[Serusers] Scaling SER

[Greger V. Teigre]

Actually it depends on the NAT implementation. There are four generally 
known/defined types (in STUN), but a lot of variants.  When we talk 
about the NAT problem, we always talk about the worst-case, which is a 
symmetric NAT, i.e. only packets from src ipA:portB will be allowed 
through and only if a previous packet has been going out to dst 
ipA:portB not longer ago than a defined time-out. Some NATs have timeout 
of 60 minutes, others (could be) as low as 30 sec.
g-)

Natambu Obleton wrote:
> Ohh.. I thought the keepalives would allow other ip address, than the one
> that originally opened the connections, to send in. 
>
> I guess that wouldn't be very secure would it.... :)
>
>
> Natambu Obleton
> Network Engineer
> FastTrack Communications
> nobleton at fasttrackcomm.net
> (970) 247-3366 office
> (970) 247-2426 fax
>  
>
> -----Original Message-----
> From: serusers-bounces at lists.iptel.org
> [mailto:serusers-bounces at lists.iptel.org] On Behalf Of Vitaly Nikolaev 
> Sent: Tuesday, September 19, 2006 8:53 AM
> To: serusers at iptel.org
> Subject: RE: [Serusers] Scaling SER
>
> To extend Juha's info:
>
> Only SER server that just received SIP packet from SIP device (either
> register or keepalive) can send something  back in case of NAT
>
> For example you have SER1 and SER2, client A registered on SER1 and
> client B on SER2, when client B sends call to client A it will first hit
> SER2 then SER2 to according to replicated location table will try to
> send it to client A straight and fail in case client A behind the nat
> (which is quite often in real world)
>
> Trick is to teach SER2 to forward call to SER1 when needed, it can be
> done when you use b2bua that looks to same location table for example
> (ser need to be taught to place its IP also in same table).
>
> Can not give you exact howto but can give (out of list) some references
> to  commercial software if interested.
>
>
> -----Original Message-----
> From: serusers-bounces at lists.iptel.org
> [mailto:serusers-bounces at lists.iptel.org] On Behalf Of Juha Heinanen
> Sent: Tuesday, September 19, 2006 8:52 AM
> To: Andrey Kuprianov
> Cc: serusers at iptel.org
> Subject: Re: [Serusers] Scaling SER
>
> Andrey Kuprianov writes:
>
>  > mediapoxy'll handle it.
>
> mediaproxy does not forward sip requests.
>
> -- juha
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