Configures the session timer refresher for
account X.
If set to 0 (UAC), refreshing the session is
performed by the IP phone.
If set to 1 (UAS), refreshing the session is
performed by a SIP server.
X ranges from 1 to 6.
Specify whether RFC 2543 (c=0.0.0.0)
outgoing hold signaling is used.
If set to 0 (Disabled), use SDP media direction
attributes (such as a=sendonly) per RFC 3264
when putting a call on hold.
If set to 0 (Enabled), use SDP media
connection address c=0.0.0.0 per RFC 2543
when putting a call on hold.