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Found 2 records.

Status: Rejected (2)

RFC6846, "RObust Header Compression (ROHC): A Profile for TCP/IP (ROHC-TCP)", January 2013

Source of RFC: IETF - NON WORKING GROUP

Errata ID: 3669

Status: Rejected
Type: Technical

Reported By: Raj Kumar
Date Reported: 2013-06-24
Rejected by: Martin Stiemerling
Date Rejected: 2013-06-24

Section 8.2 says:

 COMPRESSED ipv4_innermost_irregular {
    ENFORCE(is_innermost == 1);
    ip_id          =:=
      ip_id_enc_irreg(ip_id_behavior_innermost.UVALUE) [ 0, 16 ];
    ENFORCE(ip_inner_ecn == ip_ecn_flags.UVALUE);
  }

It should say:

COMPRESSED ipv4_innermost_irregular {
    ENFORCE(is_innermost == 1);
    ip_id          =:=
      ip_id_enc_irreg(ip_id_behavior_innermost.UVALUE) [ 0, 16 ];
    
  }

Notes:

I don't find any reason why IP-ID encoding in ipv4 irregular chain, should be dependent on ECN flags.
--VERIFIER NOTES--
"This errata is invalid. Those bits need to be bound in the format and needs to be done so in the irregular chain for the inner header which does special treatment for these."


Errata ID: 3724

Status: Rejected
Type: Technical

Reported By: Raj Kumar
Date Reported: 2013-09-12
Rejected by: Martin Stiemerling
Date Rejected: 2013-09-20

Section 8.2 says:

tcp_opt_eol(nbits)
{
UNCOMPRESSED {
type =:= uncompressed_value(8, 0) [ 8 ];
padding =:=
uncompressed_value(nbits-8, 0) [ nbits-8 ];
}
CONTROL {
pad_len [ 8 ];
}
COMPRESSED eol_list_item {
pad_len =:= compressed_value(8, nbits-8) [ 8 ];
}
COMPRESSED eol_irregular {
pad_len =:= static;
ENFORCE(nbits-8 == pad_len.UVALUE);
}
}

It should say:

tcp_opt_eol(nbits)
{
UNCOMPRESSED {
type =:= uncompressed_value(8, 0) [ 8 ];
padding =:=
uncompressed_value(nbits-8, 0) [ nbits-8 ];
}
CONTROL {
pad_len [ 8 ];
}
COMPRESSED eol_list_item {

}
pad_len can be calculated at De compressor by following formula
pad_len = 4 -(length of uncompressed header formed till EOL byte % 4)

COMPRESSED eol_irregular {
pad_len =:= static;
ENFORCE(nbits-8 == pad_len.UVALUE);
}
}

Notes:

pad_len has the potential to become Inferred field, by doing this we can save one byte in compressed header and can effectively increase the compression efficiency.
--VERIFIER NOTES--
Rejected, as this is not an errata, as the 'corrected text' is in fact a change to the formal definition of the header formats.


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