Network Working Group G. Malkin Request for Comments: 1325 Xylogics FYI: 4 A. Marine Obsoletes: RFC 1206 SRI May 1992
This memo provides information for the Internet community. It does not specify an Internet standard. Distribution of this memo is unlimited.
This FYI RFC is one of two FYI's called, "Questions and Answers" (Q/A), produced by the User Services Working Group of the Internet Engineering Task Force (IETF). The goal is to document the most commonly asked questions and answers in the Internet.
In addition to updating information contained in the previous version of this FYI RFC, the following new questions have been added:
Questions About the Internet:
How do I get a list of all the hosts on the Internet?
Questions About Internet Documentation:
What is the RFC-INFO service?
What is an FYI?
What is an STD?
What is the Internet Monthly Report?
Questions About Internet Organizations:
What is the Internet Society?
Questions About Internet Services:
What is "archie"?
How do I Connect to archie?
Mailing Lists and Sending Mail
How Do I Send Mail to Other Networks?
3. Questions About the Internet
4. Questions About TCP/IP
5. Questions About the Domain Name System
6. Questions About Internet Documentation
7. Questions about Internet Organizations and Contacts
8. Questions About Services
9. Mailing Lists and Sending Mail
10. Miscellaneous "Internet lore" questions
11. Suggested Reading
13. Condensed Glossary
14. Security Considerations
15. Authors' Addresses
New users joining the Internet community have the same questions as did everyone else who has ever joined. Our quest is to provide the Internet community with up to date, basic Internet knowledge and experience, while moving the redundancies away from the electronic mailing lists so that the lists' subscribers do not have to read the same queries and answers over and over again.
Future updates of this memo will be produced as User Services members become aware of additional questions that should be included, and of deficiencies or inaccuracies that should be amended in this document. Although the RFC number of this document will change with each update, it will always have the designation of FYI 4. An additional FYI Q/A, FYI 7, is published that deals with intermediate and advanced Q/A topics .
The Q/A mailing lists are maintained by Gary Malkin at Xylogics.COM. They are used by a subgroup of the User Services Working Group to discuss the Q/A FYIs. They include:
firstname.lastname@example.org This is a discussion mailing list. Its primary use is for pre-release review of the Q/A FYIs. It is not necessary to be on this list to get the FYI documents.
email@example.com This is how you join and leave the quail mailing list.
firstname.lastname@example.org This is a write-only list which serves as a
repository for candidate questions and answers. It is not necessary to be on the quail mailing list to forward to the quail-box. Please note that this is not a place to ask questions to which you don't know the answers.
The following people deserve thanks for their help and contributions to this FYI Q/A: Corinne Carroll (BBN), Vint Cerf (CNRI), Peter Deutsch (McGill), John Klensin (MIT), Doug Mildram (Xylogics), Tracy LaQuey Parker (UTexas), Craig Partridge (BBN), Jon Postel (ISI), Matt Power (MIT), Joyce K. Reynolds (ISI), Karen Roubicek (Faxon), Patricia Smith (Merit), Gene Spafford (Purdue), and Carol Ward (SRI).
What is the Internet?
The Internet is a large collection of networks (all of which run the TCP/IP protocols) that are tied together so that users of any of the networks can use the network services provided by TCP/IP to reach users on any of the other networks. The Internet started with the ARPANET, but now includes such networks as NSFNET, NYSERnet, and thousands of others. There are other major wide area networks, such as BITNET and DECnet networks, that are not based on the TCP/IP protocols and are thus not part of the Internet. However, it is possible to communicate between them and the Internet via electronic mail because of mail gateways that act as "translators" between the different network protocols involved.
Note: You will often see "internet" with a small "i". This could refer to any network built based on TCP/IP, or might refer to networks using other protocol families that are composites built of smaller networks.
I just got on the Internet. What can I do now?
You now have access to all the resources you are authorized to use on your own Internet host, on any other Internet host on which you have an account, and on any other Internet host that offers publicly accessible information. The Internet gives you the ability to move information between these hosts via file transfers. Once you are logged into one host, you can use the Internet to open a connection to another, login, and use its services interactively (this is known as remote login or "TELNETing". In addition, you can send electronic mail to users
at any Internet site and to users on many non-Internet sites that are accessible via electronic mail.
There are various other services you can use. For example, some hosts provide access to specialized databases or to archives of information. The Internet Resource Guide provides information regarding some of these sites. The Internet Resource Guide lists facilities on the Internet that are available to users. Such facilities include supercomputer centers, library catalogs and specialized data collections. The guide is published by the NSF Network Service Center (NNSC) and is continuously being updated. The Resource Guide is distributed free via e-mail (send a note to email@example.com to join the e-mail distribution) and via anonymous FTP (in nnsc.nsf.net:resource- guide/*). Hardcopy is available at a nominal fee (to cover reproduction costs) from the NNSC. Call the NNSC at 617-873-3400 for more information.
How do I find out if a site has a computer on the Internet?
Three good sources to consult are "!%@:: A Directory of Electronic Mail Addressing and Networks" by Donnalyn Frey and Rick Adams; "The User's Directory of Computer Networks", by Tracy LaQuey; and "The Matrix: Computer Networks and Conferencing Systems Worldwide", by John Quarterman.
In addition, it is possible to find some information about Internet sites in the WHOIS database maintained at the DDN NIC at Network Solutions, Inc.. The DDN NIC (Defense Data Network, Network Information Center) provides an information retrieval interface to the database that is also called WHOIS. To use this interface, TELNET to NIC.DDN.MIL and type "whois" (carriage return). No login is necessary. Type "help" at the whois prompt for more information on using the facility. WHOIS will show many sites, but may not show every site registered with the DDN NIC (simply for reasons having to do with how the program is set up to search the database).
How do I get a list of all the hosts on the Internet?
You really don't want that. The list includes almost 727,000 hosts. Almost all of them require that you have access permission to actually use them. However, there are many machines which serve special functions and are available to the public. There is not yet a definitive list, but below are some available machines. They are available via telnet.
A geographic information server which provides latitude, longitude and other statistics about a city.
telnet martini.eecs.umich.edu 3000
The Library of Congress maintains an online catalog.
NASA SpaceLink offers latest NASA news including shuttle launches and satellite updates.
What is TCP/IP?
TCP/IP (Transmission Control Protocol/Internet Protocol) [4,5,6] is the common name for a family of over 100 data-communications protocols used to organize computers and data-communications equipment into computer networks. TCP/IP was developed to interconnect hosts on ARPANET, PRNET (packet radio), and SATNET (packet satellite). All three of these networks have since been retired; but TCP/IP lives on. It is currently used on a large international network of networks called the Internet, whose members include universities, other research institutions, government facilities, and many corporations. TCP/IP is also sometimes used for other networks, particularly local area networks that tie together numerous different kinds of computers or tie together engineering workstations.
What are the other well-known standard protocols
in the TCP/IP family?
Other than TCP and IP, the three main protocols in the TCP/IP suite are the Simple Mail Transfer Protocol (SMTP) , the File Transfer Protocol (FTP) , and the TELNET Protocol . There are many other protocols in use on the Internet. The Internet Activities Board (IAB) regularly publishes an RFC  that describes the state of standardization of the various Internet protocols. This document is the best guide to the current status of Internet protocols and their recommended usage.
