Cisco Cisco TelePresence Video Communication Server Expressway 관리 매뉴얼
109
D14049.08
November 2010
November 2010
Grey Headline (continued)
CISCO TELEPRESENCE
VIDEO COMMUNICATION SERVER
ADMINISTRATOR GUIDE
URI dialing
URI dialing via DNS for incoming calls
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:
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
•
SRV record for
_ h323cs. _ tcp.example.com returns vcs.example.com
•
NAPTR record for
example.com returns
•
_ sip. _ tcp.example.com and
•
_ sip. _ udp.example.com and
•
_ sips. _ tcp.example.com
•
SRV record for
_ sip. _ udp.example.com returns vcs.example.com
•
SRV record for
_ sip. _ tcp.example.com returns vcs.example.com
•
SRV record for
_ sips. _ tcp.example.com returns vcs.example.com
•
A record for
vcs.example.com returns the IPv4 address of the VCS
•
AAAA record for
vcs.example.com returns the IPv6 address of the VCS
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
setting up two common DNS servers are given in the
Appendix.
In order 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
•
an appropriate transform should be written to convert URIs into the format used by the H.323
registrations. 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 the
registrations. 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 the
section for an example of how to do this.
SIP endpoints always register with an AOR in the form of a URI, so no special configuration is
required.
required.
Several mechanisms could have been used to locate the VCS. You may wish 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
placed to user@<IP_address> to be routed to an existing registration for user@example.com.
In this case you would configure a
that would strip the IP_address
suffix from the incoming URI and replace it with the suffix of example.com.
Recommended configuration
If URI dialing via DNS is being used in conjunction with firewall traversal, DNS zones should be
configured on the VCS Expressway and any VCSs on the public network only. VCSs behind the
firewall should not have any DNS zones configured. This will ensure that any outgoing URI calls
made by endpoints registered with the VCS will be routed through the VCS Expressway.
In addition, the DNS records for incoming calls should be configured with the address of the VCS
Expressway as the authoritative gatekeeper/proxy for the enterprise (see the
configured on the VCS Expressway and any VCSs on the public network only. VCSs behind the
firewall should not have any DNS zones configured. This will ensure that any outgoing URI calls
made by endpoints registered with the VCS will be routed through the VCS Expressway.
In addition, the DNS records for incoming calls should be configured with the address of the VCS
Expressway as the authoritative gatekeeper/proxy for the enterprise (see the
Appendix for more information). This ensures that incoming calls placed using URI dialing enter the
enterprise through the VCS Expressway, allowing successful traversal of the firewall.
enterprise through the VCS Expressway, allowing successful traversal of the firewall.
URI dialing and firewall traversal