Overview

Collection communication involves both messaging and data transmission. The messaging part is illustrate below

The details on alams are described under Alarm communication. File list, checksums and salts, follows the same patter as for Get communication. The "get" message is only sent to one pillar.

The data trasmission involved is described under Data transmission protocol. It can be used either in transmission of message parameters or data as a result of a request.

Sequence diagrams

Ckecksums

The sequence diagram for checks corresponds to last part of a get operattion. The sequence diagram is given below.

Checksum messages

The getChecksums message contains the same information as a get, except that it also must include:

• Checksums algorithm for checksums

In case we want to open possibility to give resulting checksums in a respons message then the following parameter must be included

• Optionally max count of checksummer in svarbesked

Furthermore we will need a getChecksumsReplyData message.

Checksum data to be transmitted

The data must as minimum include:

• Number of checksums included
• Repeatedly for each file:
  • the file id
  • the file checksum
  • the time when the checksum was calculated (especially for off-line medias, there can be long inteervals between calculations, - in such cases this information is crucial for alarming)

File lists

Evt. max antal filer i svarbesked

Specifikt for checksummer skal denne information indeholde:

• antal filer
• information per fil (evt. repeterbar)
  • fil id
  • tidspunkt hvor filen sidst blev set (hvis det ikke er online, kan denne information være vigtig for alarmering)

Salts

Evt. ekstra tegn til direkte checksumscheck (Rosenthal NONCE)

Evt. max antal checksummer i svarbesked

Minimums informationer i request beskeder:

Specifikt for checksummer skal denne information indeholde:

• antal filer
• information per fil (evt. repeterbar)
  • fil id
  • salt algoritme
  • ekstra tegn i beregnin
  • tidspunkt hvor salt blev beregnet