I'm trying to use hfsc, so I've read the
HFSC Scheduling documentation with Linux I understand some concepts but shame on me, I don't understand how the values are calculated, for example:
Quote:
|
The concept of the interaction with latency resides in the structure of the service curves of the individual classes. By selecting a two-part service curve, each section of which is linear, the transmission delay for the Voice over IP class can be reduced to 30 ms. The first section of the service curve features a 400 kbit slope of 30 ms duration, where the second section exhibits a slope of 100kbit. This gain in decreased delay of approximately 78 ms is earned at the expense of other classes. At no point, though, is the sum of the curves allowed to exceed the service curve of the total link capacity. In our example, the decreased delay for the Voice over IP class occurs at the cost of party A's unspecified data class, whose service curve must be adjusted in order not to to exceed the global limit. As a result, the maximum transmission delay of this class increases from 30ms to a total of 52.5 ms. For bulk data transport, such as FTP, for example, delay simply plays a secondary role in contrast to that of throughput, which isn't impaired by conforming to the service curve
|
Great, really greate sorry but I have no idea where is 78 ms from, or the 52.5 ms....
The final example uses it the 52.5 ms rounding the value... I guess:
Quote:
|
tc class add dev eth0 parent 1:10 classid 1:11 hfsc sc umax 1500b dmax 53ms rate 400kbit ul rate 1000kbit
|
Please could you explain how these values are obtained?
I've read the man page and result me as willing as painful.
Thanks in advance!
