Talk:IP Multimedia Subsystem

message: I believe that in the article should be add some info related to ADAMANTIUM project, which is a european research project that aims at optimizing current IMS infrastructure with a Perceived Quality of Service aware adaptation management system. For more info please have a look at http://www.ict-adamantium.eu/
I found this article useful but I don't understand the statement:
IMS is an optimization of the network, and investments for such optimization are questionable
Alastair Rae 16:07, 26 October 2005 (UTC)
thread_title:  Optimization 

message: Several people have been adding links under the "external links" section, that point to various websites of telecommunications companies. At first they were useful, when they were white-papers, that explained what IMS was. But what's the point if there are a dozen links to similar content ? Wikipedia is an encyclopedia, not a directory listing for advertisement purposes.
Last week, someone tried to add a link that was called "Leading provider of SIP MobileVOIP based Solutions" (I won't mention the name of the company). That was a pure advertisement, and didn't add any value to this page.
I finally decided to remove all links, even the one from my own company (that was pretty neutral), except the 3GPP ones (that define the standard), and the one from LightReading (that present a neutral overview). I even removed the one from my own company. When a good link is presented, that explains IMS or a particular aspect of it, we can accept it. But please, no more marketing papers or products placement.
--Bluezy 21:45, 6 December 2005 (UTC)
thread_title:  no advertising links 

message: Shouldn't the link for RTP's RFC in the "IETF Specs" section point to RFC 3550 instead of 1889 as 3550 obsoletes 1889 ?
Mat 86.203.206.68 12:19, 16 December 2005 (UTC)
thread_title:  RFC =

message: The table of interfaces needs a diagram (or at least a very prominent link to one elsewhere) to show where these various interfaces logically reside. 
At one time (late October '06), I recall there was a diagram immediately above the table but it seems to have been lost.  If it was removed because of an inaccuracy or usage problem, it should have been flagged for replacement, not just trashed. DKEdwards 22:59, 15 March 2007 (UTC)
replies: text: Diagram was deleted due to the license problem (it was a image scan from a book). I think, that image http://www.tech-invite.com/img/ims/ims.gif can be added, but I'm not sure about copyrights also. Alny 16:40, 19 March 2007 (UTC)
thread_title:  Image request: Interfaces 

message: Regarding the removal of IP Multimedia Subsystem from Voice over IP:
:Since it is included in VoIP protocols, it should not be included in the parent, unless there is a specific reason.
:- TJJFV 00:59, 24 March 2006 (UTC)
thread_title:  Categorization 

message: Here a few of the differences with other phone systems. Note that these differences can also be achieved in other ways. IMS is an implementation of VoIP by the existing telecommunication operators, but is not the only possible one.
===Differences with existing phone systems===
* IMS promises access independence - it can be used over all networks : fixed, mobile or wireless. This means that a user can be reached with a single phone number, redirecting the call to the cheapest or most appropriate network.
* Interaction with existing phone systems is provided with gateways. This not only allows to call people on non-IMS networks, but can also provide those people with advanced features, without modifying their existing telephone exchanges (which are embedded in IMS). For example, a POTS can receive a videocall by having it redirected to another device, or by storing it into a videomail server. Existing applications like SMS can be integrated with Instant messaging services.
* IMS is a standardized architecture, which should allow for faster and easier development of services (previously, services had to be developed separately for different phone systems, because of the proprietary architectures).
* User profiles are stored in a single central location (the HSS), even when shared by different servers, which makes provisioning much easier.
* New applications such as presence information, videoconferencing, Push to talk over cellular (POC), multiparty gaming, community services or content sharing.
===Differences with other VoIP systems===
* IMS promises gateways with existing phonesystems (including [[Plain old telephone service|POTS). While other VoIP systems can provide the same, IMS is implemented by the old telecommunication operators, and they might be better placed to do the integration. Or they could make it more difficult to interoperate, by charging high interoperate fees, which they won't apply to their own IMS customers.
* IMS is designed to use IPv6, unless Early IMS is used. This might make its introduction more difficult since not every device is ready to use IPv6.
* IMS networks use the Internet protocol, but that doesn't mean that you can easily use personal computers with soft phones. Telecom operators might only allow certain VoIP software to talk to their systems. Or they might even make sure to block other software like Skype, in order to protect their income.
* IMS uses the 3GPP variant of SIP, which needs to interoperate with the IETF SIP. This might force changes to existing SIP clients. For example, secure authentication is done using AKA, which can only work with a USIM. This limits a soft phone to the lesser secure HTTP Digest.
(note: this is still a work in progress !)
--Bluezy 22:35, 18 February 2007 (UTC)
replies: text: Bluezy, The original entry said: "There is a need for an IMS version that offers similar features but doesn't require the investments necessary for full IMS. This version has been defined as Early IMS, and has the following advantages:" I also note that in your comment above you refer to TR 23.981 "Interworking aspects and migration scenarios for IPv4-based IMS implementations (early IMS)". (1) The TR (whether v6.4.0 (2005-09) or v5.0.0) is actually called "Interworking aspects and migration scenarios for IPv4 based IMS Implementations". OK, so what is the point? Firstly, 3GPP does not define "early ims". It simply recognises that there will be implementations which do not have, for example, IPv6 support, and that 2G phones may need to use "ims services" without having the benefit of a USIM interface. Is it IMS or is it not? Even TR23.981 quite correctly refers to IPv4 based implementations.  (2) It is silly to talk about "advantages" because "early IMS" is an informal term used to describe a transition phase. (3)Wrt to your example above, note that 3GPP specs rule out http digest as an authentication method even for so called "early ims implementations". But admittedly the standards are evolving as there are some moves afoot to include "http digest" as a authentication method in TISPAN.   I am not averse to some comments being made about early implementations of IMS lacking certain capabilities and interworking to these implementations will be needed (perhaps in the arch section). Wirelesspont 13:56, 5 March 2007 (UTC)
thread_title: Differences

