Frame-relay Fragmentation FRF.12

Hi All,

  I was going through the FRF.12, and trying to understand a question which
I have related to it......The way in which I understand frame-relay
fragmentation is ,smaller frames are interleaved between fragemented larger
frames and so delay/latency sensitive traffic like voice which are generally
smaller in size will be interleaved between larger frames to avoid
latency.Assuming this understanding is right,please correct me if I am
wrong,when to calculate frame-relay fragment size((Serialization
delay(Generally preferred to have 10 ms for voice traffic) x (Link-speed))/8
,the o/p we get as I understand by reading will not include any
frame-headers.Assuming this is also right,My questions are

1) Why the fromula didn't account for any frame headers

2) In the below example topology ,When traffic is originated behind R1 and
destined behind R3,In R2,when router decides to send the packets out R2 Fr
interface based on the routing and assuming FR inerface is configured for
FRF.12,is the interleaving of packets is added after the frame-header or
added or before .......I am sure missing some basic.Kindly help me to
understand the same

    R1--- Ethernet link ----R2 ----Frame-relay ----R3

Thanks for the help

Regards
Anantha Subramanian Natarajan

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Received on Tue Sep 08 2009 - 07:59:23 ART