Saturday, March 26, 2011

some news, good and not so good

At the moment we transferred almost 20k happy customers to new technology. 40k pending. The first outcome - about 20% of customers prefer old access methods.

Now we have problems which appeared as result of service simplification in the past. The problem is DUMMYNET. After 6k PIPES system dies. That's it, doesn't matter how much traffic.

So, now we are adding boxes to process traffic, but this is temporary solution. I look forward now to get rid of dummynet and use ng_car for policing.

When we;ve switched from dummynet on pptp servers to ng_car, we could double user capacity per system. Hopefully this will be the case this time again.

Some task analysis: there 2 primary methods to do the policing - one is to put separate traffic multiplexer to thousands of ng_cars, the other is to use well-working ng_state for that.

Advantage of separate multiplexer is it will just work in current setup. Disadvantage - every packet should be switched that way.
Implementation with ng_state allows to process only first packet in the flow, BUT following problems arrives: traffic forwarding and class policing should be done differently then. Actually instead of using different traffic path's for different classes i should add class labels to the packet.

Will do separate multiplexer now, as faster to implement solution and also, it might be not much slower comparing to the second solution as there label lookup will be needed for each packet.

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