Transcript SIPREC Recording Metadata (draft-ietf-siprec-metadata-07) August 2nd 2012 IETF 84 meeting Authors: Ram Mohan R, R Parthasarathi, Paul Kyzivat.

SIPREC
Recording Metadata
(draft-ietf-siprec-metadata-07)
August 2nd 2012
IETF 84 meeting
Authors: Ram Mohan R, R Parthasarathi, Paul Kyzivat
1
Agenda
Changes in draft-ietf-siprec-metadata-07 from
last version.
Discuss Open & closed items in Metadata
Next Steps
2
Changes from Previous version
 The new version of draft has following changes:
–
–
–
–
Incorporated start/stop times for CS
Edits to CSRSassociation and ParticipantCSAssociation
Minor NITS received as comments in previous version
Changed “id” attribute into XML element specific id like session “id”
attribute as session_id.
– Modified the examples to reflect the change in schema
3
Metadata Model
Recording Session(RS)
1..*
0..*
1..*
0..*
Communication
Session(CS)
Group
0..1
1..*
Communication Session(CS)
1.. *
0..*
1.. *
0..*
receives
0.. *
0.. *
Participant
1.. * 0..*
sends
ParticipantCS
Association
Media
Stream
ParticipantStream
Association
4
Metadata Model: Media Stream
OpenItem: BT usecase
Participant
0.. *
1.. *
receives
sends
0..*
0..*
Media Stream
CS
1..* 0..*
•Media Stream
Reference
• Content-type
 Media stream shall
associate with multiple CS
and it shall be mixed
stream. But participant who
is contributing at the
specific time has to be
identified by RTP/RTCP
mechanism.
5
Metadata Model: Media Stream
what we really have
Issues
Participant
0.. *
1.. *
receives
sends
0..*
CS
1..* 0..*
0..*
???
 Implicit and unnamed
element for the stream
itself, with no attributes.
Media Stream
•Media Stream
Reference (label)
• Content-type
•Associate-time
•Dissociate-time
6
Metadata : Multiple CS into single
stream_id usage
<stream
stream_id="Axzg12XHdhjelfjhdldjf;34jn78==“
session_id="zzlafnvvjlCHllaHF6mn8kkSS==">
<label>99</label>
</stream>
<stream
stream_id="Axzg12XHdhjelfjhdldjf;34jn78=="
session_id=" zSfPoSvdSDCmU3A3TRDxAw==">
<label>99</label>
</stream>
 This is current proposal for
representing multiple CSs
for same stream:
 <stream> has two keys, so it
is effectively an association
class.
 Multiple instances with
same stream_id
 <send> and <recv>
reference only the
stream_id. There is no
element with that single
key.
7
Metadata Model: Media Stream
Alternative Representation
Participant
0.. *
1.. *
receives
sends
0..*
0..*
Media Stream
CS
1..* 0..*
•Media Stream
Reference
• Content-type
•Associate-time
•Dissociate-time
 Stream is identified by an
unique id within the XML
document
 The association to the CS
can be represented by an
attribute (non-key) in the
XML element.
 But this then requires a
different way to represent
the BT Use case – multiple
CS media streams recorded
as a single mix.
8
Metadata : Multiple CS into single
stream_id usage - Alternative
<stream
stream_id="Axzg12XHdhjelfjhdldjf;34jn78==“
session_id="zzlafnvvjlCHllaHF6mn8kkSS==">
<label>99</label>
</stream>
<stream
stream_id=”Byzh12XHdhjelfjhdldjf;34jn99=="
session_id=" zSfPoSvdSDCmU3A3TRDxAw==">
<label>99</label>
</stream>
 Two distinct instances of
<stream>, with unique ids.
 The mix is indicated by both
of these instances
referencing the same label,
and hence the same SDP mline.
 This allows two ways of
accomplishing the mix:
• A single RTPstream,
one SSRC
• Separate RTP stream for
each CS media session.
9
Metadata: Duplicate stream
Open Items:
Participant
0.. *
1.. *
receives
sends
0..*
0..*
Media Stream
CS
1..* 0..*
 Duplicate stream shall be
represented in SDP itself as
shown in draft-begenavtcore-rtp-duplication-01 ?
•Media Stream
Reference
• Content-type
10
Metadata Format: Participant
<participant
participant_id="srfBElmCRp2QB23b7Mpk0w=="
session_id="hVpd7YQgRW2nD22h7q60JQ==">
<name ID=sip:[email protected]> <name
xml:lang="it">Bob R</name> </nameID>
</participant>
Closed Items:
 Removing session_id
attribute from Participant
XML element to align the
XML schema with model.
Any objection?
11
Metadata Model: CSRS association
Closed Items:
 Adding CSRS association in
the model figure.
Recording Session(RS)
CSRS
Association
1..*
0..*
Communication Session(CS)
12
Metadata Format: Stream
<xs:element name="csrc" type='xs:string'
minOccurs='0' maxOccurs='1'/>
Open Items:
 Removing of CSRC attribute
from stream XML element
to align the XML schema
with model.
13
Metadata Format: URN UUID
i1Pz3to5hGk8fuXl+PbwCw==
Open Items:
 Removing the fixed padding
“==“ in base64 form of URN
UUID?
14
Next steps
Update draft based on the current closure
Add more metadata examples
Publish next version (08) and ask for WGLC
15