IBM Systems Network Architecture (SNA)
The IBM Systems Network Architecture (SNA) is one of the most popular network architecture models. Although now considered a legacy networking model, SNA is still widely deployed. SNA was designed around the host-to-terminal communication model that IBM's mainframes use.
Standard Organization: IBM

ICMP: Internet Control Message Protocol
Interne Control Message Protocol (ICMP) is an integrated part of the IP suite. ICMP messages, delivered in IP packets, are used for out-of-band messages related to network operation or mis-operation. ICMP packet delivery is unreliable, so hosts can't count on receiving ICMP packets for any network problems.
Standard Organization: IETF
RFC792 and 950

ICMPv6: ICMP for IPv6
ICMP for IPv6 (ICMPv6) is a revision of ICMP for IPv6. The original Internet Control Message Protocol (ICMP) is designed for IP version 4. ICMPv6 is used by IPv6 nodes to report errors encountered in processing packets, and to perform other internet-layer functions, such as diagnostics (ICMPv6 "ping"). ICMPv6 is an integral part of IPv6 and must be fully implemented by every IPv6 node. In addition, the multicast control functions of the IPv4 Group Membership Protocol (IGMP) are now incorporated in the ICMPv6.
Standard Organization: IETF
RFC 2461, 2463

ICP: Internet Control Protocol in VINES
Internet Control Protocol(ICP), a network layer protocol in the Banyan VINES protocol stack, defines exception-notification and metric-notification packets. Exception-notification packets provide information about network layer exceptions; metric-notification packets contain information about the final transmission used to reach a client node.
Standard Organization: Banyan

IDP: Internet Datagram Protocol
Internet Datagram Protocol (IDP), a protocol in the Xerox protocol stack, is a simple, unreliable datagram protocol which is used to support the SOCK_DGRAM abstraction for the Internet Protocol (IP) family. IDP sockets are connectionless and normally used with the sendto and recvfrom subroutines. The connect subroutine can also be used to fix the destination for future packets, in which case the recv or read subroutine and the send or write subroutine can be used.
Standard Organization: Xerox

IDPR: Interdomain Policy Routing
Interdomain Policy Routing (IDPR) is an OSI exterior routing protocol that dynamically exchanges policies between autonomous systems. IDPR encapsulates interautonomous system traffic and routes it according to the policies of each autonomous system along the path.
Standard Organization: IETF
RFC 1479

IDRP: Inter-Domain Routing Protocol
The Inter-Domain Routing Protocol (IDRP), which provides routing for ISO defined network environments, is similar to BGP in the TCP/IP network. In an ISO network, there are End Systems, Intermediate Systems, Areas and Domains. End systems are user devices. Intermediate systems are routers. Routers are organized into local groups called 'areas', and several areas are grouped together into a 'domain'. Inter-Domain Routing Protocol (IDRP) is designed to provide routing among domains. IDRP, working in conjunction with CLNP, ES-IS, and IS-IS, provides complete routing over the entire network.
Standard Organization: ISO
ISO 10747

IDSL: ISDN Digital Subscriber Line
ISDN Digital Subscriber Line (IDSL) is a technology allowing existing ISDN subscribers to access the Internet using POTS dial service. Similar to ISDN, IDSL uses a single-wire pair to transmit full-duplex data at 128 kbps and at distances of up to RRD range, and IDSL uses a 2B1Q line code to enable transparent operation through the ISDN "U" interface. Also, the user can use existing ISDN CPE to make the CO connections. However, unlike ISDN, ISDL is terminated at the Service Provider by a data equipment instead of through the voice switch.
Standard Organization: ANSI/ITU

iFCP: Internet Fibre Channel Protocol
Internet Fibre Channel Protocol (iFCP) is a gateway-to-gateway protocol which provides fiber channel fabric services to fiber channel devices over a TCP/IP network. iFCP uses TCP to provide congestion control, error detection and recovery. iFCP's primary objective is to allow interconnection and networking of existing fiber channel devices at wire speeds over an IP network. The protocol and method of frame address translation defined permit the attachment of fiber channel storage devices to an IP-based fabric by means of transparent gateways.
Standard Organization: IETF
RFC 4172