What is the Domain Name System?
The Domain Name System (DNS) is a hierarchical, distributed method of organizing the name space of the Internet. The DNS administratively groups hosts into a hierarchy of authority that allows addressing and other information to be widely distributed and maintained. A big advantage to the DNS is that using it eliminates dependence on a centrally-maintained file that maps host names to addresses.
What is a Fully Qualified Domain Name?
A Fully Qualified Domain Name (FQDN) is a domain name that includes all higher level domains relevant to the entity named. If you think of the DNS as a tree-structure with each node having its own label, a Fully Qualified Domain Name for a specific node would be its label followed by the labels of all the other nodes between it and the root of the tree. For example, for a host, a FQDN would include the string that identifies the particular host, plus all domains of which the host is a part up to and including the top-level domain (the root domain is always null). For example, PARIS.NISC.SRI.COM is a Fully Qualified Domain Name for the host at 22.214.171.124. In addition, NISC.SRI.COM is the FQDN for the NISC domain.
What is an RFC?
The Request for Comments documents (RFCs) are working notes of the Internet research and development community. A document in this series may be on essentially any topic related to computer communication, and may be anything from a meeting report to the specification of a standard. Submissions for Requests for Comments may be sent to the RFC Editor (RFC-EDITOR@ISI.EDU). The RFC Editor is Jon Postel.
Most RFCs are the descriptions of network protocols or services, often giving detailed procedures and formats for their implementation. Other RFCs report on the results of policy studies or summarize the work of technical committees or workshops. All RFCs are considered public domain unless explicitly marked otherwise.
While RFCs are not refereed publications, they do receive technical review from either the task forces, individual technical
experts, or the RFC Editor, as appropriate. Currently, most standards are published as RFCs, but not all RFCs specify standards.
Anyone can submit a document for publication as an RFC. Submissions must be made via electronic mail to the RFC Editor. Please consult RFC 1111, "Instructions to RFC Authors" , for further information. RFCs are accessible online in public access files, and a short message is sent to a notification distribution list indicating the availability of the memo. Requests to be added to this distribution list should be sent to RFC- REQUEST@NIC.DDN.MIL.
The online files are copied by interested people and printed or displayed at their sites on their equipment. (An RFC may also be returned via electronic mail in response to an electronic mail query.) This means that the format of the online files must meet the constraints of a wide variety of printing and display equipment.
Once a document is assigned an RFC number and published, that RFC is never revised or re-issued with the same number. There is never a question of having the most recent version of a particular RFC. However, a protocol (such as File Transfer Protocol (FTP)) may be improved and re-documented many times in several different RFCs. It is important to verify that you have the most recent RFC on a particular protocol. The "IAB Official Protocol Standards"  memo is the reference for determining the correct RFC to refer to for the current specification of each protocol.
How do I obtain RFCs?
RFCs are available online at several repositories around the
world. For a list of repositories and instructions about how to
obtain RFCs from each of the major US ones, FTP the file in-
notes/rfc-retrieval.txt from the host ISI.EDU. That host supports
anonymous login. You can also get information about RFC
repositories via electronic mail. Send a message to rfc-
firstname.lastname@example.org. In the body of the message, type
"help: ways_to_get_rfcs" (without the quotes).
Two examples of obtaining RFCs online follow.
RFCs can be obtained via FTP from NIC.DDN.MIL, with the pathname rfc/rfcNNNN.txt (where "NNNN" refers to the number of the RFC). Login using FTP, username "anonymous" and password "guest".
RFCs can also be obtained via FTP from NIS.NSF.NET. Using FTP,
login with username "anonymous" and password "guest"; then connect to the RFC directory ("cd RFC"). The file name is of the form RFCnnnn.TXT-1 (where "nnnn" refers to the number of the RFC). The NIS also provides an automatic mail service for those sites which cannot use FTP. Address the request to NIS-INFO@NIS.NSF.NET and leave the subject field of the message blank. The first line of the text of the message must be "SEND RFCnnnn.TXT-1", where nnnn is replaced by the RFC number.
Requests for special distribution should be addressed to either
the author of the RFC in question, to NIC@NIC.DDN.MIL, or to
NISC@NISC.SRI.COM. SRI International operates the
FTP.NISC.SRI.COM online repository of RFCs and other files, and makes the RFCs available in hardcopy for those people who have neither FTP nor e-mail access to the Internet. Hardcopy RFCs are sold by SRI on a cost-recovery basis. In addition, SRI has a hardcopy subscription service for RFCs, as well as several publications that incorporate selections of RFCs. Unless specifically noted otherwise on the RFC itself, all RFCs are for unlimited distribution.
How do I obtain a list of RFCs?
SRI maintains a file that is an index of the RFCs. It lists each RFC, starting with the most recent, and for each RFC provides the number, title, author(s), issue date, and number of hardcopy pages. In addition, it lists the online formats (PostScript or ASCII text) for each RFC and the number of bytes each such version is online. If an RFC is also an FYI, that fact is noted, with the corresponding FYI number. (There is a parallel FYI Index available). Finally, the Index notes whether or not an RFC is obsoleted or updated by another RFC, and gives the number of that RFC, or if an RFC itself obsoletes or updates another RFC, and gives that RFC number. The index is updated online each time an RFC is issued.
This RFC Index is available online for anonymous FTP from the FTP.NISC.SRI.COM host as rfc/rfc-index.txt. The FYI Index is online as fyi/fyi-index.txt. They are also available via electronic mail by sending a message to email@example.com. In the body of the message, say "send rfc-index" or "send fyi- index" (don't use quotes, but do use lowercase). The RFC Index is also available from the SRI in hardcopy for $12, as are individual RFCs. Call SRI at 1-415-859-3695 for help in obtaining the Index.
What is the RFC-INFO service?
The Information Sciences Institute, University of Southern California (ISI) has announced a service called RFC-Info. Even though this is a service, rather than a document, we'll discuss it in this section because it is so closely tied to RFC information.
RFC-Info is an e-mail based service to help in locating and retrival of RFCs and FYIs. Users can ask for "lists" of all RFCs and FYIs having certain attributes ("filters") such as their ID, keywords, title, author, issuing organization, and date. Once an RFC is uniquely identified (e.g., by its RFC number) it may also be retrieved.
To use the service send e-mail to RFC-INFO@ISI.EDU with your requests in the body of the message. Feel free to put anything in the SUBJECT, the system ignores it. All input is case independent. Report problems to RFC-MANAGER@ISI.EDU.
To get started, you may send a message to RFC-INFO@ISI.EDU with requests such as in the following examples (without the explanations between brackets):
Author: Bracken* [* is a wild card matches everything] List: RFC [list RFCs by both Postel and Gillman] Authors: J. Postel [note, the "filters" are ANDed] Authors: R. Gillman List: RFC [list RFCs by any Crocker] Authors: Crocker List: RFC [list only RFCs by S.D. Crocker]
Authors: S.D. Crocker
Doc-ID: RFC0822 [note, always 4 digits in RFC#]
Which RFCs are Standards?
