About Uri Dialing; Uri Dialing Without Dns - Cisco TelePresence Administrator's Manual

About URI dialing

A URI address typically takes the form name@example.com, where name is the alias and example.com
is the domain.
URI dialing can make use of DNS to enable endpoints registered with different systems to locate and call
each other. Without DNS, the endpoints would need to be registered to the same or neighbored systems in
order to locate each other.

URI dialing without DNS

Without the use of DNS, calls made by a locally registered endpoint using URI dialing will be placed only if
the destination endpoint is also locally registered, or is accessible via a neighbor system. This is because
these endpoints would be located using the
If you want to use URI dialing from your network without the use of DNS, you would need to ensure that all
the systems in your network were connected to each other by neighbor relationships - either directly or
indirectly. This would ensure that any one system could locate an endpoint registered to itself or any another
system, by searching for the endpoint's URI.
This does not scale well as the number of systems grows. It is also not particularly practical, as it means that
endpoints within your network will not be able to dial endpoints registered to systems outside your network
(for example when placing calls to another company) if there is not already a neighbor relationship between
the two systems.
If a DNS zone and a DNS server have not been configured on the local VCS, calls to endpoints that are not
registered locally or to a neighbor system could still be placed if the local VCS is neighbored (either directly or
indirectly) with another VCS that has been configured for URI dialing via DNS. In this case, any URI-dialed
calls that are picked up by search rules that refer to that neighbor zone will go via that neighbor, which will
perform the DNS lookup.
This configuration is useful if you want all URI dialing to be made via one particular system, such as a VCS
Expressway.
If you do not want to use DNS as part of URI dialing within your network, then no special configuration is
required. Endpoints will register with an alias in the form of a URI, and when calls are placed to that URI the
VCS will query its local zone and neighbors for that URI.
If the VCS does not have DNS configured and your network includes H.323 endpoints, then in order for these
endpoints to be reachable using URI dialing either:
the H.323 endpoints should register with the VCS using an address in the format of a URI
n
an appropriate transform should be written to convert URIs into the format used by the H.323 registrations.
n
An example would be a deployment where H.323 endpoints register with an alias, and incoming calls are
made to alias@domain.com. A local transform is then configured to strip the @domain, and the search
is made locally for alias. See
do this.
SIP endpoints always register with an AOR in the form of a URI, so no special configuration is required.
Cisco VCS Administrator Guide (X7.1)
search and zone transform
Stripping @domain for dialing to H.323 numbers
Dial plan and call processing
process, rather than a DNS query.
for an example of how to
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