IFMP: Ipsilon Flow Management Protocol
Ipsilon Flow Management Protocol (IFMP) is a protocol for allowing a node to instruct an adjacent node to attach a layer 2 label to a specified IP flow. The label allows more efficient access to cached routing information for that flow. The label can also enable a node to switch further packets belonging to the specified flow at layer 2 rather than forwarding them at layer 3.
Standard Organization: IETF

IGMP: Internet Group Management Protocol
Internet Group Management Protocol (IGMP), a multicasting protocol in the internet protocols family, is used by IP hosts to report their host group memberships to any immediately neighboring multicast routers. IGMP messages are encapsulated in IP datagrams, with an IP protocol number of 2. IGMP has versions IGMP v1, v2 and v3.
Standard Organization: IETF
RFC1112, RFC2236 and RFC3376

IGRP: Interior Gateway Routing Protocol
The Interior Gateway Routing Protocol (IGRP) is a routing protocol to provide routing within an autonomous system (AS). In the mid-1980s, the most popular interior routing protocol was the Routing Information Protocol (RIP). Although RIP was quite useful for routing within small- to moderate-sized, relatively homogeneous internetworks, its limits were being pushed by network growth. The popularity of Cisco routers and the robustness of IGRP encouraged many organizations with large internetworks to replace RIP with IGRP.
Standard Organization: Cisco

IIOP: Internet Inter-ORB Protocol
Internet Inter-ORB Protocol (IIOP) is a protocol used in the CORBA framework for accessing objects across the Internet. IIOP is the implementation of General Inter-ORB Protocol (GIOP) for TCP/IP. It is a concrete realization of the abstract GIOP definitions.
Standard Organization: OMG

IISP: Interim Inter-switch Signaling Protocol
Interim Inter-switch Signaling Protocol (IISP) is an ATM signaling protocol that provides static routing in ATM networks. It is a subset of the ATM NNI (Network-to-Network Interface) specification in which administrators need to manually configure routes. IISP, formerlly called PNNI 0, was an interim solution until PNNI Phase 1 is completed.
Standard Organization: ITU-T

IKE: Internet Key Exchange Protocol
Internet Key Exchange (IKE) Protocol is a key protocol in the IPsec architecture. IKE processes can be used for negotiating virtual private networks (VPNs) and also for providing a remote user from a remote site (whose IP address need not be known beforehand) access to a secure host or network. IKE is a hybrid protocol using part of Oakley and part of SKEME in conjunction with ISAKMP to obtain authenticated keying material for use with ISAKMP, and for other security associations such as AH and ESP for the IPsec DOI.
Standard Organization: IETF
RFC 2409

IKEv2: Internet Key Exchange version 2
Internet Key Exchange version 2 (IKEv2), a replacement for Internet Key Exchange (IKE), is an IPsec (Internet Protocol Security) standard protocol used to ensure security for virtual private network (VPN) negotiation and remote host or network access.
Standard Organization: IETF
RFC 4306

ILMI: Interim Local Management Interface
Interim Local Management Interface (ILMI) is an interim specification used to provide network management functions between end users and networks and between private and public networks in an ATM network. ILMI allows bi-direction exchange of management information between UNI Management Entities (UMEs) within UNI peers. Management information related to the Physical Layer, ATM Layer, Virtual Path Connections, Virtual Channel Connections, Address Registration, as well as ATM Layer Statistics, is represented in a standard MIB structure called the ATM UNI ILMI MIB.
Standard Organization: ITU-T

IMA: Inverse multiplexing over ATM
Inverse multiplexing over ATM (IMA) defines a sublayer-1 protocol for building a virtual link that consists of multiple physical T1 or E1 links. The IMA protocol handles link failure and automatic link recovery, and it also adds and deletes links while keeping the IMA group in service.
Standard Organization: ATM Forum

