Introduction
ClearIP can return the Caller ID Name (CNAM) in SIP responses. The CNAM Policies page under the Inbound Services menu allows granular control over when a CNAM lookup should be performed.
Setup
CNAM lookup is disabled by default unless a policy exists that explicitly enables it. CNAM lookup can be enabled for all calls by creating a policy with a blank called number and enabled status. CNAM lookup can also be enabled for individual called numbers or ranges by specifying a full called number or a prefix.
For example, the ClearIP user can configure their CNAM policies to disable ClearIP CNAM lookups for calls that obtain their CNAM from an external CNAM provider and also enable ClearIP CNAM lookups for all calls that do not obtain their CNAM from an external CNAM provider.
The custom whitelist/blacklist, Shield blacklist, and fraud control are all done before CNAM lookup is performed. Therefore, calls whitelisted, blacklisted, or diverted by any of these methods will not have a CNAM lookup performed and thus will not be billed for CNAM lookup.
SIP Response CNAM Header Options
By default, ClearIP returns the CNAM value in a P-Asserted-Identity header of a SIP 302 response.
SIP/2.0 302 Moved Temporarily
Via: SIP/2.0/TLS sip.clearip.com:5061;branch=z9hG4bKc936.6fc7313aee12792c28d3ebea5f6ac703.0;i=ce97aef5;received=::ffff:10.0.14.250
Via: SIP/2.0/TCP 192.168.1.89:3000;received=18.208.235.205;branch=z9hG4bK-777-1-0
To: <sip:14047884802@1.2.3.4:5060>;tag=fc1ab2a6-de8c-4355-9e95-f03b4de0785b
From: <sip:14045266060@192.168.1.89:3000>;tag=1
Call-ID: 1-777@192.168.1.89
CSeq: 1 INVITE
P-Asserted-Identity: "TRANSNEXUS" <sip:14045266060@192.168.1.89:3000>
Contact: <sip:14047884802@1.2.3.4:5060>;q=0.99
Reason: SIP;cause=302;text="no-fraud-detected"
Content-Length: 0
ClearIP can be configured to return the CNAM value in an alternative header if configured in the SBCs page under the CNAM Header field:
- X-Asserted-Identity
X-Asserted-Identity: "TRANSNEXUS" <sip:14045266060@192.168.1.89:3000>
- P-Asserted-Identity Embedded in Contact
Contact: <sip:14047884802@1.2.3.4:5060>;q=0.99?P-Asserted-Identity=%22TRANSNEXUS%22%20%3Csip%3A14045266060%40192.168.1.89%3A3000%3E
- P-Asserted-Identity Embedded in Contact URI
Contact: <sip:14047884802@1.2.3.4:5060?P-Asserted-Identity=%22TRANSNEXUS%22%20%3Csip%3A14045266060%40192.168.1.89%3A3000%3E>;q=0.99
Reporting
The CNAM value returned by ClearIP is reported in the CNAM field for all SIP records in the SIP Messages page.
A CNAM lookup flag is set for all SIP records. Only calls with this flag set to yes will be billed for CNAM lookup.
