review: The Design
Philosophy of the DARPA Internet Protocols
- Is TCP/IP the most effective
protocol for internetworking, or have the new expectations of the internet
made the protocol “non-effective”?
- An evaluation of the motivation
behind supporting TCP/IP as the Internet standard and a look into
possibilities of changing the standard.
- It is important to realize
the context in which the standards for the internet were chosen. The priorities have changed since the
migration from a largely military to a mainly commercial setting. The factor of survivability, which was
seen as most important in the military setting, would now be overshadowed
by the importance of performance and accountability.
- If designed today the
internet protocol would assign much different weights to the set of goals
when defining “effective”. Some of
the goals that were lower in importance when the internet was created were
less effectively met and have now become serious shortcomings. The internet protocol was very effective
in meeting its original set of priorities, but was not designed to meet
the priorities of today.
- Critique the main
System researchers and
builders should recognize that in ever changing environment of the
internet priorities often change.
It is not the ability to immediately satisfy all priorities, but
rather the ability to adapt to meet the priorities of tomorrow. It was a large step to move from
networks which had been traditionally circuit switched to the packet
switched internet. The use of datagrams allows much more flexibility in dealing with
unlike systems then continuous streams would allow. It is also important to realize that
sessions can still be used in the datagram model by creating a virtual
circuit. The issue of survivability
which was once so important to the military is pretty much non-existent
due to the extreme redundancy built into the topology of the internet
today. Much more important today is
the issue of performance.
Performance was not a large issue when the internet was created,
but could now be considered the most important issue. TCP/IP has adapted to fit the current
day needs, but it is evident by the ordering of priorities when created
that the protocol was not designed for the present day internet.
- Significance- 3
The article is very effective in showing how the internet has met its
original intention, and recognizes that it is faltering in the changing
environment, but offers no real insight on what we should do about this
besides the vague question of the importance of the datagram.
- Convincing- 2 The author makes a suggestion of flow monitoring or
“soft state”, but says very little to back this up. He says it may well permit us to reach
our goals, but offers no reassurance, and leaves it open as a type of
exploration, not a solution.
- Any type of protocol
solution or flow management would have to be backwards compatible, cost
effective, yet more robust. A new
implementation may necessitate the elimination of the old.