IMAP: Internet Message Access Protocol
Internet Message Access Protocol (IMAP) is a method of accessing electronic mail or bulletin board messages that are kept on a mail server. IMAP permits a "client" email program to access remote message stores as if they were local. Email stored on an IMAP server can be manipulated from a desktop computer remotely, without the need to transfer messages or files back and forth between these computers. The current version of IMAP is IMAP version 4.
Standard Organization: IETF

IMAP4: Internet Message Access Protocol version 4
Internet Message Access Protocol version 4 (IMAP4) is the current verson of IMAP, a method of accessing electronic mail or bulletin board messages that are kept on a mail server. IMAP permits a "client" email program to access remote message stores as if they were local. Email stored on an IMAP server can be manipulated from a desktop computer remotely, without the need to transfer messages or files back and forth between these computers. The Key features for IMAP4 include: Fully compatible with Internet messaging standards, e.g. MIME. Allows message access and management from more than one computer. Allows access without reliance on less efficient file access protocols. Provides support for "online", "offline" and "disconnected" access modes. Supports concurrent access to shared mailboxes Client software needs no knowledge about the server's file store format.
Standard Organization: IETF
RFC 3501

IMT-2000
International Mobile Telecommunication 2000 (IMT-2000) is a group of technologies defined by ITU-T for the third generation mobile telephony. It can also be applied to mobile telephone standards that meet a number of requirements in terms of transmission speed and other factors.
Standard Organization: ITU-T

INAP: Intelligent Network Application Part
Intelligent Network Application Part (INAP) is a signaling protocol used in the intelligent network architecture. It is part of the SS7/C7 protocol suite, typically layered on top of the TCAP protocol. INAP, a European parallel definition of IN standards based on the American AIN 0.1, is used to query databases for a variety of functions not related to call setup and tear down. The INAP messages are encoded using ASN.1. SCCP is used for the INAP message routing. TCAP is used to separate the transactions apart.
Standard Organization: ITU-T

InARP: Inverse Address Resolution Protocol
Inverse Address Resolution Protocol (InARP), also known as Inverse ARP, is an addition to ARP to provide address mapping in Frame Relay environment. Basic InARP operates essentially the same as ARP with the exception that InARP does not broadcast requests, since the hardware address of the destination station is already known in the Frame Relay network.
Standard Organization: IETF
RFC 2390

Integrated IS-IS: Integrated Intermediate System-to-Intermediate System
Integrated Intermediate System-to-Intermediate System (Integrated IS-IS), also known as Dual IS-IS, is a routing protocol based on the OSI routing protocol IS-IS but with support for IP and other protocols, in addition to OSI protocols. Integrated IS-IS implementations send only one set of routing updates, making it more efficient than two separate implementations.
Standard Organization: IETF
RFC 1195

IP: Internet Protocol
The Internet Protocol (IP) is a network layer (Layer 3 in the OSI model) protocol that contains addressing information and some control information to enable packets to be routed in a network. IP is the primary network layer protocol in the TCP/IP protocol suite. Along with the Transmission Control Protocol (TCP), IP represents the heart of the Internet protocols. IP is equally well suited for both LAN and WAN communications.
Standard Organization: IETF
RFC 791

IPBCP: IP Bearer Control Protocol
IP Bearer Control Protocol (IPBCP) is used for the exchange of media stream characteristics, port numbers and IP addresses of the source and sink of a media stream to establish and allow the modification of IP bearers. IPBCP is also known as BICC (Bearer Independent Call Control) IP Bearer Control Protocol, because it is suitable for use in IP network environments where the BICC protocol is deployed. The information exchanged with IPBCP is done during BICC call establishment. IPBCP can be used also in other environments.
Standard Organization: ITU-T
Q.1970

IPC: InterProcess Communications protocol
Interprocess Communication Protocol (IPC), a transport layer (layer 4) protocol in the VINES protocol stack, provides both datagram and reliable message delivery service.
Standard Organization: Banyan

