Dear all, >Kaplan, Michael A wrote:
Sure - I'm referring to mechanisms for the server
to advertise to upstream neighbors to reduce request rates. This could include methods
that appear > in RFC 6357 (e.g. rate-limits, window-based control, loss-rate
enforcement). I suppose the try-again-after method would be of interest as well.
IETF RFC 6357 "Design Considerations for Session Initiation Protocol (SIP) Overload
Control"
Can be found in the following link.
http://tools.ietf.org/rfc/rfc6357.txt Please note that mechanisms for the server to
advertise to upstream neighbors to reduce request rates must modify SIP header. This is
called "Explicit Overload Control Feedback" in RFC6357. Unfortunately Changing
the SIP header requires a time-consuming standardization process, because all the SIP
servers from different service providers in different countries have to implement new SIP
with new headers. >Kaplan, Michael A wrote:
Some of the other overload control mechanisms described
in the RFC (e.g. window based control and loss based control) would also be of interest to
me. Not sure if public implementations exist or if they are restricted to research
implementations. Yes. "Explicit Overload Control Feedback" proposed by RFC6357
are restricted to research implementations. Public implementations require cooperation
from all the service providers of SIP. However, implicit overload control does not require
any modification of SIP header and time-consuming standardization process. Any SIP server
can implement implicit overload control. >Alex Balashov wrote:
You can always construct such a reply yourself, and append headers to it.Yes. But
appending headerers requires RFC standardization process and cooperation from all the
service providers of SIP at different countries all over the world.
From FRC 6357, "The main difference between
explicit and implicit overload control is the way overload is signaled from a SIP server
that is reaching overload condition to its upstream neighbors. ...... Implicit overload
control uses the absence of responses and packet loss as an indication of overload.
"The Central Weather Bureau of Taiwan has implemented implicit SIP overload control
algorithm in their early earthquake warning system with SIP, as shown by the paper
"An Efficient
Earthquake Early Warning Message Delivery Algorithm Using an in
Time
Control-Theoretic Approach" in the following link.
http://www.springerlink.com/content/b6252x2k613rv211/?MUD=MP We have implemented three
different types of implicit SIP overload control algorithms using OPNET simulator
(
http://www.opnet.com/). Our OPNET codes are available for non-commerical use or
open-source project upon request. Please note that implicit SIP overload control
algorithms only rely on the feekback of "200 OK" messages, therefore, they do
not require any modification on SIP header or RFC standardization process. We have
published an exhaustic literature survey on explicit and implicit SIP overload control up
to the related publications until March 2011, because the submission deadline of book
chapter was March 2011. The original draft of our book chapter "A Comparative Study
of SIP Overload Control Algorithms" is available free of charge for non-commerical
use or open-source project upon request.
http://www.igi-global.com/chapter/comparative-study-sip-overload-control/67… If any
software engineers want to implement implicit SIP overload control in either Kamailio or
OpenSIPs, I can cooperate with them for software implementation. Currently I am a software
engineer for cloud web service.
http://www.inbaytech.com/products.html Best regards, Yang
From: mkaplan(a)appcomsci.com
To: sr-users(a)lists.sip-router.org
Date: Thu, 26 Jul 2012 15:37:40 +0000
Subject: Re: [SR-Users] Overload Control
Thanks, this is very much what I was looking for. It appears the ratelimit/piplimit
modules offer some degree of overload control through queue drops and invite rejections
based on a server's local cpu load. Some of the other overload control mechanisms
described in the RFC (e.g. window based control and loss based control) would also be of
interest to me. Not sure if public implementations exist or if they are restricted to
research implementations. Thanks for the pointer to ratelimit nevertheless.
-----Original Message-----
From: sr-users-bounces(a)lists.sip-router.org
[mailto:sr-users-bounces@lists.sip-router.org] On Behalf Of Alex Balashov
Sent: Wednesday, July 25, 2012 2:39 PM
To: sr-users(a)lists.sip-router.org
Subject: Re: [SR-Users] Overload Control
But also, check out this module:
http://www.kamailio.org/docs/modules/3.3.x/modules/pipelimit.html
On 07/25/2012 02:33 PM, Kaplan, Michael A wrote:
Sure - I'm referring to mechanisms for the
server to advertise to upstream neighbors to reduce request rates. This could include
methods that appear in RFC 6357 (e.g. rate-limits, window-based control, loss-rate
enforcement). I suppose the try-again-after method would be of interest as well.
-----Original Message-----
From: sr-users-bounces(a)lists.sip-router.org
[mailto:sr-users-bounces@lists.sip-router.org] On Behalf Of Alex
Balashov
Sent: Wednesday, July 25, 2012 2:29 PM
To: sr-users(a)lists.sip-router.org
Subject: Re: [SR-Users] Overload Control
Can you elaborate as to what you mean by that term, "overload control"?
On 07/25/2012 01:49 PM, Kaplan, Michael A wrote:
Folks,
I'm trying to figure out if either Kamailio or OpenSIPs provides the
various overload control algorithms recommended in the IETF or
elsewhere. I haven't found documentation to this effect. Has anyone
looked into this or used such techniques?
Thanks,
Mike
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--
Alex Balashov - Principal
Evariste Systems LLC
235 E Ponce de Leon Ave
Suite 106
Decatur, GA 30030
Tel: +1-678-954-0670
Fax: +1-404-961-1892
Web:
http://www.evaristesys.com/,
http://www.alexbalashov.com/
_______________________________________________
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_______________________________________________
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--
Alex Balashov - Principal
Evariste Systems LLC
235 E Ponce de Leon Ave
Suite 106
Decatur, GA 30030
Tel: +1-678-954-0670
Fax: +1-404-961-1892
Web:
http://www.evaristesys.com/,
http://www.alexbalashov.com/
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