Example Dns Record Configuration - Cisco TelePresence Administrator's Manual

Valid combinations of _Service and _Proto are:
n
_sips._tcp
l
_sip._tcp
l
_sip._udp (although not recommended)
l
Port is the IP port number that has been configured from
n
port for that particular transport protocol.
_sip._udp is not recommended because SIP messages for video systems are too large to be carried on a
packet based (rather than stream based) transport. UDP is often used for audio only devices. Also,
UDP tends to be spammed more than TCP or TLS.

Example DNS record configuration

A company with the domain name example.com wants to enable incoming H.323 and SIP calls using URI
addresses in the format user@example.com. The VCS hosting the domain has the FQDN
vcs.example.com.
Their DNS records would typically be as follows:
SRV record for _h323ls._udp.example.com returns vcs.example.com
n
SRV record for _h323cs._tcp.example.com returns vcs.example.com
n
SRV record for _h323rs._tcp.example.com returns vcs.example.com
n
NAPTR record for example.com returns
n
_sip._tcp.example.com and
l
_sips._tcp.example.com
l
SRV record for _sip._tcp.example.com returns vcs.example.com
n
SRV record for _sips._tcp.example.com returns vcs.example.com
n
A record for vcs.example.com returns the IPv4 address of the VCS
n
AAAA record for vcs.example.com returns the IPv6 address of the VCS
n
How you add the DNS records depends on the type of DNS server you are using. Instructions for setting up
two common DNS servers are given in the
For locally registered H.323 endpoints to be reached using URI dialing, either:
the H.323 endpoints should register with the VCS using an address in the format of a URI
n
an appropriate transform should be written to convert URIs into the format used by the H.323 registrations.
n
An example would be a deployment where H.323 endpoints register with an alias, and incoming calls are
made to alias@domain.com. A local transform is then configured to strip the @domain, and the search is
made locally for alias. See
this.
SIP endpoints always register with an AOR in the form of a URI, so no special configuration is required.
Several mechanisms could have been used to locate the VCS. You may want to enable calls placed to
user@<IP_address> to be routed to an existing registration for user@example.com. In this case you
would configure a pre-search transform
replace it with the suffix of example.com.
Cisco VCS Administrator Guide (X7.2)
DNS configuration examples
Stripping @domain for dialing to H.323 numbers
that would strip the IP_address suffix from the incoming URI and
Dial plan and call processing
VCS configuration > Protocols > SIP
section.
for an example of how to do
as the
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