[comp.os.research] Request/response protocols

schmidt@crimee.ICS.UCI.EDU (Douglas C. Schmidt) (06/17/91)

Hi,

	I've got a quick question about request/response protocols
used for distributed OSs (e.g., VMTP for the V kernel or FLIP for
Amoeba).  I'm curious to know how the requestor (i.e., client) side
keeps accurate track of the round-trip delay time in order to know how
long to set the timers that handle retransmission in the case of
packet lossage?  In particular, it seems that piggy-backing the
request ACK onto the response from the server would lead to inadequate
knowledge by the client as to how long the round-trip delay was (since
the total delay time would also include the time spent by the server
performing whatever task was envoked).

	Does anyone know if this is an issue in designing and
implementing request/response protocols?

	Thanks,

		Doug
--
His life was gentle, and the elements so            | Douglas C. Schmidt
Mixed in him that nature might stand up             | (schmidt@ics.uci.edu)
And say to all the world: "This was a man."         | (714) 856-4101
   -- In loving memory of Terry Williams (1971-1991)|