113
D14049.07
March 2010
Grey Headline
(continued)
TANDBERG
VIDEO COMMUNICATION SERVER
ADMINISTRATOR GUIDE
Introduction
Overview and
status
System
configuration
VCS
configuration
Zones and
neighbors
Clustering and
peers
Call
processing
Bandwidth
control
Firewall
traversal
Appendices
Applications
Maintenance
ENUM dialing
Configuring DNS NAPTR records
ENUM relies on the presence of NAPTR records, as defined by
RFC 2915 [7]
. These are used to obtain an H.323 or SIP URI from
an E.164 number.
The record format that the VCS supports is:
•
order flag preference service regex replacement
where:
•
order
and
preference
determine the order in which
NAPTR records are processed. The record with the lowest
order
is processed first, with those with the lowest
preference
being processed first in the case of matching
order
.
•
flag
determines the interpretation of the other fields in this
record. Only the value
u
(indicating that this is a terminal rule)
is currently supported, and this is mandatory.
•
service
states whether this record is intended to describe
E.164 to URI conversion for H.323 or for SIP. Its value must be
either
E2U+h323
or
E2U+SIP
.
•
regex
is a regular expression that describes the conversion
from the given E.164 number to an H.323 or SIP URI.
•
replacement
is not currently used by the VCS and should be
set to
.
(i.e. the full stop character).
Non-terminal rules in ENUM are not currently supported
by the VCS. For more information on these, see section
2.4.1 of
RFC 3761 [8]
,
Example
For example, the record:
•
IN NAPTR 10 100 "u" "E2U+h323" "!^(.*)$!h323:\1@
example.com!" .
would be interpreted as follows:
•
10
is the
order
•
100
is the
preference
•
u
is the
flag
•
E2U+h323
states that this record is for an H.323 URI
•
!^(.*)$!h323:\[email protected]!
describes the conversion:
•
!
is a field separator
•
the first field represents the string to be converted. In this
example,
^(.*)$
represents the entire E.164 number
•
the second field represents the H.323 URI that will be
generated. In this example,
h323:\[email protected]
states that the E.164 number will be concatenated with
@example.com
. For example,
1234
will be mapped to
.
•
.
shows that the
replacement
field has not been used.
ENUM dialing for incoming calls
Prerequisites
In order for your locally registered endpoints to be reached
using ENUM dialing, you must configure a DNS NAPTR record
that maps your endpoints’ E.164 numbers to their SIP/H.323
URIs. This record must be located at an appropriate DNS domain
where it can be found by any systems attempting to reach you by
using ENUM dialing.
About DNS domains for ENUM
ENUM relies on the presence of NAPTR records to provide the
mapping between E.164 numbers and their SIP/H.323 URIs.
RFC 3761 [8]
, which is part of a suite of documents that
define the ENUM standard, specifies that the domain for
ENUM - where the NAPTR records should be located for public
ENUM deployments - is
e164.arpa
. However, use of this
domain requires that your E.164 numbers are assigned by an
appropriate national regulatory body. Not all countries are yet
participating in ENUM, so you may wish to use an alternative
domain for your NAPTR records. This domain could reside within
your corporate network (for internal use of ENUM) or it could use
a public ENUM database such as
http://www.e164.org
.
