... this is the question.
After i've published the description of the ng_state module I've got several comments stain policing is much worse then shaping in ISP applications.
We already came through this in 2008 when we've switched from shaping to policing on our PPTP servers. That time tests shown policing has much worse user expereince quality on speeds below 256Kbits.
Today's lowest CIR is 6Mbits, and most of our customers enjoys CIRs more then 10Mbit.
So, i decided to retest.
The test should prove that shaping gives noticeable positive difference in network software behavior.
We put one PC after policing/shaping device.
About ten peoples was asked to go through 4 tests: policing and shaping on speeds 3Mbit and 6Mbit. We reduced the speeds because rate-limit artifacts more noticeable on lower bandwidth.
Each tester didn't know which exact test he is performing. After completing all 4 tests, the tester should grade each test on 1..5 scale.
So, the result was surprising: most testers preferred 'rate-limit' experience, about 60% of tests with same speeds.
Overall, most testers graded experience with high marks (4 or 5) and summary of grades for 3 and 6Mbits is very close.
So the final result : user experience is at least not worse with rate-limit then with shaping.
Maybe one of the reasons is CIRs are so high these days that most interactive applications, like Web surf, online video, games can not reach the limits.
Graph, re-transmissions, packet lost are 'better' with shaping, but if doesn't affect quality of work and at the same time is much more expensive in terms of hardware, then it's a good reason not to use it. And more - I've never heard from the Support team someone complaining about speed graph is not narrow.
After i've published the description of the ng_state module I've got several comments stain policing is much worse then shaping in ISP applications.
We already came through this in 2008 when we've switched from shaping to policing on our PPTP servers. That time tests shown policing has much worse user expereince quality on speeds below 256Kbits.
Today's lowest CIR is 6Mbits, and most of our customers enjoys CIRs more then 10Mbit.
So, i decided to retest.
The test should prove that shaping gives noticeable positive difference in network software behavior.
We put one PC after policing/shaping device.
About ten peoples was asked to go through 4 tests: policing and shaping on speeds 3Mbit and 6Mbit. We reduced the speeds because rate-limit artifacts more noticeable on lower bandwidth.
Each tester didn't know which exact test he is performing. After completing all 4 tests, the tester should grade each test on 1..5 scale.
So, the result was surprising: most testers preferred 'rate-limit' experience, about 60% of tests with same speeds.
Overall, most testers graded experience with high marks (4 or 5) and summary of grades for 3 and 6Mbits is very close.
So the final result : user experience is at least not worse with rate-limit then with shaping.
Maybe one of the reasons is CIRs are so high these days that most interactive applications, like Web surf, online video, games can not reach the limits.
Graph, re-transmissions, packet lost are 'better' with shaping, but if doesn't affect quality of work and at the same time is much more expensive in terms of hardware, then it's a good reason not to use it. And more - I've never heard from the Support team someone complaining about speed graph is not narrow.
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