Regardless of the origin of the request, the VCS will search its Local Zone and all external
zones for the alias. When creating and configuring zones, you assign at least one match and
corresponding priority to each zone, and the zones with the highest priority matches (i.e. those with
a priority closest to

) are searched first. In addition, you can use these pattern matching rules

to filter searches to specific zones. For full information about configuring searches, see the

Zone

Searching and Transforming

section.

About Transforms

The VCS allows you to transform the alias in a search request if it matches certain criteria. This
transformation can be applied to the alias at two points in the search process:

as soon as it is received and before it is searched for locall

•

y (pre-search Transforms)

after call policy has been applied and

•

before sending a search request to the Local Zone and

external zones

You can transform the alias by removing or replacing its prefix, suffix, or the entire string, and by
the use of regular expressions.

Overview of Searches and Transforms

Pre-Search Transforms

About Pre-Search Transforms

The pre-search transform function allows you to modify the alias
in an incoming search request. The transformation is applied
by the VCS before any searches take place, either locally or
to external zones. It applies to all incoming search requests
received from locally registered endpoints, Neighbor, Traversal
Client and Traversal Server zones, and endpoints on the public
internet. It does not apply to requests received from Peers
(which are configured identically and therefore will have already
applied the same transform).
Each pre-search transform defines a string against which an
alias is compared, and the changes to make to the alias if it
matches that string.
Once the alias has been transformed, it remains changed. and
all further call processing is applied to the new alias.

All Peers in a cluster should be configured identically, including any pre-search transforms.
A VCS in a cluster will treat search requests from any of its Peers as having come from its
own Local Zone, and will not re-apply any pre-search transforms on receipt of the request.

Pre-Search Transform Process

Up to 100 pre-search transforms can be configured. Each
transform must have a unique priority number between

and

65534

Every incoming alias is compared with each transform in order
of priority, starting with that closest to

. If and when a match

is made, the transform is applied to the alias and no further
pre-search checks and transformations of the new alias will
take place. The new alias is then used for the remainder of the

search process

Further transforms of the alias may take place during the
remainder of the search process. This may be as a
result of

Call Policy

(Administrator Policy) or

FindMe

(User

Policy). If this is the case, the pre-search transforms are
re-applied to the new alias. Refer to the

search process

diagram

for more information.

If you add a new
pre-search transform
that has the same

priority as an existing
transform, all transforms with
a lower priority (i.e. higher
numerical value) will have
their priority incremented by
one, and the new transform
will be added with the
specified priority. However, if
there are not enough “slots”
left to move all the priorities
down, then you will get an
error message.

Pre-search transforms
are not applied to
GRQ or RRQ

messages received from
endpoints registering with the
VCS; endpoints will be
registered with the alias(es)
as presented in these
messages.

Pre-search transforms
will be applied prior to
any possible CPL

modification and Zone
transforms.