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.
request to be 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.
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.
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.
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.
n
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.
match, they will affect the routing of Unified Communications messages, provisioning and presence
requests as well as call requests.
n
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.
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.
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.
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.
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.
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).
using a 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. 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. 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.
originating 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.
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.
To configure the transform:
Cisco Expressway Basic Configuration Deployment Guide (X8.2)
Page 14 of 57
Routing configuration