[Freeswitch-users] DNS resolving for REGISTER requests

Mike Jerris mike at freeswitch.com
Mon Jun 24 13:22:00 UTC 2019


On Mon, Jun 24, 2019 at 9:19 AM Sebastian Denz <denzs at gonicus.de> wrote:

> Using "sofia loglevel sresolv 9" i dont see any sres_cache_get() calls
> at all before FS sends a REGISTER.
>
> But they are done before any other (new) transaction.
>
> Regarding RFC 3263 Section 4. this seems to be kinda valid,
> because the ongoing RE-REGISTERS requests are happening in-dialog so
> they are not a _new_ transaction?!


They ARE a new transaction.


>
> But from a practical point of view i would expect there should be a
> mechanism which ensures the used IP is are still valid?!
>
> So i think at least the internal dns cache should be used...
>
> What do you suggest?
>
> Is there anything else i can do to narrow this down and/or should i open
> an issue in

Jira?
>
>
certainly a jira but this needs someone to dig in the code and find a
solution

Am 6/24/19 um 3:02 PM schrieb Mike Jerris:
> > if that’s the case it’s an issue with the resolver cache in sofia-sip
> >
> > On Mon, Jun 24, 2019 at 9:01 AM Sebastian Denz <denzs at gonicus.de> wrote:
> >
> >> Hello Mike,
> >>
> >> thanks for getting in the discussion!
> >>
> >> I have a pcap-trace from last saturday containing sip and dns where i
> >> can see the following behaviour:
> >>
> >> 11:39:32 FS does an SRV-Lookup for _sip._tcp.reg.sip-trunk.telekom.de
> >>          -> Answer contains three records with TTL:3600
> >>          FS does an A-Lookup for the record with the lowest priority
> >>          -> Answer contains an IPv4 adress with TTL:216
> >>
> >> FS registers to the provided ip address and re-registers every ~ 5
> minutes
> >>
> >> But there is no more dns traffic for the rest of the day (~ 12.5
> hours)...
> >>
> >> Version is 1.8.2-3-a98a958ac3~64bit on Debian Stretch.
> >>
> >> Could this be an issue with the systems resolving logic (libnss) or is
> >> the resolving completly done by FS itself?
> >>
> >> Am 6/24/19 um 2:19 PM schrieb Mike Jerris:
> >>> if the DNS entries haven’t yet expired then freeswitch won’t query
> again.
> >>> The provider should set lower expiration on their records before a
> change
> >>> or wait the full expiration after making a change to
> >>> actually move hosts or they will cause this issue.  This has always
> been
> >>> how the DNS system works.
> >>>
> >>> On Mon, Jun 24, 2019 at 8:14 AM Sebastian Denz <denzs at gonicus.de>
> wrote:
> >>>
> >>>> That is already the case..
> >>>>
> >>>> When FS starts up it does an SRV-Lookup which contains several
> adresses.
> >>>>
> >>>> One thing is.. the old endpoint is still working..
> >>>>
> >>>> The provider just changes the IP behind the A record of the first SRV
> >>>> result.
> >>>>
> >>>> But the main problem is that FS does not use DNS at all before
> sending a
> >>>> REGISTER... So i doubt this can be workarounded without touching the
> >>>> code of FS or (and that is what i am going to do) use an external
> script
> >>>> to detect the change and then trigger a gateway restart in FS...
> >>>>
> >>>> Am 6/24/19 um 1:30 PM schrieb Giovanni Maruzzelli:
> >>>>> Maybe, just maybe, putting all addresses in srv records, FS will read
> >>>> that
> >>>>> at startup, then try them all if first fail? No idea if works... Just
> >>>>> curious...
> >>>>>
> >>>>>
> >>>>>
> >>>>> On Mon, Jun 24, 2019, 12:18 Sebastian Denz <denzs at gonicus.de> wrote:
> >>>>>
> >>>>>> I already thought about something like that..
