Tag Archives: Enterprise Voice

#Skype4b: Skype for Business online Voice enhancements


Microsoft unveiled many enhancements and new feature support for Skype for Business online. With the theme of “Move your communication to Skype for Business Online”, Microsoft came up with new Enterprise voice capabilities in Skype for Business online. The following capabilities will be added as a preview in Skype for Business online.

  • Organizational Auto Attendant
  • Call queues

Both the features will make Skype for Business online as a strong contender against Skype for Business on premises. These features will allow call treatments and call queuing features to queue and routing of inbound calls.

PSTN conferencing has been extending to following countries:

Australia, Bosnia and Herzegovina, Costa Rica, Dominican Republic, Egypt, Latvia, Lithuania, Malta, Monaco, Philippines, Qatar, Russia, Serbia, Sri Lanka, Ukraine, Uruguay and Vietnam

However, people can join conferences from 90 countries and 400 cities by using local numbers which belongs to their location. Although, customers can opt for dedicated toll numbers or toll-free numbers in hundreds of cities across the globe via O365 portal.

PSTN calling has been extended to two more countries Spain and France. Therefore now PSTN calling service is generally available in United States, United Kingdom, Puerto Rico, France and Spain.

By the end of this year, administrator will be able to setup regional hosted meetings which will reduce the bandwidth challenges and latency, while it will enable high quality media and comply with legal obligations as well because data will reside in the same datacenter.

There is one more cool feature is coming for conferences which will enhance the meeting experience. Dynamic conferencing Id features will be added for all Skype for Business online meetings which will enhance security and smoother transaction between back to back meetings. Therefore now your meeting will not be interrupted if you extend your meeting for any reason.

#Skype4b: Skype for Business PSTN Calling


PSTN calling is an add-on service to Skype for Business Cloud PBX. If you want to learn more about Skype for Business online voice offerings, please read the entire series here.

PSTN calling feature in Skype for Business online allows users to make calls to and receive calls from people inside and outside the organization. This feature enables administrators to search, acquire and assign the phone numbers to the users in the organization. Users enabled for PSTN calling in Office 365 can make voice calls across all Skype for Business devices including PCs, mobile devices and VOIP phones. Users can also control their calls through mute/unmute, hold/resume, call transfers, and call forwarding features, and if necessary, make emergency calls. It provides two different types of PSTN voice calling plans:

  • PSTN Domestic Calling
  • PSTN Domestic and International Calling

PSTN Domestic Calling: PSTN Domestic Calling allows user to make domestic calls with in the same country or region. User’s license usage location determines what is considered “domestic” for a specific user. Each user gets PSTN calling minutes that consist of both domestic outgoing, and domestic and international inbound calls (originating from anywhere in the world). Following are the PSTN calling minutes for specific locations:

Untied States: 3000 minutes (including Puerto Rico)

United Kingdom: 1200 minutes

PSTN Domestic and International Calling: PSTN Domestic and International Calling allows user to make domestic and international (196 countries) calls. User’s license usage location determines what is considered “domestic” and what is considered “international” for a specific user. Each user gets PSTN calling minutes that consist of both domestic and international outgoing, and domestic and international inbound calls (originating from anywhere in the world). Following are the PSTN calling minutes for specific locations:

Untied States: 3000 domestic minutes (including Puerto Rico) OR 600 international minutes

United Kingdom: 1200 domestic minutes OR 600 international minutes

Country and regions specific monthly minute’s details can be found here.