IPCP: IP Control Protocol
IP Control Protocol (IPCP) define the Network Control Protocol for establishing and configuring the Internet Protocol (IPv4) over PPP, and a method to negotiate and use Van Jacobson TCP/IP header compression with PPP.
Standard Organization: IETF
RFC 1332

IPHC: IP Header Compression
IP Header Compression (IPHC) is a scheme to compress IP, TCP and UDP headers to increase bendwidth efficiency. It is necessary over low and medium bandwidth links such as dial up and wireless communications. The IP Header Compression defined in the IETF RFC 2507 supports compression of multiple IP headers including IPv4 and IPv6, UDP and TCP headers on a per hop basis. This header compression scheme compresses the UDP and TCP headers typically down to 2 to 5 bytes (without UDP or TCP checksum).
Standard Organization: IETF

IPsec AH: IPsec Authentication Header
IPsec Authentication Header (IPsec AH), a key protocol in the IPsec (Internet Security) architecture, is used to provide connectionless integrity and data origin authentication for IP datagrams, and to provide protection against replays. This latter (optional) service may be selected by the receiver when a Security Association is established. AH provides authentication for as much of the IP header as possible, as well as for upper level protocol data. However, some IP header fields may change in transit and the value of these fields when the packet arrives at the receiver may not be predictable by the sender.
Standard Organization: IETF
RFC 2402

IPsec IKE: Internet Key Exchange
IPsec Internet Key Exchange (IKE) Protocol is a key protocol in the IPsec architecture. IKE processes can be used for negotiating virtual private networks (VPNs) and also for providing a remote user from a remote site (whose IP address need not be known beforehand) access to a secure host or network. IKE is a hybrid protocol using part of Oakley and part of SKEME in conjunction with ISAKMP to obtain authenticated keying material for use with ISAKMP, and for other security associations such as AH and ESP for the IPsec DOI.
Standard Organization: IETF
RFC 2409

IPsec: IP Security
IP Security (IPsec) provides security services at the network layer by enabling a system to select required security protocols, determine the algorithm(s) to use for the service(s) and put in place any cryptographic keys required to provide the requested services. IPsec can be used to protect one or more "paths" between a pair of hosts, between a pair of security gateways or between a security gateway and a host.
Standard Organization: IETF
RFC 2401

IPv4: Internet Protocol version 4
Internet Protocol version 4 (IPv4), defined in the RFC 791, is the most widely deployed networking technology. When people talk about IP, most likely it refers to the IPv4. IPv6 is the new version of Internet Protocol (IP) based on IPv4. The Internet Protocol (IP) is a network-layer (Layer 3) protocol in the OSI model that contains addressing information and some control information to enable packets being routed in network. IP is the primary network-layer protocol in the TCP/IP protocol suite. Along with the Transmission Control Protocol (TCP), IP represents the heart of the Internet protocols.
Standard Organization: DARPA/IETF
RFC 791

IPv6: Internet Protocol version 6
Internet Protocol version 6 (IPv6) is the new version of Internet Protocol (IP) based on IPv4. It is a network-layer (Layer 3) protocol that contains addressing information and some control information enabling packets to be routed in the network. IPv6 is also called the next generation IP or IPng. .
Standard Organization: IETF
RFC 2460

IPv6CP: IPv6 Control Protocol
IPv6 Control Protocol (IPv6CP) defines the Network Control Protocol for establishing and configuring the IPv6 over PPP, and a method to negotiate and use Van Jacobson TCP/IP header compression with PPP.
Standard Organization: IETF
RFC 2472

IPX: Internetwork Packet Exchange
Internetwork Packet Exchange (IPX) is the legacy network protocol used by the Novell NetWare operating systems to route packets through an internetwork. IPX is a datagram protocol used for connectionless communicationssimilar to IP (Internet Protocol) in the TCP/IP suite. Higher-level protocols, such as SPX and NCP, are used for additional error recovery services.
Standard Organization: Novell

IPXCP: IPX PPP Control Protocol
IPX PPP Control Protocol (IPXCP), a protocol in the Novell NetWare stack, is for the configuration of the IPX network-layer protocol over PPP.
Standard Organization: Novell

