Increasing Maximum and Minimum Packet Receive Buffers

Packet receive buffers (also called communication buffers) store incoming data packets until they can be processed by the server.

The operating system allocates a minimum number of packet receive buffers as soon as the server boots. The minimum number is specified by the Minimum Packet Receive Buffers server parameter.

A maximum number of packet receive buffers is specified by the Maximum Packet Receive Buffers server parameter.

To determine how many buffers the server is currently allocating, refer to the Packet Receive Buffer value in the General Information window of MONITOR.


Increasing the Maximum Number of Packet Receive Buffers

If the server is slowing down and losing workstation connections, it might be running out of packet receive buffers. In this case, you can increase the Maximum Number of Packet Receive Buffers.

The General Information window of MONITOR displays the total number of packet receive buffers that are currently allocated.

  1. From MONITOR's Available Options, select Server Parameters > Communications.

    A list of Communications Parameters is displayed in the upper window. The scroll thumb on the right of the window indicates that you can use the arrow keys to scroll the list.

    NOTE:  You can also use the SET command to set communications parameters at the server console prompt. See Reference > Utilities Reference > Utilities > SET.

  2. Scroll down the Communications Parameters list.

  3. Select Maximum Packet Receive Buffers.

  4. Increase the value of this parameter and press Enter.

    A good guideline is to set this value to twice the size of the Minimum Packet Receive Buffer value. The changed value is now persistent.

    For additional suggestions, see the discussion of the Maximum Packet Receive Buffer parameter in SET Communication Parameters.


Increasing the Minimum Number of Packet Receive Buffers

Use the following procedure to increase the minimum number of packet receive buffers if the allocated number is higher than 10 and the server doesn't respond immediately after starting.

  1. From MONITOR's Available Options, select Server Parameters > Communications.

    A list of Communications Parameters is displayed in the upper window. The scroll thumb on the right of the window indicates that you can use the arrow keys to scroll the list.

    NOTE:  You can also use the SET command to change parameter values at the server console prompt. See Reference > Utilities Reference > Utilities > SET.

  2. Scroll down the Communications Parameters list.

  3. Choose Minimum Packet Receive Buffers.

  4. Increase the value of this parameter.

    A good guideline is to allocate at least two packet receive buffers for each workstation connection. The changed value is now persistent.

    For additional suggestions, see the discussion of the Minimum Packet Receive Buffer parameter in SET Communication Parameters.

    NOTE:  The Minimum Packet Receive Buffers value should be smaller than the Maximum Packet Receive Buffers value. If it is greater than the maximum value, the system changes the maximum value to match the minimum value.