SfB Broadcast: Ep. 43 Skype for Business Cloud Connector Edition for Hybrid PSTN Summary

This is a SfB Broadcast from Microsoft link to the video is here


The three points i found most interesting

  • Media Bypass – Summer 2017
  • Coexistence – Fall 2017
  • Improved diagnostics – Winter 2017

Lets go.

Bill Verthein, Principal Product Manager

Oliver Chiu – Sr Product Marketing Manager

What Hybrid ??


  • Average PSTN contracts are 5 years durations
  • There are countries where Microsoft don’t have PSTN calling
  • Some people don’t trust Microsoft as a Telco
  • Microsoft may not offer PSTN in some countries full stop
  • Some countries you cant get a PSTN licence

Hybrid allows Microsoft to

Deploy Cloud PBX worldwide

Work with PSTN carriers not against them in some countries

Cloud Connector Edition


CCE set of four customised VMs running SfB components

Two options to deliver Hybrid

  1. Via Cloud Connector Edition
  2. Via an on premises Skype for Business Server deployment

CCE run 4 packaged VMs to provide hybrid connectivity  between PSTN on premises and Cloud PBX where users are homed.

CCE only talks SIP so if you have E1 / T1 / BRI then you need a PSTN gateway / SBC

Cloud Connector available in two ways

1. Download CCE and deploy on your own hardware

2. CCE pre deployed on appliances. Two approved vendors AudioCodes and Sonus. Also includes an SBC as well.

Appliances are tested with Microsoft.



CCE is a direct extension of the SfBO service its not a standalone piece of hardware.

CCE uses AutoUpdate to update itself as SfBO requires so auto updates on the CCE is the carried out when Microsoft require. You have 60 days only to run an older version of CCE.

IT admin can set update windows, set by days /hours. When new update is found and windows is open it will download updates for CCE components. The Update will build the newer version of virtual machines side by side whilst calls are in progress. At a maintenance windows the newer version will swap over. This happens automatically ! Tested N –2

AutoUpdate can be disabled but this MUST be manually updated. You will not be in supported if you dont keep up to date.

Allows Microsoft to push updates to CCE first if required and then update the “Cloud”


CCE requires hardware, is there a hosted offering ?

There is a version of hosting in private cloud

It isnt designed to be multi tenanted or hooked into monitoring systems. If hosted modified VMs then with the next update it will wipe them.

Private cloud would be ok but be careful.


Windows Server 2016 ?

You need Windows Server Datacentre edition to licence the virtual machines. NO restrictions on number of VMs. No User cals required.

CCE is stateless it has no concept of users. All users context is in the cloud. They dont log into the cloud then log into the cloud.


Hybrid Voice options and flows


  • CC Domain Controller – Nothing to do with enterprise AD, its only for CCE.
  • Edge
  • Mediation
  • CMS

IM,Presence, Conferencing, app sharing and peer to peer all go to the cloud (Skype for Business Online)

PSTN calls to and from external numbers will go via Cloud Connector

Media bypass not supported currently be noted above (bypass enabled)

Media bypass is being added to Cloud Connector. With media bypass the medition server tells dave that the client can talk direct to the PSTN gateway. this means all media can stay withing internal ntwork and also should allows CCE to make more calls.

Currently in TAP and being tested, expected end of June 30th. 20 people running it, no bugs found at the moment.

If you have an on premises SfB server deployment you can use this deployment for Hybrid connectivity with Cloud PBX.


OPCH – on premises connected hybrid (Diagram above)


To migrate Hybrid SfB Server to CCE ?

CCE cant coexistenece currently with on premises SfB server deployment

Co existence is coming, Microsoft have a build already.

Its engineering testing and in a week or two come to end to end testing.

Coexistence will come Fall

Should be very popular, its a common question i get asked.

Requirements for coexistience

SfB Server 2015 with CU6 on Federation Edge

CU6 will contain CCE existence

Lync Server 2013 you will need SfB 2015 CU6 Federation Edge. SfB 2015 Edge is approved topology.

No coexistence with Lync Server 2010 or earlier!




Notes coexistence August 2017!

Whats Next ?


  • Media Bypass – Summer 2017
  • Coexistence – Fall 2017
  • Improved diagnostics – Winter 2017

Mid Term – two years

  • reviewing requirements to reduce hardware / software costs














Can one CCE support multiple SIP trunks ?


Will AutoUpdate update my host ?

Yes if it has two, it updates, host, guest OS and may require restart of the host.


Next Webcast will be on Polycom.


*** UPDATE *** Questions posted following the event UPDATE 19/06/2017

Below questions are taken from


What is the YouTube channel we can watch this back on please?
http://aka.ms/sfbcastpast http://aka.ms/sfbcastpast

When do you expect that we can use local PSTN connectivity and numbers with service numbers?
We expect this before the end of this calendar year.*

Is there any plan to add automatic disaster recovery?
We plan to support full DR in the first half of 2018.*

Any improvements planned to make config file easy to edit? right now the TEXT file is error prone. Any error leads to script issues and needs CCE deployment to rerun.
Our CCE Appliance partners AudioCodes and Sonus have done a good job of making configuration a set of logical questions and preventing the chance of most conflicting answers. 

