RFC Errata
RFC 6846, "RObust Header Compression (ROHC): A Profile for TCP/IP (ROHC-TCP)", January 2013
Source of RFC: IETF - NON WORKING GROUPArea Assignment: tsv
Errata ID: 3724
Status: Rejected
Type: Technical
Publication Format(s) : TEXT
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.