message: * IMS promises gateways with existing phonesystems (including [[Plain old telephone service|POTS). While other VoIP systems can provide the same, IMS is implemented by the old telecommunication operators, and they might be better placed to do the integration. Or they could make it more difficult to interoperate, by charging high interoperate fees, which they won't apply to their own IMS customers.
* IMS is designed to use IPv6, unless Early IMS is used. This might make its introduction more difficult since not every device is ready to use IPv6.
* IMS networks use the Internet protocol, but that doesn't mean that you can easily use personal computers with soft phones. Telecom operators might only allow certain VoIP software to talk to their systems. Or they might even make sure to block other software like Skype, in order to protect their income.
* IMS uses the 3GPP variant of SIP, which needs to interoperate with the IETF SIP. This might force changes to existing SIP clients. For example, secure authentication is done using AKA, which can only work with a USIM. This limits a soft phone to the lesser secure HTTP Digest.
(note: this is still a work in progress !)
--Bluezy 22:35, 18 February 2007 (UTC)
replies: text: Bluezy, The original entry said: "There is a need for an IMS version that offers similar features but doesn't require the investments necessary for full IMS. This version has been defined as Early IMS, and has the following advantages:" I also note that in your comment above you refer to TR 23.981 "Interworking aspects and migration scenarios for IPv4-based IMS implementations (early IMS)". (1) The TR (whether v6.4.0 (2005-09) or v5.0.0) is actually called "Interworking aspects and migration scenarios for IPv4 based IMS Implementations". OK, so what is the point? Firstly, 3GPP does not define "early ims". It simply recognises that there will be implementations which do not have, for example, IPv6 support, and that 2G phones may need to use "ims services" without having the benefit of a USIM interface. Is it IMS or is it not? Even TR23.981 quite correctly refers to IPv4 based implementations.  (2) It is silly to talk about "advantages" because "early IMS" is an informal term used to describe a transition phase. (3)Wrt to your example above, note that 3GPP specs rule out http digest as an authentication method even for so called "early ims implementations". But admittedly the standards are evolving as there are some moves afoot to include "http digest" as a authentication method in TISPAN.   I am not averse to some comments being made about early implementations of IMS lacking certain capabilities and interworking to these implementations will be needed (perhaps in the arch section). Wirelesspont 13:56, 5 March 2007 (UTC)
thread_title: Differences with other VoIP systems

message: 3GPP TR 24.880 is mentioning the interfaces Sr/Cr which are not in the table. 
Additionally Mb - the RTP interface between MRFP and endpoint devices - is missing.
—The preceding unsigned comment was added by 195.233.250.7 (talk) 10:55, 26 March 2007 (UTC)
thread_title:  Missing interfaces 