See "IAB Official Protocol Standards" (currently, RFC 1280) .
What is an FYI?
FYI stands for For Your Information. FYIs are a subset of the RFC series of online documents.
FYI 1 states, "The FYI series of notes is designed to provide Internet users with a central repository of information about any topics which relate to the Internet. FYI topics may range from historical memos on operational questions. The FYIs are intended for a wide audience. Some FYIs will cater to beginners, while others will discuss more advanced topics."
In general, then, FYI documents tend to be more information oriented, while RFCs are usually (but not always) more technically oriented.
FYI documents are assigned both an FYI number and an RFC number. As RFCs, if an FYI is ever updated, it is issued again with a new RFC number; however, its FYI number remains unchanged. This can be a little confusing at first, but the aim is to help users identify which FYIs are about which topics. For example, FYI 4 will always be FYI 4, even though it may be updated several times and during that process receive different RFC numbers. Thus, you need only to remember the FYI number to find the proper document. Of course, remembering titles often works as well.
FYIs can be obtained in the same way RFCs can and from the same repositories. In general, their pathnames are fyi/fyiNN.txt or fyi/fyiNN.ps, where NN is the number of the FYI without leading
What is an STD?
The newest subseries of RFCs are the STDs (Standards). RFC 1311 , which introduces this subseries, states that the intent of STDs is to identify clearly those RFCs that document Internet standards. An STD number will be assigned only to those specifications that have completed the full process of standardization in the Internet. Existing Internet standards have been assigned STD numbers; a list of them can be found both in RFC 1311 and in the IAB Official Protocol Standards RFC.
Like FYIs, once a standard has been assigned an STD number, that number will not change, even if the standard is reworked and re- specified and later issued with a new RFC number.
It is important to differentiate between a "standard" and "document." Different RFC documents will always have different RFC numbers. However, sometimes the complete specification for a standard will be contained in more than one RFC document. When this happens, each of the RFC documents that is part of the specification for that standard will carry the same STD number. For example, the Domain Name System (DNS) is specified by the combination of RFC 1034 and RFC 1035; therefore, both of those RFCs are labeled STD 13.
What is the Internet Monthly Report?
The Internet Monthly Report communicates online to the Internet Research Group the accomplishments, milestones reached, or problems discovered by the participating organizations. Many organizations involved in the Internet provide monthly updates of their activities for inclusion in this report.
The Internet Monthly Report is for Internet information purposes only.
You can receive the report online by joining the mailing list that distributes the rerpot. Requests to be added or deleted from the Internet Monthly report list should be sent to "firstname.lastname@example.org".
In addition, back issues of the Report are available for anonymous FTP from the host NIS.NSF.NET in the 'imr' directory with the file names in the form IMRYY-MM.TXT, where YY is the last two digits of the year and MM two digits for the month. For example, the June 1991 Report is in the file IMR91-06.TXT.
What is an Internet Draft? Are there any guidelines available for writing one?
Internet Drafts (I-Ds) are the current working documents of the IETF. Internet Drafts are generally in the format of an RFC with some key differences:
- The Internet Drafts are not RFCs and are not a numbered document series. - The words INTERNET-DRAFT appear in place of RFC XXXX in the upper left-hand corner. - The document does not refer to itself as an RFC or as a Draft RFC. - An Internet Draft does not state nor imply that it is a proposed standard. To do so conflicts with the role of the IAB, the RFC Editor, and the Internet Engineering Steering Group (IESG).
An Internet Drafts Directory has been installed to make available, for review and comment by the IETF members, draft documents that will be submitted ultimately to the IAB and the RFC Editor to be considered for publishing as an RFC. The Internet Drafts Directories are maintained primarily at the NSFNET Network Service Center (NNSC). There are several "shadow" machines which contain the IETF and Internet Drafts Directories. They are:
NSF Network Service Center: nnsc.nsf.net
DDN NIC: nic.ddn.mil
SRI International: ftp.nisc.sri.com
Pacific Rim: munnari.oz.au
Europe: nic.nordu.net (126.96.36.199)
To access these directories, use anonymous FTP. Login with username, "anonymous", password, "guest". Once logged in, change to the directory, "cd internet-drafts". Internet Draft files can then be retrieved.
For further information on the Internet Drafts of the IETF, or if you have problems with retrieving Internet Draft documents, contact Megan Davies (email@example.com) or Greg Vaudreuil (firstname.lastname@example.org) for assistance.
How do I obtain OSI Standards documents?
OSI Standards documents are NOT available from the Internet via anonymous FTP due to copyright restrictions. These are available from:
Omnicom Information Service
501 Church Street NE
Vienna, VA 22180 USA
Telephone: (800) 666-4266 or (703) 281-1135
Fax: (703) 281-1505
American National Standards Institute
11 West 42nd Street
New York, NY 10036 USA
Telephone: (212) 642-4900
However, the GOSIP specification which covers the use of OSI protocols within the U.S. Government is available from SRI and from the National Institute of Standards and Technology (NIST). The final text of GOSIP Version 2 is now available from both sites.
Available through anonymous ftp from osi.ncsl.nist.gov (188.8.131.52) as:
./pub/gosip/gosip_v2.txt -- ascii ./pub/gosip/gosip_v2.txt.Z -- ascii compressed ./pub/gosip/gosip_v2.ps -- PostScript ./pub/gosip/gosip_v2.ps.Z -- PostScript compressed
Available through anonymous ftp from ftp.nisc.sri.com (184.108.40.206) as:
netinfo/gosip-v2.txt -- ascii netinfo/gosip-v2.ps -- PostScript
Standards Processing Coordinator (ADP)
National Institute of Standards and Technology
Technology Building, Room B-64
Gaithersburg, MD 20899
Network Information Systems Center
SRI International, Room EJ291
333 Ravenswood Ave.
Menlo Park, CA 94025
What is the IAB?
The Internet Activities Board (IAB) is the coordinating committee for Internet design, engineering and management . IAB members are deeply committed to making the Internet function effectively and evolve to meet a large scale, high speed future. The chairman serves a term of two years and is elected by the members of the IAB. The current Chair of the IAB is Lyman Chapin. The IAB focuses on the TCP/IP protocol suite, and extensions to the Internet system to support multiple protocol suites.
The IAB performs the following functions:
1) Sets Internet Standards, 2) Manages the RFC publication process, 3) Reviews the operation of the IETF and IRTF, 4) Performs strategic planning for the Internet, identifying long-range problems and opportunities, 5) Acts as an international technical policy liaison and representative for the Internet community, and 6) Resolves technical issues which cannot be treated within the IETF or IRTF frameworks.
The IAB has two principal subsidiary task forces:
1) Internet Engineering Task Force (IETF)
2) Internet Research Task Force (IRTF)
Each of these Task Forces is led by a chairman and guided by a Steering Group which reports to the IAB through its chairman. For the most part, a collection of Research or Working Groups carries out the work program of each Task Force.
All decisions of the IAB are made public. The principal vehicle by which IAB decisions are propagated to the parties interested in the Internet and its TCP/IP protocol suite is the Request for Comments (RFC) note series and the Internet Monthly Report.
What is the IETF?
