Technical Summary
Overload occurs in Session Initiation Protocol (SIP) networks when
proxies and user agents have insuffient resources to complete the
processing of a request. SIP provides limited support for overload
handling through its 503 response code, which tells an upstream
element that it is overloaded. However, numerous problems have been
identified with this mechanism. This draft summarizes the problems
with the existing 503 mechanism, and provides some requirements for a
solution.
Working Group Summary
The SIPPING WG supports the development and advancement of
this document.
Document Quality
This document defines no new protocol elements. The document has been
thoroughly reviewed by members of the SIPPING WG and members of the design
team working on modeling and simulations for SIP overload.
Personnel
Jon Peterson reviewed this document for the IESG. Mary Barnes in the
document shepherd.
RFC Editor Note
In the Security Considerations, please append the following paragraph:
Any mechanism that improves the behavior of SIP elements under load
will result in more predictable performance in the face of
application-layer denial-of-service attacks.