May 26, 2004
4.3.0r, 4.3.0t and 5.0.0x
Note: This Field Notice is a legacy Latitude Field Notice that has been converted to the Cisco format so the information would remain available to their customers.
MeetingTime is excessively slow after upgrading the MeetingPlace Server to 4.3.0r or 4.3.0t
It was discovered that the operating systems are behaving correctly and as designed. Unfortunately, "correct" and "as designed" aren't the same as "as desired".
The 200ms ACK delay is called, appropriately enough, a delayed acknowledgement. The purpose is to limit the number of acknowledgements that are generated, thus reducing the network bandwidth requirement.
The server delay is from Nagle's algorithm, a standard feature of TCP/IP, which has the purpose of avoiding the generation of small packets. When data is being sent, the first packet goes out immediately and successive packets are delayed until there is sufficient data to meet a minimum size requirement or an acknowledgement is received. The Nagle's algorithm is used in the 4.3.0r and 4.3.0t operating system, which explains why this is a new problem.
So, what does that mean? Essentially, we should assume that any request issued from MeetingTime that requires a response larger than 1024 bytes, including the MeetingPlace message header, will take a minimum of 200ms to service. If MeetingTime issues 100 requests to retrieve a meeting list, we should expect that to take 20 seconds and so on.
Users may encounter excessive slowness when using MeetingTime.
To reduce the server delay the Nagle's algorithm has been turned off. This has been applied to the work station module. Please contact the support center to obtain this patch.
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