Transcript IPv6 Jumbograms

IPv6 Jumbograms
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What is IPv6 jumbogram?
Jumbogram:
a packet or datagram larger than the size limit of
a given technology such as udp packet larger
than 65,535 octet.
IPv6 Jumbogram:
IPv6 packet containing payload larger than
65,535 octets.
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Jumbogram requirements:
IP layer:
as known IPv4 and IPv6 has payload length of 16 bits
which restricts the maximum payload length to 2^16 in
IPv4 but in IPv6 by using extension headers the problem
can be solved.
so by using hop-by-hop option header with Jumbo
Payload Option the problem solved at IPv6.
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By setting the payload lengh and next header
fields to zero it means IPv6 jumpogram,the next
header will be hop-by-hop options header.
Extension Header :
Next Header 8 bit
L=(HEL+1)*8 byte
Header Ext Length 8bits
Options
Option type 8bit
Option length 8bit
Options data
Options begin with
4n+2 octet
TLV
format
HPH Ext Header with jumbogram option:
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Options type=0xC2
Option length=0x04 (4 octets:payload
length)
Options value:payload length
0xC2
0x04
32 bit jumbo payload length
IPv6 Jumbogram requirements cont:
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Transport layer:
UDP:
the 16bit length field limit the maximum
UDP segment size to 65,535 octets
including UDP header and data,so to make
UDP jumbograms set the length to zero.
TCP:
MSS will be 65,535 wich means infinity.
IPv6 Jumbogram requirements cont
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Data Link Layer:
Jumbograms are relevant only to IPv6
nodes that may be attached to links with a
link MTU greater than 65,575 octets, and
need not be implemented or understood by
IPv6 nodes that do not support attachment
to links with such large MTUs.
Conclusion
IPv6 jumbograms are intended for futuere use
because MTU currently available are 9KB and
exists in private networks for research purposes.