7A. Johnston, S. Donovan, R. Sparks, C. Cunningham, K.Summers, D. Willis, J. Rosenberg, H. Schulzrinne. SIP Telephony Call Flow Examples, June 2001.
8Handley M, Schulzrirme H, Schooler E et al.SIP:Session Initiation Protocol. RFC3261, IETF, 2002
9Rekhter Y, Moskowitz B, Karrenberg D et al.Address allocation for private intemets.RFC1918 ,IETF, 1996
10Rosenberg J, Weinberger J, Huitema C et aI.STUN- Simple Traversal of User Datagram Protocol(UDP) Through Network Address Translators (NATs). RFC3489, IETF, 2003