Unified CVP Algorithm for Routing
When you set up a dial plan and call routing, you can combine Unified CVP features (such as Location Based CAC, SigDigits, SendToOriginator, LocalSRV, and Use Outbound Proxy) to achieve the required effect.
The following algorithms are used to formulate the destination SIP URI for the outbound calls from Unified CVP. This description covers CONNECT messages that include labels from the ICM (for example, VXML Gateway, and Unified Communications Manager), as well as calls to the ringtone service, recording servers, and error message playback service.
Note |
The following algorithm only describes calls using the SIP subsystem, which includes audio only and basic video SIP calls. The sendtoriginator algorithm is supported only for co-located IOS VoiceXML Gateway and Ingress Voice Gateway. The sendtoriginator algorithm is not supported in Cisco VVB as the co-location concept is not applicable. |
The algorithm for creating the destination SIP URI host portion for outbound calls, which include the ICM label, is as follows:
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The ICM label is provided at the start of the algorithm. It may already have the Location siteID inserted by the ICM subsystem, or SigDigits may be prepended if used. For network VRU labels, the ICM subsystem passes in the entire prefix and correlation ID as the label.
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If SendtoOriginator is matched for the Unified CCE label, the IP or hostname of the caller (Ingress Voice Gateway) is used by the Unified CVP algorithm, which returns the SIP URI.
The setting for SendtoOriginator only applies to callers on Cisco Ingress Voice Gateways (the SIP UserAgent header is selected), because non-Cisco IOS Gateways do not have the CVP bootstrap service used by the Cisco IOS VoiceXML Gateway.
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If use outbound proxy is set, then use the host of the proxy and return SIP URI.
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If local static route is found for the label and return the SIP URI.
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If local static route is not found, the algorithm throws RouteNotFoundException exception.
The following algorithm describes planning considerations for calls using the SIP subsystem:
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To avoid complex Dialed Number strings, do not use the Sigdigits feature if Locations CAC siteIDs are used.
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An Outbound Proxy FQDN can be specified as a Server Group FQDN (local SRV FQDN). A local static route destination can also be configured as a Server Group FQDN.
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Ringtone DN (91919191), Recording Server (93939393), and Error message services (92929292) follow the same algorithm as mentioned in the procedure.
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SendToOriginator can work in conjunction with a REFER label.
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A REFER label can work with the SigDigits setting.