AASTRA SIP-DECT (Release 2.1)- OM System Manual - Installation, Administration and Maintenance EN - Manual (Page 122)

SIP – DECT OM System Manual Release 2.1 7 Configuration und Administration Aspects
depl-1230/1.3 Page: 122 (196)
A call from one PP to another that resides on the same RFP will loop back within the RFP if
no media gateway is involved. So the call will not pass through to the Local Area Network
(LAN). Although the voice packets will not impact LAN traffic, signal packets will.
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.