Cisco Cisco Expressway Manual De Manutenção
locations is used, the searching process will stop on the first location to return a response that indicates that the
target destination has been contacted.
target destination has been contacted.
2.
If the search process does not return a relevant SRV record:
—
If the Include address record setting for the DNS zone being queried is set to On, the system will fall back
to looking for an A or AAAA record for the domain in the URI. If such a record is found, the call will be routed
to that IP address and the search will terminate. Note that if the A and AAAA records that are found at this
domain are for systems other than those that support SIP or H.323, the Expressway will still forward the call
to this zone, and the call will therefore fail. For this reason, you are recommended to use the default setting
of Off.
to looking for an A or AAAA record for the domain in the URI. If such a record is found, the call will be routed
to that IP address and the search will terminate. Note that if the A and AAAA records that are found at this
domain are for systems other than those that support SIP or H.323, the Expressway will still forward the call
to this zone, and the call will therefore fail. For this reason, you are recommended to use the default setting
of Off.
—
If the Include address record setting for the DNS zone being queried is set to Off, the Expressway will not
query for A and AAAA records and instead will continue with the search, querying the remaining lower
priority zones.
query for A and AAAA records and instead will continue with the search, querying the remaining lower
priority zones.
URI Dialing via DNS for Outgoing Calls
When a user places a call using URI dialing, they will typically dial an address in the form
name@example.com
from their
endpoint. Below is the process that is followed when a URI address is dialed from an endpoint registered with your
Expressway, or received as a query from a neighbor system:
Expressway, or received as a query from a neighbor system:
1.
to see if any of them are configured with a Mode of either:
—
Any alias, or
—
Alias pattern match with a pattern that matches the URI address
2.
The associated target zones are queried, in rule priority order, for the URI.
—
If one of the target zones is a DNS zone, the Expressway attempts to locate the endpoint through a DNS
lookup. It does this by querying the DNS server configured on the Expressway for the location of the domain
as per the
lookup. It does this by querying the DNS server configured on the Expressway for the location of the domain
as per the
. If the domain part of the URI address is resolved successfully the
request is forwarded to those addresses.
—
If one of the target zones is a neighbor, traversal client or traversal server zones, those zones are queried
for the URI. If that system supports URI dialing via DNS, it may route the call itself.
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 Configuration > Zones > Zones.
2.
Click New. You are taken to the Create zone page.
3.
Enter a Name for the zone and select a Type of DNS.
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Cisco Expressway Administrator Guide
Dial Plan and Call Processing