Editing Maximum transmission unit (section)

==Tradeoffs==
A larger MTU brings greater efficiency because each [[network packet]] carries more user data while protocol overheads, such as headers or underlying per-packet delays, remain fixed; the resulting higher efficiency means an improvement in bulk protocol throughput. A larger MTU also requires processing of fewer packets for the same amount of data. In some systems, per-packet-processing can be a critical performance limitation.

However, this gain is not without a downside. Large packets occupy a link for more time than a smaller packet, causing greater delays to subsequent packets, and increasing [[network delay]] and [[delay variation]]. For example, a 1500-byte packet, the largest allowed by Ethernet at the network layer, ties up a [[14.4k modem]] for about one second.

Large packets are also problematic in the presence of communications errors. If no [[forward error correction]] is used, corruption of a single bit in a packet requires that the entire packet be retransmitted, which can be costly. At a given [[bit error rate]], larger packets are more susceptible to corruption. Their greater payload makes retransmissions of larger packets take longer. Despite the negative effects on retransmission duration, large packets can still have a net positive effect on end-to-end TCP performance.<ref>{{cite book|last=Murray|first=David |author2=Terry Koziniec |author3=Kevin Lee |author4=Michael Dixon |doi=10.1109/HPSR.2012.6260832 |isbn=978-1-4577-0833-6 |chapter=Large MTUs and internet performance |title=2012 IEEE 13th International Conference on High Performance Switching and Routing |pages=82–87 |year=2012 |s2cid=232321 |chapter-url=http://researchrepository.murdoch.edu.au/id/eprint/9920/ }}</ref>