Re: Congestion control/QoS

[Vadim Antonov <avg () pluris com>]

Dirk Harms-Merbitz <dirk () orlando power net> wrote:

> Seems to me that a good way of limiting damage from runaway
> networks/hosts would be a modifaction of RED (Random Early
> Drop).

> Controlled Early Drop (CED? I just made this up, suggestions?)
> would allow a router to give a preference to connected
> networks/hosts. Packets from certain networks would have a higher
> chance of being dropped from a router queue then packets from
> other networks.

This is a packet classification problem.

Here's a fragment from a test configuration file for my
boxes-as-being-developed:

-------------------------------------------------------------
ip-classifier FILTER1 {

        if( srcaddr = [192.40.77.20 : 192.40.77.90] and
            ((proto = tcp and srcport <> [smtp, telnet, 512]) or
             (proto = udp and dstport = domain)) ) {
                priority-select {
                0:      class PRIORITY
                1,2: {
                        if( tos = bulk ) blackhole
                        goto l1
                     }
                }
                reject
        }

        if( tos = [interactive, bulk, 017] ) class INTERACTIVE

l1:     if( dstaddr = 199.0.55.1 and tcp-syn ) reject

        class ROUTINE
}


ip-classifier DEFAULT {

        priority-select {
            0:  class ROUTINE
            1:  class PRIORITY
        }
        class INTERACTIVE
}


interface E1021-0 {
        description  "PL126612 to Joppa, MD"
        bandwidth    0.1G
        ip-address   144.227.0.11/24
        ip-secondary 199.0.88.11/24
        keepalive    no

        out-ip-classifier FILTER1

        out-class ROUTINE     { bandwidth 0.5% ; priority 4 }
        out-class PRIORITY    { bandwidth 20%  ; priority 5 }
        out-class INTERACTIVE { bandwidth 1M   ; priority 7 }

        ip-peer 144.227.0.12 {
                out-ip-classifier DEFAULT
        }

        ip-peer 144.227.0.50 {
                mac-address  01.29.00.11.91.21
        }
}

interface X123 {
        load-share [E1021-0, E1021-1, E777-0]
}
-------------------------------------------------------------

Are you netgeeks salivating yet? :)

--vadim
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