Glossary
G
37 terms.
- Galois Counter Mode
A way of using a block cipher such as AES that encrypts data and also produces an authentication tag, so one operation gives both secrecy and tamper detection.
Plain language A cipher mode that encrypts data and produces an authentication tag simultaneously.
Used in RFC 4106 RFC 5288 RFC 5289 RFC 5647 RFC 6209 RFC 8645
- Galois Field
A finite field, a set with a fixed number of elements where addition and multiplication are defined. GF(2^8) has 256 elements, each represented as a byte.
Plain language A finite field with fixed elements where addition and multiplication are defined.
- Gateway
The older name, used in RFC 791 and RFC 792, for a device that forwards datagrams between networks. Today it is called a router.
Plain language The older term (from RFC 791-792) for a device forwarding datagrams between networks.
Used in RFC 675 RFC 777 RFC 781 RFC 791 RFC 792 RFC 810 RFC 811 RFC 814 RFC 816 RFC 823 RFC 824 RFC 827 RFC 828 RFC 831 RFC 840 RFC 872 RFC 875 RFC 879 RFC 888 RFC 891 RFC 896 RFC 898 RFC 904 RFC 911 and 203 more
- Generalized label
An RSVP object that carries the label assigned to a label switched path, traveling upstream in Resv messages. Its value is defined by the companion functional description RFC 3471 and can name a time slot, a wavelength or a fiber rather than a packet label.
Plain language The name of the circuit a path uses; in GMPLS it can be a time slot, a wavelength or a fiber, not just a packet label.
- Generalized TTL Security Mechanism
A defense that sends packets with the maximum TTL or Hop Limit (255) and drops those that arrive with a lower value, so only directly connected senders are accepted.
Plain language Generalized TTL Security Mechanism, accepting only packets from directly connected senders.
- Generic Associated Channel
A control channel carried in-band alongside an LSP, pseudowire or section, used for OAM and similar adjunct traffic. It is signaled by an Associated Channel Header and a G-ACh Label.
Plain language An in-band control channel alongside an LSP for OAM and adjunct traffic.
- Generic Routing Encapsulation (GRE)
A tunnelling method that wraps packets of an arbitrary protocol inside IP so they can cross a network that does not understand them.
Plain language A tunneling method wrapping arbitrary protocols inside IP for crossing incompatible networks.
- Generic Top-Level Domain
A top-level domain that is not country-specific, such as .COM (commercial), .ORG (organization), or .NET (network). Distinguished from country-code TLDs like .UK or .FR.
- Geneve
Generic Network Virtualization Encapsulation, a flexible and extensible overlay protocol that encapsulates network packets for transport across underlying physical networks.
Plain language Generic Network Virtualization Encapsulation, a flexible overlay protocol for encapsulating network packets.
- Geofeed
A self-published file, in comma-separated values form, that associates IP address prefixes with geographic locations. Its format is defined in RFC 8805.
- Geolocation
Determining the geographic location of a device, usually expressed as latitude and longitude with associated uncertainty.
Plain language Determining a device's geographic location expressed as latitude and longitude.
- Glare
A clash that happens when both sides try to send a new offer at the same time. The higher layer protocol has to resolve it.
Plain language A clash when both sides attempt simultaneous offers requiring protocol resolution.
- Glue record
An IP address published in a parent zone for a name server whose name lies inside the zone it serves, so that resolvers can find the server at all.
Plain language An IP address in a parent zone for a name server whose name is inside its zone.
Used in RFC 1207 RFC 1912 RFC 3375 RFC 3732 RFC 4697 RFC 4932 RFC 5732 RFC 5936 RFC 7477 RFC 9471 RFC 9499 RFC 10001
- Glyph
The visual shape of a single character or symbol in a font. A font file contains glyphs for many characters.
Plain language The visual representation of a single character or symbol in a font.
- GMAC
The message authentication mode of Galois/Counter Mode. It authenticates data without encrypting anything and produces an authentication tag.
Plain language Galois/Counter Mode authentication, producing an authentication tag without encryption.
- GMPLS
Generalized Multi-Protocol Label Switching extends the MPLS control plane beyond packets to time-division, wavelength and fiber switching.
Plain language Generalized Multi-Protocol Label Switching extending MPLS to wavelength and fiber switching.
Used in RFC 3471 RFC 3472 RFC 3473 RFC 4054 RFC 4139 RFC 4202 RFC 4204 RFC 4207 RFC 4208 RFC 4209 RFC 4655 RFC 4783 RFC 4847 RFC 4920 RFC 4929 RFC 5063 RFC 5146 RFC 5150 RFC 5151 RFC 5307 RFC 5317 RFC 5440 RFC 5493 RFC 5511 and 34 more
- Go Ahead (GA)
The Telnet command (249) a process sends when it has finished sending output and has nothing queued from the keyboard, so a half-duplex terminal knows to pass control back to the user.
Plain language Telnet command indicating transmission complete so a half-duplex terminal yields control.
Used in RFC 560 RFC 596 RFC 726 RFC 764 RFC 854 RFC 857 RFC 858 RFC 1043
- GOAWAY
An HTTP/3 control stream frame (type 0x07) that tells the peer to stop starting new requests so the connection can shut down gracefully, while requests already in flight can finish.
Plain language HTTP/3 control frame telling peers to finish in-flight requests before closing.
Used in RFC 9114
- Goodput
The application-layer throughput delivered to the destination, excluding retransmitted or lost bits.
Plain language Application-layer throughput excluding retransmitted or lost data.
