An approach provides interdomain traversal to support packetized voice transmissions. A request is received from a first endpoint of a first domain for establishing a communication session with a second endpoint of a second domain. Encrypted user credential information is retrieved from a credentials...http://www.google.com/patents/US20070022289?utm_source=gb-gplus-sharePatent US20070022289 - Method and system for providing secure credential storage to support interdomain traversal
