[Asterisk-Users] Opportunistic VoIP

John Todd
Tue, 10 Jun 2003 20:37:33 -0000

You should investigate TRIP (RFC 3129):

http://www.zvon.org/tmRFC/RFC3219/Output/

Find BSD-licensed proof-of-concept code at
http://www.vovida.org/downloads/trip/trip-1.0.0.tar.gz

If someone could incorporate this into Asterisk and extend the
functionality, that would be pretty nice.  The basic ENUM support in
Asterisk already can handle specific number paths, but I think TRIP
or something like TRIP would be best for handling situations where
larger groups of numbers need to be "advertised" into a routing table
behind a particular Asterisk server.  Think "BGP for phone numbers."

JT


>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