When a transaction encounters exceptional situation

[obdCoder]

1、rsmc，Alice add a tx，but Bob offline suddenly，then，how dose obd deal with this rsmc tx? Discard it or try it later?
2、

[neocarmack]

1. if the counterparty shuts down, my node should detect this event by ping-pong, and remove the tx.

[neocarmack]

or another option is to enable user manually delete a failed message. OBD should tell its owner that the counterparty stops responding and the messages fails.