Buddy watch in newer Polycom firmwares

Apparently, the sip.cfg file in newer firmware packages for Polycom phones do not have the presence feature enabled by default. That is why the phones do not have the buddy-watch option in the speed dial or directory.

This feature can be enabled easily by editing sip.cfg.

Change
    <feature feature.1.name="presence" feature.1.enabled="0"
to
    <feature feature.1.name="presence" feature.1.enabled="1"

The phone needs to be restarted for this change to take effect.

Asterisk DISA: no dialtone provided or DTMF collected

If you are getting no dialtone with Asterisk DISA, and no DTMF is collected either, probably you need to put an "Answer()" in the dialplan before calling DISA. Otherwise, the channel is not established where DISA is supposed to play the dialtone or collect DTMF digits. I found that The Definitive Guide did not have "Answer()" in their examples of DISA regarding SLA.

Asterisk crash on SLA call

I configured Asterisk 1.8.6.0 for Shared Line Appearance. But I was getting a crash when I called the shared extension. I found that this was happening because I had turned on the "DONT_OPTIMIZE" compiler flag (from make menuselect). After I turned it off, the crash problem was solved.