Methods and systems for per-session network address translation (NAT) learning and firewall filtering in media gateway
US7380011B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 1, 2003 |
| Grant date | May 27, 2008 |
| Priority date | — |
| Expiry date | Dec 25, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L65/1023
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Methods and systems for per-session NAT learning and firewall filtering are disclosed. Media packets associated with a call/session are received and processed at a media gateway. For the first few received media packets associated with a session, the media gateway uses various unique methods to learn the actual source IP address and UDP port assigned to the remote communication terminal by its customer-premises Network Address Translators (NATs) to the media flows of the current session. After the remote IP and UDP are learned, the media gateway reconfigures its firewall filtering function to check both the dynamically learned remote IP and UDP and the locally assigned IP and UDP of the current session. The per-session NAT learning function removes reachability issues in VoIP deployment, and the per-session firewall filtering function enhances security protection in VoIP deployment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.