* [LARTC] linux/tc vs packetshaper
2001-02-01 18:07 [LARTC] linux/tc vs packetshaper Joakim
@ 2001-02-01 21:14 ` bert
2001-02-02 0:29 ` Joakim
1 sibling, 0 replies; 3+ messages in thread
From: bert @ 2001-02-01 21:14 UTC (permalink / raw)
To: lartc
<PRE>On Thu, Feb 01, 2001 at 07:07:19PM +0100, Joakim Recht wrote:
><i> Hi
</I>><i>
</I>><i> I was wondering how a Linuxbox running iproute2 and tc to do bandwidth
</I>><i> control on a 20 mbit internet connection compares? A Packeteer
</I>><i> PacketShaper 4500 costs about $20,000, and a Linuxbox can be set up for
</I>><i> much less, but can it be used for a network with some 1000 users without
</I>><i> too much trouble?
</I>
Number of users is not that big an issue. We've filtered 90mbit/s of traffic
with Linux, but we currently only shape up to 5mbit/s. However, the sites we
filter have >100 http connections per second, which each take a few seconds
to complete, so I'd guess that at any one time we have ~300 tcp/ip sessions
running.
I bet a 1000 users would not come near to that amount of sessions.
><i> Following that question, how is the latency affected by a Linux router?
</I>><i> The PacketShaper should add no more than 50 msec pr packet, how does
</I>><i> Linux compare to this?
</I>
Well, AFAIK, Packeteers, which used to be quite evil wrt to corrupting IP
options by the way!, 'shape' by fooling around with TCP Window options. That
does not induce a lot of latency.
Regular shaping might induce more, but it hasn't been a problem for us so
far. As long as you are not actively shaping (ie, remain below your
bandwidth ceiling), we don't see *any* additional latency.
><i> Now, I realize that the Packeteer thing is much easier to configure, and
</I>><i> also provides some pretty extensive statistical information, but that is
</I>><i> not necessary for me.
</I>
We've only configured our shaping solution once, using the excellent
CBQ.init script. Takes little time, and then runs on without any problems.
Regards,
bert hubert
--
PowerDNS Versatile DNS Services
Trilab The Technology People
'SYN! .. SYN|ACK! .. ACK!' - the mating call of the internet
</PRE>
^ permalink raw reply [flat|nested] 3+ messages in thread
* [LARTC] linux/tc vs packetshaper
2001-02-01 18:07 [LARTC] linux/tc vs packetshaper Joakim
2001-02-01 21:14 ` bert
@ 2001-02-02 0:29 ` Joakim
1 sibling, 0 replies; 3+ messages in thread
From: Joakim @ 2001-02-02 0:29 UTC (permalink / raw)
To: lartc
<PRE>
bert hubert wrote:
><i>
</I>><i> Number of users is not that big an issue. We've filtered 90mbit/s of traffic
</I>><i> with Linux, but we currently only shape up to 5mbit/s. However, the sites we
</I>><i> filter have >100 http connections per second, which each take a few seconds
</I>><i> to complete, so I'd guess that at any one time we have ~300 tcp/ip sessions
</I>><i> running.
</I>><i>
</I>><i> I bet a 1000 users would not come near to that amount of sessions.
</I>
Well, I've had to increase /proc/sys/net/ipv4/ip_conntrack_max from 16k
to a larger value on a network with 300 users, so something tells me
that quite a lot of connections are open.
><i>
</I>><i> Regular shaping might induce more, but it hasn't been a problem for us so
</I>><i> far. As long as you are not actively shaping (ie, remain below your
</I>><i> bandwidth ceiling), we don't see *any* additional latency.
</I>
This is the problem for me... The connection is to be distributed
between some 8 college dorms, and the users here use quite a lot of
bandwidth right now, as we are connected to a university connection.
However, we are about to buy our own, which means a pretty crowded 20
mbit connection, and as each dorm should be guaranteed an amount of
bandwidth, shaping could occur very often, at least at peak hours in the
afternoon/evening.
><i> We've only configured our shaping solution once, using the excellent
</I>><i> CBQ.init script. Takes little time, and then runs on without any problems.
</I>><i>
</I>><i> Regards,
</I>><i>
</I>><i> bert hubert
</I>><i>
</I>Thanks for your reply,
--
Joakim Recht
Tlf. 20 85 54 77
Email <A HREF="mailto:god@cs.auc.dk">god@cs.auc.dk</A>
WWW <A HREF="http://www.braindump.dk">http://www.braindump.dk</A> / <A HREF="http://www.compuclub.dk">http://www.compuclub.dk</A>
</PRE>
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