CLUE Information Signaling CriteriaChrister Holmberg

CLUE InterimStockholm

June 7-8th, 2012

PURPOSE

• Define signaling criteria, in order to determine what transport mechanims is most suitable for transporting CLUE related information*.

– * We need to make sure we have a common understanding about what information we are talking about.

– Non-CLUE specific information will be transported using existing mechanisms (SIP, SDP).

CRITERIA PROPOSALS (1/2)• Whether signaling intermediaries (e.g. SBGs) need to have access to

the information• The expected size of the information to be sent• The expected frequency of the information to be sent• Whether the information is sent during session establishment, mid-

session and/or session termination.• Whether the transport of the information is delay sensitive• Whether the information is sent as a notification, or whether some

kind of response is needed• Whether the information needs to be delivered reliably (either

using a reliable transport mechanism, and/or some kind of higher-level acknowledgement)

• Whether the information is needed by a non-CLUE entity in order to participate in a CLUE conference

CRITERIA PROPOSALS (2/2)• Whether the CLUE information and the media description (SDP) need to be in the same

message.• Whether the CLUE information and the media description (SDP) need to use the same

transport path.• Whether the CLUE information is using one transport (e.g. encoding group and MC are

using the same transport / message)• When one says transport, I think of the question of TCP v. UDP v. SCTP?• Is it bundled into SDP or some other package/MIME type?• Is it carried by SIP and thus have the same route set, or does it use some other

signal type with its own route set?• Separately, assuming SIP, does it use INVITES or some other message type to

carry? must the exchange be coincident with:• - SDP media capability discovery (SDP and CLUE exchanges are independent• and in stages)• - SIP session establishment (could CLUE be setup up before or after the SIP

session). (determine endpoint patterns and select media type later, i.e. pre-configured with/without SDP)