Program setup (for both server and client):
MaxClient: 1
Channel: RelaibleFragmented
Sent messages via 1 channel
Connection config: 129 RelaibleFragmented channels
Connection config: NetworkDropThreshold = 15%

Steps:
1. Open and build attached solution
2. Start ClientGUI.exe
3. Press Start
==>
Server runs
4. Press "Connect"
5. Set Delay around 3000
6. Press "RepeatedSend"
==>
Messages size and total received/sent bytes are mentioned on Client and Server
7. Start Clumsy with packet's Drop = 10%
==>
After some period of time server stops to receive messages
Actual result: Client is able to continue sending messages even though the server is not acknowledged the old packets
Expected result: Manager.Send returns false after some threshold when certain amount of messages are not acknowledged yet

See attached movie for details.