[rbak-nsp] SE800 QoS profiles

[Jim Tyrrell]

Hi,

I want to create and apply some QoS profiles so that protocols such as 
VOIP get priority on certain users connections.  ie If the user has an 
8Mb connection then VOIP should get priority over all their other 
traffic up to say 6Mb.  But if the user had a 2Mb line we may want VOIP 
to get priority up to 1.5Mb against the users other traffic.

Our users have DSL connections and sync anywhere between 512k and 24Mb 
but we dont necessarily  know what all the users sync speeds are.  So my 
question is, do we need to know what the end users actual line speed is 
in order to apply QoS and prioritise their various protocols?  I  was 
told by a Redback engineer that you dont need to know the end user line 
speed as you can just use rate percentage in the qos profile? 

Is this right as I dont see how the SE800 could prioritise traffic 
without knowing what the upper limit is?  The SE800 is sending the 
traffic to the user in an L2TP tunnel though a GigE card so surely it 
would need to know the user has a line rate of 8Mb so that when overall 
traffic for the specific user starts hitting that limit it needs to 
start dropping/queue the lower priority packets?  Otherwise as far as 
the Redback is concerned wouldnt the upper limit be the GigE port?

Thanks.

Jim.