The larger your frame size, the more data your system can put into it. Hence, you can increase your data throughput.
Typically, you set the maximum frame size to the largest size that is supported by your input/output adapter (IOA). However, a device along the way will drop the frame if it cannot support the larger size. For example, if frames are being sent to a remote system on a different LAN, the frame must go through a bridge to be retransmitted to the remote LAN. If the bridge cannot support the frame size that your LAN is using, the frame will be dropped or discarded. In the Ethernet environment, no indication of the smaller frame size of the bridge is received. The problem will be detected when a connection with the remote system is established and a CPA57A1 message is sent to the configured message queue.
If you cannot configure the device to support your frame size, decrease your maximum frame size to a size that the device can support. You can change one or more of the following maximum frame size fields (location of the field in parentheses):