[asterisk-dev] Asterisk 16.9.0-rc1 Now Available - unusable with Deutsche Telekom

[Michael Maier]

On 09.03.20 at 13:43 George Joseph wrote:
> On Sun, Mar 8, 2020 at 2:48 PM George Joseph <gjoseph at digium.com> wrote:
> 
>>
>>
>> On Fri, Mar 6, 2020 at 10:07 PM Michael Maier <m1278468 at mailbox.org>
>> wrote:
>>
>>> Hello!
>>>
>>> On 05.03.20 at 19:08 Asterisk Development Team wrote:
>>>>  * ASTERISK-28746 - res_pjsip_outbound_registration keeps
>>>>       retrying the first entry in a SRV record set
>>>>       (Reported by
>>>>       George Joseph)
>>>
>>> I just tested the new version 16.9.0.rc1 and promptly got an error with
>>> this patch. With Deutsche Telekom, you always get a SRV record set. On
>>> the other hand, you mostly have to register 3 numbers - each must be
>>> registered on its own - to the same destination. Therefore, on startup,
>>> there are 3 registers done to the same destination. Often, one of the
>>> three numbers fails to register on the first attempt and therefore, it
>>> is done twice.
>>>
>>> With this patch, you're now using the second of usually 3 SRV entries
>>> and registration is done successfully (which would have worked too, if
>>> you would have used the first entry again, because it's just a very
>>> temporary problem) - but all succeeding calls (outgoing INVITEs) are now
>>> rejected (403 Forbidden), because they are going to the first entry of
>>> the SRV record set - which fails on Deutsche Telekom, because they await
>>> all subsequent actions to be done at the same server as the registration
>>> was done.
>>>
>>>
> I'm thinking more about this...   Basically, the only reason this worked in
> the past is that the SRV processing was broken. :)

Yes - that's definitely true. Sometime, "broken" isn't always that bad
but can be pretty good at the same time on the other hand :-)

BTW:
While you're at it: it would be a great oportunity to get it sorted out
completely by globaly adding session stability (one trunk always uses
same IP destination for all actions. If the destionation can't be
reached any more (or misbehaves), you have to reregister to another IP
of the list and remember the new IP for all following actions).

> Anyway, What do the 3 numbers represent?  3 different DIDs and therefore it
> could be any number, or 3 numbers for each DID, etc.?  How do you use the 3
> numbers?

The 3 numbers are 3 completely different numbers and DIDs at the same
time. They are used for in- and outbound calls and each number
represents an own trunk (as seen by FreePBX e.g.). You have to register
each number on its own to be able to place outbound calls and to get
inbound calls for this number. If you don't register a number and
someone calls this number, the caller gets a "the number you dialed is
currently not available - please try again later".


Thanks
Michael