[SIPForum-discussion] Relation b/w SIP and IMS

Tue Feb 26 18:34:40 UTC 2008

testing  sorry but I'm not seeing my posts.

--- Neill Wilkinson <neill.wilkinson at quortex.com>
wrote:

> Adi,
> 
>  
> 
> OK - IMS is an evolution of the softswitch model and
> has evolved from the
> UMTS standards.
> 
>  
> 
> The scenario you refer to below is what would occur
> in a Release 4/5
> Network.
> 
>  
> 
> Let me expand - as I think you are probably aware of
> the stages of
> architecture from "standard" GSM what is now called
> release 2 and with GPRS
> added on called release 2.5 or also known as release
> 99. All these are the
> ETSI/3GPP standards releases. Beyond 2.5 we move in
> to release 3, then 4,
> then 5. Through releases 3-5 we start to decompose
> the normal switching
> functions of the of the Radio Network Controllers,
> MSCs, HLRs etc. into a
> softswitch architecture and introduce the Soft-MSC
> or MSC server and
> Media/Signalling Gateways to replace the
> circuit-switched core (CS Domain)
> and put either ATM or IP in its place.
> 
>  
> 
> Once release 6 of the standards is reached, we
> decompose this further, to
> fully introduce IMS. IMS is first introduced in
> release 5.
> 
>  
> 
> So to expand further on your example if you have
> Media Gateways and
> MCGP/MEGACO in the architecture then the call is
> originating in a release 4
> network. Release 4 networks connect to the IP world
> via the GPRS (GGSN), and
> to the TDM world via the Media Gateways. The media
> gateways controlled by
> some for of Media Gateway Control Protocol. The MSCs
> Servers are also acting
> as Protocol Interworking functions to translate
> between SIGTRAN, MEGACO,
> BICC, SIP etc. This allows us to utilise the
> existing SS7 protocols inherent
> in the earlier mobile networks whilst interworking
> to the newer SIP
> protocols of the IP world.
> 
>  
> 
> So why do I go to such lengths to point all this
> out? Two things:
> 
> 1.	up to release 5 we're dealing with an
> Interworking scenario where we
> still have some "old-world" equipment and
> interworking to GSM devices, and
> the PSTN. The idea up to Release 5 is that the core
> of the Mobile network
> can be transformed to and IP core (although ATM is
> still allowed and
> prevalent in a number of operators networks), whilst
> giving the external
> impression of still being a circuit switched core
> (CS Domain).
> 2.	IMS relies on the whole of the environment being
> IP based.
> Signalling from the mobile device (UE in UMTS terms)
> is SIP, no interworking
> is required from SIP-to-SIP connections directly
> from Mobile devices to say
> softphones. The network is simpler and requires less
> interworking and
> translation, since MGCP/MEGACO is gone and BICC is
> gone. It allows
> connections and roaming across Network boundaries to
> be pure IP all the way
> without the need for media gateways between
> Networks. The Circuit Switched
> core (CS Domain) is gone an only the GPRS function
> remains in the mobile
> elements at release 5 onwards.
> 
>  
> 
> Value added services are enabled in IMS through the
> Application Server. The
> Application Servers in turn provide a secure
> "sandbox if you will" for 3rd
> Party developers to communicate to the IMS
> subscribers and add applications.
> Adding applications in this way through APIs was
> impossible in the "old"
> mobile world (up to release 5). With IMS the ability
> to construct and add
> value-added services is much easier and should
> enable carriers to open up
> their networks to 3rd parties for new and exciting
> applications, without
> having to rely on the manufacturers features.
> 
>  
> 
> Hope that all makes sense and is of use.
> 
>  
> 
> Anyone else on the discussion group want to
> add/correct my thoughts?
> 
>  
> 
>  
> 
> Neill.;o)
> 
> Consultant
> 
> Aeonvista Ltd
> 
>  
> 
>   _____  
> 
> From: aditya kumar [mailto:adityaakumar at hotmail.com]
> 
> Sent: 23 November 2007 09:26
> To: neillw at quortex.com; discussion at sipforum.org
> Subject: RE: [SIPForum-discussion] Relation b/w SIP
> and IMS
> 
>  
> 
> 
> Thanks Neil..for giving a clear cut idea on IMS and
> SIP.
> 
> Could you please share your thoughts on the
> following scenario:
> 
> 1.One Call is from mobile to IP phone.[As per my
> knowledge by using
> MGCP/MEGACO, we can successful establish the call
> b/w these 2 different
> N/Ws]
> Then what's the need of IMS architecture,if we need
> then How it plays the
> value added services?
> 
> --Adi
> 
> 
> 
> 
>  
> 
> 
> > From: neillw at quortex.com
> > Subject: Re: [SIPForum-discussion] Relation b/w
> SIP and IMS
> > To: adityaakumar at hotmail.com;
> discussion at sipforum.org
> > Date: Thu, 22 Nov 2007 16:03:30 +0000
> > 
> > IMS is a whole platform/Architecture Framework.
> The 
> > session control protocol (signalling protocol) is
> SIP with 
> > a number of extensions.
> > 
> > The IMS architecture uses the inherent features
> that SIP 
> > brings and combines those with the features of
> Mobile 
> > networks and adds the ability to construct
> external 
> > applications through SIP Application Servers and
> the 
> > PARLAY/OSA APIs.
> > 
> > 
> > Neill...;o)
> > On Thu, 22 Nov 2007 15:00:55 +0000
> > aditya kumar <adityaakumar at hotmail.com> wr
> > >Hi guys,
> > > 
> > >1.If IMS is working on SIP protocol then what's
> the 
> 
=== message truncated ===>
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