HA/DR capabilities for CCE? can it hit SLA targets?
Yes, CCE has HA/DR capabilities. We do not yet claim full DR capability (see the answer above) for CCE. However, we believe CCE in tandem with Skype for Business Online and Cloud PBX can satisfy our SLA obligations to our customers.  We measure and track this every day and have weekly reviews of our metrics in addition to assign product engineers to 24×7 on call support for customer issues.  
Hybrid PSTN is inherently harder to track down issues and understand root causes of issues because quality often depends on the quality of the customer’s network as well as change control on their firewalls and network settings. To help improve resolving issues wherever the fault lies, we are currently and will continue to add improved diagnostics to help resolve problems to eliminate failures outside SFBO or CCE.

Will new tenant dial be supported on CCE?
Yes tenant dial plan is fully supported with Hybrid Voice options.

Is there any plan to add CAC capabilities for SfBO?
We do not have plans for CAC over the next 12 months. If this is a priority for you, please let us know.

Is tail end hop-off supported?
We currently do not support tail end hop off (we call that “destination based routing. This is planned in 2018.* Microsoft is uniquely positioned to drive this globally as we have the 2nd largest global cloud in the world and we have more global fiber than any single carrier. Today our Skype Consumer product is the #1 international long distance provider in the world.

Can you route calls via different CCE appliances based on user DDI? E.g. London based DDI will break out via London CCE and Edinburgh DDI will break out via Edinburgh CCE?
We are planning improved routing rules coming to CCE toward the end of 2017.*  In the interim many customers do this call destination routing today with an intervening SBC.

Does CCE have the capability to support HA in two different DC?
Some customers have split an HA pool of CCEs across different data centers.  We recommend that each CCE be cross connected to every telco gateway in their site so the result of splitting a site across two DCs is you may have a lot of WAN traffic between data centers and that can impact cost.  When we improve our DR performance later this year you should see less need to split across DCs.

Do the local PSTN gateways have to be AudioCodes/Sonus or can they be existing Cisco gateways?
We support ANY SBC that interops with SFB mediation servers.  This includes Cisco and Avaya SBCs (as well as Acme).  There are a lot of smaller SBC companies that we don’t test with that MAY also work as well. Usually all SBCs have well understood config profiles to interop with SFB20015 Mediation Servers (this is what CCE uses).

For the coexistence topology referenced will only SFB 2015 Federation Edge be required? Is there a requirement to deploy next hop SFB 2015 or next hop can still be Lync Server 2013?
The Federation Edge needs to be SFB2015 CU6 Edge and the next hop needs to be SFB2015 CU6 as well.

When CCE will support Media Bypass?

We are targeting this for mid-year 2017.* TAP has already begun.

What the requirements from the legacy PBX side? What is tried, tested and supported?
CCE will interoperate with any device that works with SFB2015 Mediation Server’s SIP interface. There is a long list of partners that have submitted their equipment and officially certified interop.  Others have their own Skype for Business template for interop that they certify. Many other popular solutions have public discussions on how to configure those links (eg. Cisco’s SBC has well known profiles that interop with SFB2015 Mediation Server).

Can one CCE box support multiple SIP trunks?
Yes, CCE can be connected to several SIP trunks. When our Media Bypass release is available, it will support up to 16 SIP trunks per CCE.

Does Microsoft have plans to deliver the topology of co-existince between SFBS and CCE within a single tenant? For example, a HQ user with SFBS on-prem PSTN breakout and an oversea branch user with CCE for branch PSTN breakout?
Yes, we will have coexistence capabilities between CCE and onPrem SFB coming by end of calendar year, 2017.*

When an online user at the internet external network dials a PSTN call, what is the voice codec you use between the online user client and CCE’s edge? This is a media relay through mediation server…is it SILK codec (in this case, mediation do transcoding) or PSTN G711 codec ?

To edge, we use G.711. In some cases we might initiate different codec. We will update our TechNet documentation shortly with describing the codec negotiation.

If we are using RCC today with a hybrid SFBOenviroment. can we use CCE to replace RCC?
CCE does not support RCC, but it does support SIP interop with legacy PBXs like Cisco and Avaya.  RCC was deprecated for SFB2015 (Call via Work was the recommended alternative) and RCC is not supported in CCE.

What are the Reverse Proxy requirements for meetings

All user with CCE are homed online and receive meeting services from Skype for Business Online. Therefore, there is no need for a local reverse proxy server

Is there any planned capabilities to selectively route traffic to PSTN to A) CCE and B) MSFT PSTN Calling Plans, for a given user? i.e. route traffic to an existing PBX (for coexistence purposes), but route to ‘outside world’ via PSTN Calling Plan.
There will be cloud based routing and dial plans for SFB Online where you can distinguish where to send certain destination phone numbers.

Once media bypass delivers, can users use SILK voice call from SFBO user until PSTN GW?
We are working on documenting codec negotiation and plan to update TechNet with detailed logic soon.

