# Broadband IP Network: Upstream MTU Setting



## Vazdan64 (Nov 14, 2010)

I have a at&t U-Verse Broadband internet connection. And upon looking around with my modem connection settings; I came across something I did not understand-or what it was. An "Upstream MTU" setting.

What does this setting do? Does this setting need to be raised for performance?


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## Rivendale (Sep 17, 2010)

hello, 

MTU is "maximum transmission unit".

it specifies the maximum packet size permitted for transmission using a specific protocol

you can *not *set this larger than what is provided by the upstream, or packets will be truncated and you will loose communication

you want it as large as possible for best performance however

some routers will get this value from the ISP, others will have a setting

you can try 1492, a common default, but only the ISP or WAN administrator can tell you the optimum value

Riv


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