[802.21] Higher layer requirements for IETF: meeting minutes
Please find enclosed the minutes of the 802.21 teleconference on July 26. Please let me know if I missed any important points. Srini, thank for taking electronic notes that I could use to write up the minutes.
BR,
Stefano
P.S. the next audio conference on the same topic is on July 28 at 9PM EST, please check previous e-mails on reflector for details.
Purpose
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802.21 Higher layer requirements for IETF
Date
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July 26, 9am-11am EST.
Participants
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Alistair Buttar, Subir Das, Stefano Faccin, Peretz Feder, Andrea Francini, Prasad Govindarajan, Eleanor Hepworth, Benjamin Koh, Kalyan Koora, Hong-Yon Lach, Xiaoyu Liu, Andrew McDonald, Yoshiro Ohba, Ajay Rajkumar, Reijo Salminen, Ajoy Singh, Srinivas Sreemanthula, Qiaobing Xie
(I apologize in advance if I missed somebody, as I'm sure I did; also, i apologize for any mispelling)
Discussion
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* Ajay summarized discussion that took place last week at IEEE meeting regarding 802.21 and IETF
* the current result of the discuss with Gabriel Montenegro (chair of MIPSHOP WG) is that the MIPSHOP is willing to take up IS-related work through re-chartering. Requirements would have to come from 802.21 WG. The MIPSHOP WG chair made clear that ES and CS most probably do not fit the MIPSHOP framework
* Ajoy brought up CARD applicability. It was agreed that the L3 requirements are being worked out and the protocol selection is out of scope at this time
* Stefano presented the high-level kickoff slides (previously distributed)
* With respect to next IETF: Stefano indicates he will give up the slot currently allocated to the Faccin/Daley ID to present the requirements coming from 802.21. Also, a MIHEP Bar BOF will take place to complement the 20min slot in MIPSHOP at IETF meeting.
* Ajoy commented that ES and CS need not be on L3. No real discussion took place, since it was agreed that present focus (due urgency to provide requirements for IS to IEEE.
* The question of what is "L3 transport" came up. The term may be misunderstood by IETF (e.g. Gabriel had indeed misunderstood it), and there does not seem to be complete consensus in 802.21 yet. Comments were raised that if by "L3 transport" for 802.21 we actually consider just transport aspects, in theory 802.21 could define the protocol by itself and then specify TCP or UDP transport, and ask IANA for allocation of port numbers.
* During the discussion it was indicated that by "L3 transport" we mean also architectural aspects such as discovery of MIHF functions/capabilities and security (i.e. aspects that are more protocol oriented)
* Discussion led to identifying three scenarios: (1) 802.21 defines only IEs, IETF defines the transport aspects, and no protocol definition takes place; (2) 802.21 defines both the IEs and the protocol, and IETF defines the transport aspects; (3) 802.21 defines the IEs, IETF defines the transport aspects, and 802.21 and IETF collaborate in defining the protocol. Security aspects are definitely defined in IETF (out of scope for 802.21). discovery aspects are defined by 802.21 and specified in IETF. Ajay also indicated that the target at present is (2) or (3)
* Some parties commented that (3) is more in line with the way IETF works
* As for discovery aspects, some parties indicated that it can be part of work already on-going in other WGs, as an extension of current discovery solutions or as part of host configuration solutions
* Ajoy asked if we should first define the protocol 802.21, then bring it to IETF. Stefano indicated that timing is very important and that we should not miss the current opportunity we have with MIPSHOP willing to re-charter to include 802.21 aspects. Stefano reminded that the re-chartering must close soon (Gabriel indicated he needs to provide the new charter to the ADs just after the next IETF, but Gabriel mentioned he can stay a bit vague to allow for adjustments)
* Ajoy asked if #1 can be more suitable for the success of 802.21, i.e. 802.21 would not need to have the work in IETF completed before saying it has completed its duties. WG think #3 would be better for the success. Ajay reminded that the success of 802.21 does not depend on completion of work in IETF
* Discussion about basic and extended information service. Kalyan asked if the "L3 transport" is only for extended-set? No, it is applied to all of IS, since in some scenarios it is relevant only for extended IS, in some other also for basic IS
* Ajoy raised a question if two MIH servers can talk to each other. It is not clear if two MIH functions in network can talk to each other. Yoshi mentioned there is no need for such communication. Kalyan asked how e.g. is the neighbor graph exchanged? Yoshi mentioned that transferring neighbor graph is out of scope of 802.21. Peretz indicated that one scenario is where MIH is proxied, e.g. MIHF in UE talks to an MIHF in the network it is attached to, and the MIHF in the network proxies MIH information to another MIHF e.g. in the home network. It was mentioned this could be decided later, but since it affects the L3 requirements, Stefano suggested to assume that there "may" be communication between two MIH functions and discuss this later in the emails. Qiaobing also reminded this discussion is closely related to the model discussion that took place at the meeting last week. Benjamin reminded that the MIH model discussed at the ad-hoc was not agreed yet by the whole WG.
* Stefano presented 3 scenarios to trigger discussion for L3 requirements.
* Yoshi pointed #1 and #2 are similar. Another scenario was proposed (and numbered as #4): no L3 protocol is used between the MIHF in the terminal and the MIHF in the PoA, L2 is used instead, but then from MIHF in PoA and MIHF in the network a L3 solution is used. UE----L2--->sPoa---L3--->MIS
* Ajoy mentioned another scenario where UE----L3--->sPoa----L3.---->cPoa or UE----L3--->sPoa----L3---->MIH, Stefano replied it is a subset of the current third scenario (but it will be described explicitly)
* Ajay indicated that we still need to clarify to IETF what we mean exactly by PoA, since it impacts this discussion and may be confusing to IETF. Stefano suggested that a way forward is to present to IETF example of PoAs, without necessarily providing a comprehensive and exhaustive definition.
* Stefano indicates we need to consider two kinds of MIS interface since requirements may be different and should be at first looked separately (we can merge requirements if they are the same)
* i) MIHF in UE to MIHF in network
* ii) MIHF in network to MIHF in network
* Qiaobing mentioned discovery should not be part of transport requirements. It was emphasized that the discussion is not just for plain transport (in IETF sense of the term) but "L3 and above" requirements for MIIS. It was agreed this needs ot be made very clear in slideset.
* Also, Qiaobing suggested that we separate the requirements that relate only to transport from those that relate to architectural/protocol aspects
* Hong-Yon asked why we are considering also protocol requirements. Stefano indicated we should try to list all the requirements we can come up with, then choose which one we think are relevant for the discussion in IETF.
* Stefano will send out new slideset for discussion on mailing list.
* It was agreed to send contributions to requirements at least 4 (four) hours before the next tele-conference so that the input can be consolidated
* WG is encouraged to discuss and send scenarios and L3 requirements by next conf meeting on Thursday 9 PM EST.