Sunday, 2 August 2009

OCS R2 Dial In Conferencing (July Update)

Dial In Conferencing was a feature added in OCS R2 and has been modified since the initial release by the Patches released in April and July.

The purpose of this post is to cover off the changes in the July Patch.

The first change is to the Announcements made during the login phase. “Authenticated User” has been replaced for “Leader” and a Leader is now required to login to conferences protected by a PIN.

Previously if a conference was protected by a PIN the Leader or any Authenticate users did not need to login, this has now changed.

It should be noted that while the prompt says Leader, anyone who has an Extension and PIN on the OCS System can login. Microsoft have purely just changed Authenticated to Leader.

The main thing I wanted to comment on though is that a user can now enter their Extension rather than their full DDI to login as an authenticated user.

So if my Extension is 1234 and my DDI is +44201231234. I can now enter 1234 or 44201231234, being able to enter the Extension does make life a bit easier.

So now that I can save a second or two when logging into conference calls I became interested in how OCS or more specifically the Conference Attendant translates 1234 to +44201231234 in order to look up my User in Active Directory and check that my PIN is valid.

In order to translate the Extension number into the E.164 number it uses the Location Profile assigned to the Pool. For many organisation this would not be an issue but for Organisation who assign different Location Profiles to each user, using an Extension would result in failures.

Using multiple Location Profiles are common in situations were Companies are using OCS to replace multiple independent PBXs with overlapping Dial Plans. Something which is made easier in R2 (R1 required Group Policy Settings).

So while for the majority of OCS Users using the Extension may be possible for some organisations it will cause issues. Personally I would prefer to have an option to turn this off and for Voice Prompts to just say enter your Full Phone Number.

I am also unsure how this will work in OCS Deployments that have multiple Pools as I am assuming OCS will use the Location Profile in the Pool that the Conference is Hosted on, which again will create issues were extensions overlap.

The last area of confusion for me is Communicator Web Access (CWA). The July CWA update adds in an Extension field as shown below:

02-08-2009 20-42-47

I am unsure how the Phone Extension is worked out, since it does not appear to come from active directory as for all instances it appears to be calculated as detailed above and Normalisation Rules are one way.

I might get a surprise tomorrow when I login, some overnight process might run and populate the field and get rid of the error.

Or I am missing something in Active Directory, if I do find out there is an AD field I will update the post.


  1. Did you ever find out more information about that CWA message saying your phone extension is not configured?

  2. I have not seen anyone else comment on it. Hoepfully is will be fixed at somepoint.

  3. The field becomes populated if you use the ext structure in your tel URI. So, for example, if your number was +12045551212;ext=1212 the 1212 extension would be listed on the CWA page.

  4. Not the nicest of ways to do it. I think I prefer letting the Location Profile handle it. I just wish there was away to disable that error if people do not want to set the extension in the tel URI.

  5. Seems like that would cause issues if you had two people with numbers such as:


    The extensions are the same but the DID portion of it is not.

  6. Answer to that question can be found here,

    Took a bit longer to write than I thought it would.


  7. I agree on the need to disable the error. I have a normal tel uri as follows:


    why would I add ;ext=6000 to the tel uri to get rid of this error? Also, dialing into the bridge allows me to use the last digits 6000 to dial as my extension anyway yet the error states please use the complete number as your extension. I just loaded the April 2010 CWA Main .196 update and it didn't fix this...stupid stupid stupid!


  8. Hi,

    I noticed another strange issue in that new Dial In conferencing concept.

    If Leader of a conference is not yet logged on, attendant in dial in conferencing always asks for phone number or extention of a leader. At this moment anyone who is assigned phone number or extension and PIN can uthenticate himself, although he is not a leader. But once the Leader authenticates himself, the question for providing extension and PIN no longer appears. It means that after Leader is in th meting (via dial in conferencing or via Live Meeting) noone else is able to authenticate himself vie dial in conferencing. Although other users also have extensions and PIN, they can join the meeting only as anonymous users.

    Is that how it should be designed ?