V2.BUFSIZE = (maximum transmission buffer size, TCP/IP send/receive buffer size)
The second positional parameter is used to alter the TCP/IP send and receive buffer sizes within TCP/IP. The maximum value is 2M. The minimum value is set by TCPCONFIG in the TCP/IP PROFILE data set. If a value is specified that is lower than the TCPCONFIG value, the TCPCONFIG value is used. The default of the second parameter is double the first parameter, unless this is lower than the value set by TCPCONFIG in the TCP/IP stacks PROFILE data set. For example, TCPCONFIG TCPSENDBFRSIZE 64K TCPRCVBFRSIZE 64K in the TCP/IP PROFILE would set the default to 64 KB. This default value of 64K would be used unless the first parameter is greater than 32 KB, or the second parameter is greater than 64 KB.
The default is V2.BUFSIZE=(32K,128K)
In general terms, the second positional parameter should be at least the same and not less than the first parameter and should be big enough to handle the largest V2.BUFSIZE override from the netmap. A good common practice is to have the second parameter be a multiple of the first parameter and at least twice or more than the first parameter.
Also, note that the first positional parameter can be overridden in the ADJACENT.NODE entry in the netmap using the BUFFER.SIZE parameter. For details, see BUFFER.SIZE=V2.buffer override.
Modifiable through MODIFY INITPARMS command: NO