TANDBERG D14049.04 Network Card User Manual


 
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D14049.04
JULY 2008
Grey Headline (continued)
TANDBERG VIDEO COMMUNICATIONS SERVER
ADMINISTRATOR GUIDE
Introduction Getting Started
Overview and
Status
System
Conguration
VCS
Conguration
Zones and
Neighbors
Call
Processing
Bandwidth
Control
Firewall
Traversal
Appendices
Applications Maintenance
URI Dialing
URI Dialing for Incoming Calls
Example DNS Record Conguration
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
SRV record for
_ h323cs. _ tcp.example.com returns vcs.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 Appendix DNS Conguration.
Recommended Conguration
If URI dialing is being used in conjunction with rewall traversal, DNS zones and DNS Servers
should be congured on the VCS Expressway and any VCSs on the public network only. VCSs
behind the rewall should not have any DNS zones or servers congured. 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 should be congured with the address of the VCS Expressway as
the authoritative gatekeeper/proxy for the enterprise (see the Appendix DNS Conguration).
This ensures that incoming calls placed using URI dialing enter the enterprise through the VCS
Expressway, allowing successful traversal of the rewall.
URI Dialing and Firewall Traversal
In order for locally registered endpoints to be reached using URI dialing, they must register
using a full URI. This applies to both SIP and H.323 endpoints. If endpoints do not register
using a full URI, they will be discoverable only by the VCS to which they are registered, and
any neighbor VCSs.
Several mechanisms could have been used to locate the VCS. You may wish to enable calls
placed to user@<VCS_IP_address> to be routed to an existing registration for
user@example.com. In this case you would congure a Pre-Search Transform that would
strip the IP address of the VCS from the incoming URI and replace it with the domain name of
example.com.