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Ingress works




Hi Jamal,

It all works as expected. I generate traffic of 6 Mbps marked 0x88, the
packets are remarked to 0x88, 0x90 and 0x98. The policing works.

How it worked? Its a bit bizarre

The weird thing was, I was using the program "ttt" on the ingress
interface of the edge router and facing all the problems that I have been
reporting. It froze this morning, so I killed it, Lo Behold! my packet
remarking started to appear on my tcpdump output.

I used ttt on the egress interface, however that didn't affect the
policing. So my guess is the ttt implementation is to blame and somehow
interferes with the ingress implementation. 

I have used ttt before with other scripts (without ingress) on the same
interface without any problems. 

My throughput results now match yours. 

Regards
Muneyb.

On Tue, 15 Feb 2000, jamal wrote:
> 
> 
> Muneyb,
> 
> I have tested this particular script and it works. This was a while back
> though. Luckily i took notes and they just coincidentally happen to be
> right next to me ;->
> 
> On Wed, 16 Feb 2000, Muneyb Minhazuddin wrote:
> 
> > I have checked that the ingress and egress interfaces are correctly
> > set. The problem still exist.
> > 
> >   _________              ______________         ____________
> >  |         |eth0    eth0| Edge Router  |eth1   |            |
> >  | Source  |----------->| Edge31-ca-u32|------>|Destination |          
> >  |_________|            |______________|       |____________|
> > 
> > INDEV = eth0
> > EGDEV = eth1
> > 
> > Source single ttcp source from source to Destination. I have added an
> > option -q to ttcp that sets the tos byte to the value given on the command
> > line.
> > 
> > Monitored output with ttt and verified the tos byte value by running
> > tcpdump on Edge router's eth1(Egress) interface and the destination. 
> 
> You are correct about getting close to 6Mbps; My notes show around
> 5.1Mbps. (this is the sum of the meters in the ingress). To see a drop,
> fix the BE for AF41 so that it drops the packets instead of demoting them
> to BE. With the fixed script, i get around 4.2Mbps
> 
> The difference in our metering results is most probably related
> to the clock sources; mine is based on the pentium TSC -- by default
> you use the system clock which runs at a granularity of 10ms. The
> clock is not such a big deal though if you have a constant packet arrival.
> So there could be other factors; 
> i used tcpblast with 1000 byte packets, you used tttcp etc
> 
> > They
> > are still marked to 0x88 (all of them). The problem still exist.
> > 
> 
> Check carefully. Most of them are marked as 0x88, but not all of them.
> 
> 
> Some more tests i ran:
> 
> -tos 0x90 at source: throughput around 3.6 Mbps (fixed script 2Mbps)
> -tos 0x98: 2.5Mbps (fixed script 1Mbps)
> -tos 0x0 for BE or any other TOS not being filtered: 1,5 Mbps (1.6Mbps)
> 
> cheers,
> jamal
> 
> 
> 

_________________________________________________________
Muneyb Minhazuddin - Telecommunications Research Engineer    
CSIRO Telecommunication and Industrial Physics                
Marsfield, NSW, Australia.                                    
                                                             
Phone no. : 61 2 9372 4113
FAX       : 61 2 9372 4490          
e-mail    : mminhazu@tip.csiro.au  
Home Page : http://www.atnf.csiro.au/~mminhazu
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