There are two possibilities to influence the FXO port configuration regarding the "cidstart" parameter as follows:

1 Change parameter "cidstart" in conf file

Parameter can be changed in  /etc/asterisk/chan_dahdi.conf:

cidstart = ring
or
cidstart = polarity

Finally please proceed with following commands:

1. stop asterisk: service asterisk stop
2. restart dahdi: service dahdi restart
3. start asterisk: service asterisk start

2 Change parameter "cidstart" in SQL database

With following SQL-Statement, the parameter "cidstart" can be changed.

update countrydefaultisdn set cidstart='polarity' where nationalcode like 'at';

cidstart = ring

select id, nationalcode, countrycode,cidstart from countrydefaultisdn where nationalcode like 'at';

 id | nationalcode | countrycode | cidstart 

----+--------------+-------------+----------

  2 | at           | 43          | ring

cidstart = polarity

select id, nationalcode, countrycode,cidstart from countrydefaultisdn where nationalcode like 'at';

 id | nationalcode | countrycode | cidstart 

----+--------------+-------------+----------

  2 | at           | 43          | polarity