Hi!
I'm using HTB to shape traffic to/from clients, but one of the problems I
have is that once a class utilizes its maximum potential, they latency
spirals out of control.
For example:
.-----.
| isp |
`-----'
|
.--------.
| shaper |
`--------'
|
.--------.
| client |
`--------'
lets say I want to limit traffic to/from client to 64kbit. now, client opens
a tcp connection blasting away at full speed.
If client now pings isp, it gets on average around 7 seconds latency. I
tried to improve this by using SFQ on the leaf nodes of my HTB hierarchy,
but that does not really improve the situation, only makes it much worse.
with SFQ I get anything between 250ms and 13 seconds latency.
I then tried fifos. With small packet fifos the packet loss is just
to great to be of any use and even then the latency is quite high (~200ms).
If I make the fifos big enough so that unreasonable numbers of packets isn't
dropped, it just doesn't do much to the latency/or throughput. This
behaviour kind of makes sense, but doesn't help me :P
I'm thinking of using RED, but the number of parameters is daunting and I
have no idea how the HTB rate correlates to packet size and burst rates for
red.
Does anybody have any idea how to get the latency down and still maintain
the correct throughput?
--
Regards
Abraham
Sooner or later you must pay for your sins.
(Those who have already paid may disregard this cookie).
___________________________________________________
Abraham vd Merwe [ZR1BBQ] - Frogfoot Networks
P.O. Box 3472, Matieland, Stellenbosch, 7602
Cell: +27 82 565 4451 Http: http://www.frogfoot.net
Email: abz@frogfoot.net
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