Cisco TelePresence Video Communication Server Administrator's Manual page 143

If one of the target zones is a neighbor, traversal client or traversal server zones, those zones
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are queried for the URI. If that system supports URI dialing via DNS, it may route the call
itself.
Adding and configuring DNS zones
To enable URI dialing via DNS, you must configure at least one DNS zone. To do this:
1. Go to the Zones page
2. Click New. You are taken to the Create zone page.
3. Enter a Name for the zone and select a Type of DNS.
4. Configure the DNS zone settings as follows:
Field Guidelines
Hop When dialing by URI via DNS, the hop count used is that configured for the DNS
count zone associated with the search rule that matches the URI address (if this is lower
than the hop count currently assigned to the call).
If URI address isn't matched to a DNS zone, the query may be forwarded to a
neighbor. In this case, the hop count used will be that configured for the neighbor
zone (if this is lower than the hop count currently assigned to the call).
H.323 The H.323 and SIP sections allow you to filter calls to systems and endpoints located
and SIP via this zone, based on whether the call is located using SIP or H.323 SRV lookups.
modes
Include This setting determines whether, if no NAPTR (SIP) or SRV (SIP and H.323) records
address have been found for the dialed alias via this zone, the VCS will then query for A and
record AAAA DNS records before moving on to query lower priority zones.
You are recommended to use the default setting of Off, meaning that the VCS will not
query for A and AAAA records, and instead will continue with the search, querying
the remaining lower priority zones. This is because, unlike for NAPTR and SRV
records, there is no guarantee that the A/AAAA records will point to a system capable
of processing the relevant SIP or H.323 messages (LRQs, Setups, etc.) - the system
may instead be a web server that processes http messages, or a mail server that
processes mail messages. If this setting is On, when a system is found using
A/AAAA lookup, the VCS will send the signaling to that destination and will not
continue the search process. If the system does not support SIP or H.323, the call
will fail.
Zone For most deployments, this option should be left as Default.
profile
5. Click Create zone.
Configuring search rules for DNS zones
If you want your local VCS to use DNS to locate endpoints outside your network, you must:
configure the DNS servers
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create a DNS zone and set up associated search rules that use the Pattern string and Pattern
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type fields to define the aliases that will trigger a DNS query
For example, rules with:
Cisco VCS Administrator Guide (X6.1)
(VCS configuration > Zones).
used by the VCS for DNS queries
Dial plan and call processing
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