What is the Domain Name System?
The Domain Name System (DNS) helps users to find their way
only around the Internet. Every computer on the Internet has a unique
address just like a telephone number which is a rather complicated string
of numbers. It is called its "IP address" (IP stands for
"Internet Protocol").
But it is hard to remember everyone's IP address. The DNS makes it easier by
allowing a familiar string of letters (the "domain name") to be used
instead of the arcane IP address. So instead of typing 192.0.34.65, you can type
www.icann.org
It is a "mnemonic" device that makes addresses easier to remember.
Translating the name into the IP address is called "resolving the domain
name."
The goal of the DNS is for any Internet user any place in the world to reach a
specific website IP address by entering its domain name. Domain names are also
used for reaching e-mail addresses and for other Internet applications.
What is universal resolvability and why is it important to users?
Think of the phone system home, office or mobile when you dial a number, it
rings at a particular location because there is a central numbering plan that
ensures that each telephone number is unique. The DNS works in a similar way.
If telephone numbers or domain names were not globally unique, phone calls or
e-mail intended for one person might go to someone else with the same number or
domain name. Without uniqueness, both systems would be unpredicatable and
therefore unreliable.
Ensuring predictable results from any place on the Internet is called "universal
resolvability."
It is a critical design feature of the DNS, one that makes the Internet the
helpful, global resource that it is today. Without it, the same domain name
might map to different Internet locations under different circumstances, which
would only cause confusion.
When you send an e-mail to your Aunt Sally, do you care who receives it?
Do you care if it goes to your Uncle Juan instead? Wait a minuteŠdo you have an
Uncle Juan? Then whose Uncle Juan received it? Do you care if it reaches Aunt
Sally if you send it from work but my Uncle Juan if you send it from home?
Of course you care who receives it , that's why you wrote it in the first
place.
Whether you're doing business or sending personal correspondence, you want to be
certain that your message gets to the intended addressee.
If at any point the DNS must make a choice between two identical domain names
with different IP addresses, the DNS would not function. It would not know how
to resolve the domain name. When a DNS computer queries another computer and
asks, "are you the intended recipient of this message?", "yes"
and "no" are acceptable answers, but "maybe" is not.
Where does ICANN come in?
This is where ICANN comes in
ICANN is responsible for managing and coordinating the DNS to ensure universal
resolvability.
ICANN is the global, non-profit, private-sector coordinating body acting in the
public interest. ICANN ensures that the DNS continues to function effectively
by overseeing the distribution of unique numeric IP addresses and domain names.
Among its other responsibilities, ICANN oversees the processes and systems that
ensure that each domain name maps to the correct IP address.
What goes on behind the scenes?
Behind the scenes, the story becomes a little more complicated.
In an Internet address such as icann.org the .org part is known as a Top
Level Domain, or TLD. So-called "TLD registry" organizations house
online databases that contain information about the domain names in that TLD.
The .org registry database, for example, contains the Internet whereabouts or
IP address of icann.org. So in trying to find the Internet address of
icann.org your computer must first find the .org registry database. How is this
done?
At the heart of the DNS are 13 special computers, called root servers. They are
coordinated by ICANN and are distributed around the world. All 13 contain the
same vital information this is to spread the workload and back each other up.
Why are these root servers so important? The root servers contain the IP
addresses of all the TLD registries both the global registries such as .com,
.org, etc. and the 244 country-specific registries such as .fr (France), .cn
(China), etc. This is critical information. If the information is not 100%
correct or if it is ambiguous, it might not be possible to locate a key registry
on the Internet. In DNS parlance, the information must be unique and authentic.
Let us look at how this information is used.
Scattered across the Internet are thousands of computers called "Domain
Name Resolvers" or just plain "resolvers" - that routinely
download and copy the information contained in the root servers. These resolvers
are located strategically with Internet Service Providers (ISPs) or
institutional networks. They are used to respond to a user's request to resolve
a domain name that is, to find the corresponding IP address.
So what happens to a user's request to reach our familiar friend at icann.org?
The request is forwarded to a local resolver. The resolver splits the request
into its component parts. It knows where to find the .org registry remember,
it had copied that information from a root server beforehand so it forwards
the request over to the .org registry to find the IP address of icann.org. This
answer is forwarded back to the user's computer. And we're done. It's that
simple! The domain name icann.org has been "resolved"!
Why do we need the resolvers? Why not use the root servers directly? After all,
they contain essentially the same information. The answer is for reasons of
performance. The root servers could not handle hundreds of billions of requests
a day! It would slow users down.
If you are still with the story, you are already wondering about more
complicated names with more parts such as www.icann.org. Well, the DNS is a
hierarchical system. First, the resolver finds the IP address for the .org
registry, queries that registry to find the IP address for icann.org, then
queries a local computer at that address to find the final IP address for
www.icann.org. Just what you would expect.
