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We have 2 PC with Ubuntu 12.04 and connect with 1000M/bit cable. Then start iperf on both PC and get 900m/bit speed in iftop util.

But when on 1-st PC setup PPPoE server and on 2-d PC PPPoE client, and direct iperf in PPPoE, we get only 430 m/bit.

Is it normal that PPPoE on linux so slow? Is any way to get speed as in direct connection or nearly?

share|improve this question
What is the MTU of the PPPoe session? – jwbensley Apr 9 '13 at 19:17
MTU size for pppoe interface 1492 – savva Apr 10 '13 at 11:45
What happens if you lower the MTU, to 1472 for example? Also, what sort of MSS do you have? – NickW Apr 10 '13 at 16:23
What is the cpu usage when running the PPPoE test? – jwbensley Apr 10 '13 at 16:52

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