46 Radio PC Card Configuration
MX2 Reference Guide E-EQ-MX2RG-L-ARC
mtu
mtu specifies the Maximum Transmission Unit size, in bytes. Datagrams larger than this limit are
fragmented into smaller pieces at the IP layer. The maximum value of mtu for the various
interfaces is:
Ethernet - 1500
For serial links a standard value for mtu is 576. (576 is the maximum according to specifications,
but may be increased on reliable connections as long as both sides use the same value.)
numbuf
numbuf specifies how many incoming datagrams may be queued on the receive queue at one time.
If this limit is exceeded, further received datagrams are discarded. This mechanism is used to
prevent fast interfaces from filling up memory when data cannot be handled fast enough.
buflim
buflim specifies the maximum number of outgoing datagrams or packets to queue before starting
to discard datagrams. This mechanism is used to prevent the memory from filling up when a serial
link goes down.
bufsize
bufsize specifies the size of the ring buffer in bytes to be allocated to the receiver in raw mode.
intvec
intvec specifies the software interrupt number (vector) in hexadecimal to use for resident packet
drivers.
ioaddr
ioaddr is the I/O base address in hexadecimal of a serial port or the hardware controller and must
correspond with the jumper or switch settings used during the setup of the controller board. The
standard values for serial ports are:
COM1 03F8h
COM2 02F8h
COM3 03E8h
COM4 02E8h
iovec
iovec is the hardware interrupt vector used by the serial port or controller and must correspond
with the jumper or switch settings used during setup of the controller. The standard values for
serial ports are:
COM1 4
COM2 3
COM3 4
COM4 3
irq
irq is the hardware interrupt vector used by the network interface controller. This is only used for
faster response in Sockets.
modemfile
A file containing the modem commands and scripts.
speed
speed specifies the transmission speed for serial interface devices (baud rate). Before using a
serial connection you have to set flow control with the param command.
