Cisco Cisco Expressway
Routing Configuration
Pre-search Transforms
Pre-search transform configuration allows the destination alias (called address) in an incoming search request to be
modified. The transformation is applied by the Expressway before any searches are sent to external zones.
modified. The transformation is applied by the Expressway before any searches are sent to external zones.
The pre-search transform configuration described in this document is used to standardize destination aliases originating
from both H.323 and SIP devices. This means that the same call searches will work for calls from both H.323 and SIP
endpoints.
from both H.323 and SIP devices. This means that the same call searches will work for calls from both H.323 and SIP
endpoints.
For example, if the called address is an H.323 E.164 alias “01234”, the Expressway will automatically append the
configured domain name (in this case example.com) to the called address (that is, 01234@example.com making it into a
URI), before attempting to set up the call.
configured domain name (in this case example.com) to the called address (that is, 01234@example.com making it into a
URI), before attempting to set up the call.
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Pre-search transforms should be used with care because they apply to all signaling messages – if they match,
they will affect the routing of Unified Communications messages, provisioning and presence requests as well as
call requests.
they will affect the routing of Unified Communications messages, provisioning and presence requests as well as
call requests.
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Transformations can also be carried out in search rules – consider whether it is best to use a pre-search transform
or a search rule to modify the called address to be looked up.
or a search rule to modify the called address to be looked up.
Search Rules
Search rules define how the Expressway routes calls (to destination zones, such as to Unified CM or to a Cisco VCS) in
specific call scenarios. When a search rule is matched, the destination alias can be modified according to the conditions
defined in the search rule.
specific call scenarios. When a search rule is matched, the destination alias can be modified according to the conditions
defined in the search rule.
The search rules described in this document are used to ensure that SIP (and H.323, if registered to a Cisco VCS for
example) endpoints can dial H.323 devices that have registered E.164 numbers or H.323 IDs without a domain
portion. The search rules first search for received destination aliases without the domain portion of the URI, and then
search with the full URI.
example) endpoints can dial H.323 devices that have registered E.164 numbers or H.323 IDs without a domain
portion. The search rules first search for received destination aliases without the domain portion of the URI, and then
search with the full URI.
The routing configuration in this document searches for destination aliases that have valid SIP URIs (that is, using a valid
SIP domain, such as id@domain).
SIP domain, such as id@domain).
You can configure routing which enables calls to unregistered devices on an internal network (routing to the addresses
of IP of the devices) by configuring a search rule with a mode of
of IP of the devices) by configuring a search rule with a mode of
Any IP address. However this is not recommended (and
not described in this document). The best practice is to register all devices and route using destination aliases.
Task 6: Configuring Transforms
The pre-search transform configuration described in this document is used to standardize destination aliases originating
from both H.323 and SIP devices.
from both H.323 and SIP devices.
The following transform modifies the destination alias of all call attempts made to destination aliases which do not
contain an ‘@’. The old destination alias has @example.com appended to it. This has the effect of standardizing all
called destination aliases into a SIP URI format.
contain an ‘@’. The old destination alias has @example.com appended to it. This has the effect of standardizing all
called destination aliases into a SIP URI format.
To configure the transform:
1.
Go to Configuration > Dial plan > Transforms.
2.
Click New.
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Cisco Expressway-E and Expressway-C - Basic Configuration Deployment Guide