Courtesy: Microsoft

Skype for Business Cloud Connector Edition: Release 1.4.1


Skype for Business Cloud Connector Edition release 1.4.1 is 3rd release. To learn more about Skype for Business Cloud PBX, Cloud Connector Edition and different releases, click here. Skype for Business Cloud Connector Edition version 1.4.1 was released in August 22, 2016 with the following updates:

  • Customization available in CloudConnector.ini file:
Configuration setting Description
Site Name Site name is required and it should be unique for each site and must match with PSTN site name defined in Office 365.
Hardware Type Type of Hardware can be defined, by default it is set to “Normal” but it can be set to “Minimum” for smaller deployments that can support up to 50 simultaneous calls.
CorpDNSIPAddress “CorpDNSIPAddress” must be configured in .ini file to allow windows update for the base VM image. It will be configured on internal interface of temporary VM and should provide the name resolution to the public names. Otherwise, internet connection will fail because of name resolution and deployment will not finish.
WSUSServer The address of WSUS server can be configured for Microsoft updates if required.
WSUSStatusServer The address of WSUS server can be configured for WSUS status update if required.
EnableReferSupport EnableReferSupporyt parameter is used to define the SIP REFER support, either enabled or disabled on the Trunk configuration to your IP/PBX. By default it is set to “True” otherwise it can be changed to “False”. If you are not sure if your gateway supports REFER, please reference Microsoft Unified Communications Open Interoperability Program for Qualified IP-PBXs Gateways.
ForwardPAI ForwardPAI determines whether PAI (P-Asserted-Identity) field is forwarded from the Mediation Server to the gateways. By default, it is set to “True” but it can changed to “False”
  • New CCE Management service has been added on host server to manage HA Detection/Recover, binary auto-upgrade, and operating system auto-upgrade.
  • There has been 5 new cmdlets introduced and at the same time 3 cmdlets have been deprecated. You can refer to the Cloud Connector cmdlet reference for latest cmdlets. While 2 cmdlets have been updated Install-CcInstance and Uninstall-CcInstance to Install-CcAppliance and Uninstall-CcAppliance.

Skype for Business Cloud Connector Edition: Release 1.3.8


Skype for Business Cloud Connector Edition release 1.3.8 is 2nd release. To learn more about Skype for Business Cloud PBX, Cloud Connector Edition and different releases, click here. Skype for Business Cloud Connector Edition version 1.3.8 was released in May 24, 2016 with the following updates:

  • This version had resolved the issues related to failures of transferring calls to a phone number. If you are facing following challenges then upgrade to latest version of Skype for Business Cloud Connector Edition.
    • Your Office 365 user account is configured to use Cloud PBX.
    • You have an active PSTN call using the Skype for Business client on Windows, where the voice for this call uses Skype for Business Cloud Connector Edition.
    • You start a transfer to another phone number by selecting or entering the phone number from a list of suggested phone numbers on the transfer menu.

In this scenario, the other phone number rings, and you can answer the transferred call, but you hear no audio. Additionally, the client window of the existing active PSTN call shows the following error:

Cannot complete the transfer.

  • This version also take care about unnecessary files after finishing deployment process such as
    • The temporary copies of certificates
    • Exported topology files for the Skype for Business Cloud Connector Edition appliance
  • There was one major improvement as well in terms of DNS
    • Now, you can specify multiple DNS IP addresses, separated by spaces, in the CloudConnector.ini file for “CorpnetDNSIPAddress” and “InternetDNSIPAddress” values.

Courtesy: Microsoft Technet

Skype for Business Cloud Connector Edition Releases/Versions


Skype for Business Cloud Connector Edition is a revolutionary offering from Microsoft to connect on-premises voice infrastructure with Skype for Business online. I wrote a series of articles about Skype for Business Cloud PBX and Cloud Connector Edition and this post will give you a holistic view of all the Cloud Connector Edition current and upcoming releases (versions).

Below are the series of blogposts related to Skype for Business Cloud PBX and Cloud Connector Edition:

Skype for Business Cloud PBX

Skype for Business Cloud Connector

Skype for Business Cloud Connector Components

Skype for Business Cloud Connector Supported Topology

Skype for Business Cloud Connector Infrastructure Requirements Part I

Skype for Business Cloud Connector Infrastructure Requirements Part II

Skype for Business Cloud Connector Edition Public DNS, IP and Certificates requirements

Call flow with Cloud Connector Edition

Now, I am going to cover the different releases of Skype for Business Cloud Connector Edition in the following table.

