Jumbo frame

In computer networking, jumbo frames are Ethernet frames with more than 1500 bytes of payload, the limit set by the IEEE 802.3 standard. The payload limit for jumbo frames is variable: while 9000 bytes is the most commonly used limit, smaller and larger limits exist. Many Gigabit Ethernet switches and Gigabit Ethernet network interface controllers and some Fast Ethernet switches and Fast Ethernet network interface cards can support jumbo frames. Each Ethernet frame must be processed as it passes through the network. Processing the contents of a single large frame is preferable to processing the same content broken up into smaller frames, as this makes better use of available CPU time by reducing interrupts. This also minimizes the overhead byte count and reduces the number of frames needing to be processed. This is analogous to physically mailing a packet of papers instead of several single envelopes with one sheet each, saving envelopes and cutting sorting time. Jumbo frames gained initial prominence in 1998, when Alteon WebSystems introduced them in their ACEnic Gigabit Ethernet adapters. Many other vendors also adopted the size; however, jumbo frames are not part of the official IEEE 802.3 Ethernet standard. Jumbo frames have the potential to reduce overheads and CPU cycles and have a positive effect on end-to-end TCP performance. The presence of jumbo frames may have an adverse effect on network latency, especially on low-bandwidth links. The frame size used by an end-to-end connection is typically limited by the lowest frame size in intermediate links. 802.5 Token Ring can support frames with a 4464-byte MTU, FDDI can transport 4352-byte, ATM 9180-byte and 802.11 can transport 7935-byte MTUs. The IEEE 802.3 Ethernet standard originally mandated support for 1500-byte MTU frames, 1518 byte total frame size (1522 byte with the optional IEEE 802.1Q VLAN/QoS tag). The IEEE 802.3as update grandfathered in multiple common headers, trailers, and encapsulations by creating the concept of an envelope where up to 482 bytes of header and trailer could be included, and the largest IEEE 802.