What is "jumbogram"

In packet-switched computer networks, a jumbogram ( portmanteau of jumbo and datagram) is an internet layer packet exceeding the standard maximum transmission unit (MTU) of the underlying network technology.

Large packets for link layer technologies are referred to as jumbo frames.

The payload length field of IPv4 and IPv6 has a size of 16 bits, thus allowing data of up to . This theoretical limit for the Internet Protocol (IP) MTU, however, is reached only on networks that have a suitable Link Layer infrastructure.

While IPv4 has no facilities to exceed its theoretical IP MTU limit, the designers of IPv6 have provided a protocol extension to permit packets of larger size. Thus, in the context of IPv6, a jumbogram is understood as an IPv6 packet carrying a payload larger than .