RPC Technologies

Philip Earnhardt pae at athena.mit.edu
Wed Jun 5 04:40:00 AEST 1991


In <4bc8788d.20b6d at apollo.HP.COM> mishkin at apollo.HP.COM (Nathaniel Mishkin) writes:

>>On page 43, the "Suggested Time" for fragment acknowledgment is 1
>>second (it's my understanding that all of these timers are hardwired
>>in a given NCS implementation). Isn't a 1-second timeout far too
>>short for fragment acknowledgment? If the mean round-trip time for 2
>>Internet hosts is 5 seconds, won't this mean that fragments will get
>>needless multiple retransmissions?

> Ugh.  Suffice it to say that the spec should be taken with a grain of
> salt when it comes to parameters such as the one you're pointing to.
> We focused most of our energy on specifying the non-parametric aspects
> of the protocol.  A correct implementation (e.g., NCS 2.0) would do round
> trip time estimations.

The Network Computer Architecture Book (describing NCS 1.x implementations)
gives "suggested times" for timer implementations.  For your current products,
how do retransmission timers work?  Specifically, do NCS 1.x implementations
on top of UDP/IP have a fixed retransmission timer or do they employ some sort
of adaptive algorighm?

Phil Earnhardt          Netwise, Inc.  2477 55th St.  Boulder, CO 80301
Phone:303-442-8280      UUCP: onecom!wldrdg!pae
My opinions do not reflect any official position of Netwise.




More information about the Comp.sys.sun mailing list