbone service providers. NSF's three primary NAPS are in San Francisco California bay area, Chicago, and Pennsauken NJ near Philadelphia. Metropolitan Fiber Systems MAE-East was designated by NSF as a secondary Washington DC NAP.

MAE-East

Metropolitan Area Ethernet - East was built by Metropolitan Fiber Systems (MFS) as an interchange for PSI, UUNET and SprintLink in late 1993. Today MAE-East has nearly two dozen major service providers as users and is by far the busiest Internet hub in the world with data flow reaching in late 1995 speeds of more than 160 megabits per second. MFS has opened MAE West in California and will soon open MAEs in Chicago, Texas, and Los Angeles.

Peering

Peering is the exchange of routing announcements between two service providers for the purpose of ensuring that traffic from the first can reach all customers of the second, and vis-versa. Peering takes place predominantly at NAPs and usually is offered without charge. One cannot however plug into a NAP and assume that those there will automatically grant peering.

Transit

Transit comes into play when a provider wants to reach customers of some third party that the first provider doesn't peer with. If the ISP that peers with the first provider also peers with the third party, then that provider is in a position to offer the first provider transit to the third party. Transit will normally cost a flat monthly charge.

Routing Arbiter

"Funded by the National Science Foundation, the Routing Arbiter project is charged with the task of providing routing coordination for the new NSFNET architecture. The project is a joint effort of Merit Network, Inc., the University of Southern California Information Sciences Institute, Cisco Systems, as a subcontractor to ISI, and the University of Michigan ROC, as a subcontractor to Merit." [Text from RA Web page at http://www.ra.net/routing.arbiter/RA/index.html.] If the routing Arbiter were working as intended, peering for many of those connected at the NAPs would be taking place via the route servers, relieving some of the stress on the current backbone routers. Because the Routing Arbiter Database was populated with material from the old NSFnet PRDB, some of the largest providers are refusing to use it.

Route Server

"The RA project's Route Servers -- Sun SPARC 20 workstations installed at each interconnection point-- eliminate the need for pair-wise peering among the attached ISPs. The Route Servers input routing information from each ISP router, create a "view" (a Routing Information Base) reflecting that ISP's policy requirements, and pass the processed routing information to each ISP's router. T he Route Servers thus reduce the number of peering sessions each ISP router needs to process from O(n) to O(1). The Route Servers do not forward traffic at the interconnection points; they handle only the flow of routing information. For a technical description of Route Server services, see The RA Route Server Service Overview." [Text from RA Web page.]

Routing Arbiter Database

The RADB is "Successor to the PRDB, and one of several routing databases collectively known as the Internet Routing Registry (IRR). Routing policy is expressed in the RADB using RIPE-181 syntax. Analysis code developed jointly by ISI and Merit processes customer data entered in the RADB and produces GateD and Cisco router configuration files for the Route Servers." [Text from RA Web page.]

NANOG

The North American Network Operators Group is composed of Internet Service Providers who have technical and operations oriented meetings three times a year and who maintain a useful mail list (nanog@merit.edu) for the discussion of Internetwork operations issues.

Internet Service Provider Terminology

ISP

An Internet Service Provider is an entity that provides commercial access to the Internet. These can range in size from someone operating dial up access with a 56 kilobit line and several dozens of customers to providers with multiple pops in multiple cites and substantial backbones and thousands or even tens of thousands of customers. The best collection we have seen of information on specific Internet service providers is found on the web at www.thelist.com.

NSP

A National Service Provider is an Internet service provider of national scope - one that would provide service in many different states and be connected to NAPs on each coast. There is no clear dividing line between a small NSP and large ISP.

Regional Network

A Regional Network usually refers to one of the academic and research oriented nets started in the late 1980s with help from the NSF. There were about 30 of these and virtually all are still functioning. A Regional Network may now also refer to a large ISP that is not yet really national in its scope.

R&E

Research and Education (R&E) refers to the clientele served by the NSF's networking efforts. The old NSFnet acceptable use policy (AUP) divided traffic into R&E compliant and commercial or R&E non compliant.

POP

A Point of Presence (POP) refers to a node of an Internet service provider (ISP) containing a DSU-CSU, terminal server and router and sometimes one or more hosts, but no network information center (NIC) or network operations center (NOC).

DSU-CSU

A DSU-CSU is the digital equivalent of a modem. It is used for connecting a leased line, usually to a router.

NOC

A Network Operations Center (NOC) is the nerve center for an ISP where a seven day a week 24 hour a day staff is on duty to monitor equipment and correct problems. Equipment at POPs with no humans on duty can often be fixed remotely by some one at a NOC.

NIC

A Network Information Center (NIC) covers services like domain name service (DNS) and customer assistance. NIC functions are sometimes merged with NOC functions - that is to say NOC staffers also handle NIC kinds of duties.

SLIP

Serial Line Internet Protocol (SLIP) is software that an ISP customer can use with a modem to dial up a terminal server and make an IP connection to the network. The ISP must have a unique IP number to assign to each slip customer. Netscape and other web browsers will work only with SLIP or PPP connections to the Internet.

