A bit more about DNS...

Some of the players are:

IETF RFC Contributors


IETF is the Internet Engineering Task Force.  An RFC document is a Request For Comments document.  RFC contributors and the IETF produce RFCs.  There are several RFCs that describe the Domain Name System (DNS).  It is these DNS RFCs that are typically used as a standard by which DNS implementors measure whether or not they’re doing DNS the right way.



ICANN is the Internet Corporation for Assigned Names and Numbers.  ICANN is the organization of which IANA is a department, as of the time this article was written.



IANA is the Internet Assigned Numbers Authority.  IANA manages the DNS “root zone,” including the choices of who are expected to provide DNS service for this root zone.

DNS Service Implementors

People and organizations develop software which can be used to provide DNS service.  If DNS was akin to an automobile, such implementors would be akin to the manufacturers of automobiles.  These implementors use RFCs as their guides.  They also respect IANA’s choices about the DNS root zone providers.

Root Zone Servers


IANA chooses who is expected to provide DNS service for the root zone.  DNS service providers and the DNS software they use are expected to operate consistently with IANA’s choices.  Co-operation is nice.

When fully resolving a name like www.synthetel.com, the first step is with the root servers: Asking the root servers who the DNS service providers are for the “com” domain.  The root servers respond with details about the providers of the “com” domain, which is a so-called “top-level” domain (TLD), having only one piece in its name.  (Pieces are separated by periods / dots.)

Root zone servers are also expected to respect IANA regarding TLD Registries.

TLD Registries


Top-level domains (TLDs) can be classified as country-code TLDs (ccTLDs) or generic TLDs (gTLDs).  Each TLD is operated by a so-called “registry.”  For the “ca” domain, that registry is CIRA, the Canadian Internet Registration Authority.  “ca” is the country-code for Canada, so the “ca” domain is a ccTLD.  “com”, “net”, “org”, “biz” and “info” are examples of gTLDs.

When fully resolving a name like www.synthetel.com, the second step is with the registries: Asking the registry for “com” who the DNS providers are for the synthetel.com domain.


A registrar facilitates the registration of a domain name with a registry.  This usually involves money and is commonly understood as “purchasing domains.”  An example of a registrar is Tucows.  If you were to “purchase” the domain name synthetel.ca with Tucows, you’d be paying Tucows (a registrar) to register that domain with the CIRA registry.

A domain name registration includes details about the DNS service provider(s) for that domain name.  That is, a registrar also facilitates a registrant’s choice of DNS provider.


Like a registrar, a re-seller also facilitates the registration of a domain name, but with a registrar, as opposed to a registry.  That is, a re-seller is simply another step between a registrant and a registry.  Re-sellers might have different pricing than the registrars they are associated with.

An example of a re-seller is Synthetel, which is a re-seller for Tucows. 

DNS Service Providers

DNS services can roughly be classified into two types:

At your home or at your office, your Internet Service Provider (ISP) is likely to provide you with recursive DNS resolution.  This service allows your computers and other Internet-aware devices to find the IP address of any domain name.  It can be useful to think of this as “outbound” DNS.

Every domain name needs at least one DNS service provider in order to be accessible to the Internet.  Any registrant can choose any DNS service provider.  There are free DNS services, there are cheap DNS services, there are expensive DNS services.  Some factors that might account for these differences include ease of use, availability of technical support, resistance to Internet attacks.  This type of DNS service applies to particular domain names on behalf of a domain name registrant.  It can be useful to think of this as “inbound” DNS.

Synthetel is a DNS provider of the latter type.

Registrants (You!)

A person or an organization can be a registrant for a domain name as long as that person or organization meets whichever criteria is mandated by the responsible registry.  For example, CIRA has certain Canadian Presence Requirements (CPR) for registration of a “ca” domain, and a registrant must choose the appropriate category.  At the time this article was written, CIRA’s CPR categories are:

A DNS Example

When you visit http://www.synthetel.ca in your web-browser, the following steps are involved:

  1. Your DNS resolver (probably your ISP) contacts one of the root zone servers and asks who the DNS provider is for the “ca” domain (which is also known as the registry for the “ca” ccTLD).  The root zone server responds.
  2. Your DNS resolver contacts the DNS provider for the “ca” domain (which happens to be the CIRA Registry) and asks who the DNS provider is for the synthetel.ca domain.  CIRA responds.
  3. Your DNS resolver contacts the DNS provider for the synthetel.ca domain and asks about www.synthetel.ca.  The IP address for that name is sent along in a response.
  4. Your web-browser connects to the IP address (wherever that system exists in the world) and fetches the web-page

Hopefully this article has been useful to you!

Copyright © 2016 Synthetel Corporation. All rights reserved.