Hello Aman,
could you please check also all other traces at around the time 13:20?
In the most cases call stacks and dpmon output can already give a hint, in which area you have to search for the reason of hanging situation. If it happens to often, then a higher trace level needs to be activated for the work processes and dispatcher, but this will influence the performance.
If you have still the error "ERROR => DpMsgProcess: MsReceive () -> MSEPARTNERUNKNOWN, partner:", but you do not see any problems in the network, then it does only mean, that the dispatcher tries to communicate with another instance through the message server, but this instance is currently not logged on to the message server. The message server gives the information back, that it does not know the instance.
Regards, Alwina