isapi and mod_jk(?)

max_packet_size is documented to be the maximum number in Bytes used by the AJP protocol. There is no mention that the actually used buffer size is actually aligned to the next 1024 Byte. In Tomcat, the packetSize parameter is used as is, e.g. if you specify a buffer of 32000 bytes, Tomcat will use and expect a maximum size of 30000 bytes, while (at least the ISAP redirector for IIS) will send 30720 bytes. Either alignment in the connector should be changed or documentation should indicate, that only 1024byte-aligned values should be supplied.

The problem has been found during debugging of isapi connector for IIS.