🚀 go-pugleaf

After going through a many SNA manuals, including the friendly FAPLs,
I've come to realize that SNA provides no reliability in terms
of a checksum at any level above the data link.  Obviously you'll
have the data link reliability (16-bit CRC for SDLC, 32-bit FCS
for the token ring, etc.), but unlike TCP, UDP or Xerox's IDP,
there is no "checksum".  Am I missing something ??

I'll assume the designers of SNA assumed that a DLC check was
adequate.  Do TCP or UDP really need a checksum, especially when
running over an Ethernet, say ?  I see that ISO only specifies the
use of a checksum for TP-4.

	Richard Stevens
	Health Systems International, New Haven, CT
	   stevens@hsi.uu.net
           ... { uunet | yale } ! hsi ! stevens