[Serusers] still no help - usrloc synchronization

Greger V. Teigre greger at teigre.com
Fri Apr 8 19:16:07 CEST 2005 

Tina,
I'm not really sure what you would like to do. Is it related to replication?  The problem of getting through a NAT from a SER server (replicated), but where the client has not registered, is that you really don't get the redundancy you want.  If the server where one client is registered goes down, that client cannot be reached even if you stand on your head yelling "please!" (of course, unless you do load balancing as described in my just recent email). The restricted NAT in front of the client will look at the IP address of the SER replication server and say "nope."

Anyway, have you looked at the new LCR module?  (for the HEAD CVS, but backported, you can find the backport at http://onsip.org)
g-)
---- Original Message ----
From: Tina
To: Greger V. Teigre
Cc: serusers at lists.iptel.org
Sent: Friday, April 08, 2005 02:11 AM
Subject: Re: [Serusers] still no help - usrloc synchronization

> Hi sir,
> thanks a lot for the great work you are doing!
> I have a silly question...
> I need to keep some session information (to forward the call via
> "appropriate" server). Is it possible to obtain hostname from ser.cfg
> or I should implement some proprietary external coding...?  
> Thanks in advance,
> Tina
> 
> "Greger V. Teigre" <greger at teigre.com> wrote:
> I was thinking about a load balancing scenario where the load
> balancer will replace the IP addresses. 
> g-)
> 
> ---- Original Message ----
> From: Tina
> To: Greger V. Teigre
> Sent: Wednesday, April 06, 2005 09:45 PM
> Subject: Re: [Serusers] still no help - usrloc synchronization
> 
>> Thank you for givingme the scenario with "restricted IP" NAT, I am
>> starting to find some acceptable solution.
>> Unfortunately, "one-public-IP" approach is not free from problems
>> also. If your SIP router inserts this "one-public-IP" into the VIA
>> header, the reply routing goes via wrong SIP server...
>> If your SIP server inserts its real-IP-address - the scenario
>> mentioned above is still not resolved.
>> Any comments?
>> Tina
>> 
>> "Greger V. Teigre" <greger at teigre.com> wrote:
>> See inline.
>> 
>>> If you use DNS server for load balancing... the client receives one
>>> of your domain IP addresses according to SRV. I don't see the
>>> problem 
>>> with a call here, cause UAC asks t! he address only once (before
>>> sending INVITE). UAC already has the IP for BYE/reINVITEs. So why
>>> would you replicate INVITEs?
>> 
>> I would never replicate INVITEs, I would just make sure that they are
>> proxied through the correct SER server (i.e. IP).
>> 
>> The problems depends on your setup. If you have SERs with different
>> IPs, ex UA1 has registered with server  A and UA2 has registered with
>> server B: If UA2 wants to call UA1 and UA is behind an IP restricted
>> NAT, server A is stored in the NAT table of the NAT in front of UA1.
>> If server B sends an INVITE to UA1, the INVITE will be refused by
>> UA1's NAT.
>>     This is why a "one public IP" in front of a load balancing
>> cluster probably is a good way to go.
>> 
>>> If you use IPVS/LVS... I believe you can force SER to insert it's
>>> public IP into VIA,! so there is no problem with replies. With
>>> regard 
>>> to another requests, I believe load balancer keeps connection
>>> template, then when another request comes it would be forwarded to
>>> the same ser.
>> 
>> Yes. There are different "keys" to use to load balance SIP messages.
>> One good way from a NAT point of view is to use originating IP
>> address.  What you must remember is that the problem is not on the
>> server side, but on the client side.  The NAT will in many situations
>> stop incoming UDP packets if the originating ip:port is not already
