[ih] Why FTP uses two ports?

[John Day]

Yes, this is what the Urgent was for in TCP to signal that.  Just 
having it in Telnet wouldn't get there any sooner, it required a 
mechanism in the protocol that carried Telnet.

At 13:29 -0400 2012/06/21, Bernie Cosell wrote:
>On 21 Jun 2012 at 10:03, Jack Haverty wrote:
>
>>  The decision was made to adopt the in-band approach. There were then a
>>  lot of details to work out, especially with respect to the "Urgent
>>  Pointer" mechanism of TCP. While it was straightforward to define the
>>  details of Urgent in the TCP protocol, it was much less clear how the
>>  programs at either end of the connection should behave. E. G., when
>>  you are notified that there is urgent data further downstream, but your
>>  own buffers are full, what do you do - discard everything until you get
>>  the urgent data?
>
>Off topic, but wasn't there a mechanism like this in telnet?  I don't
>remember the details any more but I thought there was a way to tell the
>reciver "I've put a datamark in the data stream, throw everything away
>until you get to it".  I recall working with Bob Clements [I think] to
>get that to work between the TIP to TENEX [so if you hit control-C it'd
>dump the other input you'd "typed ahead"]
>
>   /Bernie\
>
>--
>Bernie Cosell                     Fantasy Farm Fibers
>mailto:bernie at fantasyfarm.com     Pearisburg, VA
>     -->  Too many people, too few sheep  <--