Re: 6.2 mtu now limits size of incomming packet

Artyom Viklenko wrote:

Artem Belevich wrote:


Here's one example where MTU!=MRU would be useful.

Think of asymmetric bandwith-limited ADSL links. Lower MTU would allow
lower TX latency for high priority packets when upstream is saturated,
yet large MRU on the downstream would be great for downloads.

Right now with 6.2 one has to trade off lower latency for faster download.

--Artem



You can prioritize small packets with ACKs, for example, by other
techniques - ALTQ one of them.
Unconditional lovering MTU even on ADSL tend to loss throughtput.

And let's think about TCP MSS. When TCP connection establishes,
TCP stack uses MTU as measure to choose MSS.

Any two hosts, connected to single Layer2 network MUST use
same MTU. Any other cases lead to hard-to-solve problems.

This is all IMHO. But I would not like to see different
MTU and MRU on my Ethernet interfaces! :)



Yes but the mss is what the endpoints in the connection know about their own mtu's,
at this point there is no knowledge of the mtu/mru's of intermediate routers.

Steve

--

"They that give up essential liberty to obtain temporary safety, deserve neither liberty nor safety." (Ben Franklin)

"The course of history shows that as a government grows, liberty decreases." (Thomas Jefferson)



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