[Serusers] SIP to AS communication

[Dragos Vingarzan]

That is relative. Almost all new mobile phones support now also WiFi ,so 
it is not only about UMTS and what the phones are implementing by 
default. Both Symbian and Windows Mobile are capable of running IMS 
soft-clients on top. And let's not forget TISPAN's NGN and the fixed 
networks.

About the walled garden, well, no operator would give to end-users QoS 
control because simply it would just cost too much and nobody would 
afford it. As such, I do not see any opened solutions.

Then we could just take 90% of these IMS modules and brand them as 
"Diameter SIP Application". It's practically the same thing and you get 
a nice network architecture with great scalability properties.

http://www.ietf.org/internet-drafts/draft-ietf-aaa-diameter-sip-app-12.txt

But you would miss the Application Server thing, with the possibility of 
easily enabling per-user functionality. Sure that you can do this now 
from the SER script, but the effort of maintaining it dynamic, per user 
and with the AS having access to the subscriber data is just huge. In my 
opinion SER's script is great for managing things at the SIP level, but 
once you build applications on top, you just want to abstract from that. 
And let's not forget the standardization aspect - any IMS core network 
should be able to use and standard IMS Application Servers.

The target use case? I would just say: same as until now ;-). Plus that 
any Service Provider is looking into IMS as a possibility to get out of 
the provider lock by asking for interface-standard components and 
avoiding black-box solutions. As such, SER is great as experimentation toy.

-Dragos

Juha Heinanen wrote:
> Dragos Vingarzan writes:
>
>  > From an operator's point of view, 
>  > IMS does not make too much sense if you don't control the Access Network 
>  > because of the most hyped thing in IMS, QoS. 
>
> well, i just heard that in current 3g networks pdp contexts with
> different QoSes have not been implemented at all.  neither does QoS pdp
> context support in 3g phones.
>
> what comes to ims in general, i don't see it having any chance of
> success, because it locks users into walled gardens.  this, of course,
> doesn't prevent the community from developing IMS features in ser, but i
> would feel that much more relevant would be to focus on XMPP/SIP
> integration.
>
> even if ser would include full IMS support, what would the use case be?
> mobile operators are not likely to deploy third party IMS solutions,
> because they are locked to their mobile vendor.
>
> -- juha
>
>   


-- 
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Dipl. Eng. Dragos Vingarzan
FOKUS/NGNI
Kaiserin-Augusta-Allee 31
10589 Berlin,Germany
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We could change the world if God would give us the source code...
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