Product Release Remarks
Skype for Business Cloud Connector Edition 1.3.4 Initial release
1.3.8  Read more
1.4.1  Read more

For the initial release, please read the series of blogposts and for specific release updates read the respective blogposts which covers the changes and enhancement.

#Skype4B: Call via work (Part IV)


This post is the IVth part of the Call via Work series and continuation of part III. In this blogpost, I am going to cover the limitations of Call via Work. However, CvW is a great feature of Skype for Business Server 2015 which can be implemented easily with a limited hardware configuration but it comes with its own limitations.

There are following limitation which comes with CvW:

  • CvW call back number doesn’t work directly. If a user has setup a call forwarding on CvW call back number and someone invites him through that number, in that situation call will fail because the invitation will not reach to the user. To avoid this situation, you should invite the user for meeting by clicking on his name, not by the number.
  • Following things cannot be used by CvW enabled user
    • Team Call
    • Response Group
    • Delegation
  • Following actions can’t be performed by CvW user through SfB:
    • Record a meeting
    • Mute or Unmute the call
    • Hold or Transfer the call
    • Call Parking
  • CvW can’t be used by user to access their PBX voicemail messages.
  • User of CvW can’t perform following things:
    • Add more users to a 2-person call.
    • Can’t escalate voice call to a collaborative meeting which includes other modalities such as video, PowerPoint etc.
  • No support for deskphone pairing or VDI plugin pairing.
  • Enhanced 911 capability and malicious call tracing are not available during Call Via Work calls.
  • If your PBX system does not support REFER with Replaces, the following behavior will happen. While on a Call Via Work call, if the user transfers the ongoing call from the PBX Phone, the call window will not disappear from their Skype for Business window. If the user then closes the call window, the call between the transfer target and the transferee will end.

Courtesry: Microsoft Technet

I hope you enjoyed the entire series of Call via Work. Please write your queries and feedback in the comment section.

Call via Work Part I

Call via Work Part II

Call via Work Part III

#Skype4B: Call via work (Part III)


Part I and Part II of this blog post cover CvW fundamentals and how does it work. Now this part of the blogpost will cover CvW prerequisites and deployment process.

CvW is a cool feature of Skype for Business but it can only be configured in few scenarios. Below are the prerequisites and infrastructure should meet these requirements.

  • Unified Communication Web API (UCWA): Comes default with Skype for Business Server and installed automatically on all Skype for Business Front End Servers.
  • Mediations Server: Should be deployed standalone or part of the Front End server.
  • Direct Inward Dialing (DID): Each user should have DID on the PBX phone system for users who will be enabled for CvW and enabled for enterprise voice in SfB with the corresponding DID.
  • Automatic Configuration: CvW users must have Automatic configuration selected in their Advanced connections settings. The enables the client to discover the UCWA URLs.


  • Call forwarding and Simultaneous ring: CvW users must enable for call forwarding and simultaneous ring.
  • Dial-in and Dial-out conferencing: CvW users must enable for dial-in and dial-out conferencing which enable these users to get into and out of SfB conferences.


  • Delegation, team call, and response group: CvW users should be disabled for delegation, team call and response groups.

Deploy Call via Work: Now, let’s have a look into deployment part of the CvW.

  • Create a global phone number: for your deployment which Skype for Business displays on the PBX caller ID of users who are making Call Via Work calls.
         Set-CsRoutingConfiguration -CallViaWorkCallerId +<PhoneNumber>
  • Create one or more Call Via Work policies:
        New-CsCallViaWorkPolicy [-Identity] <XdsIdentity> [-Tenant <guid>] [-Enabled <bool>] [-UseAdminCallbackNumber <bool>] [-AdminCallbackNumber <string>] [-InMemory] [-Force] [-WhatIf] [-Confirm] [<CommonParameters>]
  • Assign a Call Via Work policy to each user who will be enabled for Call Via Work:
        Grant-CsCallViaWorkPolicy -Identity <UserName> -PolicyName Tag:<PolicyName>

Part IV of this article covers limitation in Call via Work.

