est
BHS Header Digest
AHS in TLV format
AHS in TLV format
Size of Sum(AHS)
Data size
First Re
ad
BHS
BHS
AHS in TLV format
AHS in TLV format
Header Digest
Size of Sum(AHS)
Data size
First Re
ad
BHS
Second
Read
Second
Read
Fixe
d Max
No
Max
2nd
R
ead
3rd
R
ead
4th
R
ead
Current (0.5)
Reinhold
Russell
Major advantages over current draft:
1. Entire length of all AHS and Digests known after 1st read.
2. AHS use TLV format which allows the length of AHS segment to be determined
without understanding TYPE field. Allows for future AHS to be addeded without
impacting legacy devices. Also allows vendor/organizational unique AHS to be added
3. Simpler conceptual mode.
4. Reinhold model provides a digest in a known place - avoids possible block on TCP
read from a bad length field
5. Russell model limits total size of AHS to 1020 bytes - pre allocated buffer can be
used. AHS in TLV format
AHS in TLV format
Header Digest
Use byte 2 for Size of Sum(AHS)
- units of 4 bytes (max of 1020 bytes possible) in AHS
- keeps BHS at 48 bytes
Data size
First Re
ad
BHS
Second
Read
Fixe
d Max
Russell Sum(AHS) Digest
BHS Header Digest
AHS in TLV format
AHS in TLV format
Size of Sum(AHS)
Data size
First Re
ad
BHS
Second
Read
No
Max
Reinhold