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D14049.05
February 2009
Grey Headline
(continued)
TANDBERG
VIDEO COMMUNICATIONS SERVER
ADMINISTRATOR GUIDE
Introduction
Getting started
Overview and
status
System
configuration
VCS
configuration
Zones and
neighbors
Call
processing
Bandwidth
control
Firewall
traversal
Appendices
Applications
Maintenance
Dialing by address types
The destination address that is entered using the caller’s endpoint can take a number of different
formats, and this will affect the specific process that the VCS follows when attempting to locate the
destination endpoint. The address types supported by the VCS are:
IP address
•
e.g.
10.44.10.1
or
3ffe:80ee:3706::10:35
H.323 ID
•
e.g.
john.smith
or
(note that an H.323 ID can be in
the form of a URI)
E.164 alias
•
e.g.
441189876432
or
6432
URI
•
e.g.
ENUM
•
e.g.
441189876432
or
6432
Each of these address types may require some configuration of the VCS in order for them to be
supported. The following sections describe the configuration required for each address type.
Dialing by IP address is necessary when the destination endpoint is not registered with any system
(e.g. a VCS, gatekeeper or Border Controller).
If the destination endpoint is registered with one of these systems, it may be possible to
call it using its IP address but the call may not succeed if the endpoint is on a private
network or behind a firewall. For this reason we recommend that, where possible, calls to
registered endpoints are placed using one of the other addressing schemes, such as its
AOR or H.323 ID. For the same reason we do not recommend that callers outside your network are
given IP addresses to use to contact endpoints within your network
The
Calls to Unknown IP addresses
setting determines how the VCS will handle calls made to IP
addresses which are not on its local network, or registered with it or one of its neighbors. See the
Calls to unknown IP addresses
section for full details on this setting.
Endpoints registered to a VCS Expressway
Calls made by dialing the IP address of an H.323 endpoint registered directly with a VCS
Expressway will be forced to route through the VCS Expressway. The call will therefore be subject to
any restrictions configured on that system.
About the different address types
No special configuration is required in order to place a call using an H.323 ID or E.164 alias. The
VCS follows the usual
search process
, applying any transforms and then searching the Local Zone
and external zones for the alias, depending on the match and priority settings of each zone.
!
SIP endpoints will always register using an AOR in the form of a URI. We recommend that
H.323 endpoints also register with an H.323 ID in the form of a URI to facilitate
interworking.
When a user places a call using URI dialing, they will typically dial
.
If the destination endpoint is locally registered or registered to a neighbor system, no special
configuration is required in order for the call to be placed. The VCS follows the usual
search
process
, applying any transforms and then searching the Local Zone and external zones for the
alias, depending on the match and priority settings of each zone.
If the destination endpoint is not locally registered, URI dialing may make use of DNS to locate the
destination endpoint. In order to support URI dialing via DNS, you must configure the VCS with at
least one DNS server and at least one DNS zone,
Full instructions on how to configure the VCS to support URI dialing via DNS (both outbound and
inbound) are given in
URI dialing
.
ENUM dialing allows an endpoint to be contacted by a caller dialing an E.164 number - a telephone
number - even if that endpoint has registered using a different format of alias. The E.164 number
is converted into a URI by the DNS system, and the rules for URI dialing are then followed to place
the call.
The ENUM dialing facility allows you to retain the flexibility of URI dialing whilst having the simplicity
of being called using just a number - particularly important if any of your callers are restricted to
dialing using a numeric keypad.
In order to support ENUM dialing on the VCS you must configure it with at least one DNS server and
the appropriate ENUM zone(s).
Full instructions on how to configure the VCS to support ENUM dialing (both outbound and inbound)
are given in
ENUM dialing
.
Dialing by IP address
Dialing by H.323 ID or E.164 alias
Dialing by H.323 or SIP URI
Dialing by ENUM