#Skype4B: Call via work (Part II)


Part I of this blog post covers introduction of Call via work, differentiate remote call control and describe how does CvW work etc. Part II will cover different scenarios of call via work which takes place.

Outbound routing scenario has been covered in Part I. Now, let me describe inbound scenarios.

Skype for Business Server and PBX can be configured in two different ways for incoming traffic:

  1. Skype first in line
  2. PBX first in line

Case 1: User experience when external PSTN user makes an inbound call:

In this scenario, Skype First offers all the features such as Skype toast, missed call alert and voicemail while PBX first only offers voicemail.

Scenario 1: Skype first in line scenario for inbound PSTN call:

User Experience:

  1. PSTN user makes a call
  2. Skype for Business Server receives call
  3. User A client endpoints is alerted
  4. Since User A is enabled for CvW and Simulring, a ms-SkipRnl header is used to force a call out to user A desk phone

Scenario 2: PBX first in line scenario for inbound PSTN call:

User Experience:

  1. PSTN user makes a call
  2. PBX receives call
  3. Since User A has PBX desk phone, therefore user desk phone rings

Case 2: User experience when internal user makes an inbound call:

In this scenario, Skype for Business user (as a first party) offers all the features such as Skype toast, missed call alert and voicemail while PBX desk phone (as a first party) offers voicemail.

Scenario 1: Skype for business user scenario for inbound PSTN call:

User Experience:

  1. User B makes a call to User A from SfB Client
  2. Skype for Business Server receives call
  3. User A client endpoints is alerted
  4. Since User A is enabled for CvW and Simulring, a ms-SkipRnl header is used to force a call out to user A desk phone

Scenario 2: PBX user scenario for inbound PSTN call:

User Experience:

  1. User B makes a call from PSTN desk phone
  2. PBX receives call
  3. Since User A has PBX desk phone, therefore user desk phone rings

I hope, this post gives you clarification about inbound scenarios of CvW. If you have any comments or queries, please write in comments box. I’ll be happy to hear from you and resolve all your queries.

#Skype4B: Call via work (Part I)


Skype for Business Server 2015 introduced Call via Work (CvW) and replaced remote call control (RCC) which was available in previous versions of Lync server. It enables integration between Skype for Business and your PBX phone system. A SfB user enabled for CvW can initiate a PSTN call from SfB client and leverages PBX phone to have a call with another user within organization or outside the organization.

How is it different from Remote Call Control?

RCC is a replacement of CvW but doesn’t work in same way, you can understand it in this way: RCC required computer-supported telecommunications application (CSTA) gateway to integrate Lync Server with PBX system while CvW uses Unified Communication Web API (UCWA) as the back-to-back user agent (B2BUA) between Skype for Business Server and PBX systems. Therefore, CvW only work in case you have direct SIP between Skype for Business Server and PBX systems.

Call via Work offers the following for PBX phone users:

  • Click-to-call experience form Skype for Business client
  • IM, App and Desktop Sharing, File Transfer
  • One-click meeting join experience

How does it work?

The end user selects another end user in their Skype for Business client, and clicks the phone icon to call him. Or, during an IM conversation, the end user clicks to call another user they are having the session with. The PBX phone of the user who placed the call starts to ring. The caller ID for this phone shows a global phone number which you have set up to show in the caller ID of all users placing Call Via Work calls. This global phone number is not an actual phone number that corresponds to any one person’s phone. Instead, it is a visual signal to let a user know that this is their own outgoing call, and not an incoming call happening at the same time. When you deploy Call Via Work, you should educate those users about this global phone number and what it means. The user who placed the call picks up their PBX phone. Skype for Business then initiates the voice call to the callee. When the callee answers, the voice call begins. If the two users already had an IM session going, it can continue. Courtesy: Microsoft TechNet

Let’s take an outbound call scenario where Users A which is enabled for Call via Work initiates a call from SfB client to external PSTN number.

