In the current implementation of the Software Bus, sequence counter management is handled in the routing table. The routing table only includes entries that have subscribed messages. This results in the sequence counter being incremented only if there are subscribers to a message. If a message is unsubscribed to and then resubscribed, the sequence counter will be reset to zero.

A message sequence count should reflect the production of the message vs. the receipt of a message. One use case for this implementation is to support the filtering of a message via the sequence count.

APL/SPP project implemented a solution to increment the sequence count upon production of the message regardless of whether or not there are any subscribers. The solution involved removing the sequence count table from the routing table. This exact solution may not support the new/expanded APID/message ID name space. Expanding the message ID name space will need to be considered when implementing the overall solution to increment the sequence count to reflect message production.