tc, netem: Emulating multiple connections, problem with limit on the number of PRIO bands

Hi,

to emulate a wireless network I have to assign a packet loss depending on
the target IP address. The idea was to use a PRIO qdisc with n bands for n
nodes and use filters to assign packets to the appropriate band depending
on the target address.

Unfortunately, the number of bands is limited to 16 (TC_PRIO_MAX in kernel
and iproute2). Because of the possible occurence of side-effects of
changing TC_PRIO_MAX to let's say 1000 I am looking for an alternative.
Distributing all packets to about 60 ifb-devices doesn't seem to be a
perfect idea either.

Any ideas would be greatly appreciated.

Thank you in advance.

Patrick

Patrick Reinhardt wrote:

> Hi,
>
> to emulate a wireless network I have to assign a packet loss depending on
> the target IP address. The idea was to use a PRIO qdisc with n bands for n
> nodes and use filters to assign packets to the appropriate band depending
> on the target address.
>
> Unfortunately, the number of bands is limited to 16 (TC_PRIO_MAX in kernel
> and iproute2). Because of the possible occurence of side-effects of
> changing TC_PRIO_MAX to let's say 1000 I am looking for an alternative.
> Distributing all packets to about 60 ifb-devices doesn't seem to be a
> perfect idea either.

You could build a HTB hierachy and use NETEM as the leaf queuing discipline.

Markus