User guide

130 TALKSWITCH USER GUIDE • NORTH AMERICA
What is the drawback of using Dynamic DNS?
When DNS records are updated, they have to be sent all over the world so
that everyone will be aware of the changes. Basically, one DNS server
connects to another and swaps information. In many cases, the DNS servers
are updated very quickly. Updates should take no longer than 15 minutes to
propagate throughout the DNS system. It is possible that propagation could
take longer under extenuating circumstances. Propagation shouldn’t take
much more than an hour at the very most.
How often will my Public IP address change?
This depends on the policies of your Internet Service Provider (ISP, the
company that provides your Internet access). It can be a matter of days,
weeks or even months before your IP address changes. A power loss or reboot
to your cable or DSL modem usually results in the assignment of a new
IP address.
TalkSwitch has technology that helps keep this information up to date so
that the system can function properly after an IP address change has been
detected and updated.
What is a port number?
In an IP address like 64.26.209.103:5060, the port number is the number
after the colon, 5060 in this example.
Port numbers are required so that a computer or device can support multiple
applications or streams of simultaneous data communication. Each stream or
application uses a unique port number. You can think of it like mailing a
letter to friend in an apartment building at a specific address. You need to
specify the apartment number as well as the building address, so that the
mail can reach the proper final destination.