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Figure 16 Configuring the Gatekeeper to authenticate with an LDAP server using TLS
encryption
3.9 URI Dialing If an alias is not located in the Gatekeeper’s list of registrations, it may attempt to find an
authoritative Gatekeeper through the DNS system.
URI dialing makes it easier for endpoints registered with different Gatekeepers to call each
other. Without URI dialing, you need to neighbor all the Gatekeepers to each other. This does
not scale well as the number of Gatekeepers grows. It is also inconvenient for making one off
calls to endpoints registered with previously unknown Gatekeepers.
Using URI dialing, you call using an H.323 URI which looks like an email address. The
destination Gatekeeper is found from the domain name – the part after the @ - in the same
way that an email server is found.
The decision as to whether or not to do this is governed by the current state of
xConfiguration Gatekeeper DNSResolutionMode <On/Off>
You will also need to configure a DNS server for the systems to query. This is set using
xConfiguration DNS Server Address: <address>
or using the web interface on the System Configuration > IP page (see Figure 17 for the IP
Configuration screen).
If you want others to be able to reach you using URI dialing, add a record to your DNS
information as described in the Appendix: Configuring DNS Servers
Endpoints will typically register with the Gatekeeper without their domain name. The
Gatekeeper needs to match a request for “fred@example.com” to a registration for “fred”. To
do this, it must be configured with the name of the domain in which its endpoints belong. This
is set using
xConfiguration Gatekeeper LocalDomain DomainName: <name>