ATM_SETBATCHSIZE(4NDEVICES AND NETWORK INTERFACEATM_SETBATCHSIZE(4N)



NAME
     atm_setbatchsize, atm_getbatchsize  - set/get batch size for
     null AAL interface

SYNOPSIS
     #include <fore_atm/fore_atm_user.h>

     int atm_setbatchsize(fd, batch_size)
     int fd;
     int batch_size;

     int atm_getbatchsize(fd, batch_size)
     int fd;
     int *batch_size;

DESCRIPTION
     atm_setbatchsize() is used to  set  the  minimum  amount  of
     cells  that  must be received by the connection specified by
     fd before atm_recv(4N) will return.  This applies only to an
     ATM  connection  that  is  established  with  an AAL of type
     aal_null. By default, the batch size  is  set  to  1,  which
     causes  atm_recv(4N)  to  return  each cell received for the
     incoming connection specified by fd. A different size can be
     specified     using     the     batch_size    argument    to
     atm_setbatchsize(). Setting the batch size to a value  other
     than  1  can  improve  performance  by reducing the overhead
     incurred per cell.  The value must be chosen carefully since
     a batch size other than 1 will prevent data from moving from
     the physical level to the ATM  level  until  the  number  of
     cells  received  for  the  connection is equal to or greater
     than the batch size.  In addition, care  must  be  taken  to
     ensure  that the data size, in bytes (56 bytes per cell), is
     not greater than the Maximum Transmission Unit (MTU) for the
     connection.   The  MTU  for  the  link  is  returned  by the
     atm_open(4N) operation.

     atm_getbatchsize() returns the current value  of  the  batch
     size in the batch_size argument.

RETURN VALUES
     atm_setbatchsize() and atm_getbatchsize() return 0  on  suc-
     cess.  On failure, they return -1 and set atm_errno to indi-
     cate the error. atm_error(4N) can be used to  print  a  text
     description  of errors of returned by atm_setbatchsize() and
     atm_getbatchsize().

ERRORS
     atm_setbatchsize() and atm_getbatchsize() can also fail with
     errors returned from the ioctl(2) system call.






FSI Release 2.3     Last change: 7 June 1994                    1






ATM_SETBATCHSIZE(4NDEVICES AND NETWORK INTERFACEATM_SETBATCHSIZE(4N)



SEE ALSO
     atm_intro(4N)





















































FSI Release 2.3     Last change: 7 June 1994                    2