1. Consideration on CDF
TTC
31 March - 2 April 2008

2. Introduction (1/2) From the meeting report of the CJK 11thNGN-WG:
11thNGN-WG_012, CDF in IPTV Architecture, raised several open issues regarding content distribution functions in the IPTV architecture based on the input diagram from Q3/13’s Rapporteur, which is being discussed by ITU-T Q3/13 exploder and pointed out several issues for which CJK members’ opinions are desired.
Location of storage function: There was general agreement on the role of this function but its location will need further discussion. Is it only in the transport stratum or elsewhere such as in the service stratum or both?
Distribution and Output functions: Do these two functions belong to the user-, control-, or management-plane functions, which are typical functional categories for explaining all telecommunication operations? If they are not typical functions, do they belong to a new concept of functions which needs new study? Are these two functions physically new concepts or a logical separation of specific actions carried out by those three typical functions (U-/C-/M-plane functions)?
Q3/13 Rapporteur’s proposal tries to categorize CDF as a separate system containing all NGN strata: Is the proposal acceptable, especially taking into consideration multicast/unicast delivery with the roles between multicast and unicast delivery functional blocks in transmission & storage functions and IPTV service control functional blocks for setting up multicasting/unicasting in service control functions.

3. Introduction (2/2)
The author encouraged CJK members to get involved in the discussion of the Rapporteur’s proposal. He also encouraged focusing on this topic because this is the most important topic for the IPTV architecture. He encouraged solving this issue in order to consent the draft in the May meeting.
There was an opinion that this investigation is useful, but should be done carefully so as not to cause dramatic changes to other parts of the IPTV architecture. We were reminded that mapping of the IPTV architecture to the NGN architecture should be studied. The meeting did not reach any conclusion, but agreed to keep studying this topic.

4. Q.3/13 Rapporteur’s Proposal

5. Exiting Figure 8-1, produced by FG IPTV
Content Delivery Functions
Manage -
ment
Functions
Application Functions
Service Control Functions
End
User
Content
Provider
Network Functions

6. Discussion
Clear position of CDF including further division of itself needs further consideration, which may take a lot of time.
Instead, we should study the positioning of CDF under the work of NGN.
Functional description should be fixed first.

7. Alternative – 3 Applications Service Stratum Transport Stratum
Service Control
Functions
Content Delivery
Functions
Service Stratum
Transport Stratum

8. Alternative – 4: Proposal in C-611
Applications
Service Control and
Service Delivery Functions
Service Stratum
Transport Stratum