VoIP and NAT/firewalls: issues, traversal techniques, and a real-world solution

H. Khlifi, J.-C. Gregoire, J. Phillips
2006 IEEE Communications Magazine  
In spite of the major expectations of mobility and accessibility that voice over IP applications are supposed to bring, few of these expectations have become reality. Existing firewalls and Network Address Translation devices prevent VoIP protocols from reaching endpoints, and available traversal techniques are either limited or not supported by endpoints. In this article we explain the various difficulties VoIP devices face due to the presence of firewalls and NATs, and review the traversal
more » ... ew the traversal techniques that have been proposed to overcome these difficulties. We also describe our own experience in dealing with this issue and the approach we have adopted to provide permanent accessibility to VoIP users.
doi:10.1109/mcom.2006.1668388 fatcat:y46veyvfj5h57nsl3bkagkceya