> >>>>>>
> >>>>>> But the main reason for the problem seems to be, that FreeSWITCH
> does
> >>>>>> not query the dns (remote or local) at all before sending the
> >>>>>> REGISTER... :-/
> >>>>>>
> >>>>>> I could workaround the current issue easily by using static
> addresses
> >>>>>> but then i would loose the failover capability and i would have to
> >> check
> >>>>>> for changes manually or by script... normally dns would just solve
> >> that
> >>>>>> by itself :)
> >>>>>>
> >>>>>> I think i could put Kamailio in front of FreeSWITCH and let it
> handle
> >>>>>> the dns resolution, but that feels like using a sledgehammer to
> crack
> >> a
> >>>>>> nut ;)
> >>>>>>
> >>>>>> And i would prefer a tiny approach, ideally with FreeSWITCH behaving
> >>>>>> correctly...?!
> >>>>>>
> >>>>>> Am 6/24/19 um 12:24 PM schrieb Giovanni Maruzzelli:
> >>>>>>> obviously, you can locally provide dns with dnsmasq or such, easily
> >>>>>>> configured, for other domains too.
> >>>>>>>
> >>>>>>> Maybe you can put all SRV addresses, with different weights, in
> your
> >>>> own
> >>>>>>> (eg, locally defined) zone definition for deutsche telekom, and
> >>>>>> freeswitch
> >>>>>>> will try them all.
> >>>>>>>
> >>>>>>> Not sure this will work, but maybe yes :)
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>> On Mon, Jun 24, 2019 at 12:19 PM Sebastian Denz <denzs at gonicus.de>
> >>>>>> wrote:
> >>>>>>>
> >>>>>>>> Thank you for giving me that pointer!
> >>>>>>>>
> >>>>>>>> I thought i would have searched for everything regarding that
> topic,
> >>>>>>>> but obviously i missed that post!
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>
> >>>>
> >>
> https://lists.freeswitch.org/pipermail/freeswitch-users/2018-January/128837.html
> >>>>>>>>
> >>>>>>>> I'll contact Kai directly as i was not able to found a
> corresponding
> >>>>>>>> issue in the tracker...
> >>>>>>>>
> >>>>>>>> But if anyone has another idea regarding the problem, i would of
> >>>> course
> >>>>>>>> appreciate any hints too! ;)
> >>>>>>>>
> >>>>>>>> Sebastian
> >>>>>>>>
> >>>>>>>> Am 6/24/19 um 11:21 AM schrieb Giovanni Maruzzelli:
> >>>>>>>>> I believe this question  was already asked in the past in this
> >>>> mailing
> >>>>>>>>> list, and IIRC the answer was no.
> >>>>>>>>>
> >>>>>>>>> You may wanto to check on the mailing list archives (in
> signature),
> >>>>>>>> because
> >>>>>>>>> maybe my merory is wrong.
> >>>>>>>>>
> >>>>>>>>> -giovanni
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> On Mon, Jun 24, 2019 at 11:14 AM Sebastian Denz <
> denzs at gonicus.de>
> >>>>>>>> wrote:
> >>>>>>>>>
> >>>>>>>>>> Hello,
> >>>>>>>>>>
> >>>>>>>>>> i am using FreeSWITCH as SBC to our SIP provider (Deutsche
> Telekom
> >>>> in
> >>>>>>>>>> germany).
> >>>>>>>>>>
> >>>>>>>>>> This works quite well, but ~ once in a month we are unable to do
> >>>>>>>>>> outbound calls.
> >>>>>>>>>>
> >>>>>>>>>> It turned out, that the provider changes some IPs from time to
> >>>> time..
> >>>>>>>>>>
> >>>>>>>>>> That leads to FreeSWITCH being registered to the old IP while
> >>>>>>>>>> INVITE-requests of new dialogs are sent to the new address. The
> >>>>>> provider
> >>>>>>>>>> terminates this with 403 - forbidden.
> >>>>>>>>>>
> >>>>>>>>>> The registration happens every 5 minutes, but FreeSWITCH does
> not
> >>>>>> update
> >>>>>>>>>> the dns cache for the target IP address. So i gets stuck in that
> >>>>>>>>>> situation being registered on the old IP while sending INVITEs
> to
> >>>> the
> >>>>>>>>>> new one..
> >>>>>>>>>>
> >>>>>>>>>> The only solution to that is reloading the profile or restarting
> >>>>>>>>>> FreeSWITCH...