The Internet has grown to encompass a large number of widely geographically dispersed networks in academic and research communities. It now provides an infrastructure for a broad community with various interests. Moreover, the family of Internet protocols and system components has moved from experimental to commercial development. To help coordinate the operation, management and evolution of the Internet, the IAB established the Internet Engineering Task Force (IETF).
The IETF is chaired by Phill Gross and managed by its Internet Engineering Steering Group (IESG). The IETF is a large open community of network designers, operators, vendors, and researchers concerned with the Internet and the Internet protocol suite. It is organized around a set of several technical areas, each managed by a technical area director. In addition to the IETF Chairman, the area directors make up the IESG membership.
The IAB has delegated to the IESG the general responsibility for making the Internet work and for the resolution of all short- and mid-range protocol and architectural issues required to make the Internet function effectively.
What is the IRTF?
To promote research in networking and the development of new technology, the IAB established the Internet Research Task Force (IRTF).
In the area of network protocols, the distinction between research and engineering is not always clear, so there will sometimes be overlap between activities of the IETF and the IRTF. There is, in fact, considerable overlap in membership between the two groups. This overlap is regarded as vital for cross-fertilization and technology transfer.
The IRTF is a community of network researchers, generally with an Internet focus. The work of the IRTF is governed by its Internet Research Steering Group (IRSG). The chairman of the IRTF and IRSG is Jon Postel.
What is the Internet Society?
The Internet Society is a relatively new, professional, non-profit organization with the general goal of fostering the well-being and continued interest in, and evolution and use of the Internet. The Society (often abbreviated ISOC) anticipates that it will integrate the IAB, IETF, and IRTF functions into its operation.
The following goals of the Society are taken from its charter:
More information about the Internet Society is available for anonymous FTP from the host NNSC.NSF.NET in the directory isoc. Here is a list of the files available:
Filename (Topic) Description index-isoc An index of the isoc directory announcement Internet Society Announcement charter Internet Society Charter inet-conference INET 92 Internet Society Annual Meeting Announcement and Call for Participation isoc-advisory-council The Internet Society advisory council isoc-founding-members List of the Internet Society founding members
isoc-secretariat Information about the Internet Society secretariat isoc-trustees List of the Internet Society trustees questions-and-answers Internet Society Questions & Answers by Vint Cerf
membership-organizations Internet Society Organizational Membership Form
membership-individuals Internet Society Individual Membership Form
This information is also available via electronic mail via the NNSC Info-Server. The Info-Server is an automated program that retrieves information through electronic mail. To receive these files via the Info-Server, send a mail message to: info- email@example.com. In the body of the message, type "Request: isoc" followed by the topic names of any files you'd like. For example:
Topic: inet-conference Topic: questions-and-answers Topic: charter Topic: announcement Request: end
Notice that the "Topics" for the Info-Server correspond to the file names used when FTPing.
What is the IANA?
The task of coordinating the assignment of values to the parameters of protocols is delegated by the Internet Activities Board (IAB) to the Internet Assigned Numbers Authority (IANA). These protocol parameters include op-codes, type fields, terminal types, system names, object identifiers, and so on. The "Assigned Numbers" Request for Comments (RFC)  documents the currently assigned values from several series of numbers used in network protocol implementations. Internet addresses and Autonomous System numbers are assigned by the Network Information Center at Network Solutions, Inc. This responsibility has been delegated by the IANA to the DDN NIC which serves as the Internet Registry. The IANA is located at USC/Information Sciences Institute.
Current types of assignments listed in Assigned Numbers and
maintained by the IANA are:
Address Resolution Protocol Parameters
ARPANET and MILNET X.25 Address Mappings
ARPANET and MILNET Logical Addresses
ARPANET and MILNET Link Numbers
BOOTP Parameters and BOOTP Extension Codes
Domain System Parameters
IANA Ethernet Address Blocks
Ethernet Numbers of Interest
IEEE 802 Numbers of Interest
Internet Protocol Numbers
Internet Version Numbers
IP Time to Live Parameter
IP TOS Parameters
Mainl Encryption Types
Network Management Parameters
Point-to-Point Protocol Field Assignments
PRONET 80 Type Numbers
Protocol and Service Names
Protocol/Type Field Assignments
Public Data Network Numbers
Reverse Address Resolution Protocol Operation Codes TELNET Options
Terminal Type Names
For more information on number assignments, contact IANA@ISI.EDU.
What is a NIC? What is a NOC?
"NIC" stands for Network Information Center. It is an organization which provides network users with information about services provided by the network.
"NOC" stands Network Operations Center. It is an organization that is responsible for maintaining a network.
For many networks, especially smaller, local networks, the functions of the NIC and NOC are combined. For larger networks, such as mid-level and backbone networks, the NIC and NOC organizations are separate, yet they do need to interact to fully perform their functions.
What is "The NIC"?
"The NIC" usually refers to the Defense Data Network, Network Information Center (DDN NIC), which is now at Network Solutions, Inc. The DDN NIC is a network information center that maintains a repository for RFCs and Internet Drafts. The host name is NIC.DDN.MIL. Shadow copies of the RFCs and the Internet Drafts are maintained on several other hosts as well, including NIS.NSF.NET and FTP.NISC.SRI.COM.
The DDN NIC also provides various user assistance services for DDN users; contact NIC@NIC.DDN.MIL or call 1-800-365-3642 for more information. In addition, the DDN NIC is the Internet registration authority for the root domain and several top and second level domains; maintains the official DoD Internet Host Table; is the site of the Internet Registry (IR); and maintains the WHOIS database of network users, hosts, domains, networks, and Points of Contact.
This NIC was located for many years at SRI International, so you may also hear the term "SRI NIC". SRI also maintains an online information repository and provides general Internet information services. For example, the SRI Network Information Systems Center is currently the only site that provides paper copies of the RFCs, which are made available on a cost recovery basis. Call 415-859- 3695 for more information on this service.
What is the IR?
The Internet Registry (IR) is the organization that is responsible for assigning identifiers, such as IP network numbers and autonomous system numbers, to networks. The IR also gathers and registers such assigned information. The IR may, in the future, allocate the authority to assign network identifiers to other organizations; however, it will continue to gather data regarding such assignments. At present, the DDN NIC at Network Solutions, Inc., serves as the IR.
How do I find someone's electronic mail address?
There are a number of directories on the Internet; however, all of them are far from complete. The largest directories are the WHOIS database at the DDN NIC, the PSInet White Pages, and KNOWBOT. Generally, it is still necessary to ask the person for his or her email address.
How do I use the WHOIS program at the DDN NIC?
To use the WHOIS program to search the WHOIS database at the DDN NIC, TELNET to the NIC host, NIC.DDN.MIL. There is no need to login. Type "whois" to call up the information retrieval program. Next, type the name of the person, host, domain, network, or mailbox for which you need information. If you are only typing part of the name, end your search string with a period. Type "help" for a more in-depth explanation of what you can search for and how you can search. If you have trouble, send a message to NIC@NIC.DDN.MIL or call 1-800-365-3642.
How do I become registered in the DDN NIC's WHOIS database?
If you would like to be listed in the WHOIS database, you must have an electronic mailbox accessible from the Internet. First obtain the file netinfo/user-template.txt. You can retrieve this file via anonymous FTP from NIC.DDN.MIL.
