In computer networking, the interpacket gap (IPG), also known as interframe spacing, or interframe gap (IFG), is a pause which may be required between network packets or network frames. Depending on the physical layer protocol or encoding 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.
Ethernet
Ethernet devices must allow a minimum idle period between transmission of Ethernet packets<!-- intentional redirect -->.
!Ethernet variant
!Minimum transmitted IPG
!Minimum received IPG
|-
|10 Mbit/s Ethernet
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| (47 bit times)
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|100 Mbit/s (Fast) Ethernet
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| (96 bit times)
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|Gigabit Ethernet
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| (64 bit times)
|-
|2.5 Gigabit Ethernet
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| (40 bit times)
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|5 Gigabit Ethernet
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| (40 bit times)
|-
|10 Gigabit Ethernet
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| (40 bit times)
|-
|25 Gigabit Ethernet
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| (40 bit times)
|-
|40 Gigabit Ethernet
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| (8 bit times)
|-
|50 Gigabit Ethernet
|
| (8 bit times)
|-
|100 Gigabit Ethernet
|
| (8 bit times)
|-
|200 Gigabit Ethernet
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| (8 bit times)
|-
|400 Gigabit Ethernet
|
| (8 bit times)
|}
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, there is a sequence of primitives between successive frames, sometimes called interframe gap as well. The minimum sequence consists of six primitives, <code>IDLE|IDLE|R_RDY|R_RDY|IDLE|IDLE</code>. 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.