  1. User A initiates a call from SfB client.
  2. Skype for Business Server places call to user’s PBX phone.
  3. PBX System routes call and user answer that call.
  4. When Sfb server perceives that call has been answered by local user then it initiates a far-end call by using user A DID.
  5. PBX system routes a call out to PSTN with user’s DID.
  6. Far-end calls answers and call is established.

Once call has been initiated, media will directly flow between both the end points.

Let’s take an another outbound call scenario where Users A which is enabled for Call via Work initiates a call from SfB client to User B within same organization. Here, User B is enabled for call via work and Simulring.

  1. User A initiates a call from SfB client.
  2. Skype for Business Server places call to user’s PBX phone.
  3. PBX System routes call and user answer that call.
  4. When Sfb server perceives that call has been answered by local user then it initiates a call to user B.
  5. Since User B is internal user and enabled for call via work and set to simulring their own desk phone, a ms-skipRnl header is used on an outbound call to force another call out to user B desk phone
  6. User B answers call from either skype client or desk phone and call is established.

Once call has been initiated, media will directly flow between both the end points.

The above examples are simple scenarios but there are many other scenarios which take place when deploy call via work. Rest of the scenarios, I’ll coven in next part of this blog series.

Call flow with Cloud Connector Edition


Cloud Connector Edition is an option for those customers who are new to Microsoft Real Time Communication and directly adopting Skype for Business Online (Office 365) for real time communication. At present to find an organization without any telephony system is almost impossible. When customers are looking for best RTC solution and adopting SfB online, it is crucial for them to leverage existing telephony investment while maintaining seamless user experience across all RTC modalities. Microsoft is committed to provide seamless PSTN calling experience through Cloud Connector Edition to those users who are accessing all the SfB modalities except PSTN calling form SfB online infrastructure.

Let’s discuss more about PSTN calling. In Skype for Business each conversation is divided into two pieces i.e. signaling and media. When you are using CCE all media traffic for PSTN calling will be managed by CCE and PSTN Gateway while signaling will be managed by CCE and SfB online infrastructure.

Whenever, we talk about telephony communication, it could be either inbound or outbound.

Outbound Calling: If a user place a call from internal network:

  1. Users dial an external PSTN number in E.164 format
  2. SIP traffic routes to Skype for Business online infrastructure
  3. SfB online performs a reverse number lookup for the dialed number
  4. The RNL fails because it is an external number and doesn’t belongs to any SfB user
  5. The call is routed to the Edge component of CCE
  6. If the PSTN routes exist Edge Server relays the traffic through Mediation component of CCE
  7. Mediation component sends the traffic to the PSTN gateway and establish a connection between the user end point and PSTN Gateway through Mediation component for media flow

Inbound Calling: If an internal user receive a call from PSTN network:

  1. PSTN Gateway receives a call from external PSTN number for a SfB online user who is in internal network as of now
  2. Gateway routes the SIP traffic to Mediation component of CCE
  3. Traffic goes out from Mediation component to SfB Online through Edge component of CCE
  4. SfB online performs a reverse number lookup
  5. The RNL passes and SfB online finds that this number belongs to the SfB online user
  6. SIP signaling goes to all the point of presence of that user
  7. Finally, Media traffic will be established between PSTN gateway and Mediation component and between Mediation component and the user end point for media flow

These are the features which are available through CCE as of now.

There are many limitation if you will compare it with Skype for Business on-premises or hybrid. Below are the list of limitations:

  1. No call via work or remote call control
  2. No media bypass
  3. No response group
  4. Active call can’t be transferred to the cell phone which is registered in your Active Directory by picking it from a list of suggested phones in the transfer menu. You can transfer to any other number.
  5. Call between SfB user and PSTN number can’t be escalated as conference call
  6. Users must use full number in E.164 format only
  7. Only specific series of Polycom phones are supported as of now
  8. No integration available with contact centers
  9. Private lines and common area phones are also not supported

I tried to cover most of the stuffs but there is no guarantee if you face any other limitation.