>> stored in the NAT table.  The Via header does not matter for the NAT.
>> g-)
>> 
>>> Any comments?
>>> 
>>> "Greger V. Teigre" <greger at teigre.com> wrote:
>>> Yes, I believe that is so. But still you get a problem if the NAT is
>>> restricted, port-restricted or symmetric... The best would be to
>>> load>> balance and always make sure that a given client is handled
>>> through a given 
>>> SER (REGISTER and INVITEs). That includes forwarding INVITEs from
>>> one 
>>> SER to
>>> another... OR you must load balance in front of your servers with
>>> one 
>>> common
>>> public IP.
>>> g-)
>>> 
>>> Matt Schulte wrote:
>>>> Ack, I didn't even think about NAT. Would these be added before it
>>>> gets sent off to the second proxy? ie:
>>>> 
>>>> if (!src_ip==blah.netlogic.net) {
>>>> add_rcv_param();
>>>> t_replicate("blah.netlogic.net", "999");
>>>> };
>>>> 
>>>> -----Original Message-----
>>>> From: Greger V. Teigre [mailto:greger at teigre.com]
>>>> Sent: Tuesday, April 05, 2005 7:49 AM
>>>> To: Matt Schulte; kramarv at yahoo.com
>>>> ! ; Cc: serusers at lists.iptel.org
>>>> Subject: ! Re: [Serusers] still no help - usrloc synchronization
>>>> 
>>>> 
>>>> Well, you still have the NAT issues unless you do load balancing
>>>> and your
>>>> SER servers have the same public IP.
>>>> Have you looked at 0.9.0 nathelper function add_rcv_param() ? It
>>>> will add received info to the contact header for the other SER to
>>>> process. Haven't really tried yet...
>>>> g-)
>>>> 
>>>> Matt Schulte wrote:
>>>>> I'm starting to lean this direction, using t_replicate and all. I
>>>>> could never get usrloc (db mode) to function properly..
>>>>> t_replicate is
>>>> 
>>>>> a dirty but very effective workaround.
>>>>> 
>>>>> -----Original Message-----
>>>>> From: Greger V. Teigre [mailto:greger at teigre.com]
>>>>> Sent: Saturday, April 02,! 2005 1:33 AM
>>>>> To: kramarv at yahoo.com
>>>>> Cc: serusers at lists.iptel.org
>>>>> Subject: Re: [Serusers] still ! no help - usrloc synchronization
>>>>> 
>>>>> 
>>>>> Have a look at this thread:
>>>>> http://lists.iptel.org/pipermail/serusers/2005-January/014669.html
>>>>> g-)
>>>>> 
>>>>> Java Rockx wrote:
>>>>>> Tina,
>>>>>> 
>>>>>> I thought I saw you post the other day that you did not want to
>>>>>> use t_replicate(), however, this is probably your best bet to
>>>>>> getting this
>>>>> 
>>>>>> to work, IMHO.
>>>>>> 
>>>>>> Regards,
>>>>>> Paul
>>>>>> 
>>>>>> On Apr 1, 2005 4:08 PM, Tina wrote:
>>>>> ! >>
>>>>>> ! ;> Hi, please help me, I'm stuck with it!!!!!
>>>>>>> I am trying to set up several sers with a shared MySQL database
>>>>>>> for location service.
>>>>>>> 
>>>>>>> I set in each ser.cfg:
>>>>>>> 
>>>>>>> modparam("usrloc", "db_mode", 2)
>>>>>>> modparam("usrloc",
>>>>>>> "db_url","sql://ser:heslo@192.168.25.163/ser")
>>>>>>> 
>>>>>>> and the servers are not synchronized.
>>>>>>> The I set
>>>>>>> modparam("usrloc", "db_mode", 2)
>>>>>>> 
>>>>>>> 
>>>>>>> made UAC (Xlite) register to one of the servers.
>>>>>>> I see it via usrloc, but there is no record in "location" mySQL
>>>>>>> table....So others do not see the client and I'm unable to make
>>>>>>> calls....
>>>>>>> 
>>>>>>> 
>>>>>>> Please help how to work with usrloc and mySQL...
>>>>>>> 
>>>>>>> Tina,
>>>>>>> software engineer
>>>>>>> 
>>>>>>> ________________________________
>>>>>>> Do you Yahoo!?
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>>>>>>> 
>>>>>>> 
>>>>>>> _______________________________________________
>>>>>>> Serusers mailing list
>>>>>>> serusers at lists.iptel.org
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>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>> 
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>> Do you Yahoo!?
>> Better first dates. More second dates. Yahoo! Personals
> 
> 
> Do you Yahoo!?
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