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Date:      Sat, 6 Mar 2004 14:10:34 -1000 (HST)
From:      Vincent Poy <vince@oahu.WURLDLINK.NET>
To:        Nicolas DEFFAYET <nicolas.deffayet@ndsoftware.net>
Cc:        freebsd-ipfw@freebsd.org
Subject:   Re: Latency problem with traffic shaping
Message-ID:  <20040306140955.T8264-100000@oahu.WURLDLINK.NET>
In-Reply-To: <1078597745.1981.15.camel@w1-par1-fr.corp.ndsoftware.com>

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On Sat, 6 Mar 2004, Nicolas DEFFAYET wrote:

> Hello,
>
> I have latency problem when i do traffic shaping with ipfw:
>
> $ ping -c 10 xxx.xxx.xx1.2
> PING xxx.xxx.xx1.2 (xxx.xxx.xx1.2): 56 data bytes
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=0 ttl=64 time=1.037 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=1 ttl=64 time=1.951 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=2 ttl=64 time=1.924 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=3 ttl=64 time=1.852 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=4 ttl=64 time=2.779 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=5 ttl=64 time=1.982 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=6 ttl=64 time=1.778 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=7 ttl=64 time=1.866 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=8 ttl=64 time=1.777 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=9 ttl=64 time=1.876 ms
>
> --- xxx.xxx.xx1.2 ping statistics ---
> 10 packets transmitted, 10 packets received, 0% packet loss
> round-trip min/avg/max/stddev = 1.037/1.882/2.779/0.395 ms
>
> Current maximum traffic is 6 Mbit/s, shapping is at 35 Mbit/s.
>
>
> I use a vlan interface but i have same problem with a physical
> interface:
>
> $ ifconfig vlan3
> vlan3: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
>         inet xxx.xxx.xx1.1 netmask 0xfffffffc broadcast xxx.xxx.xx1.3
> <cut>
>
>
> I use very simple rules:
>
> # ipfw sh
> 03000  195958827   88359539155 pipe 1 ip from any to any out via vlan3
> 03000  145717180   37638278479 pipe 1 ip from any to any in via vlan3
> 65535 7732545351 2700054229295 allow ip from any to any
>
> # ipfw pipe sh
> 00001:  35.000 Mbit/s    0 ms   50 sl. 1 queues (1 buckets) droptail
>     mask: 0x00 0x00000000/0x0000 -> 0x00000000/0x0000
> BKT Prot ___Source IP/port____ ____Dest. IP/port____ Tot_pkt/bytes
> Pkt/Byte Drp
>   0 igmp  xxx.xxx.xx1.1/0           224.0.0.5/0     341678025
> 125998357178  0    0 295
>
>
> If the rule 3000 of ipfw is deleted, latency is good and normal; but i
> don't have shaping:
>
> $ ping -c 10 xxx.xxx.xx1.2
> PING xxx.xxx.xx1.2 (xxx.xxx.xx1.2): 56 data bytes
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=0 ttl=64 time=0.375 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=1 ttl=64 time=0.219 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=2 ttl=64 time=0.251 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=3 ttl=64 time=0.281 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=4 ttl=64 time=0.290 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=5 ttl=64 time=0.308 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=6 ttl=64 time=0.380 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=7 ttl=64 time=0.254 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=8 ttl=64 time=0.227 ms
> 64 bytes from xxx.xxx.xx1.2: icmp_seq=9 ttl=64 time=0.227 ms
>
> --- xxx.xxx.xx1.2 ping statistics ---
> 10 packets transmitted, 10 packets received, 0% packet loss
> round-trip min/avg/max/stddev = 0.219/0.281/0.380/0.055 ms
>
>
> I don't have the problem with FreeBSD 5.0-RELEASE.
> I have the problem with FreeBSD 5.1-RELEASE, FreeBSD 5.2-RELEASE,
> FreeBSD 5.2.1-RELEASE.
>
> I use a custom kernel with:
>
> options         IPFIREWALL              #firewall
> options         IPFIREWALL_VERBOSE      #enable logging to syslogd(8)
> options         IPFIREWALL_FORWARD      #enable transparent proxy
> support
> options         IPFIREWALL_VERBOSE_LIMIT=100    #limit verbosity
> options         IPFIREWALL_DEFAULT_TO_ACCEPT    #allow everything by
> default
> options         IPV6FIREWALL            #firewall for IPv6
> options         IPV6FIREWALL_VERBOSE
> options         IPV6FIREWALL_VERBOSE_LIMIT=100
> options         IPV6FIREWALL_DEFAULT_TO_ACCEPT
> options         IPDIVERT                #divert sockets
> options         DUMMYNET
> options         BRIDGE
>
>
> How fix this latency problem ?

	Not much except maybe read dummynet(4) manpage and look at the HZ
option in the kernel.


Cheers,
Vince - vince@WURLDLINK.NET - Vice President             ________   __ ____
Unix Networking Operations - FreeBSD-Real Unix for Free / / / / |  / |[__  ]
WurldLink Corporation                                  / / / /  | /  | __] ]
San Francisco - Honolulu - Hong Kong                  / / / / / |/ / | __] ]
HongKong Stars/Gravis UltraSound Mailing Lists Admin /_/_/_/_/|___/|_|[____]
Almighty1@IRC - oahu.DAL.NET Hawaii's DALnet IRC Network Server Admin




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