Optimising Polycom VVX background images

If you go looking for the details of the wallpaper or background image sizes for the VVX family of phones you might fall into the same trap I did.

You might have seen this table in the documentation:

Phone model Optimal background image size (in pixels)
VVX 300 and 310 208 x 104 pixels
VVX 400 and 410 320 x 240 pixels
VVX 500 320 x 240 pixels
VVX 600 480 x 272 pixels
VVX 1500 800 x 480 pixels

What isn’t immediately apparent is that this is the FULL screen size, not the USEABLE size. Place a logo too close to the top or bottom and it will be cut off by the “title bar” with the time display and line details at the top, or the softkeys at the bottom.

It also became clear in the process of testing this that despite the 400- and 500-series having the same absolute size, their useable size differ slightly, potentially requiring a different background image for each.

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Lync 2013 / SfB 2015 Client Update – August 2018

Coming not a fortnight after our last update to the client, this one reeks of a “whoops” – and yes it does look like it could fix some amusing/embarrassing issues. The Office 2013-based client jumps 10 builds to 15.0.5059.1000 courtesy of Kb4032250.

What’s Fixed

  • Kb4346579 User’s display name that has special characters is shown with an emoticon in Skype for Business
  • Kb4346578 Can’t input messages until clicking participants list after taking control in screen sharing in Skype for Business 2015 (Lync 2013)
  • Kb4346577 The display name with an ampersand (&) is incorrectly shown in IM conversation window in Skype for Business 2015 (Lync 2013)

What’s New / Changed

Nothing documented.

Known Issues

Nothing documented.

Continue reading ‘Lync 2013 / SfB 2015 Client Update – August 2018’ »


If you click the Sonus category here you’ll quickly notice that I’ve written about the Sonus/Ribbon REST interface on and off for years now, as it’s such a handy way of peeking and poking into the SBC without interacting with the browser.

And so it came to pass last week that when presented with a challenge, I’ve again resorted to REST and PowerShell to deliver the fix.

The challenge – refresh the AD Cache

My customer is planning on migrating a couple of thousand users to Skype for Business quite gradually, and for that we’ve proposed the fairly standard upstream model, with the SBC doing AD lookups to determine if a user is enabled for SfB and thus decide where to send the call. If you’re not familiar with it I drew a picture and added an explanation at the top of this post back in 2014.

The catch is that the SBC’s minimum refresh period is an hour, and the customer doesn’t want to be potentially waiting that long for it to kick in after a user’s been migrated. They’re also big users of automation, and so logging into the SBC to clear the cache by hand isn’t really an option.

The fix

Thankfully Sonus added the option to clear the cache to their REST interface, and it didn’t take me a lot of effort to “save-as” a script I’m working on (more on that soon) to come up with “Update-RibbonADCache.ps1”.

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Lync 2013 / SfB 2015 Client Update – July 2018

Having recently hopped to the identity-challenged 15.0.5041.1000, this month we jump to the more self-assured 15.0.5049.1000 courtesy of Kb4022225.

What’s Fixed

  • Kb 4340831 Unread messages of a reopened chat room are indicated incorrectly when restarting Skype for Business 2015 (Lync 2013)
  • Kb 4340830 Rate My Call privacy statement incorrectly redirects to Lync 2010 privacy statement
  • Kb 4340829 You’re prompted for Exchange credentials after switching network in a Skype for Business hybrid environment

What’s New / Changed

Nothing documented.

Known Issues

Nothing documented.

Continue reading ‘Lync 2013 / SfB 2015 Client Update – July 2018’ »

Recover Ribbon SBC AD Password

The Sonus/Ribbon Enterprise family of SBCs has a great feature where it can use your Active Directory as both a means to authenticate logins, and also to dynamically make changes to your call routing.

It does this by using a service account to authenticate to AD and query the relevant attributes or group membership, depending on which of the above features is involved.

Whilst the password to this account is saved in the backup files and encrypted, I recently found that if you possess a REST login for the SBC you can use that to recover the password.

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Lync 2013 Server Update – July 2018

A full year between updates, this July update – to be Lync’s last – takes the server to 5.0.8308.1001 from last July’s 5.0.8308.992. This time ’round 7 components receive an update.

What’s Fixed?

  • Kb 4090984 Can’t receive notification email when a team-call group member answers your work calls
  • Kb 4090977 Loss of static meetings in Microsoft Lync Server 2013
  • Kb 4339732 Add a header to HTTP response over SIP TLS channel for HSTS compliance in Lync Server 2013
  • Kb 4090981 A deadlock was found in RtcSrv.exe that can cause Lync Server 2013 Front-end servers to stop listening for requests
  • Kb 4343061 Event ID 1000 (0xc0000005) and the RtcSrv.exe of the SBA/SBS crashes after the startup in the Lync Server 2013
  • Kb 4102001 Event ID 32002 and 32007 when RGS crashes with the “System.Reflection.TargetInvocationException” exception during announcement
  • Kb 4339731 Support viewing scheduled meetings in Skype for Business on Mac when AllowExchangeConnectivity is set to false
  • Kb 4339730 UCWA encounters an unhandled exception “System.ArgumentNullException” in Lync Server 2013
  • Kb 4090979 Can’t share desktop in a meeting in Lync Server 2013
  • Kb 4090980 Fix the startup to initialize McuInfra components only after ASMCU is completely ready to take new requests in Lync Server 2013

Continue reading ‘Lync 2013 Server Update – July 2018’ »

Calls to O365UM bounce back – the call leg was cancelled

My Brisbane-based colleague Glen recently reported an interesting problem he’d encountered with calls to O365 UM going unanswered, and in some cases bouncing back to the Attendant.

In the FE he was seeing these diagnostic messages:

ms-diagnostics : 10049;source="LYNCFE01.contoso.com";reason="The current signaling session took too long to establish the connection, so the call leg was canceled.";component="MediationServer"

He also noticed a pattern: all the calls that failed were being routed to a server(s) in Hong Kong (e.g. HK20C00EDG02.LYNC0C001.LOCAL), where those that succeeded were going elsewhere.

He logged it with O365 Support and they were promptly able to resolve the issue, although they didn’t reveal the root cause.

– G.

Lync 2013 / SfB 2015 Client Update – June 2018

Our May client update took us to 15.0.5031.1000, and now Kb4022170 increments us to 15.0.5041.1000 – but there’s a trick to this one: see “Before/After”.

What’s Fixed

We have just one update this month, but it’s a doozie and surely a Godsend for some of you:

  • Kb4294971 Skype for Business 2016 or Skype for Business 2015 (Lync 2013) crashes in a Citrix-based VDI environment

What’s New / Changed

Nothing documented.

Known Issues

Nothing documented.

Continue reading ‘Lync 2013 / SfB 2015 Client Update – June 2018’ »

Bypass CredSSP to regain RDP access

In my line of work RDP is an essential tool. Take it away and you might as well have cut off one of my arms.

And so it was this morning where after my Windows 10 machine (running the latest 1803 build) applied updates overnight, all my attempts at RDP-ing to systems presented me with this:


An authentication error has occurred.
The function requested is not supported
Remote computer: blah.contoso.com
This could be due to CredSSP encryption oracle remediation.
For more information, see https://go.microsoft.com/fwlink/?linkid=866660

You can read more about it here:

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