Extending the SIP Reason Header with Warning Codes drafthautakorpireasonheaderforwarnings00'txt

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Extending the SIP Reason Header with Warning
Codesdraft-hautakorpi-reason-header-for-warnings
-00.txt

• Jani.Hautakorpi_at_ericsson.com

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The Main Idea

• New protocol value for SIP Reason header field
• Warning codes from RFC3261.
• Motivation Ability to convey richer information
  about why a SIP request was generated.
• Example

Reason SIP-Warning cause304
text"Media type not available"
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Example Scenario
A
Controller
B
INVITE
200 OK
ACK
INVITE
480 Temp. Unavailable Warning 399
pc2.example.org Low battery
ACK
BYE Reason SIP cause480 text"Request
Terminated" Reason SIP-Warning cause399
text"Low battery"
200 OK
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Way Forward

• One big open issue
• RFC3261 only allows Warning codes that are
  related to the SDP. Should this be the case also
  in the future?
• Comments?