PPP

Point to Point Protocol is a variation of SLIP used for essential the same purpose.

Terminal Server

A terminal server is a device into which modems located at a POP are plugged. The terminal server attached to the router which in turn is attached to the DSU-CSU.

Modem

A modem takes digital data from a computer and converts it into electrical pulses that can be sent over a telephone line where they can be received by a second modem and converted back into digital data. State of the art modems currently can send 28,000 bits of data over an ordinary telephone line. It is unlikely that modem technology will result in a significant increase in this speed.

Server

A server is normally thought of as a powerful computer that can answer queries from clients. The client-server function is usually some variation of a database function. That is to say the client asks the server to send information to the client. The client software, usually residing on the machine of each end user, is tailored to work directly with the server software.

Web

The World Wide Web is software that enables digital data that has been "marked up" with HTML to be put into hypertext databases where data in one database can be linked to data in another so that by clicking on the marked text the user is automatically and transparently logged into the new web server where the linked data is found. In 1994 -1995 the World Wide Web became the driving force behind Internet growth.

Web Browser

A Web Browser is client server software used to query world wide web sites. Mosaic was the first popular browser. Netscape however has come to dominate the market with about an 80% share.

Hypertext links

Hypertext links make it possible to connect or link a passage in a document to another document on the same web site or a document on web site on a machine residing on the opposite side of the world. One click on the link takes the user automatically to the document to which the object that has been clicked on is linked.

HTML

Hypertext Mark Up Language (HTML) is the code that must be applied to data to produce desired displays of pages on the world wide web.

Usenet news

Usenet news is composed of nearly 15,000 subject matter discussion groups where data is composed of ascii text and binary files. More than a gigabyte (billion bytes) of new data is generated every day. Access to usenet news is an expected part of Internet service.

File Transfer Protocol (FTP)

FTP is the application program used to send or receive large ascii or binary files over the Internet. More and more however such files are being sent and received by means of access to web sites.

Gopher

Gopher was the first software developed to make the use of FTP easier for the non technical user. Like FTP Gopher is being subsumed by the world wide web.

Telnet

Telnet is the application program used to reach the login prompt of any computer not behind a firewall on the Internet. The syntax is command followed by domain name as in: telnet tmn.com.

Host

In general terms a host is a single or multi user computer that can send and receive data over the Internet.

IPv4

IPv4 is the current version of the IP protocol in use today. Several aspects of the protocol today such as numbers of addresses available are not scaling very well in the current exponential growth of the Internet.

IPv6

IPv6 (also referred to as IP(ng) or IP next generation) is a new version of IP designed for the new commercial Internet. Look for test implementations in 1996 and full scale implementation in 1997-98.

Internet Related Organizations and Associated Terminology

IAB

The Internet Architecture Board (Formerly Internet Activities Board) is the coordinating and oversight body for the actions of the Internet Engineering Task Force (IETF) and the Internet Research Task Force (IRTF). In June of 1992 the IAB, IETF, and IRTF were given a new legal home under the aegis of the Internet Society.

Internet Research Task Force (IRTF)

The IRTF develops and carries out Internetworking research experiments.

IETF

The Internet Engineering Task Force is the standards promulgating body of the Internet. It has a very successful record of developing standards such as the Simple Network Management Protocol that are quite quickly adopted by major segments of the network industry.

IESG

The Internet Engineering Steering Group (IESG) is the governing body for the IETF.

Internet Secretariat

The Internet Secretariat provides logistical and administrative assistance to the various Internet governing bodies (IAB, IETF, IRTF, IESG, etc). Agencies belonging to the FNC have given enough funding to the Corporation for National Research Initiatives (CNRI) to allow it to house and pay for the expenses of the Secretariat which includes staff positions for Executive Director of the IETF and a Secretary for the IESG.

Requests for Comment

Requests for Comment (RFCs) are individually numbered official Internet documents that give information about Internet standards specifications, organizational notices; and individual points of view. Information on how to access RFC files may be found in most standard published technical guides to the Internet.

Internet Assigned Numbers Authority (IANA)

IANA has policy authority for the creation and use of domain names and IP numbers or Internet addresses. The InterNIC implements policy that IANA approves.

FARnet

The Federation of American Research Networks is an association in which the mid-level networks of the NSFnet, two commercial providers (ANS, and PSI), and some of the telephone companies meet usually four times a year to discuss common interests. With the complete commercialization of the Internet FARnet has declined considerably in importance.

FCCSET

The FNC reports to the Federal Coordinating Committee on Science Engineering and Technology. FCCSET in turn reports to the executive branch's OSTP (Office of Science and Technology Policy). FCCSET is required by the High Performance Computing and Communications legislation to provide a report to the Congress by December 1992 on the planned implementation of NREN.

NREN

The National Research and Education Network (NREN) was Al Gore's dreamed of government funded, gigabit-per-second hi-tech backbone for the American Internet. It will never be built.

EDUCOM

A national lobbying organization composed primarily of major academic computing centers.