Fill out the name and address information requested in the file and return it to REGISTRAR@NIC.DDN.MIL. Your application will be processed and you will be added to the database. Unless you are an official Point of Contact for a network entity registered at the DDN NIC, the DDN NIC will not regularly poll you for updates, so you should remember to send corrections to your information as your contact data changes.
How do I use the White Pages at PSI?
Performance Systems International, Inc. (PSI), sponsors a White Pages Pilot Project that collects personnel information from member organizations into a database and provides online access to that data. This effort is based on the OSI X.500 Directory standard.
To access the data, TELNET to WP.PSI.COM and login as "fred" (no password is necessary). You may now look up information on participating organizations. The program provides help on usage. For example, typing "help" will show you a list of commands, "manual" will give detailed documentation, and "whois" will provide information regarding how to find references to people. For a list of the organizations that are participating in the pilot project by providing information regarding their members, type "whois -org *".
For more information, send a message to WP-INFO@PSI.COM.
How do I use the Knowbot Information Service?
The Knowbot Information Service is a white pages "meta-service" that provides a uniform interface to heterogeneous white pages services in the Internet. Using the Knowbot Information Service, you can form a single query that can search for white pages information from the NIC WHOIS service, the PSI White Pages Pilot Project, and MCI Mail, among others, and have the responses displayed in a single, uniform format.
Currently, the Knowbot Information Service can be accessed through TELNET to port 185 on hosts nri.reston.va.us and sol.bucknell.edu. From a UNIX host, use "telnet nri.reston.va.us 185". There is also an electronic mail interface avaliable by sending mail to netaddress at either nri.reston.va.us or sol.bucknell.edu.
The commands "help" and "man" summarize the command interface. Simply entering a user name at the prompt searches a default list of Internet directory services for the requested information. Organization and country information can be included thorgh the syntax: "firstname.lastname@example.org". For example, the queries "droms@bucknell" and "email@example.com" are both valid. Note that these are not Domain Names, but rather a syntax to specify an organization and a country for the search.
The default list of directory services currently includes the whois services at the DDN NIC and the white pages service for MCIMail. If an organization is specified, the PSI X.500 service is also searched. Other services can be requested explicitly.
What is USENET? What is Netnews?
USENET is the formal name, and Netnews a common informal name, for a distributed computer information service that some hosts on the Internet use. USENET handles only news and not mail. USENET uses a variety of underlying networks for transport, including parts of the Internet, UUCP, BITNET, and others. USENET is not part of the Internet proper. Netnews can be a valuable tool to economically transport traffic that would otherwise be sent via mail. USENET has no central administration.
How do I get on USENET?
To get on USENET, you must acquire the software, which is available for some computers at no cost from some anonymous FTP sites across the Internet, and you must find an existing USENET site that is willing to support a connection to your computer. In many cases, this "connection" merely represents additional traffic
over existing Internet access channels.
One well-known anonymous FTP archive site for software and information regarding USENET is ftp.uu.net. There is a "news" directory which contains many software distribution and information sub-directories.
It is recommended that new users subscribe to and read news.announce.newusers since it will help to become oriented to USENET and the Internet.
What is anonymous FTP?
Anonymous FTP is a conventional way of allowing you to sign on to a computer on the Internet and copy specified public files from it . Some sites offer anonymous FTP to distribute software and various kinds of information. You use it like any FTP, but the username is "anonymous". Many systems will allow any password and request that the password you choose is your userid. If this fails, the generic password is usually "guest".
What is "archie"?
The archie system was created by a group at McGill University in Montreal to automatically track anonymous FTP archive sites, and this is still its primary function. The system curently makes available the names and locations of some 1,500,000 files at some 900 archive sites.
Archie's User Access component allows you to search the "files" database for these filenames. When matches are found, you are presented with the appropriate archive site name, IP address, the location within the archive, and other useful information.
You can also use archie to "browse" through a site's complete listing in search of information of interest, or obtain a complete list of the archive sites known to that server.
The archie server also offers a "package descriptions" (or "whatis") database. This is a collection of names and descriptions gathered from a variety of sources and can be used to identify files located throughout the Internet, as well as other useful information. Files identified in the whatis database can then be found by searching the files database as described above. Additional databases are planned for the coming months.
How do I connect to archie?
You can connect to archie in a variety of ways. There is a conventional TELNET interface, an electronic mail interface, and a variety of client programs available. There are currently nine archie servers located throughout the world.
To try the TELNET interface to archie you can TELNET to the host ARCHIE.MCGILL.CA and login as user "archie" (there is no password required). Type "help" to get you started. The "servers" command can be used to locate an archie server closer to your site. Using an archie server closer to you relieves some of the load on the McGill host.
You can obtain details on using the electronic mail interface by sending mail to "firstname.lastname@example.org" with the word "help" in either the subject or body of the message.
Documentation on archie is available for anonymous ftp from ARCHIE.MCGILL.CA in the subdirectory "archie/doc". A variety of archie client programs are available in the subdirectory "archie/clients". Questions, comments, and suggestions can be sent to the archie development group by sending mail to "archie- email@example.com".
What is "TELNET"?
The term "TELNET" refers to the remote login that's possible on the Internet because of the TELNET Protocol . The use of this term as a verb, as in "telnet to a host" means to establish a connection across the Internet from one host to another. Usually, you must have an account on the remote host to be able to login to it once you've made a connection. However, some hosts, such as those offering white pages directories, provide public services that do not require a personal account.
What is a mailing list?
A mailing list is really nothing more than an alias that has multiple destinations. Mailing lists are usually created to discuss specific topics. Anybody interested in that topic, may (usually) join that list. Some mailing lists have membership restrictions, others have message content restrictions, and still others are moderated. Most large, "public" mailing lists, such as IETF and TCP-IP, have an additional mail address to which requests to be added or deleted may be sent. Usually, these are of the
There is a "list-of-lists" file available on the host
ftp.nisc.sri.com that lists most of the major mailing lists, describes their primary topics, and explains how to subscribe to them. The file is available for anonymous ftp in the netinfo directory as interest-groups (that is, the path is:
netinfo/interest-groups). It can also be obtained via electronic mail. Send a message to firstname.lastname@example.org with the body of the message reading, "Send netinfo/interest-groups" and the file will be returned in moderate size pieces via electronic mail.
How do I contact the administrator of a mailing list rather than posting to the entire list?
For every mailing list mentioned in the "interest-groups" file, there is a description of how to join the list or send other such administrative messages to the person in charge of the list. In general, however, it is usually safe to assume that you can send a message to an address in the format of ListName-request@domain. The convention of having a parallel mailbox conforming to the "- request" format is very widely followed. All administrative messages regarding using, joining, or quitting the list should be sent to that mailbox instead of to the whole list so that the readers of the list don't have to read them.
What are some good mailing lists?
The TCP-IP, IETF, and RFC Distribution lists are primary lists for new Internet users who desire further information about current and emerging developments in the Internet. The first two lists are unmoderated discussion lists, and the latter is an announcement service used by the RFC Editor.
How do I subscribe to the TCP-IP mailing list?
