Note: I changed the subject from ‘P2P’ to ‘Person to Person’. P2P was not the right phrase in this context
The Telecoms industry continues to promote IMS applications
Typically the list goes something like this.
Push to talk
(From the book IP multimedia subsystem (IMS) by Gonzalo and others – A book I recommend)
Before we address the problem of P2P IMS, let me reiterate that .. IMS itself is a bit like 3G. It is needed by Operators since an IP core reduces cost. In that sense, it is futile to talk of IMS
Success/failure – just like it is futile to talk of 3G success or failure.
The question is: what do we need IMS for beyond the IP core? What applications are possible? – and furthur – why cannot they be done by the Web? – i.e. where is the value proposition end to end for IMS if the Web can do most of what IMS can do – but for free?
Agreed that IMS provides QOS, but look how many people use Skype? They dont worry about QOS as long as we have global connectivity at an affordable cost?
The problems with P2P IMS applications are
a) Lack of a value proposition: Many of these applications can be done by non IMS means on the Web. So, why would I need IMS for them(say for IM). This is the main reason for the interplay between Web 2.0 and IMS i.e. IMS is the ‘Telco’ way of doing the same functions that are done on the Web. The difference is the Web is free and it is global. Telecoms is not free and it is mainly local(sub national i.e. many operators within a country not all of which can interconnect). This is a killer for P2P applications.
b) No End to End: Many of the IMS applications promoted are P2P i.e. need IMS on both ends of the network AND need IMS devices at both ends i.e. customers need IMS devices.
This is not visible at the moment and far from any roadmap I can see. So, why will P2P IMS applications take off?. The IMS devices problem is well known .. As in .. there are not any on the horizon.
c) Merged services – same problem – bigger scale: Some IMS applications are based on merged services(phone call at the same time as we view a video clip). Again the P2P, device problems apply. So this is also a non starter unless other issues are resolved (for example partnerships with other vendors).
So, questions are:
a) Are these problems valid? I think they are. I cant seem to find anyone who can reliably answer these questions – and
b) What can be done about them?
We have a precedent here in MMS .. i.e. P2P MMS did not really take off at all because it has exactly the same problem for IMS applications(in a simpler form) – a.k.a you need network and device support at both ends, the user experience needs to be seamless, the charging needs to be transparent ..
Here are some approaches who claim to address this problem (end to end IMS / P2P applications)
Much of the industry seems to be taking an ostrich like view to this i.e. somehow all operators will simultaneously upgrade + all devices will be quickly capable of supporting IMS (and will be Operator locked down i.e. other means like Wifi connectivity are not possible – ) and then anyone can call anyone else using a video call by IMS
For that matter – to use video calling, we strictly don’t need IMS at all .. that’s a different problem which we are not addressing for now
I don’t endorse any solution and I have no commercial relationships with them – but to create a value proposition for IMS beyond reducing OPEX – we need to address the problem of P2P IMS.
a) IPX network – you can see more using the link
http://www.gsmworld.com/technology/index.shtml tab on Technology -> IP Interworking -> IPX (for general descriptions) Also, tab on Technology -> IP Interworking -> IPI Documents
IPX is undergoing pre-commercial implementation (PCI) trials. It still has many questions unanswered in my view .. I welcome any comments on IPX if you know more(pros and cons)
b) By adding a new network element like Application Session Controller or ASC. This approach is explained HERE.
c) SDP as the glue that unites IMS i.e. SDP on top of IMS. See this approach HERE(and its the most common of the approaches so far )
d) SDP as a replacement for IMS! Relatively new .. Who needs IMS when you have SDP 2.0?(pdf)
In any case, the problem needs to be addressed .. and there is little point of speaking of End to End IMS applications unless we do
I am also interested in knowing more about the experiences in Japan and Korea
While we do have interconnect and interoperability in Japan and Korea – I do not see the same picture being replicated in the west
So, my question is: are there any P2P IMS applications in Japan and Korea – specifically ones with differential charging(which is the goal of IMS from an Operator standpoint). These are topics of separate blogs – differential charging with IMS and its viability and the experience of IMS in Japan and Korea ..
However, the questions I raised before are valid .. and I don’t see any answers for them in a western scenario i.e. Why do we think that P2P/end to end IMS applications will take off in the West?