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4.4.7 Security Requirements
The Message Sequences and Data Integrity requirements
from the Applicability Matrix
are
supported natively within VEI via the Agent Transport Layer (ATL). The transport
layer is entrusted with end-to-end data integrity achieved by retransmitting of lost
blocks and discarding duplicated blocks. This layer is also in charge of sequence
control to ensure that the higher levels of the protocol receive packets in the
exact order
in which they were sent. The ATL achieves this integrity and sequencing by assigning a
sequence number to each block and acknowledging
blocks by sequence number at the
message
level.
The
Authentication and Encryption requirements from the Applicability Matrix are
supported by VEI via the Agent Session Layer (ASL). The session layer handles
identification,
authentication and optional compression and encryption of messages.
Any time a connection is established, it must successfully
exchange the identification
and
authentication messages before normal communication can continue. If messages
are sent without the identification/authentication,
the receiver must disconnect, and
optionally
attempt to reconnect.
4.4.8 Timing & Routing
VEI
leaves timing and routing of the messages to the discretion of implementing
organization.
4.4.9 Usability
The VEI specification is available for public use without any patent
and copyright
requirements.
Based on a phone interview with Agent Systems, APTA can take any, or
all parts of it for its individual use. However, if APTA desires to adapt the VEI
specification
in its entirety and request for changes and additions, these modifications
will be handled by Agent Systems for a consulting fee.
This data was obtained through
phone
interviews and/or email correspondence. The information is accurate as of July
2004. If APTA is interested in using any part of the specification,
formal notification
and/or
negotiations are necessary.
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