On Mon, 8 Jul 2002, Dmitriy wrote:
> Can anybody tell me: is there any way(module, qdisc) which is possible to
> make a packet wait for a fixed time then dequeue? It is needed for me to
> get a fixed RTT. Using htb,tbf... I can get only total speed limitations
> but then a queue is empty rtt of small ICMP packets is smth like 200-300
> usec. Will be thankful for any info.(Note: I`d like to make this thing
> using only Linux tc).
Just a random thought but dont know if this is doable.
If it is possible to do a range check on the length field of a packet
using some filters (u32 filter??) then you could Q them in different Qs
and then control when they can be sent (>= SOME FIXED TIME) say using tbf.
but I am not sure if u32 can do these kinda range check.
Any comments?
>
>
> Example:
> (speed is limited to 33.6 Kbit/sec using tbf as leaf node of one CBQ class)
>
> [root@rack1 root]# time scp root@10.10.10.65:/boot/vmlinuz-netli /tmp
> root@10.10.10.65''s password:
> vmlinuz 100% |*************************************************|
907 KB 03:09
>
> real 4m1.375s
> user 0m0.003s
> sys 0m0.012s
>
>
> [root@rack1 root]# ping 10.10.10.65
> PING 10.10.10.65 (10.10.10.65) from 10.10.10.64 : 56(84) bytes of data.
> 64 bytes from 10.10.10.65: icmp_seq=0 ttl=254 time=354 usec
> 64 bytes from 10.10.10.65: icmp_seq=1 ttl=254 time=229 usec
>
> --- 10.10.10.65 ping statistics ---
> 2 packets transmitted, 2 packets received, 0% packet loss
> round-trip min/avg/max/mdev = 0.229/0.291/0.354/0.064 ms
> [root@rack1 root]#
>
>