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PPSP Session@IETF 88 
Plaza C,Tuesday Afternoon Session III, Nov 5, 2013
 
16:10 Agenda bashing (Chairs, 5 minutes)
No comments
 
16:15 Status of the WG (Chairs, 10 minutes)
1)  Peer draft¡GMore review needed, especially on security and encoding perspectives.
2)  Tracker base draft¡GNeed author team to progress the draft faster, more calls are needed.
3¡^Survey draft¡GNeed 2nd WGLC before submitting to IESG.
 
16:25 Peer Protocol (Arno remotely,50 minutes), draft-ietf-ppsp-peer-protocol-08
1)  New revision has addressed all comments from AD review.
2)  Some comments from Roni need to be addressed, e.g. if peer protocol need to define how to do NAT traversal. To be discussed on the list.
3)  Chunk size issue from Yunfei for the efficiency issue.
Arno answered and consensus was achieved.

4)  Chunk addressing issue:Negotiation is better. 

Lingli: in the latest version, the part for online translation between communicating peers using different chunk addressing schemes are removed. Why?

A: It is too complicated and not necessary.

 
17:15 Tracker Protocol (Rui remotely, 50 minutes), draft-ietf-ppsp-base-tracker-protocol-02  
1)  In the draft, still XML format in main body. Need to move XML example to appendix with more references.

Yunfei: The new version doesn¡¦t reflect the consensus made in the last meeting, which is to move the encoding issues to the appendix while keep the main body to just define messages. Currently the messages are still text based. Is there any consideration on the situation where different encodings are used? E.g., some peers use text encoding while others use binary.

Lingli: There is different understanding between Rui and the other co-authors. By binary encoding, Rui thinks it¡¦s the binary encoding of the XML, while others think it¡¦s the binary encoding of the tracker protocol. There are standards from ISO for binary encoding of XML, which is EXI.

Yunfei: But EXI can¡¦t do the translation between binary encoding of the messages to XML of the messages.

Lingli: Websocket has similar mechanisms to do this kind of translation. We can reference it. I can help with the new version.
 
18:05 Efficient Chunk Availability Compression (Lingli,20 minutes), draft-deng-ppsp-bfbitmap-03
Arno: in reality, streaming downloading happens sequentially, hence scope-based schemes works well.
A: in VoD cases, user behavior can interrupt the sequential viewing pattern. And even in live streaming case, because the concurrently peer-to-peer downloading pattern, out-of-order chunk transmission is inevitable.
Dave: what is the objective of introducing BF scheme?
A: the motive is elaborated in the last meeting¡¦s presentation. There is an comparison of the worst case performance of different bitmap compression schemes in terms of various bitmap relevant operations in PPSP.
Arno: in peer protocol, peers don¡¦t share bitmaps, only chunk ranges updates are exchanged. Peer protocol doesn¡¦t need bitmap compression.
A: ranges or updates are special forms of compression. BF scheme can be introduced into peer protocol as a new chunk addressing method.
 
open issue 1:looks like the proposed option is better no need to translation
Open issue 2:looks like it is helpful to include content scope into requests, but not to the responses.
No adoption at the moment. Need more mailing list discussion and offline with the tracker protocol author.
 
Rachel: in extended tracker protocol, the content scope information is already incorporated in the requests. But if we incorporate the same information into the responses, it would be duplicated with the subsequent peer information handshaking.
Ning: Would it be possible to increase neighborhood establishment by always including SEEDER peers in response?
A: I think it make sense to do so to ensure FIND always hit, as long as the specific content range in need is incorporated in corresponding requests.
 
18:25 Conclusion and next step (Chairs, 10 minutes)
Peer draft needs more review. Tracker base draft needs call between co-authors to progress the draft faster. 2nd WGLC on survey draft starts soon.
 
18:35 End
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