Archive for October, 2005

“Managing Client Initiated Connections in the Session Initiation Protocol (SIP)”, C. Jennings, R. Mahy, October 2005, draft-ietf-sip-outbound-01

  • Abstract: Session Initiation Protocol (SIP) allows proxy servers to initiate TCP connections and send asynchronous UDP datagrams to User Agents in order to deliver requests. However, many practical considerations, such as the existence of firewalls and NATs, prevent servers from connecting to User Agents in this way. Even when a proxy server can open a TCP connection to a User Agent, most User Agents lack a certificate suitable to act as a TLS server. This specification defines behaviors for User Agents, registrars and proxy servers that allow requests to be delivered on existing connections established by the User Agent. It also defines keep alive behaviors needed to keep NAT bindings open and specifies the usage of multiple connections for high availability systems.

“Payment for Services in Session Initiation Protocol (SIP)”, C. Jennings, G. Jun, J. Fischl, H. Tschofenig, October 2005, draft-jennings-sipping-pay-03.txt

  • Abstract: Service usage might require some form of compensation and this is also true for many communication systems where an entity receiving a call should be able to charge the caller. This is necessary for allowing fair communication between two communicating parties and is a major strategy for reducing the viability of SPAM. This draft proposes an approach for doing this in SIP using the Security Assertion Markup Language (SAML). It relies on a third party to act as a payment provider and is designed for low value transactions. It does not aim to provide the same capability as other authentication, authorization and accounting systems. This draft is in a fairly early state and has many details that are missing. Earlier versions of this document did not use SAML. This version offers a sketch of what the SAML based solution would look like but still lacks many details that would be needed for an actual implementation.

“Remote Call Control in SIP using the REFER method and the session-oriented dialog package”, R. Mahy, C. Jennings, Oct 2005, draft-mahy-sip-remote-cc-02

  • Abstract: This document describes how to use the SIP REFER method and the dialog package to manipulate conversations, dialogs, and sessions on remote User Agents. Specifically it extents the REFER mechinims to allow the specificate of a response that a UA should send in a dialog. This functionality is most useful for collections of loosely coupled User Agents that wish to present a coordinated user experience. It does not require a Third-Party Call Control controller to be involved in any of the manipulated dialogs.

“Computational Puzzles for SPAM Reduction in SIP”, C. Jennings, October 2005, draft-jennings-sip-hashcash-03

Abstract: One of the techniques used in SPAM prevention and various solutions for denial of service attacks is to force the SIP client requesting a service to perform a calculation that limits the rate and increases the cost of the request. This draft defines a way to allow a UAS to ask the UAC to compute a computationally expensive hash based function and present the result to the UAS. Although the computation is expensive for the UAC to compute, it is cheap for the UAS to verify. The solution also allows for proxies to compute and check the puzzle on behalf of the UAC or UAS.

“The Internet Assigned Number Authority (IANA) tel Uniform Resource Identifier (URI) Parameter Registry”, C. Jennings, October 2005, draft-jennings-iptel-tel-reg-00

  • Abstract: This document creates an Internet Assigned Number Authority (IANA) registry for the tel Uniform Resource Identifier (URI) parameters, and their values. It also lists the already existing parameters to be used as initial values for that registry.

So wired magazine has some charity contest thing – One of the top items is pretty cool and valued at $102,000

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However they seem to have an item that is worth even more.

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So webster has priceless defined as

Main Entry: priceless

  1. a : having a value beyond any price : Invaluable b : costly because of rarity or quality : precious
  2. : having worth in terms of other than market value
  3. : delightfully amusing, odd, or absurd

So I guess it could mean any one of these three. But it did get me thinking, if lunch with Brad is priceless, what about lunch with me? Any takers at 50 cents? What if I buy? And what really should lunch with the head system administrator at Cisco be worth?

LA

Nice view of LA Basin

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Continue reading ‘LA’ »

This pilot was fine tuning his next career as as busker. He was pretty good.

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Safe Sex and Family Values in PC Seattle. I was recently in a men’s washroom in SEA airport – right where one might expect a condom vending machine, there was a different sort of vending machine. Photo below…

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Nikki & Jackson

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Continue reading ‘Santa Fe’ »