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diff --git a/doc/rfc/rfc250.txt b/doc/rfc/rfc250.txt new file mode 100644 index 0000000..a95845d --- /dev/null +++ b/doc/rfc/rfc250.txt @@ -0,0 +1,59 @@ + + + + + + +Network Working Group H. Brodie +Request for Comments #250 UCLA-NMC +NIC #7691 Computer Science +Categories: D5, D7 7 October 71 +Updates: None +Obsoletes: None + + Some Thoughts on File Transfer + + There are several aspects of the proposed Data Transfer Protocol (RFC + #171) and File Transfer Protocol (RFC #172) which we believe could + use further clarification and perhaps revision. Interest in + transferring larger amounts of data than is typically sent via the + usual TELNET connection is increasing, and at least at UCLA-NMC + implementation attempts have pointed out several difficulties with + the proposed protocols. + + First, and probably most easily decided, is the ambiguity in RFC #171 + with regards to the sequence number field of the descriptor and count + transaction. The description provided for the transaction header + provides for 16 bit sequence number. However, the sequence number + field in the error codes transaction only provides for 8 bits. We + are of the opinion that 8 bits is sufficient for a sequence number + field. If the sequence number is reduced to 8 bits, and the two NUL + bytes are deleted from the descriptor and count header, then its size + is reduced to 48 bits, which would seem to be as convenient to handle + as the proposed 72 bit transaction header. + + Another source of difficulty lies in the implementation of the (the + SEX time-sharing system) the 'end' of a file (which presumably would + be the begin point of an Append transaction) is almost com- pletely + context-defined--i.e., the program reading the file determines when + it has reached the end of the file. Therefore, the meaning of + 'Append' is somewhat hazy, and since the proposed Mail Box Protocol + uses the Append feature, not implementing this command in a File + Transfer service is costly in terms of lost useability. + + We believe that resolution of these ambiguities will lead to a + greatly accelerated implementation schedule, at least here at UCLA- + NMC. + + [ This RFC was put into machine readable form for entry ] + [ into the online RFC archives by BBN Corp. under the ] + [ direction of Alex McKenzie. 12/96 ] + + + + + + + + [Page 1] + |