At 14:59 16/01/2007, Greg Fausak wrote: >Jiri, > >Thanks for the pointer! I think I'll have to give this a look.
Hi Greg, with pleasure. Just keep in mind that having robustness in there takes couple of other steps. Particularly IP blacklisting to avoid attempts to send to the DNS-conveyed destinations, which are unavailable and ... >We are having specific problems with the DNS resolver on failover >(when one >DNS resolver is not reachable, the next is queried, and openser is >not acting >predictably when this happens). It is as if the tm module is not >properly threaded. Like when one thread gets stuck waiting for >a response from DNS resolver, another thread picks up a retry >SIP message and doesn't know about the retry in process! ... building the ser script in a way that retransmissions are absorbed (kind of having "shock absorber" in place) -jiri >We see the bad resolver behavior when 2 resolvers are listed in /etc/ >resolv.conf, and >we turn off the first one. > >The DNS failover is also interesting. I think failover applies to A >records >and SRV records (not NAPTR records). > >-g > >On Jan 16, 2007, at 7:12 AM, Jiri Kuthan wrote: > >>indeed, the stuff is not well linked, we are working on it. Here >>you go. >>http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/doc/ >>dns.txt?rev=HEAD&content-type=text/vnd.viewcvs-markup >> >>-jiri >> >>At 02:46 16/01/2007, T.R. Missner wrote: >>>Greg, >>> >>>This is a ref to SER. Apparently this functionality has been added >>>to the new pre-release version. I did find some talk about it in >>>the release notes. >>>I couldnt find any specific documentation. Admittedly I dont >>>understand the layout of SERs site very well as I havent spent >>>much time there. >>> >>>-- TR >>> >>> >>>On 1/15/07 8:33 PM, "Greg Fausak" <[EMAIL PROTECTED]> wrote: >>> >>>In the text below I quote Kerker 'SER does support DNS failover.'. >>>Is this ser or openser? Where can I read more about this? >>> >>>-g >>> >>>On Jan 15, 2007, at 10:40 AM, Klaus Darilion wrote: >>> >>> >>>Staffan, >>> >>> >>> >>> >>> >>>Kerker Staffan wrote: >>> >>> >>>... >>> >>> >>> >>> >>>Now, if I disable one of the Gateways, I hang every second call. >>>OpenSER does >>> >>> >>>not >>> >>> >>>try the second A record address if the first doesn't answer. How >>>can I solve >>> >>> >>>this? Shouldn't OpenSER fail over to the second A record listed in >>>the NAPTR >>> >>> >>>=> SRV >>> >>> >>>resolving? Or will OpenSER continue to resend all SIP INVITES >>>until timers >>> >>> >>>fire? Would >>> >>> >>>it help if the proxy recieved an ICMP port/destination unreachable >>>from the >>> >>> >>>network? Is >>> >>> >>>there anyway to get around this? In the other direction, from POTS >>>to sip, >>> >>> >>>the PGW2200 >>> >>> >>>nicely switches over to the second of my two OpenSER servers if I >>>shut one of >>> >>> >>>them down. These servers have the same DNS entries (but for >>>another SIP domain, NAPTR => >>> >>> >>>SRV => 2x A record). >>> >>> >>> >>> >>>Yes, OpenSER or for that matter every transaction stateful proxy >>>should >>> >>> >>>do RFC 3263 based fail-over. But as you can imagine this is pretty >>> >>> >>>complex to implement and that's why openser does not support it >>>yet, it >>> >>> >>>is listed on the development roadmap. The newest release of SER does >>> >>> >>>support DNS failover. >>> >>> >>> >>> >>> >>> >>> >>> >>>_______________________________________________ >>>Users mailing list >>>[email protected] >>><http://openser.org/cgi-bin/mailman/listinfo/users>http:// >>>openser.org/cgi-bin/mailman/listinfo/users >>> >>> >>>_______________________________________________ >>>Users mailing list >>>[email protected] >>>http://openser.org/cgi-bin/mailman/listinfo/users >> >>-- >>Jiri Kuthan http://iptel.org/~jiri/ > >-- >Jiri Kuthan http://iptel.org/~jiri/ _______________________________________________ Users mailing list [email protected] http://openser.org/cgi-bin/mailman/listinfo/users
