Fully qualified domain name, Dynamic name resolution, Dynamic name resolution 21 – Airlink Raven GPRS User Manual

Page 29

Advertising
background image

Cingular GPRS Raven User Guide Version 2.01

21

IP Manager

Fully Qualified Domain Name

A fully qualified domain name (FQDN) generally has several parts.

Top Level Domain (TDL): The TDL is the ending suffix for a domain name
(.com, .net, .org, etc.)

Country Code Top Level Domain (ccTDL): This suffix is often used after the
TDL for most countries except the US (.ca, .uk, .au, etc.)

Domain name: This is the name registered with ICANN (Internet Corporation
for Assigned Names and Numbers) or the registry for a the country of the
ccTDL (i.e. if a domain is part of the .ca TDL, it would be registered with the
Canadian domain registry.) It is necessary to have a name registered before it
can be used.

Sub-domain or server name: A domain name can have many sub-domain or
server names associated with it. Sub-domains need to be registered with the
domain, but do not need to be registered with ICANN or any other registry. It is
the responsibility of a domain to keep track of its own subs.

A URL (Universal Resource Locator) is different from a domain name in that it
also indicates information on the protocol used by a web browser to contact that
address, such as http://www.airlink.com.

.com is the TDL

airlink is the domain (usually noted as airlink.com since the domain is specific
to the TDL)

www is the server registered with AirLink.com

http:// is the protocol (html or web) used to access the webpage for AirLink

Dynamic Name Resolution

When an IP address is not expected to change, the DNS server can indicate to all
queries that the address can be cached and not looked up for a long period of time.
Dynamic DNS servers, conversely, have a short caching period for the domain
information to prevent other Internet sites or queries from using the old informa-
tion.

Advertising