10.37 MLPPP LFI over Frame Relay

SG says to confire the VT with a bandwidth of 512K because the physical is 512K even though the CIR is only 256K.

The logic behind this is that is that the interface serialises at 512K so the fragment size should be based on that rather than the CIR.


I am struggling wit hthis for a couple of reasons:


1) This breaks the "bandwidth remaining percent" as it effectivly doubles the amount per class (CIR is 256K)

   Class-map: VOICE_BEARER (match-all)

      Priority: 56 kbps, burst bytes 1500, b/w exceed drops: 0

    Class-map: VOICE_SIGNALING (match-all)

      bandwidth remaining 5% (22 kbps)

    Class-map: class-default (match-any)

      bandwidth remaining 95% (433 kbps)


2) PPP reports a fragment weight and size of 640 weight, 630 frag size which is bytes and equates to 5120 bits which according to my FRTS would be two intervals breaking my Tc of 10ms, sustain = 2560 bits per interval.

QoS woes...


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