leedesmond’s blog

To reduce the number of packets traversing the data network for VoIP call setup (H.225) and device capabilities negotiation (H.245), the more efficient H.323 Fast Connect option can be deployed instead.

Reference:
H.323 Specification (Cisco eLearning)

Technorati tags: VoIP, Unified Communications

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The H.225 and H.245 are protocols from the H.323 family that deal specifically with VoIP calls. In a H.323 gateway-to-gateway call, several network packet exchanges must occur. H.225 ’s job is to take care of setting up the call (or “call setup”). This is followed by H.245 negotiating gateway capabilities (such as supported CODEC) and performing call control of the end-points. Once the connection is established, the Real Time Protocol (RTP)* is responsible for streaming the audio payload directly between the gateways.

When one or more gatekeepers (GK) are present, a H.323 end-point or gateway must first request (ARQ message) and be granted** permission (ACF message) from the former. Only then can it initiate the call setup process as previously described to actually place the call. Using a gatekeeper topology, H.323 calls can easily scale- out and -up to improve both availability and redundancy. To communicate with one another (GW to GK, GK to GK), gatekeepers and gateways make use of the Registration, Admission and Status (RAS) channel setup as part of a call by the H.225 protocol.

* RTP Control Protocol = companion media control/monitoring protocol over UDP for QoS e.g. delay, jitter, packet lost
** or denied permission (ARJ = Admission Reject)

ARQ = Admission Request
ACF = Admission Confirm

Technorati tags: VoIP, Unified Communications

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Run x64 guest operating systems on x86 physical host? Support for VMware .vmdk and Microsoft Virtual PC/Virtual Server/Hyper-V .vhd file format and snapshots? Intel VT-x and AMD-V hardware virtualization on Mac OS X hosts? OpenGL 3-D acceleration?

These exciting features can be yours in the form of a free alternative host-based virtualization environment call VirtualBox Open Source Edition (OSE). Enterprise features such as iSCSI Initiator, USB support, serial ATA and gigabit ethernet controller are available separately in the closed-source, full VirtualBox edition (more here).

See also:  blogs.sun.com December 26th, 2008 News

Technorati tags: Virtualization

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The holiday season should be quite fun indulging in the just released CTP3 for the upcoming Windows PowerShell v2 (download). PowerShell ISE* with a graphical debugger and context sensitive F1 help, extensible API, a bunch of new cmdlets (over 60), new WS-Man PS provider, enhanced performance, implicit remoting (separate download of WinRM 2.0 CTP3 required**), new parameters to existing cmdlets, “advanced functions”, etc. are highlights of just some of the new exciting features.

Windows PowerShell 1.0 scripts and cmdlets are backward compatible in v2 except if they conflict with updated keywords or cmdlets.

Make sure that you consult the release notes and installation “about” topics to learn more. This is still a pre-release version and deployment in a production environment is AYOR. As usual, you are encouraged to post your comments and feedback (here, here or here).

* graphical POSH host
** supported only in Vista SP1 and Windows Server 2008

Technorati tags: PowerShell

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KB957465 is both a cumulative update and hotfix rollup pack (updates build to 2.0.6362.111). It supersedes all previously released updates and fixes issues described in KB960423 and KB960424. To interoperate with Office Communicator 2007 R2, this hotfix rollup package for Microsoft Office Communicator 2007 is the minimum required.

For Communicator 2005, three specific issues are addressed with KB949280 and can only be applied if KB950614 is already present. This new hotfix replaces KB945573.

Technorati tags: LCS/OCS, OCS 2007

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That is what sources here and here seem to suggest, although no official announcement from the product team, blogs or Microsoft channels has yet been heard. The most recent official news around OCS 2007 R2 can be found here (VoiceCon tradeshow in Amsterdam/NL 14 Oct 2008).

Update:
Register for the official Office Communications Server 2007 R2 virtual launch event here (scheduled for Tue 3 Feb 2009 with no agenda or program schedule/time specified)

Technorati tags: LCS/OCS, OCS 2007, Unified Communications, VoIP

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Talk is cheap with a variety of VoIP choices today* …

… but a potentially huge nightmare for corporates to standardize, secure, interoperate, communicate and collaborate effectively.

* signboard seen at a Internet café. How many can you recognize?

Technorati tags: Unified Communications, VoIP

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Understanding IPv6, Second Edition
by Joseph Davies

Writing Secure Code for Windows Vista
By Michael Howard and David LeBlanc

Programming Microsoft LINQ*
by Paolo Pialorsi and Marco Russo

Introducing Microsoft® SilverlightTM 2, Second Edition*
by Laurence Moroney

Programming Microsoft® ASP.NET 3.5*
by Dino Esposito

Understanding Microsoft Virtualization Solutions (from the Desktop to the DataCenter)
by Mitch Tulloch with the MS Virtualization Team

Collection 6333: Exploring Microsoft Virtualization Technologies (MS e-Learning)
- Clinic 5935: Introducing Hyper-V in Windows Server 2008
- Clinic 6334: Exploring Microsoft System Center Virtual Machine Manager 2008
- Clinic 6335: Exploring Microsoft Application Virtualization
- Clinic 6336: Exploring Terminal Services in Windows Server 2008

Offer good till Wednesday 24 Dec 2008 for some titles only per Microsoft so grab it while it’s hot.

* sample chapters only

Technorati tags: Community/User Group

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On the heals of Microsoft’s MS08-078 security advisory, Mozilla Foundation has also released security updates - some critical - to a number of products. Vulnerabilities range from cross-site scripting attack and Firefox browser engine crash that could lead to remote code execution. Since products such as Thunderbird share the Firefox Gecko browser engine, it is important to update affected products like this as well. The built-in auto-update feature should prompt you to download the latest versions of Firefox 3.0.5, Firefox 2.0.0.19, Thunderbird 2.0.0.19 (.18?) or SeaMonkey 1.1.14. Otherwise, you can always manually obtain them at source.

References:
Security Advisories for Firefox 3.0, Mozilla Foundation Security Advisory 2008-60

Technorati tags: Security

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… a large European based airline in economy class (A340-300)

- that charges really high fees for flight ticket
(surcharges like expensive service and fuel charges even though oil prices have significantly dropped and you are the one doing all the work booking online)

- serves unbelievably small portions for main meals* in all long-haul flights regardless of destinations
(notice the pathetic size of the special made tapered edged utensil / dish container = about 2 x mini salad bowls shown)

- promised on certain flights but still offers no personal interactive entertainment system on board (where others have this as standard for years, many at the second or third generation now); just plain old overhead color-faded CRT monitors and some LCD screens

- no fruits or snacks between meal times (passengers were asked to return to their seats as the airline even ran out of whatever left overs there were, such as pieces of bread)

In sharp contrast, most Asian based airlines offer much, much more with excellent services at extremely competitive prices. Good examples to consider are Singapore Airlines and Emirates. It may just be worth the effort to make the change as you (still) have a choice to decide where your hard-earned money goes! Costly or pricey items ! (not) always = quality or service.

How are your own personal experiences like?

* breakfast, lunch and dinner

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