User guide

184 TALKSWITCH USER GUIDE
What is a IP Proxy and Registrar?
The basic IP architecture is client/server in nature. The main entities in the
IP server are the proxy, redirect server and the registrar.
TalkSwitch has the IP server fully integrated for easy deployment and
maintenance of your VoIP network. If you are deploying a multi-site
configuration which can comprise of TalkSwitch units, certified third-party
gateways and certified third-party IP phones, one TalkSwitch
can act as the IP proxy and registrar. The other IP end-points will register
with this TalkSwitch and all calls will be negotiated through this TalkSwitch.
When you first set up your VoIP device (TalkSwitch unit, gateway or phone),
it will register itself with the TalkSwitch that is configured as the IP server
so that calls can be directed to your location.
When you initiate a VoIP call, your device (TalkSwitch unit, gateway or
phone) will contact the TalkSwitch that is configured as the IP server to
obtain the contact information for the destination you are trying to reach.
Once the information is received, the call is established directly between
your location and the destination. The IP server is no longer involved in
the call.
If the location of the IP proxy and registrar has a dynamic IP address, you
have to use the dynamic DNS since the IP server location becomes
unreachable as soon as the IP address changes.
What is Dynamic DNS?
Dynamic DNS is a Domain Name Service used with dynamic IP addresses. DNS
is used to allow devices to find other devices on the Internet by name rather
than by IP address. Dynamic DNS allows you to use a Fully Qualified Domain
Name (FQDN) to locate a device with a dynamic IP address. The FQDN does
not change. There are companies on the Internet who can provide you with a
DNS address, even if your IP address changes. Such companies are
www.dyndns.org, hn.org or www.no-ip.com. Please consult with them how
to use their service. The basic idea is that you will receive an address like
myname.homeip.net which points to your IP address (i.e. 209.210.230.140).
This is important for locations where the IP server resides and where the
public IP address is dynamic. All other locations will point to this IP server’s
domain instead of an IP address.
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 not take longer than 15 minutes to
propagate throughout the DNS system. It is possible that propagation could