AASTRA SIP-DECT (Release 1.8)-Installation- and Administration Guide EN - Manual (Page 14)

Installation, Administration and Maintenance
Aastra depl-0900/0.4 Page: 14 (104)
If the PP user is moving, the PP detects that another RFP has a better signal
strength and, therefore, it starts the handover process. The media stream
from the IP phone cannot move to the secondary RFP, so the primary RFP
uses the LAN to direct the voice to the secondary RFP, as shown in the
following figure.
As the PP user moves into the next RFP zone of coverage, the PP detects
that the RFP has a better signal strength. Again the media stream from the
SIP phone cannot move to the secondary RFP, so the primary RFP uses the
LAN to direct the voice to the new secondary RFP.