> >>>>>>>>>>
> >>>>>>>>>> Is there an option to make FreeSWITCH asking the dns _before
> >> every_
> >>>>>>>>>> REGISTER? Or do you have any other suggestion on how to fix
> this?
> >>>>>>>>>>
> >>>>>>>>>> Best regards,
> >>>>>>>>>> Sebastian Denz
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>
> >>>>>>
> >>>>
> >>
> _________________________________________________________________________
> >>>>>>>>>>
> >>>>>>>>>> The FreeSWITCH project is sponsored by SignalWire
> >>>>>>>> https://signalwire.com
> >>>>>>>>>> Enhance your FreeSWITCH install with disruptive priced SMS and
> >> PSTN
> >>>>>>>>>> services.
> >>>>>>>>>> Build your next product on our scalable cloud platform.
> >>>>>>>>>>
> >>>>>>>>>> Join our online community to chat in real time
> >>>>>>>>>> https://signalwire.community
> >>>>>>>>>>
> >>>>>>>>>> Professional FreeSWITCH Services
> >>>>>>>>>> sales at freeswitch.com
> >>>>>>>>>> https://freeswitch.com
> >>>>>>>>>>
> >>>>>>>>>> Official FreeSWITCH Sites
> >>>>>>>>>> https://freeswitch.com/oss
> >>>>>>>>>> https://freeswitch.org/confluence
> >>>>>>>>>> https://cluecon.com
> >>>>>>>>>>
> >>>>>>>>>> FreeSWITCH-users mailing list
> >>>>>>>>>> FreeSWITCH-users at lists.freeswitch.org
> >>>>>>>>>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> >>>>>>>>>> UNSUBSCRIBE:
> >>>>>>>> http://lists.freeswitch.org/mailman/options/freeswitch-users
> >>>>>>>>>> https://freeswitch.com
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>
> >>>>
> >>
> _________________________________________________________________________
> >>>>>>>>>
> >>>>>>>>> The FreeSWITCH project is sponsored by SignalWire
> >>>>>> https://signalwire.com
> >>>>>>>>> Enhance your FreeSWITCH install with disruptive priced SMS and
> PSTN
> >>>>>>>> services.
> >>>>>>>>> Build your next product on our scalable cloud platform.
> >>>>>>>>>
> >>>>>>>>> Join our online community to chat in real time
> >>>>>>>> https://signalwire.community
> >>>>>>>>>
> >>>>>>>>> Professional FreeSWITCH Services
> >>>>>>>>> sales at freeswitch.com
> >>>>>>>>> https://freeswitch.com
> >>>>>>>>>
> >>>>>>>>> Official FreeSWITCH Sites
> >>>>>>>>> https://freeswitch.com/oss
> >>>>>>>>> https://freeswitch.org/confluence
> >>>>>>>>> https://cluecon.com
> >>>>>>>>>
> >>>>>>>>> FreeSWITCH-users mailing list
> >>>>>>>>> FreeSWITCH-users at lists.freeswitch.org
> >>>>>>>>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> >>>>>>>>> UNSUBSCRIBE:
> >>>>>> http://lists.freeswitch.org/mailman/options/freeswitch-users
> >>>>>>>>> https://freeswitch.com
> >>>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>
> >>>>
> >>
> _________________________________________________________________________
> >>>>>>>>
> >>>>>>>> The FreeSWITCH project is sponsored by SignalWire
> >>>>>> https://signalwire.com
> >>>>>>>> Enhance your FreeSWITCH install with disruptive priced SMS and
> PSTN
> >>>>>>>> services.
> >>>>>>>> Build your next product on our scalable cloud platform.
> >>>>>>>>
> >>>>>>>> Join our online community to chat in real time
> >>>>>>>> https://signalwire.community
> >>>>>>>>
> >>>>>>>> Professional FreeSWITCH Services
> >>>>>>>> sales at freeswitch.com
> >>>>>>>> https://freeswitch.com
> >>>>>>>>
> >>>>>>>> Official FreeSWITCH Sites
> >>>>>>>> https://freeswitch.com/oss
> >>>>>>>> https://freeswitch.org/confluence
> >>>>>>>> https://cluecon.com
> >>>>>>>>
> >>>>>>>> FreeSWITCH-users mailing list
> >>>>>>>> FreeSWITCH-users at lists.freeswitch.org
> >>>>>>>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> >>>>>>>> UNSUBSCRIBE:
> >>>>>> http://lists.freeswitch.org/mailman/options/freeswitch-users
> >>>>>>>> https://freeswitch.com
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>
> >>
> _________________________________________________________________________
> >>>>>>>
> >>>>>>> The FreeSWITCH project is sponsored by SignalWire
> >>>> https://signalwire.com
> >>>>>>> Enhance your FreeSWITCH install with disruptive priced SMS and PSTN
> >>>>>> services.