ISOC

The Internet Society was launched in 1992. It had been put together even earlier by a group of about a dozen long time and well respected Internet professionals. In 1992 CNRI, Educom, and the European Research and Education Network (Ripe - since renamed Terena) became founding members of ISOC with the basic privilege that ISOC by-laws could not be changed without their approval. This has lead to some discord with in ISOC where the group that wishes to keep it primarily a society for individual Internet engineering professionals is dominant over a minority that wishes to encourage industry wide support.

CIX

Commercial Internet Exchange was initially the agreement between PSI, Uunet, CERFnet, US Sprint (Sprintlink), that lets the traffic of any member of one network flow without restriction over the networks of the other members. Any TCP/IP service provider may join the CIX for a cost of $7,500 and connect to and send traffic to other CIX member networks. Until a major dispute over whether it would filter the routes of downstream customers of member networks who were not also CIX members at the end of 1994, the CIX represented the vast majority of the commercial Internet. With the opening of the NAPs in 1995 the CIX's influence has greatly diminished.

FNC

The Federal Networking Council is the coordinating body for the networking interests of the so-called federal mission agencies. It is run primarily by representatives from DARPA, DOE, NAS, and NSF. Several other Federal Agencies are represented, but without significant power because relatively little money is authorized for them.

CNRI

The Corporation for National Research Initiatives (CNRI) was founded in the 1980s by Robert Kahn (co-author with Vint Cerf of the TCP/IP protocol) as a civilian Defense Advanced Research Projects Agency (DARPA). CNRI currently houses the IETF secretariat.

MILnet

Military Network is the production, non-classified TCP/IP network of the Defense Department.

Esnet

Energy Sciences Network is the TCP/IP network of the Department of Energy.

NSInet

NASA Sciences Internet is the TCP/IP network of the National Aeronautics and Space Administration.

NSFnet

The National Science Foundation Network was expected to become the core network of the National Research and Education Network or NREN. The NSFnet was composed of the backbone of 19 sites or nodes and 32 mid-level or regional networks that connected more than 1000 institutions to the backbone. NSFnet, until its turn off on April 30 1995, was the major backbone of the Internet. The NSFnet regional networks now are connected to the three primary NAPs by either MCI or Sprint.

FIX West and FIX East

Federal Internet Exchange West is a link at NASA Ames (Moffit Field) California and Federal Internet Exchange East College Park Maryland between the backbones of MILnet, ESnet, and NSInet with the NSFnet. With the dissolution of the NSFnet, the FIXes now connect to the Internet at MAE East and MAE West.

MERIT

Michigan Education & Research Information Triad (MERIT ) was the holder of the 1987 cooperative agreement with the National Science Foundation for the provision of the T-1 and then the T-3 NSFnet backbone. The five year agreement lasted 7.5 years and ended on April 30 1995. MERIT maintained a subcontracting relationship with IBM and MCI as joint study partners and since September of 1990 with Advanced Network and Services. MERIT now is one of two awardees for the Routing Arbiter Cooperative Agreement.

ANS

Advanced Network & Services is the 501(c) (3), non profit, IBM and MCI spin off corporation launched on September 17, 1990. Launched with a $5 million dollar contribution from each of its corporate parents, it found itself in a position to inherit control of a privatized National Research and Education Network. From 1990 ANS received between $10 and 15 million per year from the National Science Foundation for providing the T-3 backbone to which it was also free to sell commercial access. The ANS/NSFnet backbone connected 32 mid-level networks which in turn connected over 1,000 institutions.

Internet Business Model Terminology

Settlements

Settlements comes from the old telephony terminology where if one party makes a disproportionate use of another's network, one has to pay that network monetary compensation. Settlements have been talked about for Internet service providers. The assumption has been that they might be based on numbers of gigabytes sent and received. This would likely lead to some form of measured usage charging - something that is anathema to Internet culture - where charges have always been based on the size the bit pipe leased by the provider. We believe that it is unlikely that settlements can be imposed in the absence of unanimity among the major service providers, for those who imposed settlements would likely loose customers to those who did not. Charging for route announcements, however, is really another form of settlements. As there is some necessity to keep the number of routes announced from growing as rapidly as it has been, there is a distinct possibility that settlements via route announcements might be imposed.

Guaranteed Service Standards

The lack of guaranteed service is a complaint of those who want to impose settlements - something that would intensify power in the hands of the large providers and be likely to drive many small providers out of business. Because of the disparity of resources between large and small providers, there is a considerable divergence in service quality. Yet the net works as well as it does because of cooperation between entities which also must compete with each other. The tension most strongly felt now in the newly commercial Internet is where the line between competition and cooperation should be drawn.

Metered Service

Metered Service is a short hand term for charging for measured use by amount of data sent and received. A point of confusion arises because some people also use metered service to refer to charging dial up customers a fee for the amount of time they remain connected to the network.

Route Announcements

All networks have to announce routes to their upstream providers in order to be reachable from the rest of the Internet. Constraints in the ability of routers to handle the explosive growth in numbers of routes announced have led to pressures to reduce these numbers. Discussion is beginning about imposing charges for each route announced as a means of further discouraging large numbers of route announcements. Imposing such charges would be tantamount to settlements in a different form. Depending on how it were done, it could likely be a significant force in driving smaller providers out of business.