To be added to the TCP-IP mailing list, send a message to:
How do I subscribe to the IETF mailing list?
To be added to the IETF mailing list, send a message to:
How do I subscribe to the RFC Distribution list?
To be added to the RFC Distribution list, send a message to:
Note that all announcements to this list are also sent to the IETF list. So, if you are on the IETF list, you don't need to be on this list, too.
How do I send mail to other networks?
Mail to the Internet is addressed in the form user@domain. Remember that a domain name can have several components and the name of each host is a node on the domain tree. So, an example of an Internet mail address is email@example.com.
There are several networks accessible via e-mail from the Internet, but many of these networks do not use the same addressing conventions the Internet does. Often you must route mail to these networks through specific gateways as well, thus further complicating the address.
Here are a few conventions you can use for sending mail from the Internet to three networks with which Internet users often correspond.
Internet user to Internet user:
Internet user to BITNET user:
Internet user to UUCP user:
Internet user to SprintMail user:
/G=Mary/S=Anderson/O=co.abc/ADMD=SprintMail/C=US/@SPRINT.COM -or- /PN=Mary.Anderson/O=co.abc/ADMD=SprintMail/C=US/@SPRINT.COM (Case is significant.)
Internet user to CompuServe user:
Replace the comma in the CompuServe userid (represented
with x's) with a period, and add the compuserve.com
CompuServe user to Internet user:
>Internet:user@host Insert >internet: before an Internet address.
Internet user to MCIMail user:
What is a newsgroup?
A newsgroup is a bulletin board which readers, interested in that newsgroup's particular topic, can read and respond to messages posted by other readers. Generally, there will be a few "threads" of discussion going on at the same time, but they all share some common theme. There are approximately 900 newsgroups, and there are more being added all the time.
There are two types of newsgroups: moderated and unmoderated. A moderated newsgroup does not allow individuals to post directly to the newsgroup. Rather, the postings go to the newsgroup's moderator who determines whether or not to pass the posting to the entire group. An unmoderated newsgroup allows a reader to post directly to the other readers.
How do I subscribe to a newsgroup?
You don't subscribe to a newsgroup. Either you get it on your machine or you don't. If there's one you want, all you can do is ask the systems administrator to try to get it for you. The same is true for creating newsgroups.
What does :-) mean?
In many electronic mail messages, it is sometimes useful to indicate that part of a message is meant in jest. It is also sometimes useful to communicate emotion which simple words do not readily convey. To provide these nuances, a collection of "smiley faces" has evolved. If you turn your head sideways to the left, :-) appears as a smiling face. Some of the more common faces are:
:-) smile :-( frown :) also a smile ;-) wink :-D laughing 8-) wide-eyed :-} grin :-X close mouthed :-] smirk :-o oh, no!
What do "btw", "fyi", "imho", "wrt", and "rtfm" mean?
Often commmon expressions are abbreviated in informal network postings. These abbreviations stand for "by the way", "for your information", "in my humble [or honest] opinion", "with respect to", and "read the f*ing manual" (with the "f" word varying according to the vehemence of the reader).
What is the "FAQ" list?
This list provides answers to "Frequently Asked Questions" that often appear on various USENET newsgroups. The list is posted every four to six weeks to the news.announce.newusers group. It is intended to provide a background for new users learning how to use the news. As the FAQ list provide new users with the answers to such questions, it helps keep the newsgroups themselves comparatively free of repetition. Often specific newsgroups will have and frequently post versions of a FAQ list that are specific to their topics.
Other information is also routinely posted. Here are the subject lines of several general information postings provided on USENET:
Answers to Frequently Asked Questions (the "FAQ" list)
Introduction to news.announce
What is Usenet?
Rules for posting to Usenet
How to Create a New Newsgroup
How to Create a New Trial Newsgroup
A Primer on How to Work With the Usenet Community
Emily Postnews Answers Your Questions on Netiquette Hints on writing style for Usenet
USENET Software: History and Sources
List of Active Newsgroups
Alternative Newsgroup Hierarchies, Part I
Alternative Newsgroup Hierarchies, Part II
How to Construct the Mailpaths File
Regional Newsgroup Hierarchies, Part I
Regional Newsgroup Hierarchies, Part II
Regional Newsgroup Hierarchies, Part III
List of Moderators
Publicly Accessible Mailing Lists, Part I
Publicly Accessible Mailing Lists, Part II
Publicly Accessible Mailing Lists, Part III
List of Periodic Informational Postings
How to Get Information about Networks
A Guide to Social Newsgroups and Mailing Lists
All of these articles are normally archived for FTP access on pit-manager.mit.edu in /pub/usenet/news.announce.newusers.
For further information about the Internet and its protocols in general, you may choose to obtain copies of the following works:
Bowers, K., T. LaQuey, J. Reynolds, K. Roubicek, M. Stahl, and A. Yuan, "Where to Start - A Bibliography of General Internetworking Information", RFC 1175, FYI 3, CNRI, U Texas, ISI, BBN, SRI, Mitre, August 1990.
Comer, D., "Internetworking with TCP/IP: Principles, Protocols, and Architecture", Prentice Hall, New Jersey, 1989.
Krol, E., "The Hitchhikers Guide to the Internet", RFC 1118, University of Illinois Urbana, September 1989.
 Reynolds, J., and J. Postel, "Assigned Numbers", RFC 1060, USC/Information Sciences Institute, March 1990.
 Postel, J., Editor, "IAB Official Protocol Standards", RFC 1280, Internet Activities Board, March 1992.
 Postel, J., and J. Reynolds, "File Transfer Protocol (FTP), RFC 959, USC/Information Sciences Institute, October 1985.
 Postel, J., "Internet Protocol - DARPA Internet Program Protocol Specification", RFC 791, DARPA, September 1981.
 Postel, J., "Transmission Control Protocol - DARPA Internet Program Protocol Specification", RFC 793, DARPA, September 1981.
 Leiner, B., R. Cole, J. Postel, and D. Mills, "The DARPA Internet Protocol Suite", IEEE INFOCOM85, Washington D.C., March 1985. Also in IEEE Communications Magazine, March 1985. Also as ISI/RS-85-153.
 Cerf, V., "The Internet Activities Board" RFC 1160, CNRI, May 1990.
 Postel, J., "Simple Mail Transfer Protocol", RFC 821, USC/Information Sciences Institute, August 1982.
 Postel, J., and J. Reynolds, "TELNET Protocol Specification", RFC 854, USC/Information Sciences Institute, May 1983.
 Postel, J., "Request for Comments on Request for Comments - Instructions to RFC Authors", RFC 1111, USC/Information Sciences Institute, August 1989.
 Malkin, G., A. Marine, and J. Reynolds, "FYI on Questions and Answers: Answers to Commonly Asked 'Experienced Internet User' Questions", FYI 7, RFC 1207, FTP Software, SRI, USC/Information Sciences Institute, February 1991.
 Postel, J., "Introduction to the STD Notes", RFC 1311, USC/Information Sciences Institute, March 1992.
As with any profession, computers have a particular terminology all their own. Below is a condensed glossary to assist in making some sense of the Internet world.
