CONTENTS

�1���� Scope�
�2���� Introduction������
�3���� References�
�4���� Abbreviations���
�5���� Terms and definitions�������
�6���� Network configurations for using IP telephony������
������� 6.1���� Configuration A: Phone-to-phone communication (with IP transit network)�
������� 6.2���� Configuration B-1: IP phone-to-phone communication��������
������� 6.3���� Configuration B-2: Phone-to-IP phonecommunication�������
������� 6.4���� Configuration C: IP phone-to-IP phonecommunication������
�7���� Network capabilities to support IP telephony�������
������� 7.1���� Service aspects������
������� 7.2���� Charging considerations�����
������� 7.3���� Quality of Service considerations����
������� 7.4���� User identification and addressing considerations����
������� 7.5���� Security considerations������
�8���� Network capabilities to support IP telephony interworking between the PSTN and the IP network����
�9���� Network Address Translation (NAT) and firewalls�����������
10���� Control protocols for support of IP telephony������
Appendix I � Supplementary services and the corresponding ITU-T Recommendations that define them����
Appendix II � Standard development related to IP telephony����
Appendix III � J-series Recommendations in support of IP telephony����