Minimum-Latency Transport Protocols with Modulo-N Incarnation Numbers
Abstract
To provide reliable connection management,
a transport protocol uses 3-way handshakes
in which user incarnations are identified by
bounded incarnation numbers from some modulo-$N$ space.
Cacheing schemes have been proposed
to reduce the 3-way handshake to a 2-way handshake,
providing the minimum latency
desired for transaction-oriented applications.
In this paper,
we define a class of cacheing protocols
and determine the minimum $N$
and optimal cache residency time
as a function
of real-time constraints
(e.g.\ message lifetime, incarnation creation rate,
inactivity duration, etc.).
The protocols use the client-server architecture
and handle failures and recoveries.
Both clients and servers generate incarnation numbers from
a local counter (e.g.\ clock).
These protocols assume a maximum duration for each incarnation;
without this assumption,
there is a very small probability ($\approx \frac{1}{N^2}$)
of misinterpretation of incarnation numbers.
This restriction can be overcome with some additional cacheing.
(Also cross-referenced as UMIACS-TR-93-24.1)