RFC 4820, "Padding Chunk and Parameter for the Stream Control Transmission Protocol (SCTP)", March 2007Source of RFC: tsvwg (tsv)
Errata ID: 897
Publication Format(s) : TEXT
Reported By: Alfred Hoenes
Date Reported: 2007-04-09
Rejected by: Lars Eggert
Date Rejected: 2009-01-14
Section 3 says:
This chunk is used to pad an SCTP packet. A PAD chunk can be used to enlarge the packet by 4 to 65536 bytes in steps of 4 bytes. An SCTP packet MAY contain multiple PAD chunks.
It should say:
This chunk is used to pad an SCTP packet. A PAD chunk can be used to enlarge the packet by 4 to 65532 bytes in steps of 4 bytes. An SCTP packet MAY contain multiple PAD chunks.
The text below Figure 1 explains:
"Length: 2 bytes (unsigned integer)
This value holds the length of the Padding Data plus 4"
Because a 2-byte unsigned integer can accept values ranging
from 0 to 65535 and it can be inferred from the above text that
`Length` should be divisible by 4, the maximum value possible
for `Length`, and hence the maximum padding size is 65532 !
(In the spirit of the SCTP specification, I do not recommend to
change the definition of `Length` allowing 0 to encode 65536.)
Discussion between authors and errata submitter resulted in an agreement that this errata is in fact incorrect.