ACM Association for Computing Machinery A group established in 1947 to promote professional development and research on computers.
address There are two separate uses of this term in internet networking: "electronic mail address" and "internet address". An electronic mail address is the string of characters that you must give an electronic mail program to direct a message to a particular person. See "internet address" for its definition.
AI Artificial Intelligence The branch of computer science which deals with the simulation of human intelligence by computer systems. AIX Advanced Interactive Executive IBM's version of Unix. ANSI American National Standards Institute A group that certifies organizations which develop U.S. standards for the information processing industry. ANSI accredited groups participate in defining network protocol standards. ARP Address Resolution Protocol An Internet protocol which runs on Ethernet and all IEEE 802.X LANs which maps internet addresses to MAC addresses. ARPA Advanced Research Projects Agency The former name of what is now called DARPA.
ARPANET Advanced Research Projects Agency Network
A pioneering long haul network funded by ARPA. It served as the basis for early networking research as well as a central backbone during the development of the Internet. The ARPANET consisted of individual packet switching computers interconnected by leased lines.
AS Autonomous System A collection of gateways (routers) under a single administrative authority using a common Interior Gateway Protocol for routing packets.
ASCII American (National) Standard Code for Information Interchange B Byte One character of information, usually eight bits wide. b bit - binary digit The smallest amount of information which may be stored in a computer. BBN Bolt Beranek and Newman, Inc. The Cambridge, MA company responsible for development, operation and monitoring of the ARPANET, and later, the Internet core gateway system, the CSNET Coordination and Information Center (CIC), and NSFNET Network Service Center (NNSC).
BITNET Because It's Time Network
BITNET has about 2,500 host computers, primarily at universities, in many countries. It is managed by EDUCOM, which provides administrative support and information services. There are three
main constituents of the network: BITNET in the United States and Mexico, NETNORTH in Canada, and EARN in Europe. There are also AsiaNet, in Japan, and
connections in South America. See CREN.
bps bits per second A measure of data transmission speed. BSD Berkeley Software Distribution Term used when describing different versions of the Berkeley UNIX software, as in "4.3BSD UNIX".
catenet A network in which hosts are connected to networks
with varying characteristics, and the networks
are interconnected by gateways (routers). The
Internet is an example of a catenet.
CCITT International Telegraph and Telephone Consultative Committee
Historically, one of a set of gateways (routers)
operated by the Internet Network Operations Center at BBN. The core gateway system forms a central part
of Internet routing in that all groups had to advertise paths to their networks from a core gateway.
CREN The Corporation for Research and Educational Networking BITNET and CSNET have recently merged to form CREN. CSNET Computer + Science Network A large data communications network for institutions doing research in computer science. It uses several different protocols including some of its own. CSNET sites include universities, research laboratories, and commercial companies. See CREN. DARPA U.S. Department of Defense Advanced Research Projects Agency The government agency that funded the ARPANET and later started the Internet.
A self-contained, independent entity of data carrying sufficient information to be routed from the source to the destination data terminal equipment without reliance on earlier exchanges between this source and destination data terminal equipment and the
DCA Defense Communications Agency Former name of the Defense Information Systems Agency (DISA). See DISA. DDN Defense Data Network Comprises the MILNET and several other DoD networks.
DDN NIC The network information center at Network Solutions, Inc. It is the primary repository for RFCs and Internet Drafts, as well as providing other services.
DEC Digital Equipment Corporation
DECnet Digital Equipment Corporation network
A networking protocol for DEC computers and network devices.
A routing table entry which is used to direct any data addressed to any network numbers not explicitly listed in the routing table.
DISA Defense Information Systems Agency Formerly called DCA, this is the government agency responsible for installing the Defense Data Network (DDN) portion of the Internet, including the MILNET lines and nodes. Currently, DISA administers the DDN, and supports the user assistance services of the DDN NIC. DNS The Domain Name System is a mechanism used in the Internet for translating names of host computers into addresses. The DNS also allows host computers not directly on the Internet to have registered names in the same style, but returns the electronic mail gateway which accesses the non-Internet network instead of an IP address. DOD U.S. Department of Defense DOE U.S. Department of Energy
dot address (dotted address notation)
Dot address refers to the common notation for Internet addresses of the form A.B.C.D; where each letter represents, in decimal, one byte of the four byte IP address.
Dynamic Adaptive Routing
Automatic rerouting of traffic based on a sensing and analysis of current actual network conditions. NOTE: this does not include cases of routing decisions taken on predefined information.
EARN European Academic Research Network
EBCDIC Extended Binary-coded Decimal Interchange Code
EGP Exterior Gateway Protocol A protocol which distributes routing information to the gateways (routers) which connect autonomous systems.
A network standard for the hardware and data link levels. There are two types of Ethernet: Digital/Intel/Xerox (DIX) and IEEE 802.3.
FDDI Fiber Distributed Data Interface FDDI is a high-speed (100Mb) token ring LAN.
FIPS Federal Information Processing Standard FTP File Transfer Protocol The Internet standard high-level protocol for transferring files from one computer to another.
gateway See router
GB Gigabyte A unit of data storage size which represents 10^9 (one billion) characters of information. Gb Gigabit 10^9 bits of information (usually used to express a data transfer rate; as in, 1 gigabit/second = 1Gbps). GNU Gnu's Not UNIX A UNIX-compatible operating system developed by the Free Software Foundation.
header The portion of a packet, preceding the actual data,
containing source and destination addresses and
The part of an internet address that designates which node on the (sub)network is being addressed.
HP Hewlett-Packard I/O Input/Output IAB Internet Activities Board The IAB is the coordinating committee for Internet design, engineering and management. IBM International Business Machines Corporation ICMP Internet Control Message Protocol ICMP is an extension to the Internet Protocol. It allows for the generation of error messages, test packets and informational messages related to IP. IEEE Institute for Electrical and Electronics Engineers
IETF Internet Engineering Task Force The IETF is a large open community of network designers, operators, vendors, and researchers whose purpose is to coordinate the operation, management and evolution of the Internet, and to resolve short- and mid-range protocol and architectural issues. It is a major source of proposed protocol standards which are submitted to the Internet Activities Board for final approval. The IETF meets three times a year and extensive minutes of the plenary proceedings are issued.
Any connection of two or more local or wide-area networks.
The global collection of interconnected local, mid-level and wide-area networks which use IP as the network layer protocol.
An assigned number which identifies a host in an internet. It has two or three parts: network number, optional subnet number, and host number.
IP Internet Protocol The network layer protocol for the Internet. It is a packet switching, datagram protocol defined in RFC 791. IRTF Internet Research Task Force The IRTF is a community of network researchers, generally with an Internet focus. The work of the IRTF is governed by its Internet Research Steering Group (IRSG). ISO International Organization for Standardization KB Kilobyte A unit of data storage size which represents 10^3 (one thousand) characters of information. Kb Kilobit 10^3 bits of information (usually used to express a data transfer rate; as in, 1 kilobit/second = 1Kbps = 1Kb).
