computer networking A computer network is a collection of communicating computers and other devices, such as printers and smart phones. In order to communicate, the computers and devices must be connected by wired media like copper cables, optical fibers, or b ...

, the interpacket gap (IPG), also known as interframe spacing, or interframe gap (IFG), is a pause which may be required between

network packet In telecommunications and computer networking, a network packet is a formatted unit of Data (computing), data carried by a packet-switched network. A packet consists of control information and user data; the latter is also known as the ''Payload ...

s or network frames. Depending on the

physical layer In the seven-layer OSI model of computer networking, the physical layer or layer 1 is the first and lowest layer: the layer most closely associated with the physical connection between devices. The physical layer provides an electrical, mechani ...

protocol or

encoding In communications and Data processing, information processing, code is a system of rules to convert information—such as a letter (alphabet), letter, word, sound, image, or gesture—into another form, sometimes data compression, shortened or ...

used, the pause may be necessary to allow for receiver clock recovery, permitting the receiver to prepare for another packet (e.g. powering up from a low-power state) or another purpose. It may be considered as a specific case of a

guard interval In telecommunications Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information over a distance using electronic means, typically through cables, radio waves, or other communication techno ...

Ethernet

Ethernet Ethernet ( ) is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...

devices must allow a minimum idle period between transmission of Ethernet packets. A brief recovery time between packets allows devices to prepare for reception of the next packet. While some physical layer variants literally transmit nothing during the idle period, most modern ones continue to transmit an idle pattern signal. The standard minimum interpacket gap for transmission is 96 bit times (the time it takes to transmit 96 bits of data on the medium). The time is measured from the end of the frame check sequence of one frame to the start of the

preamble A preamble () is an introductory and expressionary statement in a document that explains the document's purpose and underlying philosophy. When applied to the opening paragraphs of a statute, it may recite historical facts pertinent to the su ...

for the next. During data reception, some interpacket gaps may be smaller due to variable network delays, clock tolerances (all speeds), and the presence of repeaters (10 Mbit/s only). Some manufacturers design adapters transmitting with a smaller interpacket gap for slightly higher data transfer rates. That can lead to data loss when mixed with standard adaptors.

Fibre Channel

For

Fibre Channel Fibre Channel (FC) is a high-speed data transfer protocol providing in-order, lossless delivery of raw block data. Fibre Channel is primarily used to connect computer data storage to Server (computing), servers in storage area networks (SAN) in ...

, there is a sequence of primitives between successive frames, sometimes called ''interframe gap'' as well. The minimum sequence consists of six primitives, IDLE, IDLE, R_RDY, R_RDY, IDLE, IDLE. Each primitive consists of four channel words of 10 bits each for 8b/10b encoded variants (1–8 Gbit/s), equivalent to four data bytes.FC-PH REV 4.3, June 1, 1994, Table 25 ''Primitive Signals''

References

{{Reflist Ethernet