n
Port
is the IP port on the VCS that has been configured to listen for that particular service and protocol
combination
n
Target
is the FQDN of the VCS.
Configuring H.323 SRV records
Annex O of
ITU Specification: H.323
defines the procedures for using DNS to locate gatekeepers and
endpoints and for resolving H.323 URL aliases. It also defines parameters for use with the H.323 URL.
The VCS supports the location, call and registration service types of SRV record as defined by this Annex.
Location service SRV records
Location records are required for gatekeepers that route calls to the VCS. For each domain hosted by the
VCS, you should configure a location service SRV record as follows:
n
_Service
is
_h323ls
n
_Proto
is
_udp
n
Port is the port number that has been configured from
Configuration > Protocols > H.323
as the
Registration UDP port
Call signaling SRV records
Call signaling SRV records (and A/AAAA records) are intended primarily for use by non-registered endpoints
which cannot participate in a location transaction, exchanging LRQ and LCF. For each domain hosted by the
VCS, you should configure a call signaling SRV record as follows:
n
_Service
is
_h323cs
n
_Proto
is
_tcp
n
Port is the port number that has been configured from
Configuration > Protocols > H.323
as the
Call
signaling TCP port
.
Registration service SRV records
Registration records are used by devices attempting to register to the VCS. For each domain hosted by the
VCS, you should configure a registration service SRV record as follows:
n
_Service
is
_h323rs
n
_Proto
is
_udp
n
Port is the port number that has been configured from
Configuration > Protocols > H.323
as the
Registration UDP port
Configuring SIP SRV records
RFC 3263
describes the DNS procedures used to resolve a SIP URI into the IP address, port, and transport
protocol of the next hop to contact.
If you want the VCS to be contactable using SIP URI dialing, you should configure an SRV record for each
SIP transport protocol enabled on the VCS (that is, UDP, TCP or TLS) as follows:
n
Valid combinations of
_Service
and
_Proto
are:
l
_sips._tcp
l
_sip._tcp
l
_sip._udp
(although not recommended)
Cisco VCS Administrator Guide (X8.1.1)
Page 208 of 507
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