[SR-Users] multidomain: running multiple kamailio on one host

[Klaus Darilion]

Am 05.11.2010 18:19, schrieb MÉSZÁROS Mihály:
> 2010-11-05 09:31 keltezéssel, Alex Balashov írta:
>> On 11/05/2010 04:10 AM, MÉSZÁROS Mihály wrote:
>>> Hello all!
>>>
>>> Is there any known problem to run multiple kamailio/sip-router instance
>>> in one host.
>>> I need this to handle multidomain situation.
>>>
>>> The multidomain what is built in is not satisfactory, because the UA-s
>>> what are from varying vendors.
>>> And some has strange or a very limited SIP implementation.
>>> Some can only register ip address, some can use RFC3263, but some can
>>> use only DNS A record. :(
>>>
>>> Any answer, suggestion appreciated very well!
>>
>> I still don't see why handling multiple domains in a single instance
>> would be a problem.
>>
> I will try to explain where i saw the problem.
> Of course it can be that i am wrong, so AFAIK ..
>
>
> If there is domain atlanta.test with with such a DNS.
>
> $TTL    60
> $ORIGIN atlanta.test.
> @       IN      SOA     a1.atlanta.test. root.a1.atlanta.test. (
>                       2009071301         ; Serial
>                           604800         ; Refresh
>                            86400         ; Retry
>                          2419200         ; Expire
>                           604800 )       ; Negative Cache TTL
> ;
> @               IN      NS      a1
> @               IN      NS      a2
> a1              IN      A       192.168.0.1
> a2              IN      A       192.168.0.2
> ;;                              order   pref    flags   service
> regexp replacement
> @               IN      NAPTR   10      10      "s"     "SIPS+D2T"
> ""     _sips._tcp
> @               IN      NAPTR   20      10      "s"     "SIP+D2T"
> ""     _sip._tcp
> @               IN      NAPTR   30      10      "s"     "SIP+D2U"
> ""     _sip._udp
> ;;                              Priority        Weight  Port    Target
> _sips._tcp      IN      SRV     10              0       5061    a1
> _sips._tcp      IN      SRV     20              0       5061    a2
> _sip._tcp       IN      SRV     10              0       5060    a1
> _sip._tcp       IN      SRV     20              0       5060    a2
> _sip._udp       IN      SRV     10              0       5060    a1
> _sip._udp       IN      SRV     20              0       5060    a2
>
>     * UA type1
>       It is implementing RFC3263 correctly. (Very rare such a good
>       implementation.)
>       so it will send a register
>       REGISTER atlanta.test
>       To:alice at atalnta.test
>           o Correctly this client will use the proxy preference and in
>             best case use tcp + tls.

Fine.

>     * UA2
>       It is implementing only dns A record support.
>       so it will send a register
>       REGISTER a1.atlanta.test
>       To: alice at a1.atlanta.test

It depends. Most of the clients, regardless if they support SRV/NAPTR or 
not, allow you to configure an outboundproxy. This means you will tell 
the client that the domain is "atlanta.test" and configure as 
outboundproxy "a1.atlanta.test". So, all the SIP URIs still use 
"atlanta.test" in domain-part.

>     * UA3
>       It is a strange UA resolves everything to ip address.
>       so it will send the register
>       REGISTER 192.168.0.1
>       To: alice at 192.168.0.1

Do such clients really exists? Send them back to the vendor.

>     * UA4
>       Maybe there are more case, and can be continued. But till now i
>       faced only to the above three cases.
>
>
> Where i saw the problem with kamailio multidomain setup (AFAIK):
> I want to use the three as one "sip routing domain" or i don't know how
> to name it correctly.
> When it saves the AoR <=> Contact bindings to location database (mysql),
> the registrar will create and save the contacts to three separated
> domain according to the above three UA behavior:
>
>     * atlanta.test
>     * a1.atlanta.test
>     * 192.168.0.1
>
> So i must add three times the user in subscriber table for the three
> domain, to allow the user alice to authenticate from any UA.
> And i will have three domain in location database for only one "sip
> routing domain".

If you need to host only one "sip routing domain" which uses different 
hostparts, then it would simplest by just not enabling multidomain mode:

modparam("alias_db|auth_db|usrloc|uri_db", "use_domain", 0)


> So if i want to have a second domain, called biloxi.test with similar
> setup, on the same host where atlanta.test is,
> then i get bigger mess. And i have six domain...
> I hope you see where i have a problem.
> And AFAIK i can't set to registrar function save() the domain, if i use
> database backend.

I guess it also depends on how the userpart is constructed and how 
strong the separation between the atlanta and biloxi has to be. E.g. if 
the userpart of atlanta and biloxy does not overlap, (e.g. random 
generated usernames or E164 phone numbers) then you still can leave 
multidomain support disabled.

If you need separation of atlanta and biloxy and you really need to 
support SIP clients which only use IP addresses then of course you are 
forced to use different sockets (different ports or IP addresses). Once 
you use different sockets you can also separate Kamailio instances, one 
for biloxy and one for atlanta. Those Kamailio instances will then be 
operated with use_domain=0 and thus the host-part will be ignored.

> Highly appreciated if You can suggest a solution for this.
> It will be nice if you, or anyone can suggest some solution to this problem.

Get rid of stupid/broken clients - if possible.

PS: Above is mainly for Kamailio. Provisioning in Kamailio is SIP-URI 
centric - this means a user has one SIP URI (and thus is in one domain). 
ser/sip-router modules use a different provisioning model which is 
user-id centric. In this schema a user is mapped to an ID. This ID may 
be mapped to various SIP URIs which may reside in different domains. So 
the ser database model may help you with provisioning - anyway you would 
have to assign 3 SIP URIs to a user's account.

regards
Klaus