IPv4 (Internet Protocol version 4)

• Protocol: 8 bits identifying the higher-layer protocol that created the message contained in the Data field. Examples include Transmission Control Protocol (TCP) and User Datagram Protocol (UDP).

• Header Checksum: 16 bits used for error control in the header.The process is that of a cyclic redundancy check (CRC).

• Source IP Address: 32 bits containing the IP address of the source host.

• Destination IP Address: 32 bits containing the IP address of the destination host.

• IP Options, If Any: An optional, variable-length field used by gateways to control fragmentation and routing options.

• Padding: A variable-length field used only when necessary to ensure that the IP header extends to an exact multiple of 32 bits.

• Data: A variable-length field that contains the actual data content, or payload.

See also bandwidth, best effort, connectionless, CRC, datagram, dial-up, dotted decimal notation, error control, IETF, IPv4, IPv4 address, IPv6, gateway, header, host, Internet, network, Network Layer, octet, OSI Reference Model, packet, payload, PPP, protocol, QoS, router, segmentation, SLIP, TCP, TCP/ IP protocol suite, and UDP.

• 1A
• 1A1
• 1A2
• 1Base5 (1 Mbps; Baseband; 500 meters)
• 1B+D
• 1. Domain Name System. The naming convention that divides the Internet into logical domains identified in Internet Protocol version 4 (IPv4) as a 32-bit portion of the total address.The standard convention is user@organization.domain, where user is the name of the end user, organization is the name of the enterprise or other organization owning or sponsoring the address, and domain is the type of entity owning or sponsoring the address.The administration of the DNS is the responsibility of Internet Corporation for Assigned Names and Numbers (ICANN). See also domain, ICANN, Internet, and IPv4. 2.
• 1. In storage, irrelevant material, usually zero (0) bits, added to a data block in order to fill it to a minimum size, to force certain fields of control data or user data into certain positions or sizes, or to prevent the user data from duplicating a bit pattern that has a specific control meaning. See also block. 2.
• 1 cps, 1 Hz
• 1+ Dialing
• 1G (1st Generation)
• 1G (1st Generation)
• 1-persistent carrier sense multiple access (1-Persistent CSMA)
• 1-Persistent CSMA (1-Persistent Carrier Sense Multiple Access)
• 1+ WATS
• 1xEV-DO (one carrier EVolution-Data Optimized)
• 1xRTT (one times Radio Transmission Technology)
• 2
• 20
• 2:1
• 2:1
• 2:1
• 218–219 MHz Service
• 22
• 23B+D
• 23B+D