> On 17 Feb 2016, at 21:09, Bogdan-Andrei Iancu <bog...@opensips.org> wrote: > > Hi Dave, > > We (OpenSIPS project) had several systems deployed (including production) > with both IPv6 and IPv4, able to do bridging between the two networks at SIP > level. > > What exactly are you looking to be shared ?
The problem is this: Set up two SIP servers on dual stack, add both A and AAAA records to the dns name for them. Block IPv6. According to the old ways, a server setting up a connection to the buddy will prefer IPv6. The question is how OpenSIPS handles this situation? How long will it take until it switches over to IPv4? This is what was observed in the world of HTTP and led to the Happy Eyeballs ideas of how to solve the problem. The solution was to simultaneously set up TWO connections (remember they are in the world of TCP) and judge which one got through first, close the slowest one and continue. If IPv6 was blocked, the IPv4 connection would happen quickly and the eyes of the user would stay happy. Web browsers implemented this and we tested on World IPv6 day without an issue reported. We have the same issues with SIP, but with standard T1 settings it will take up to 32 seconds until we fail, and in best case try over the other protocol. That’s not acceptable for a SIP call. You can get some ideas from my slideshare presentations: - http://www.slideshare.net/oej/sipforum-sip-ipv6-discussion-slides (from 2012) - http://www.slideshare.net/oej/sip-ipv6-time-for-action (from 2011) (Mentions OpenSIPS :-) ) Please continue to ask if you have other questions. Maybe we should set up a testbed like the one we have at SIPit events for all implementors of SIP servers and clients to test with? Regardless, set up tests and please tell us what happens. If you solved this issue - how did you do it? /O > > Best regards, > > Bogdan-Andrei Iancu > OpenSIPS Founder and Developer > http://www.opensips-solutions.com > > On 17.02.2016 21:42, Dale R. Worley wrote: >> In the IETF Sipcore working group, we're starting work on "Happy >> Eyeballs for SIP", getting systems that use both IPv4 and IPv6 to work >> well, even in situations where connectivity in IPv6 is not assured. We >> expect that the changes to the SIP specifications will be small or none, >> but that there are a number of best practices that can be recommended to >> improve user experience. >> >> I'm asking here to find out if anyone has implementation experience in >> this area that they'd be willing to share. >> >> Dale >> _______________________________________________ >> Sip-implementors mailing list >> Sip-implementors@lists.cs.columbia.edu >> https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors >> > > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
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