IPXWAN: Novell IPX over Various WAN Media
IPXWAN is a protocol of Novell IPX over Various WAN Media that negotiates end-to-end options for new links. When a link comes up, the first IPX packets sent across are IPXWAN packets negotiating the options for the link. When the IPXWAN options have been successfully determined, normal IPX transmission begins.
Standard Organization: IETF
RFC 1634

IRCP: Internet Relay Chat Protocol
Internet Relay Chat Protocol (IRCP), which is well-suited to running on many machines distributely, enables teleconferencing on the Internet. The IRC protocol has been developed on systems using the TCP/IP network protocol, although there is no requirement that this remains the only environment in which it operates. The IRC protocol is a text-based protocol, with the simplest client being any socket program capable of connecting to the server.
Standard Organization: IETF
RFC 1459

IRDP: ICMP Router Discovery Protocol
ICMP Router Discovery Protocol (IRDP) enables a host to determine the address of a router that it can use as a default gateway. IRDP is similar to ES-IS in the OSI network but used with IP.
Standard Organization: IETF
RFC 1256

ISAKMP: Internet Security Association and Key Management Protocol
Internet Security Association and Key Management Protocol (ISAKMP), a key protocol in the IPsec (Internet Security) architecture, combines the security concepts of authentication, key management and security associations to establish the required security for government, commercial and private communications on the Internet.
Standard Organization: IETF
RFC 2408

iSCSI: Internet Small Computer System Interface
Internet Small Computer System Interface (iSCSI) is a TCP/IP-based protocol for establishing and managing connections between IP-based storage devices, hosts and clients, for creating a Storage Area Network (SAN). The SAN makes possible to use the SCSI protocol in network infrastructures for high-speed data transfer at the block level between multiple elements of data storage networks.
Standard Organization: IETF
RFC 3347 and RFC 3720

ISDN: Integrated Services Digital Network
Integrated Services Digital Network (ISDN) is a system with digitized phone connections. For decades, telephony has used purely analogue connections. This is the first protocol to define a digital communications line that allows for the transmission of voice, data, video and graphics, at high speeds, over standard communication lines. The various media are simultaneously carried by bearer channels (B channels) occupying a bandwidth of 64 kbits per second (some switches limit bandwidth to 56 kb/s). A defined data channel (D channel) handles signaling at 16 kb/s or 64 kb/s, depending on the service type.
Standard Organization: ITU-T

IS-IS: Intermediate System-to-Intermediate System
Intermediate System-to-Intermediate System (IS-IS) is a routing protocol developed by the ISO. It is a link-state protocol where ISs (routers) exchange routing information based on a single metric to determine network topology. It behaves similarly to Open Shortest Path First (OSPF) in the TCP/IP network.
Standard Organization: ISO

ISL: Inter-Switch Link Protocol
Inter-Switch Link. Protocol (ISL), a Cisco proprietary protocol, maintains VLAN information as traffic flows between switches and routers. Inter-Switch Link (ISL) tagging accomplishes the same task as 802.1Q trunking but uses a different frame format. ISL trunks are Cisco proprietary and define only a point-to-point connection between two devices, typically switches. The name Inter-Switch Link hints at this design. ISL frame tagging uses a low-latency mechanism for multiplexing traffic from multiple VLANs on a single physical path.
Standard Organization: Cisco

iSNS: Internet Storage Name Service
Internet Storage Name Service (iSNS) facilitates scalable configuration and management of iSCSI and Fibre Channel (FCP) storage devices in an IP network, by providing a set of services comparable to that available in Fibre Channel networks. iSNS thus allows an IP network to function at a comparable level of intelligence to a Fibre Channel fabric. iSNS allows the administrator to go beyond a simple device-by-device management model, where each storage device is manually and individually configured with its own list of known initiators and targets.
Standard Organization: IETF
RFC 4171

iSNSPL: Internet Storage Name Service Protocol
Internet Storage Name Service Protocol (iSNSP) is a flexible and lightweight protocol that specifies how Internet Storage Name Service (iSNS) clients and servers communicate. It is suitable for various platforms, including switches and targets as well as server hosts.
Standard Organization: IETF
RFC 4171

