Protocol Stack Section

You can configure the RT-TCP/IP protocol stack through the RTX64 control panel.

Configurable Parameter	Default Value	Description
Setting the amount of allocated memory	1024	Required. Memory (in Kbytes) that will be allocated for stack use. This memory does not include memory allocated by device drivers at startup.
Priority of the Timer System	66	Required. Priority of the protocol timer. 127 Max (highest priority), 1 Min (lowest priority). Default value is 66.
Specifying the number of sockets	64	Required. The maximum number of sockets available at one time. Minimum number is 1. Maximum number is 32765. Simultaneous connection attempts greater than the number defined in MaxSockets will be denied.
Setting the Maximum Transmission Unit (MTU)	1500	Optional. Sets the Maximum Transmission Unit size (in bytes) or the largest packet size that can be sent by the stack, independent of the underlying medium. Default is 1500 bytes. This setting can be used to: Configure the stack to use MTU values larger than 1500 bytes, thereby allowing jumbo frames to be used. Restrict the MTU value that the stack uses below the default value of 1500 bytes that most NICs support.
Setting the Stack timer interval	100	Optional. The number of milliseconds/tick the stack timer is configured to use. Minimum is 1 millisecond. Maximum is 1000 milliseconds.

The RT-TCP/IP Stack, when running, needs a block of memory to store its internal information (packet buffers and various control information). This block of memory is allocated during startup and is of fixed size specified by the Amount of Memory configured for the Stack. The memory to allocate depends on how much memory is available on the system and how much network traffic is expected.

If you are not sure how much memory should be allocated for stack use, , use the default. The RT-TCP/IP Stack will return WSAENOBUFS to an application when memory reserves have been exhausted. This provides an indication to the user to increase this value.