Used in RFC 2647 RFC 3511 RFC 5166 RFC 7928 RFC 8238 RFC 8239 RFC 8289 RFC 8868
- Gopher
An early Internet protocol for browsing menus of documents and directories and for searching them. It was widely implemented in the early 1990s.
Plain language An early Internet protocol for browsing document menus and searching, used in the early 1990s.
Used in RFC 1588 RFC 1689 RFC 1727 RFC 1736 RFC 1739 RFC 1855 RFC 1941 RFC 4266
- Grace period
A window after a registry action during which the client can delete the object and receive a credit for what that action cost. EPP defines several, such as the add and renew periods.
Plain language A window after a registry action during which deletion refunds the action cost.
- Graceful restart
A way for a router to restart its control plane while its neighbors and its own forwarding keep working, so traffic is not disrupted.
Plain language Router restart where the control plane restarts while forwarding continues.
Used in RFC 3473 RFC 3478 RFC 3612 RFC 3623 RFC 4167 RFC 5063 RFC 5187 RFC 5495 RFC 5882 RFC 5919 RFC 7356 RFC 7770 RFC 7911 RFC 8538 RFC 8706 RFC 9494
- Grandmaster clock
A master clock that gets its time from a locally attached clock device, not through the network, and then distributes that time to other clocks.
Plain language A master clock receiving time from a local device and distributing it to other clocks.
- Grant type
In OAuth, a method a client uses to obtain an access token. RFC 6749 defines authorization code, implicit, resource owner password credentials and client credentials.
Plain language In OAuth, a method for clients to obtain access tokens, such as authorization code.
- Granule position
An increasing position number stored in an Ogg page header, whose meaning depends on the codec of that logical bitstream.
Plain language A position number in an Ogg page whose meaning depends on the logical bitstream's codec.
- GRASP
The GeneRic Autonomic Signaling Protocol, which ASAs use to discover each other, synchronize configuration, negotiate resource allocation, and distribute information across the autonomic network.
- Gratuitous ARP
An ARP packet a host sends about its own address without anyone asking, used to refresh other hosts' tables or to notice that another host already uses the same address. Common practice; RFC 826 does not use this name.
Plain language An ARP packet a host sends about its own address to refresh tables or detect duplicates.
Used in RFC 826 RFC 2002 RFC 2006 RFC 2281 RFC 2338 RFC 3344 RFC 3927 RFC 5227 RFC 5798 RFC 5944 RFC 6820 RFC 7342 RFC 8302 RFC 8388 RFC 9047 RFC 9135 RFC 9161 RFC 9568
- GRE
Generic Routing Encapsulation, a protocol for wrapping an arbitrary protocol inside another arbitrary network-layer protocol so it can cross a network as a tunnel.
Plain language Generic Routing Encapsulation, wrapping arbitrary protocols inside other protocols for tunneling.
Used in RFC 1702 RFC 1853 RFC 2341 RFC 2637 RFC 2890 RFC 5332 RFC 5565 RFC 5640 RFC 5845 RFC 6037 RFC 8086 RFC 8903 RFC 9601
- GREASE
"Generate Random Extensions And Sustain Extensibility", the practice of sending reserved or random values so that implementations keep handling unknown ones correctly (RFC 8701). ECH clients send a GREASE ECH extension when they have no real configuration.
Plain language The practice of sending reserved or random values to keep implementations handling unknown ones correctly.
- Group Controller and Key Server (GCKS)
The entity that authenticates and authorizes members of a secure group, creates the group's keys, and distributes them in registration and rekey messages.
Plain language The entity authenticating secure group members, creating group keys and distributing them.
- Group Security Association (GSA)
The set of security associations for a secure group, made up of a Registration SA, an optional Rekey SA and a Data SA.
Plain language The set of security associations for a secure group including registration and data SAs.
- GRTT
The group round-trip time, a conservative estimate by the sender of the worst-case round trip from the sender to any receiver in the group. NACK timers are scaled from it.
Plain language Group round-trip time, an estimate by the sender of worst-case round trip to any receiver.
- GRUU
A Globally Routable User Agent URI is an address that identifies one specific SIP user agent instance and can be reached from anywhere. It is defined in RFC 5627.
Plain language Globally Routable User Agent URI, an address reaching one specific SIP user agent instance.
Used in RFC 4538 RFC 5359 RFC 5627 RFC 5628 RFC 5767 RFC 6665 RFC 7247 RFC 7572 RFC 7647 RFC 7904
- GSER
Generic String Encoding Rules, a method for encoding ASN.1 values as strings rather than in binary formats, primarily used for human-readable data representation.
- GSS-API
Generic Security Service Application Program Interface, a standard API that lets applications use different security mechanisms underneath, such as Kerberos or NTLM.
Plain language Generic Security Service API letting applications use different security mechanisms underneath.
Used in RFC 1731 RFC 1961 RFC 1964 RFC 2025 RFC 2078 RFC 2203 RFC 2228 RFC 2478 RFC 2743 RFC 2744 RFC 2847 RFC 3645 RFC 4121 RFC 4178 RFC 4401 RFC 4462 RFC 5056 RFC 5178 RFC 5403 RFC 5587 RFC 5801 RFC 6339 RFC 6649 RFC 6680 and 8 more
- Guard band
A safety margin around each marking change, covering clock error and network delay, so that packets are counted in the right block. Counters must be read outside it.
- GUID
A Globally Unique Identifier (GUID) is a 128-bit number designed to be unique across all computers and time, used to identify specific machines or objects.
Plain language Globally Unique Identifier, a 128-bit number designed to uniquely identify objects and machines.