Lie Arne wrote:
What would be "optimal" value for ppp0 device's txqueuelen,
when it is used with HSDPA gsm modem for link which downlink
speed is 1Mbit/s and uplink speed is 384kbit/s and ping
~80..100 ms? Is the default value 3 just OK?
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Best Regards, Jar
I would suggest using normal TCP calculation, i.e. that you dimension
the txqueue size after the "BDP rule": bandwidth x delay product. Using
your outbound numbers this is:
1,000,000 x 0.1 = 100,000 bits = 12,500 bytes. Assuming 1500 byte
packets, this is txqueue = 12,500 / 1500 = 8.3 packets. So you could try
txqueue size in the region 8-10, this should prevent queue starvation at
packet drop events caused by traffic overload, even if you only have one
single TCP flow.
OK, thanks. But is txqueuelen for transmit data only and then the
downlink value (384kbit/s) should be used in the calculation? With
384kbit/s the txqueuelen would be 3.2 which is quite same as ppp0 default 3.
--
Best Regards, Jar
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