Aastra 55i IP Phone - Model 536 M and 560 M Expansion Modules; Model 536 M; Model 560 M

166 Model 55i IP Phone User Guide
Additional Features
2. The "UPnP Mapping Lines" field is set to 0 by default. If required, change the
setting to a specific line by selecting a line from the list. Valid values are 0 through
10. The line you select is the line that your remote phone uses to perform Univer-
sal Plug and Play on the network you are connecting to.
3. Click to save your settings.