message: My addition of IP Centrex to the list of services generated a back-and-forth reverting session that kind of surprises me. The list of services does not claim that these services are IMS-specific; it is just a series of examples of services that can be implemented by application servers on top of an IMS core. Can I ask that an agreement be reached as to the purpose of the list of applications in the Application Servers section? JanCeuleers 13:14, 11 April 2007 (UTC)
replies: text: In my opinion the list was not really useful, it added to the length of the article and more served as a bit of a propaganda item (as did the comment that the AS makes it easy to integrate applications in).  Suggest that the list should be minimal and really only refer to some specific IMS things. I am fine with, for example, VCC as this is is being dealt with actively in the standards environment.  What is the point of adding mms, sms and every call feature one can think off? Then might as well put every mobile application under the sun and make this completely and totally useless. So I am grateful to you for adding IP centrex as that was the "tipping" point which made me go back and think "hey, what are we doing here?". There are also some other issues, e.g. some examples equated the AS with the whole of an OMA enabler such as PoC. PoC could be a AS but is not necessarily so. BTW, some thoughts on rewording this section won't go amiss .... 194.72.92.36 14:04, 13 April 2007 (UTC)
replies: text: I believe that the point that IMS can support "mundane" applications (such as voice mail and supplementary services such as call forwarding) is important and worth making. It conveys the message (by example) that IMS is not a "fly-by-night" architecture aimed at providing new services that might not remain relevant for very long. It demonstrates that IMS is sufficiently generic an architecture that it can (in time) supplant the legacy rather than having to be implemented as an overlay. I'll grant you that a mere list of such services is perhaps not the best way of making that point. Such a list would certainly not need to aim to be complete either. JanCeuleers 17:14, 13 April 2007 (UTC)
replies: text:  OK. Several fair points here. To address the point we need to state here that IMS may used to provide present services *too*.  Lots of patchwork is being done to IMS - the replication is proving to be non-trivial hence all the interesting additional work in 3GPP R7, R8 and also TISPAN and so on. I note that there are several pieces of on-going working to, for example, perform interworking to legacy systems - often non-trivial. 194.72.92.36 13:01, 19 April 2007 (UTC)
thread_title:  Application Servers and Applications 

message: (I think that the 'NGN Interconnection' section should be rewritten)
--Bluezy 09:55, 18 October 2007 (UTC)
thread_title:  'NGN Interconnection' section 

message: Is it correct to say as in the Intelligent network article:
"The upcoming IP Multimedia Subsystem (IMS) standards can be seen as a hybrid of intelligent network services and Internet services for cellular multimedia communication." Mange01 15:04, 17 October 2007 (UTC)
replies: text: No, IMS is  a way to utilise packet networks for tecommunications and so replace PSTN (POTS and ISDN) and PLMN. IN added the possible use of external databases for call control decisions in telecommunication switches. ETSI defines the relationship between IMS and IN: "The purpose of the IM SSF is to enable access to IN service logic programs hosted in legacy SCPs". --Kgfleischmann (talk) 10:26, 26 January 2008 (UTC)
thread_title:  Relation to Intelligent network services? 

message: This section has many entries; some of them do not seem to be related to IMS (or very indriectly): SIGTRAN, Generic Access Network, VOLGA Forum - Voice over LTE. Unless someone can justify their relation to IMS, I suggest to remove them.
--Aintneo (talk) 09:49, 21 September 2009 (UTC)
replies: text: I removed all the links that I could find already present in the article.  Many of the remaining links should be worked into the main body of the article, such as a listing of existing/proposed IMS services.  What remains, ideally, should have a brief sentence explaining what it is in relation to IMS. -Verdatum (talk) 21:24, 21 September 2009 (UTC)
thread_title:  "See also" section 

message: I would expect some mention of Network 2020 as part of this IMS article... but this is missing...  :-(  87.205.171.87 (talk)  —Preceding undated comment added 19:15, 10 January 2017 (UTC)
thread_title:  Network 2020 from GSMA 

message: Towards bottom of History paragraph, the float/expansion over the highlighted "EPS" term, maps to the "SAE" definition.  Anybody qualified out there to update and correct it?
v/r
rog
Rog frx (talk) 17:07, 26 August 2020 (UTC)
thread_title:  nit/typo in History paragraph