Editing Maximum transmission unit (section)

{{Short description|Size of largest allowed packet on a network segment}}

In [[computer networking]], the '''maximum transmission unit''' ('''MTU''') is the size of the largest [[protocol data unit]] (PDU) that can be communicated in a single [[network layer]] transaction.{{Ref RFC|791|rp=25}} The MTU relates to, but is not identical to the maximum [[Frame (networking)|frame]] size that can be transported on the [[data link layer]], e.g., [[Ethernet frame]].

Larger MTU is associated with reduced [[overhead (computing)|overhead]]. Smaller MTU values can reduce [[network delay]]. In many cases, MTU is dependent on underlying network capabilities and must be adjusted manually or automatically so as to not exceed these capabilities. MTU parameters may appear in association with a communications interface or standard. Some systems may decide MTU at connect time, e.g. using [[Path MTU Discovery]].