Uri Dialing Via Dns For Incoming Calls - Cisco TelePresence Administrator's Manual

Field Guidelines
Include This setting determines whether, if no NAPTR (SIP) or SRV (SIP and H.323) records have been found
address for the dialed alias via this zone, the VCS will then query for A and AAAA DNS records before moving
record 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
n
create a DNS zone and set up associated search rules that use the Pattern string and Pattern type fields
n
to define the aliases that will trigger a DNS query
For example, rules with:
a Pattern string of .*@.* and a Pattern type of Regex will query DNS for all aliases in the form of typical
n
URI addresses
a Pattern string of (?!.*@example.com$).* and a Pattern type of Regex will query DNS for all aliases in
n
the form of typical URI addresses except those for the domain example.com
To set up further filters, configure extra search rules that target the same DNS zone. You do not need to
create new DNS zones for each rule unless you want to filter based on the protocol (SIP or H.323) or use
different hop counts.
Note: you are not recommended to configure search rules with a Mode of Any alias for DNS zones. This will
result in DNS always being queried for all aliases, including those that may be locally registered and those
that are not in the form of URI addresses.

URI dialing via DNS for incoming calls

DNS record types
The ability of the VCS to receive incoming calls made using URI dialing via DNS relies on the presence of
DNS records for each domain the VCS is hosting.
These records can be of various types including:
Cisco VCS Administrator Guide (X7.1)
used by the VCS for DNS queries
Dial plan and call processing
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