ISO Protocols
ISO Protocols are a group of protocols defned by the nternational Organization for Standardization (ISO based on the Open Systems Interconnection (OSI) model. The OSI model defines the communications process into 7 layers, dividing the tasks involved in moving information between networked computers into seven smaller, more manageable task groups.
Standard Organization: ISO

ISO VTP: ISO Virtual Terminal service and protocol
The ISO Virtual Terminal (VT) service and protocol (VTP) allows a host application to control a terminal with screen and keyboard and similar devices, like printers. In addition, VTP also supports the less common application-application and terminal-terminal communication.
Standard Organization: ISO
ISO 9040

ISO-IP: ISO Internetworking Protocol
ISO Internetworking Protocol refers to the Connectionless Network Protocol(CLNP) as the primary network layer protocol in an OSI network. It is similar to the IP (Internet Protocol) in the TCP/IP network.
Standard Organization: ISO / ITU-T
X.213

ISO-PP: ISO Presentation Protocol
The ISO Presentation Protocol (ISO-PP) is for information transit between open systems using connection oriented or connectionless mode transmission at the presentation layer of the OSI 7 layer model. An application protocol is specified in terms of the transfer of presentation data values between application entities (PS users), using the User data parameter of presentation service primitives.
Standard Organization: ISO / ITU-T
X.216

ISO-SP: OSI Session Layer Protocol
The OSI Session Layer Protocol (ISO-SP) provides session management, e.g. opening and closing of sessions. In case of a connection loss, it tries to recover the connection. If a connection is not used for a longer period, the session layer may close it down and re-open it for next use. This happens transparently to the higher layers. The Session layer provides synchronization points in the stream of exchanged packets.
Standard Organization: ISO / ITU-T
X.215

ISO-TP: OSI Transport Protocol
The OSI Transport Protocol (ISO-TP) manages end-to-end control and error checking to ensure complete data transfer. It performs transport address to network address mapping, makes multiplexing and splitting of transport connections and also provides functions such as Sequencing, Flow Control and Error detection and recover.
Standard Organization: ISO / ITU-T
X.214

ISUA: SS7 ISUP-User Adaptation Layer
SS7 ISUP-User Adaptation Layer (ISUA), an integral part of the OpenSS7 SIGTRAN stack, is an SS7 Signalling User Adaptation Layer for providing ISUP-User signalling over SCTP. ISUA is intended to be used on a Provider/User basis where ISUP resides on a Signalling Gateway (SG) and ISUP call control applications reside on an Application Server (AS).
Standard Organization: IETF
RFC 4233

ISUP: ISDN User Part
The ISDN User Part (ISUP), a key protocol in the SS7/C7 signaling system, defines the protocol and procedures used to set-up, manage and release trunk circuits that carry voice and data calls over the public switched telephone network (PSTN) between different switches. ISUP is used for both ISDN and non-ISDN calls.
Standard Organization: ITU-T

ITOT: ISO Transport Service on top of TCP
ISO Transport Service on top of TCP (ITOT) is a mechanism that enables ISO applications to be ported to a TCP/IP network. There are two basic approaches which can be taken when "porting" ISO applications to TCP/IP (and IPv6) environments. One approach is to port each individual application separately, developing local protocols on top of TCP. A second approach is based on the notion of layering the ISO Transport Service over TCP/IP
Standard Organization: ISO

IUA: ISDN Q.921-User Adaptation Layer
ISDN Q.921-User Adaptation Layer(IUA), a protocol in the SIGTRAN protocol suite, defines a method for backhauling of ISDN Q.921 User messages over IP using the Stream Control Transmission Protocol (SCTP). IUA is used between a Signaling Gateway (SG) and Media Gateway Controller (MGC). It is assumed that the SG receives ISDN signaling over a standard ISDN interface.
Standard Organization: IETF
RFC 4233