Introduction

On the GroupWise messaging server, the Minshall Algorithm is disabled by default. However, in some cases you should enable the algorithm to improve BlackBerry Enterprise Server performance and user experience.


References

Article Title: Enabling the Minshall Algorithm
Article Number: KB04224
Link: View Document

Article Title: Message flow is delayed or ceases due to non-responsive threads in the BlackBerry Messaging Agent on event NEW_MB_PCKT_NOTIFY
Article Number: KB13764
Link: View Document

[30038] (07/25 04:51:01.017):{0x20EC} Worker Thread: *** No Response *** Thread Id=0x1338, Handle=0x15B8, WaitCount=1, WorkingTime=18 min, LastActivity=18 min, Event: NEW_MB_PCKT_NOTIFY, User: First Last, Server: GWPOA1, Activity: Starting


How To enable Minshall's Algorithm

Syntax: set tcp minshall algorithm = string
Range: On | Off Default: Off

This parameter is used to enable or disable support for Minshall's Algorithm. An interaction between the sender's Nagle Algorithm and the receiver's Delayed ACK policy can create an especially severe problem: that of a temporary deadlock. The Nagle Algorithm prevents the sender from transmitting more data until it receives an outstanding ACK, while the delayed ACK policy prevents the receiver from transmitting an ACK until more data arrives. Sooner or later, the delayed-ACK timeout breaks the deadlock, but this adds delays to operations that should have completed much faster.

Minshall's Algorithm is an enhancement to the Nagle Algorithm that helps avoid the deadlock without disabling the Nagle Algorithm. The algorithm states that a small packet should be sent only if the connection does not have a small packet unacknowledged. From this statement, it is clear that the Minshall Algorithm allows one unacknowledged small packet per connection.

Link: Tuning the NetWare 6 TCP/IP Stack via SET Parameters