by mflorell » Sun Apr 13, 2008 9:43 pm
Not really, it is quite literally "DNS manager" . You see, before they added it in, Asterisk would only lookup an IP address for a domain once, the entire time it was up, no matter if it was hours or months. the dnsmgr feature allows you to set timeouts on DNS lookups.
This is really only used for items like SIP or IAX domain names that you would register to, like if you were using a SIP trunk.