Summary

This Recommendation specifies a mechanism that allows endpoints to query a Gatekeeper or Border Element for routes and alternate routes multiple times for a single call. While querying the Gatekeeper or Border Element multiple times may increase the time required to establish the call, it is expected that most calls will establish with a single query. However, this expectation does not always prove to be the case. This Recommendation is focused on the cases where the call cannot complete to the first provided route to a destination. In such cases, the endpoint may query for alternate routes. The alternate routes may also include different source or destination alias information, different security tokens, or other information that may have been expensive or too time consuming to produce and/or provide in the initial query.