> >>>>>>> Build your next product on our scalable cloud platform.
> >>>>>>>
> >>>>>>> Join our online community to chat in real time
> >>>>>> https://signalwire.community
> >>>>>>>
> >>>>>>> Professional FreeSWITCH Services
> >>>>>>> sales at freeswitch.com
> >>>>>>> https://freeswitch.com
> >>>>>>>
> >>>>>>> Official FreeSWITCH Sites
> >>>>>>> https://freeswitch.com/oss
> >>>>>>> https://freeswitch.org/confluence
> >>>>>>> https://cluecon.com
> >>>>>>>
> >>>>>>> FreeSWITCH-users mailing list
> >>>>>>> FreeSWITCH-users at lists.freeswitch.org
> >>>>>>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> >>>>>>> UNSUBSCRIBE:
> >>>> http://lists.freeswitch.org/mailman/options/freeswitch-users
> >>>>>>> https://freeswitch.com
> >>>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>
> >>
> _________________________________________________________________________
> >>>>>>
> >>>>>> The FreeSWITCH project is sponsored by SignalWire
> >>>> https://signalwire.com
> >>>>>> Enhance your FreeSWITCH install with disruptive priced SMS and PSTN
> >>>>>> services.
> >>>>>> Build your next product on our scalable cloud platform.
> >>>>>>
> >>>>>> Join our online community to chat in real time
> >>>>>> https://signalwire.community
> >>>>>>
> >>>>>> Professional FreeSWITCH Services
> >>>>>> sales at freeswitch.com
> >>>>>> https://freeswitch.com
> >>>>>>
> >>>>>> Official FreeSWITCH Sites
> >>>>>> https://freeswitch.com/oss
> >>>>>> https://freeswitch.org/confluence
> >>>>>> https://cluecon.com
> >>>>>>
> >>>>>> FreeSWITCH-users mailing list
> >>>>>> FreeSWITCH-users at lists.freeswitch.org
> >>>>>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> >>>>>> UNSUBSCRIBE:
> >>>> http://lists.freeswitch.org/mailman/options/freeswitch-users
> >>>>>> https://freeswitch.com
> >>>>>
> >>>>>
> >>>>>
> >>
> _________________________________________________________________________
> >>>>>
> >>>>> The FreeSWITCH project is sponsored by SignalWire
> >> https://signalwire.com
> >>>>> Enhance your FreeSWITCH install with disruptive priced SMS and PSTN
> >>>> services.
> >>>>> Build your next product on our scalable cloud platform.
> >>>>>
> >>>>> Join our online community to chat in real time
> >>>> https://signalwire.community
> >>>>>
> >>>>> Professional FreeSWITCH Services
> >>>>> sales at freeswitch.com
> >>>>> https://freeswitch.com
> >>>>>
> >>>>> Official FreeSWITCH Sites
> >>>>> https://freeswitch.com/oss
> >>>>> https://freeswitch.org/confluence
> >>>>> https://cluecon.com
> >>>>>
> >>>>> FreeSWITCH-users mailing list
> >>>>> FreeSWITCH-users at lists.freeswitch.org
> >>>>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> >>>>> UNSUBSCRIBE:
> >> http://lists.freeswitch.org/mailman/options/freeswitch-users
> >>>>> https://freeswitch.com
> >>>>>
> >>>>
> >>>>
> >>>>
> >>
> _________________________________________________________________________
> >>>>
> >>>> The FreeSWITCH project is sponsored by SignalWire
> >> https://signalwire.com
> >>>> Enhance your FreeSWITCH install with disruptive priced SMS and PSTN
> >>>> services.
