Page 384 - Asterisk™: The Future of Telephony

relaxdtmf
You can set relaxdtmf to yes or no. Setting it to yes will relax the DTMF detection
handling. Use this if Asterisk is having a difficult time determining the DTMF on
the SIP channel. Note that this may cause “talkoff,” where Asterisk incorrectly
detects DTMF when it should not:
relaxdtmf=yes|no
rtautoclear (global)
This specifies whether or not Asterisk should auto-expire friends created on the fly
on the same schedule as if they had just registered. If set to yes, when the registra-
tion expires, the friend will vanish from the configuration until requested again. If
set to an integer, friends expire within that number of seconds instead of the normal
registration interval:
rtautoclear=yes|no|seconds
rtcachefriends (global)
If rtcachefriends is turned on, Asterisk will cache friends that come from the
realtime engine, just as if they had come from sip.conf. This often helps with items
such as message-waiting indications on realtime peers:
rtcachefriends=yes|no
rtsavesysname (global)
Specifies whether or not Asterisk should save the systemname in the realtime
database at the time of registration:
rtsavesysname=yes|no
rtupdate (global)
If set to yes Asterisk will update the IP address, origination port, and registration
period of a peer upon registration. Defaults to yes:
rtupdate=yes|no

sipdebug
Specifies whether or not Asterisk should turn on SIP debugging from the time that
Asterisk loads the SIP channel driver:
sipdebug=yes|no
sendrpid
Specifies whether or not Asterisk should send a Remote-Party-ID header:

sendrpid=yes|no
srvlookup
DNS SRV records are a way of setting up a logical, resolvable address where you
can be reached. This allows calls to be forwarded to different locations without the
need to change the logical address. By using SRV records, you gain many of the

356 | Appendix A: VoIP Channels