219Provisioning Client User Guide• A domain, subdomain, or subscriber has access to the routes if the assignedCoS permits access to the routes.The domain-based CoS value is used to determine the telephony routes forincoming sessions from gateways or other SIP networks. In these scenarios theUniform Resource Identifier (URI) domain does not host the originator so for thesecurity purposes the CoS of the URI domain is applied to screen the call.• If the From: header and Request URI: do not have the same domain, then thedomain specified in the Request URI: determines the telephony routes.• If the From:, To:, and Request URI: domains are the same, and the originatoris an MCP subscriber, then the originator’s CoS determines the telephonyroutes. If the originator does not have an assigned CoS, then the CoS for theoriginator’s subdomain is used. If the subdomain does not have an assignedCoS, then the call cannot access any telephony route.• The same CoS values can be assigned to a domain, subdomain, and asubscriber.Session Manager routing stagesThe following figure shows the relationship between the telephony routing stagesprovided by the Session Manager. If the CoS value of the subscriber andsubdomain route do not match, then the parent and subsequent subdomains arechecked for routes that permit access.
