[LARTC] linux/tc vs packetshaper

[LARTC] linux/tc vs packetshaper

[Joakim]

<PRE>Hi

I was wondering how a Linuxbox running iproute2 and tc to do bandwidth 
control on a 20 mbit internet connection compares? A Packeteer 
PacketShaper 4500 costs about $20,000, and a Linuxbox can be set up for 
much less, but can it be used for a network with some 1000 users without 
too much trouble?
Following that question, how is the latency affected by a Linux router? 
The PacketShaper should add no more than 50 msec pr packet, how does 
Linux compare to this?

If someone has experience with a machine connected to an 
internetconnection with the same bandwidth, I would like to hear about 
it very much.

Now, I realize that the Packeteer thing is much easier to configure, and 
also provides some pretty extensive statistical information, but that is 
not necessary for me.

yours,

-- 
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>

[LARTC] linux/tc vs packetshaper

[bert]

<PRE>On Thu, Feb 01, 2001 at 07:07:19PM +0100, Joakim Recht wrote:
&gt;<i> Hi
</I>&gt;<i> 
</I>&gt;<i> I was wondering how a Linuxbox running iproute2 and tc to do bandwidth 
</I>&gt;<i> control on a 20 mbit internet connection compares? A Packeteer 
</I>&gt;<i> PacketShaper 4500 costs about $20,000, and a Linuxbox can be set up for 
</I>&gt;<i> much less, but can it be used for a network with some 1000 users without 
</I>&gt;<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 &gt;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.

&gt;<i> Following that question, how is the latency affected by a Linux router? 
</I>&gt;<i> The PacketShaper should add no more than 50 msec pr packet, how does 
</I>&gt;<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.

&gt;<i> Now, I realize that the Packeteer thing is much easier to configure, and 
</I>&gt;<i> also provides some pretty extensive statistical information, but that is 
</I>&gt;<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>

[LARTC] linux/tc vs packetshaper

[Joakim]

<PRE>
bert hubert wrote:

&gt;<i> 
</I>&gt;<i> Number of users is not that big an issue. We've filtered 90mbit/s of traffic
</I>&gt;<i> with Linux, but we currently only shape up to 5mbit/s. However, the sites we
</I>&gt;<i> filter have &gt;100 http connections per second, which each take a few seconds
</I>&gt;<i> to complete, so I'd guess that at any one time we have ~300 tcp/ip sessions
</I>&gt;<i> running. 
</I>&gt;<i> 
</I>&gt;<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.

&gt;<i> 
</I>&gt;<i> Regular shaping might induce more, but it hasn't been a problem for us so
</I>&gt;<i> far. As long as you are not actively shaping (ie, remain below your
</I>&gt;<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.

&gt;<i> We've only configured our shaping solution once, using the excellent
</I>&gt;<i> CBQ.init script. Takes little time, and then runs on without any problems.
</I>&gt;<i> 
</I>&gt;<i> Regards,
</I>&gt;<i> 
</I>&gt;<i> bert hubert
</I>&gt;<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>