LAN Local Area Network A network that takes advantage of the proximity of computers to offer relatively efficient, higher speed communications than long-haul or wide-area networks. LISP List Processing Language A high-level computer language invented by Professor John McCarthy in 1961 to support research into computer based logic, logical reasoning, and artificial intelligence. It was the first symbolic (as opposed to numeric) computer processing language. MAC Medium Access Control For broadcast networks, it is the method which devices use to determine which device has line access at any given time. Mac Apple Macintosh computer. MAN Metropolitan Area Network MB Megabyte A unit of data storage size which represents 10^6 (one million) characters of information. Mb Megabit 10^6 bits of information (usually used to express a data transfer rate; as in, 1 megabit/second = 1Mbps).
MILNET Military Network
A network used for unclassified military production applications. It is part of the DDN and the Internet.
MIT Massachusetts Institute of Technology MTTF Mean Time to Failure The average time between hardware breakdown or loss of service. This may be an empirical measurement or a calculation based on the MTTF of component parts. MTTR Mean Time to Recovery (or Repair) The average time it takes to restore service after a breakdown or loss. This is usually an empirical measurement. MVS Multiple Virtual Storage An IBM operating system based on OS/1.
NASA National Aeronautics and Space Administration NBS National Bureau of Standards Now called NIST.
The part of an internet address which designates the network to which the addressed node belongs.
NFS Network File System A network service that lets a program running on one computer to use data stored on a different computer on the same internet as if it were on its own disk. NIC Network Information Center An organization which provides network users with information about services provided by the network. NOC Network Operations Center An organization that is responsible for maintaining a network. NIST National Institute of Standards and Technology Formerly NBS. NSF National Science Foundation
NSFNET National Science Foundation Network
The NSFNET is a highspeed "network of networks" which is hierarchical in nature. At the highest level is a backbone network currently comprising 16 nodes connected to a 45Mbps facility which spans the continental United States. Attached to that are mid-level networks and attached to the mid-levels are campus and local
networks. NSFNET also has connections out of the U.S. to Canada, Mexico, Europe, and the Pacific Rim. The NSFNET is part of the Internet.
NSFNET Mid-level Level Network
A network connected to the highest level of the NSFNET that covers a region of the United States. It is to mid-level networks that local sites connect. The mid-level networks were once called "regionals".
OSI Open Systems Interconnection A set of protocols designed to be an international standard method for connecting unlike computers and networks. Europe has done most of the work developing OSI and will probably
use it as soon as possible.
OSI Reference Model
An "outline" of OSI which defines its seven layers and their functions. Sometimes used to help describe other networks.
OSPF Open Shortest-Path First Interior Gateway Protocol A proposed replacement for RIP. It addresses some problems of RIP and is based upon principles that have been well-tested in non-internet protocols. Originally acronymed as OSPFIGP.
packet The unit of data sent across a packet switching network.
The term is used loosely. While some Internet
literature uses it to refer specifically to data sent across a physical network, other literature views the Internet as a packet switching network
and describes IP datagrams as packets.
PC Personal Computer PCNFS Personal Computer Network File System PPP Point-to-Point Protocol The Point-to-Point Protocol (PPP) provides a method for transmitting datagrams over serial point-to-point links.
A formal description of message formats and the rules two computers must follow to exchange those messages. Protocols can describe low-level details of
machine-to-machine interfaces (e.g., the order in which bits and bytes are sent across a wire)
or high-level exchanges between allocation
programs (e.g., the way in which two programs
transfer a file across the Internet).
RFC The Internet's Request for Comments documents series The RFCs are working notes of the Internet research and development community. A document in this series may be on essentially any topic related to computer communication, and may be anything from a meeting report to the specification of a standard.
RIP Routing Information Protocol One protocol which may be used on internets simply to pass routing information between gateways. It is used on many LANs and on some of the NSFNET intermediate level networks. RJE Remote Job Entry The general protocol for submitting batch jobs and retrieving the results.
router A special-purpose dedicated computer that attaches to
two or more networks and routes packets from one
network to the other. In particular, an Internet router forwards IP datagrams among the networks it connects. Gateways route packets to other
gateways until they can be delivered to the final destination directly across one physical network.
RPC Remote Procedure Call An easy and popular paradigm for implementing the client-server model of distributed computing.
server A computer that shares its resources, such as printers
and files, with other computers on the network. An
example of this is a Network Files System (NFS)
Server which shares its disk space with one or more workstations that may not have local disk drives of their own.
SLIP Serial Line Internet Protocol SLIP is currently a defacto standard, commonly used for point-to-point serial connections running TCP/IP. It is not an Internet standard but is defined in RFC 1055. SMTP Simple Mail Transfer Protocol The Internet standard protocol for transferring electronic mail messages from one computer to another. SMTP specifies how two mail systems interact and the format of control messages they exchange to transfer mail. SNA System Network Architecture IBM's data communications protocol. SNMP Simple Network Management Protocol The Simple Network Management Protocol (RFC 1157) is the Internet's standard for remote monitoring and management of hosts, routers and other nodes and devices on a network.
subnet A portion of a network, which may be a physically independent network, which shares a network address with other portions of the network and is distinguished by a subnet number. A subnet is to a network what a network is to an internet.
A part of the internet address which designates a subnet. It is ignored for the purposes internet routing, but is used for intranet routing.
T1 A term for a digital carrier facility used to transmit a DS-1 formatted digital signal at 1.544 megabits per second. T3 A term for a digital carrier facility used to transmit a DS-3 formatted digital signal at 44.746 megabits per second. TCP Transmission Control Protocol A transport layer protocol for the Internet. It is a connection oriented, stream protocol defined by RFC 793.
TCP/IP Transmission Control Protocol/Internet Protocol
This is a common shorthand which refers to the suite of application and transport protocols which run over IP. These include FTP, TELNET, SMTP, and UDP (a transport layer protocol).
Telenet A public packet-switching network operated by US Sprint. Also known as "SprintNet".
TELNET The Internet standard protocol for remote terminal
connection service. TELNET allows a user at one site
to interact with a remote timesharing system at
another site as if the user's terminal was connected directly to the remote computer.
A type of LAN. Examples are IEEE 802.5, ProNET-10/80 and FDDI. The term "token ring" is often used to denote 802.5
Tymnet A public character-switching/packet-switching network operated by British Telecom.
UDP User Datagram Protocol A transport layer protocol for the Internet. It is a datagram protocol which adds a level of reliability and multiplexing to IP datagrams. It is defined in RFC 768.
ULTRIX UNIX-based operating system for Digital Equipment Corporation computers.
UNIX An operating system developed by Bell Laboratories that supports multiuser and multitasking operations. UUCP UNIX-to-UNIX Copy Program A protocol used for communication between consenting UNIX systems. VMS Virtual Memory System A Digital Equipment Corporation operating system. WAN Wide Area Network WHOIS An Internet program which allows users to query a database of people and other Internet entities, such as domains, networks, and hosts, kept at the DDN NIC. The information for people shows a person's company name, address, phone number and email address. XNS Xerox Network System A data communications protocol suite developed by Xerox. It uses Ethernet to move the data between computers.
Security issues are not discussed in this memo.
Gary Scott Malkin
53 Third Avenue
Burlington, MA 01803
Phone: (617) 272-8140
April N. Marine
Network Information Systems Center
333 Ravenswood Avenue, EJ294
Menlo Park, CA 94025
Phone: (415) 859-5318