Panasonic NS1000 Manual page 156

IP Phones – "P2P"
1. DSP is not used at any stage of a P2P call – DSP function is taken care of within handset itself
once connected.
2. If selected compression method of phones differs, the handsets negotiate the lowest
bandwidth codec of the two:
(G729 > G711 > G722)
3. This applies to both SIP and IP-PT types - makes no difference
1.3 DSP Resource Usage (2)
Call Setup Only
P2P Communication