[Serusers] NAT ping and consumer router

[Jesus Rodriguez]

On Wed, 25 Aug 2004, Jiri Kuthan wrote:

> At 04:13 PM 8/25/2004, Jesus Rodriguez wrote:
> >That's like known SBCs work. Before, they sent an OPTIONS packet but last
> >software versions modify the Expire of the 200 OK from REGISTER so is the
> >UA the one that sends a new REGISTER and generates traffic from the
> >internal side every 30 seconds. These REGISTER are not forwarded to the
> >proxy. The SBC keeps a table where saves the "real" REGISTER expire sent to
> >the proxy. This way you don't flood the proxy with all those REGISTER.
>
> Which appears like a questionnable benefit -- I mean it does not seem to
> make a big difference to me if the extra REGISTER load is put on SER PC
> or some other PC in front of it... (Not mentioning what other pain SBCs
> cause -- I just spent a good part of day/night reviewing a network setup
> in which such an SBC caused real harm.)

I was just explaining the method used by this box and not supporting it ;)

I agree that SBC and ALGs are not a good thing and getting a good nat
capable UA is a better and easier solution.





> I objected several ideas on this mailing list, like ALGs, SBC, and other
> in-network NAT/SIP patches, so I should perhaps state what I consider
> a good idea. First it takes good NAT support in end-devices. Creating
> network-based patches to deal with NAT-incapable devices just creates
> a great amount of complexity which typically breaks other things. Make
> clients detect connectivity using STUN, perhaps ICE, let it send keep-alive,
> implement SIP stack correctly, be symmetric, etc. That's something which
> is achievable short-term, it is also buyer's responsibility to buy those
> that get it right.
>
> Long-term removing indeterminism from NATs as in IETF/behave is another
> important acchitectural activity.
>
> If people ask me how to make SIP/NAT stable right now, regardless of sanity,
> my preference is to find a good UAC and stick to it. (I have to admit
> I don't have a specific recommednations -- the capabilities change rapidly
> fimrware by firmware in a pace I can't follow.) Configure SER to help
> by reducing registration intervals, using a voice proxy, sending pings.
>
>
> -jiri
>
>


Saludos
JesusR.

-------------------------------
Jesus Rodriguez
VozTelecom Sistemas, S.L.
jesusr at voztele.com
http://www.voztele.com
Tel. 902360305
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