It is important to remember the central and critical role played by the root
servers that store information about the unique, authoritative root. Confusion
would result if there were two TLDs with the same name: which one did the user
intend? The beauty of the Internet architecture is that it ensures there is a
unique, authoritative root, so that there is no chance of ambiguity.
What about "alternate roots?" How do they fit into this picture?
Anyone can create a root system similar to the unique authoritative root managed
by ICANN. Many people and entities have. Some of these are purely private
(inside a single corporation, for example) and are insulated from having any
effect on the DNS. Some, however, overlap the authoritative global DNS root by
incorporating the unique, authoritative root information, and then adding new
pseudo-TLDs that have not resulted from the consensus-driven process by which
official new TLDs are created through ICANN. The alternate root operators
persuade some users to have their resolvers "point" to their alternate
root instead of the authoritative root. Others (New.net is a recent example)
also create browser plug-ins and other software work-arounds to accomplish
similar effects. The one uniform fact about all these efforts is that these
pseudo-TLDs are not included in the authoritative root managed by ICANN and,
thus, are not resolvable by the vast majority of Internet users.
Why do alternate roots create a problem?
There are many potential problems caused by these unofficial, alternate root
efforts to exploit the stability and reach of the authoritative root. These
efforts are often promoted by those unwilling to abide by the consensus policies
established by the Internet community, policies designed to ensure the continued
stability and utility of the DNS.
For example:
* First, the names of some of these pseudo-TLDs could overlap
TLD names in the authoritative root or those that appear in other alternate
roots. Our familiar friend icann.org could appear in two different roots. Your
e-mail to Aunt Sally could end up with my Uncle Juan.
* Second, the unknowing users might not be linked to one of
these alternate roots and not be able to reach these pseudo-TLD addresses at
all. Your e-mail to Aunt Sally could end up as a dead-letter.
* Third, those purchasing domain names in these pseudo-TLDs
may not be aware of these and other consequences of the lack of universal
resolvability. Or they may be under the impression that they are experiencing
universal resolvability when in fact they are not. They may be very upset to
learn that the names they registered are also being used by others, or that a
new TLD in the authoritative root will not include those names.
These problems are not significant so long as these alternate roots remain very
small, that is, house few domain names with little potential for conflict. But
if they should ever attract many users, the problems would become much more
serious, and could affect the stability and reliability of the DNS itself. Users
would lose confidence in the utility of the Internet.
What is ICANN's role?
ICANN's mission is to protect and preserve the stability, integrity and utility
on behalf of the global Internet community of the DNS and the
authoritative root ICANN was established to manage. ICANN has no role to play
with alternate roots so long as these and other analogous efforts do not create
instabilities in the DNS or otherwise impair the stability of the authoritative
root. But ICANN does have a role to play in educating and informing about
threats to the Internet's reliability and stability.
ICANN is a consensus development body for the global Internet community, and its
focus is the development of consensus policies relating to the single
authoritative root and the DNS. These policies include those that allow the
orderly introduction of new TLDs.
There are thoseincluding operators of commercialized alternate rootswho
pursue unilateral actions outside the ICANN consensus-development process. Many
hope to circumvent these processes by claiming to establish some prior right to
a top-level domain name. ICANN, however, recognizes no such prior claim. ICANN
will continue to reflect the public policy consensus of the global Internet
community over the private claims of the few who try to bypass this consensus.
In Short . . . . . .
Just as there is a single root for telephone numbers internationally, there must
be a single authoritative root for the Internet, administered in the public
interest.
Differenze
tra
DOMINIO e MARCHIO
Il Dominio è un indirizzo telefonico
Il Marchio è un segno distintivo
Il Dominio distingue un indirizzo
Il Marchio distingue un prodotto o un servizio
Il Dominio senza collegamento telefonico non è visibile
Il Marchio è visibile anche senza collegamento telefonico
Il Dominio può essere composto solo da caratteri
alfanumerici
Il Marchio può includere disegni, forme, raffigurazioni, profumi, suoni
ecc. ecc.
Il Dominio è sempre anticipato dalla sigla WWW
( World Wide Web = Ragnatela sparsa in tutto il mondo)
Il Marchio non ha prefissi e si può esprimere in forme presso ché infinite
Il Dominio è visibile solo a computer
Il Marchio è visibile anche senza computer
Il Dominio è valido per qualsiasi tipo di prodotto ed
indipendentemente dalla categoria merceologica di appartenenza
il Marchio è suddiviso in Classi e in Nazionalità
Il Dominio è valido in tutto il mondo
Il Marchio deve essere esteso, Stato per Stato
Il Dominio ha validità annuale ed è esteso e protetto
in tutto il pianeta già poche ore dopo la sua registrazione
Il Marchio va esteso Stato per Stato, dura 10 anni rinnovabili (secondo
le regole di ogni Paese) e dopo sei mesi perde la priorità se non
tempestivamente esteso.
Il Dominio digitato all¹interno del Browser porta al sito
desiderato
Il Marchio digitato all¹interno del Browser dà segno di errore