> >>>> Build your next product on our scalable cloud platform.
> >>>>
> >>>> Join our online community to chat in real time
> >>>> https://signalwire.community
> >>>>
> >>>> Professional FreeSWITCH Services
> >>>> sales at freeswitch.com
> >>>> https://freeswitch.com
> >>>>
> >>>> Official FreeSWITCH Sites
> >>>> https://freeswitch.com/oss
> >>>> https://freeswitch.org/confluence
> >>>> https://cluecon.com
> >>>>
> >>>> FreeSWITCH-users mailing list
> >>>> FreeSWITCH-users at lists.freeswitch.org
> >>>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> >>>> UNSUBSCRIBE:
> >> http://lists.freeswitch.org/mailman/options/freeswitch-users
> >>>> https://freeswitch.com
> >>>
> >>>
> >>>
> _________________________________________________________________________
> >>>
> >>> The FreeSWITCH project is sponsored by SignalWire
> https://signalwire.com
> >>> Enhance your FreeSWITCH install with disruptive priced SMS and PSTN
> >> services.
> >>> Build your next product on our scalable cloud platform.
> >>>
> >>> Join our online community to chat in real time
> >> https://signalwire.community
> >>>
> >>> Professional FreeSWITCH Services
> >>> sales at freeswitch.com
> >>> https://freeswitch.com
> >>>
> >>> Official FreeSWITCH Sites
> >>> https://freeswitch.com/oss
> >>> https://freeswitch.org/confluence
> >>> https://cluecon.com
> >>>
> >>> FreeSWITCH-users mailing list
> >>> FreeSWITCH-users at lists.freeswitch.org
> >>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> >>> UNSUBSCRIBE:
> http://lists.freeswitch.org/mailman/options/freeswitch-users
> >>> https://freeswitch.com
> >>>
> >>
> >>
> >>
> _________________________________________________________________________
> >>
> >> The FreeSWITCH project is sponsored by SignalWire
> https://signalwire.com
> >> Enhance your FreeSWITCH install with disruptive priced SMS and PSTN
> >> services.
> >> Build your next product on our scalable cloud platform.
> >>
> >> Join our online community to chat in real time
> >> https://signalwire.community
> >>
> >> Professional FreeSWITCH Services
> >> sales at freeswitch.com
> >> https://freeswitch.com
> >>
> >> Official FreeSWITCH Sites
> >> https://freeswitch.com/oss
> >> https://freeswitch.org/confluence
> >> https://cluecon.com
> >>
> >> FreeSWITCH-users mailing list
> >> FreeSWITCH-users at lists.freeswitch.org
> >> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> >> UNSUBSCRIBE:
> http://lists.freeswitch.org/mailman/options/freeswitch-users
> >> https://freeswitch.com
> >
> >
> > _________________________________________________________________________
> >
> > The FreeSWITCH project is sponsored by SignalWire https://signalwire.com
> > Enhance your FreeSWITCH install with disruptive priced SMS and PSTN
> services.
> > Build your next product on our scalable cloud platform.
> >
> > Join our online community to chat in real time
> https://signalwire.community
> >
> > Professional FreeSWITCH Services
> > sales at freeswitch.com
> > https://freeswitch.com
> >
> > Official FreeSWITCH Sites
> > https://freeswitch.com/oss
> > https://freeswitch.org/confluence
> > https://cluecon.com
> >
> > FreeSWITCH-users mailing list
> > FreeSWITCH-users at lists.freeswitch.org
> > http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> > UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> > https://freeswitch.com
> >
>
>
> _________________________________________________________________________
>
> The FreeSWITCH project is sponsored by SignalWire https://signalwire.com
> Enhance your FreeSWITCH install with disruptive priced SMS and PSTN
> services.
> Build your next product on our scalable cloud platform.
>
> Join our online community to chat in real time
> https://signalwire.community
>
> Professional FreeSWITCH Services
> sales at freeswitch.com
> https://freeswitch.com
>
> Official FreeSWITCH Sites
> https://freeswitch.com/oss
> https://freeswitch.org/confluence
> https://cluecon.com
>
> FreeSWITCH-users mailing list
> FreeSWITCH-users at lists.freeswitch.org
> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> https://freeswitch.com
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