Zones searching takes place after call policy has been applied.
The zone search and transform process is applied to the Local
Zone and all other external zones simultaneously, and is as
follows:

The VCS looks at all matches for the Local Zone and all

external zones to find those with either:

•

Mode

AlwaysMatch

, or

•

Mode

PatternMatch

and a

Pattern String

that matches

the alias being searched for.

These matches are listed in order of the

Priority

that has been

assigned to them.
If there are any duplicates in the list, the entry with the lower

Priority

is removed. (This applies to a zone with the same

pattern string and the same transform but different priorities.)
If there is a zone which has an

AlwaysMatch

as well as

PatternMatch

with no transforms, the

PatternMatch

removed from the list.
All zones with a Priority 1 match on the list are queried using

the same protocol (i.e. SIP or H.323) as the incoming call
request. For

AlwaysMatch

matches, the query will use the

original alias; for

PatternMatch

matches the query will use the

alias specified by the transform rules.
If the alias is found, the call will be forwarded to that zone.

If the alias is found by more than one zone, the call will be
forwarded to the zone that responded first.
If the alias is not found using the native protocol, the query

is repeated (as per steps 5 and 6) using the interworked
protocol.
If the alias is not found, all zones with a Priority 2 match are

queried as per steps 5 to 7.
The process is repeated with subsequent Priority levels until

either:

the alias is found, or

•

all zones with a match that meets the specified criteria

•

have been queried.

Zone Searching and Transforming

About Zone Transforms

The VCS allows you to change the alias being searched for
before a search request is sent to the Local Zone or out to a
particular zone. This feature uses the

PatternMatch

mode of the

zone search function.
To set up a zone transform, you must:

configure the zone with a

•

Mode

PatternMatch

specify the pattern that the alias to be transformed must

•

match
specify the way in which the alias will be transformed.

•

All searches that match the specified pattern will then be
transformed when sent to the zone, and the zone will be queried
using the new alias.

About Zone Searching

The VCS allows you to filter the search requests sent to each
zone, including the Local Zone, and prioritize the order in which
these zones are searched. This allows you to reduce the
potential number of search requests sent out, and speed up the
search process.
The VCS uses the concept of zone “matches” to filter search
requests. Each zone has up to five configurable “matches”
available to it. Each match is assigned a

Mode

and

Priority

(described below). The combination of the two determines if and
when that zone will be queried.

Using Zone Searches and Transforms Together

The zone searching feature and the zone transforms feature
both make use of the

PatternMatch

mode. You can use these

two features together or separately.
The remainder of this section:

describes the

•

zone search and transform process

explains how to

•

configure zone searches and transforms

gives some

•

examples

of how zone searches and transforms

could be used together.

It is possible for the same priority to be given to more
than one match, either in the same zone or in different
zones. In this case, all zones with that match priority will

be queried at the same time.

Match Mode

The match

Mode

allows you to specify whether and how

requests to the zone will be filtered. You can also use this mode
to prevent search requests from ever being sent to the zone.
The

Mode

options are:

AlwaysMatch

•

: always query the zone

PatternMatch

•

: only query the zone if the alias being searched

for matches a specified pattern

Disabled

•

: never query the zone (this mode does not need a

corresponding Priority option).

Match Priority

The match

Priority

allows you to specify when in the search

process that zone will be queried. Search requests are sent to
all zones with a Priority 1 match first, followed by all zones with
Priority 2 matches, and so on.

Each zone has up to five configurable matches. This
means that you can specify up to five different
transforms for each zone. This could be:

one alias or string transformed five different ways

•

five aliases or strings each transformed individually

•

a combination of both.

•

Zone transforms support the use of Regular Expressions
in both the

Pattern String

and

Replace String

fields. See the Appendix

Regular Expression Reference

for more information.