Any ETA for supporting collocating SFB on-premises or Hybrid + CCE
This is solved through coexistence which is coming later in calendar year 2017.*

Can a PSTN -> SfB conversation be elevated to a conference call?
Yes, but the call will transparently escalate to a cloud AVMCU (there is no audio mixer in the CCE).

Does Microsoft have plans to deliver the topology of co-exist SFBS and CCE within single tenant? for example, HQ user use SFBS on-prem PSTN breakout and oversea branch user use CCE for branch PSTN breakout?
When we release Coexistence, you will be able to do this.

When can we expect CCE to work with on premise Lync or SFB server
CCE Coexistence is coming later this calendar year, 2017.*,

What is the expected RTO (Recovery time objective) for DR failover (Hybrid PSTN site policy change)?
Right now, customers must run recovery scripts to reassign users to a different surviving CCE site. Scripts moves approximately 3 users per second. This is expected to improve by early 2018.*

My customer has several Lync 2013 pools and needs to move to the cloud, but need to add CCE in phases. In the new office, can we have a mix of CCE and Lync in the same organization? The goal is to remove all the onpremises servers

Coexistence will allow you to use CCE in parallel to an existing onpremises deployment. Either Lync 2013 OR SFB2015 can coexist but in either case you will need to deploy a SFB2015 CU6 Edge as the Federation Edge (even for Lync 2013). Earlier versions of Lync (or OCS) such as Lync 2010 are not supported for coexistence with any modification. With earlier versions you will need to upgrade to Lync2013/SFB2015 and then configure the topology for coexistence.

Can we use PSTN Conferencing Number to land on on-premise PSTN and join the meeting hosted by users who are enabled on Office 365?
Our Cloud PBX team is currently testing this capability and we will have more to share later. 

How to migrate from Hybrid SFB on-premise to CCE?
Coexistence will be needed.

Will dynamic E911 capabilities be introduced to SFBO at some point in time? And if yes, will that feature support Hybrid PSTN scenarios either with CCE or Cloud PBX with on-premises PSTN connectivity?
Currently, we only have Basic 911. By 1st half of 2018* we will have enhanced call routing capabilities that will allow us to route on location of the user. The accuracy of E911 is highly dependent on what types of location data can feed our routing engine and ultimately the calls need to route to the appropriate carrier of record who has the legal obligation to provide 911 services. Even if we route to the right carrier for a user’s current location the customer still has to have a proper 911 address set up for a given local phone # that would be used to proxy the userâ’s phone number. We can’t send a Chicago phone# to a Dallas PSAP when that Chicago user is at Dallas office. Expect this in 1st half of 2018 as well.*

Can you confirm the license requirements for CCE – WInServ16 terms unlike 2012 indicate that everyone needs a Cal?
We have no current plans to move to WS2016 for the next few years. Our OS needs are generic and we mainly just require HyperV.  Our current WS2012r2 based CCE does NOT require per user licensing.

Will auto-update update my host? Is there any MP coming for CCE?
Not sure what MP is (Media Processor?), but yes AutoUpdate will update all the Operating Systems that need it, VM Guest OS as well as the Host OS.

CCE requires on-premises hardware. Is a hosted version of CCE planned and what’s the timeline?
Well we are currently working on a significantly smaller footprint for Hybrid PSTN. In the interim we understand that some people just can’t have on-premises hardware. For these cases, we can support private cloud deployments of stand-alone CCEs in a Hoster’s Data Center that will VPN back to the customer’s enterprise network.
First some background on why CCE is difficult to host. CCE has very intricate scripts that configure and update the SFB VMs. Most of our engineering effort for CCE has been in building the new script capabilities and evolving the older versions in the field. Because CCE needs to AutoUpdate, any 3rd party Hoster modified scripts for hosting will either fail when the next AutoUpdate does its magic OR you can miss a required update for cloud interop. So there is NO Microsoft supported multitenant version of CCE.
Next, while running CCE in Azure seems like a no brainer, Azure is not optimized for bidirectional media like voice, so there are quality risks. There are additional limitations in the current way network interfaces are handled in Azure. Until the network virtualization and the bidirectional media performance issues are addressed we cannot endorse an Azure version of CCE at present.
From PBX integrations perspective can calls be routed via CCE to users who use PSTN Calling plan and Service Numbers such as Dial-in conferencing. This is to avoid call charges during coexistence phases.
Today SFB Hybrid PSTN (both CCE and on-premises Config Hybrid, aka Split Domain Hybrid PSTN) can coexist with cloud homed users who have Microsoft’s PSTN plans. Hybrid PSTN and our PSTN calling can be arbitrarily assigned to all the online users in a tenant. All the users can call each other and can move between both methods of PSTN. All calls will be VoIP calls without going to PSTN network

*Disclaimer: Any date estimates may be changed substantially prior to final release of the solution.  This only represents the current view of Microsoft Corporation at the date of the blog. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information presented after we publish this blog. Dates are for informational purposes only. Microsoft makes no warranties, expressed, implied, or statutory as to this information in this blog.


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