UNICAST2:

• The sender has an AckSenderWindow (without retransmission) and the receiver a NakReceiverWindow
• The receiver asks the sender for retransmission only if there's a gap
• Stability ensures that the sender doesn't keep messages around forever

Suggestions:

• Similar to NAKACK2, don't use a separate retransmitter for every member (window), but have just 1 retransmitter task scan the message tables and do retransmission
• Table<Message> can replace the NakReceiverWindow on the receiver side
• Wwe can probably also replace the sender's window with a Table<Message>

If we can do this, then we have

• only 1 proven data structure (Table<Message>)
• not 1 retransmitter per window, but 1 for all the windows (saving space) !

Similar to https://issues.jboss.org/browse/JGRP-1396: use Table rather than NakReceiverWindow. Should be simple as Table offers almost the same interface as NRW.