Remote Gateway 9150 Installation and Administration Guide 79June 2005 Planning for Remote Gateway 9150 unit installationRefer to “RLC connection configuration” on page 198 for the correctprocedures.Translation tables within NAT routers control the communication path from theprivate network to the public network. Most NAT devices contain timers thatmonitor the translation table entries. Each time the device uses a translation tableentry, the timer restarts. Individual table entries are deleted if thecommunications path is not used and the timer expires.It is possible, when using a Remote Gateway 9150 unit behind a NAT device,that prolonged periods of silence cause the NAT translation table entries to clearand drop the audio path. An example of this would be a remote user listening toa conference call with the user’s digital telephone set on mute. After fiveminutes (the default NAT translation table timer on many NAT routers) theremote user would not be able to hear the conference. To restore the NAT tableentry and recover the audio path, the remote user could go off mute and speakinto the digital telephone set.To prevent the NAT translation table from dropping the audio path: configure the translation tables on the NAT router with a large timer value(for example, two hours) configure a static translation table entry for UDP port 20480Implementing QoS Transitioning TechnologyWhen the QoS Transitioning Technology is implemented, calls transition: to the PSTN when IP QoS degrades back to the IP network when IP QoS returns to normalTo implement QoS Transitioning Technology:1 To implement the QoS Transitioning Technology, you must understandwhat your IP network is doing, such as when the busy times are on the network how much traffic is processed (during normal and busy traffic periods) how to evaluate and adjust your network’s QoS
