[Asterisk-Users] Opportunistic VoIP

Anthony Wood
Tue, 10 Jun 2003 00:18:46 -0000

This is an idea from FreeSWAN, which was implemented in the recently released
version 1.0.

Basically the idea is that FreeSWAN sites automatically encrypt traffic between
them
when possible, without having to set up the link ahead of time.

How this works is:
The sites publish some info in DNS.
FreeSWAN gets some traffic destined for that site.
 - looks up the info in DNS
 - if the info is there: sets up an encrypted connection
 - if the info is missing: sets up a normal connection
This is a feature which can be turned off.

How does this apply to asterisk?

Asterisk has a call destined for a PSTN number
Looks up the number in a central location
If it's there, then connect to the reported IAX/SIP/whatever connection
over the internet if it's up/ping is good/hops is good/whatever.
Otherwise connects through the PSTN.

Points:

saves money
possible quality issues for VoIP over many internet hops
this isn't as good as the FreeSWAN way as there is no logical mapping
between PSTN and DNS -- therefore need a central location
potential for abuse
what would be a good spot for the central location?

comments?
--
Woody