Subject: [sipcore] Call for Consensus: INFO Specification and Congestion

From: Adam Roach <[email-masked]>
Date: Fri, 30 Apr 2010 16:59:07 -0500

[as chair]

During IESG review of the INFO specification, several members expressed 
concerns about the congestion properties of INFO. The draft authors and 
IESG worked together to craft text that satisfies these concerns.

Since the resulting text contains normative language, we are bringing 
the proposal to the SIPCORE working group for a 2-week consensus call. 
Please comment on the following proposed text before Friday, May 14th. 
If you agree with the proposal, please send a short response indicating 
that fact.

"10.9.  Rate and size of INFO Requests

     "INFO messages differ from many other sorts of SIP messages in that
      they carry application information, and the size and rate of the
      INFO message is directly determined by the application. This can
      cause application information traffic to interfere with other traffic
      on that infrastructure, or to self-interfere when data rates become
      too high.

     "A designer of an INFO package, and the application that uses it,
      need to consider the impact that the size and the rate of the INFO
      messages have on the network and on other traffic, since it normally
      cannot be ensured that INFO messages will be carried over a
      congestion-controlled transport protocol end-to-end. Even if an
      INFO message is sent over a such a transport protocol, a downstream
      SIP entity might forward the message over a transport protocol that
      does not provide congestion control.

     "Therefore, an application SHOULD generally have at most one 
outstanding INFO message.
      The guidelines in RFC3261 Section 18 MUST be followed for sending 
and receiving INFO
      requests and responses, such as the guideline to not exceed messages
      sizes of 1300 bytes when the path MTU is unknown. RFC5405 provides
      additional guidelines for applications using the User Datagram
      Protocol (UDP) that may be useful background reading."

Thanks.

/a

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From: Peter Saint-Andre <[email-masked]>
Date: Fri, 30 Apr 2010 22:45:33 -0600

>      Protocol (UDP) that may be useful background reading."

Seems good to me.

Peter

-- 
Peter Saint-Andre
https://stpeter.im/