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 Expressway applies the transformation before any searches are sent to external zones.
modified. The Expressway applies the transformation 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 work for calls from both H.323
and SIP endpoints.
originating from both H.323 and SIP devices. This means that the same call searches 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 automatically appends 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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Use pre-search transforms 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.
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's best to use a pre-search
transform or a search rule to modify the called address to be looked up.
transform 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.
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.
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 search rules described here are used to enable the following routing combinations:
Calling party
Called party
Registered devices (Expressway-C)
Registered devices (Expressway-C)
Registered devices (Expressway-C)
External domains and un-registered devices (via
Expressway-E using DNS zone)
Expressway-E using DNS zone)
Registered devices (Expressway-C)
Public external IP addresses (via Expressway-E)
External domains and un-registered devices
Registered devices (Expressway-C)
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.
valid 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 Any IP address with target Local Zone.
However this is not recommended (and not described in this document). The best practice is to register all devices
and route using destination aliases.
addresses of IP of the devices) by configuring a search rule with a mode of Any IP address with target Local Zone.
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 8: 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.
originating from both H.323 and SIP devices.
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Cisco Expressway-E and Expressway-C - Basic Configuration Deployment Guide
Routing Configuration