LXE MX1-IS, Справочное руководство

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SOCKETS TCP/IP Stack 81
E-EQ-MX1ISRG-F MX1 I-Safe Reference Guide
class
class specifies how IP datagrams are to be encapsulated in the link level protocol of the interface.
Some interfaces offer a choice between classes while others use a fixed class. The following
classes are available and are listed with their associated types.
Type Class (defined in the following list)
Pdr dix, ieee, token, driver, slip
Asy raw, slip, cslip, ppp
Class Description
Dix The DEC/Intel/Xerox Ethernet interface also known as Blue Book Ethernet
or Ethernet II.
Token IBM Token Ring. Source routing is supported for multiple rings.
Ieee IEEE: 802.3 Ethernet with SNAP headers.
Driver Use the default class for the packet driver.
Slip Serial Link Internet Protocol (SLIP) for point-to-point
asynchronous links. This mode is compatible with UNIX SLIP.
Cslip Compressed Serial Link Internet Protocol (SLIP) for faster reaction
over point-to-point synchronous links.
Ppp Point-to-point protocol over asynchronous links.
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.