What is The Skype for Business Cloud Connector.

As you all aware that the Skype for Business Cloud Connector Edition is now available to download and ready to use (Also license free). Before deciding to go ahead and deploy the CCE it’s important to know if the CCE is the best choice for the requirement. To assist with the planning and decision making, the “Plan Your Cloud PBX Solution”  Technet article can be used.

The ultimate purpose of the CCE is to allow clients that having On-Premises PSTN connectivity, to be used with O365 Skype for Business Online. In a nutshell, CCE only have the components that require to to handle the PSTN related workload. The rest is all O365 Skype for Business Online.

The ideal topology for CCE as shown below. It must have 2 Cloud Connectors deployed within DMZ to support High Availability and 2 PSTN Gateways to support PSTN level High Availability.


The users will be registered in O365 and when they make\receive PSTN calls, then only the CCE comes in to play. The peer to Peer Skype for Business calls and conferences will be handled by O365 Skype for Business Online.  CCE can be an ideal solution for greenfield Skype for Business requirements that must support on-premises PSTN or existing Skype for Business Online deployment that require on-premises PSTN.

Looking at the hardware requirement for CCE, it is based on the number of concurrent PSTN calls. If the requirement is to have 500 calls, then the hardware requirement per CCE would be;

  • 64-bit dual processor, six core (12 real cores), 2.50 gigahertz (GHz) or higher
  • 64 gigabytes (GB) ECC RAM
  • Four 600 GB (or better) 10K RPM 128M Cache SAS 6Gbps disks, configured in a RAID 5 configuration
  • Three 1 Gbps RJ45 high throughput network adapters
  • Must be on an isolated host (must not have any other VMs running on this host)

If the requirement is smaller, say 50 calls, then the requirement per CCE would be;

  • Intel i7 4790 quad core with Intel 4600 Graphics (no high end graphics needed)
  • 32 GB DDR3-1600 non ECC
  • 2: 1TB 7200RPM SATA III (6 Gbps) in RAID 0
  • 2: 1 Gbps Ethernet (RJ45)
  • Must be on an isolated host (must not have any other VMs running on this host)

Apart from above, it require;

  • Public IPs\DNS
  • Certificate
  • O365 E5 tenant
  • Firewall configuration to allow required ports and protocols

Even though the CCE might seems to be the ideal solution, there are set of unsupported scenarios that need to be aware of.

CCE does not support Hosting Scenarios.

Delivering hosted Skype for Business services using hosting model, leveraging on CCE is not supported. The 70% traffic must generated within the internal interfaces of CCE. Rest of the 30% can be on external interface. To make the  long story short, Skype for Business services cannot be delivered using Edge services, if the CCE is in use.

If a MPLS is in use between the client site and the data center that host CCE, then it is consider as Private Cloud and it is supported as the traffic that generated is considered as an Internal Traffic.

CCE does not support VMWare Hyper-visor 

This one is going to be a mood changer for most of System Administrators. As of now, CCE is not supported to be deployed on top of VMWare based Hyper-Visor. Only Hper-V is considered as the supported Hyper-Visor platform. This statement will probably change in the future or probably not. But, have to play ball, if you plan to deploy the CCE.

Does not support custom Dial Plans

CCE is not designed to support custom Dial Plans or voice routes. Set of default Dial Plans will get crated based on the Country that mentioned within the .ini file, by the time that CCE was deployed.

Does not support integration between on-premises\Hybrid Skype for Business deployments

This one is a huge let down. CCE cannot coexist with any on-premises or hybrid Skype for Business\ Lync deployments. As mentioned above, CCE can only be deployed in a greenfield environment.

Further to above there are several other known limitations mentioned in Technet.

  • Consultative transfer is not supported.
  • You cannot transfer an active call to your cell phone that 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.
  • Escalation to conference from a call between a PSTN and Skype for Business user is not possible (you can, however, escalate call to conference between two Skype for Business users).
  • Dial plan is not applied on Polycom phones and Skype for Business clients for Android and Windows phone. To dial a number, you must use the full E.164 phone number.

So that was Skype for Business Cloud Connector edition in brief. In detailed information can be found in “Plan for Skype for Business Cloud Connector Edition” Technet article.


Fixing PSTN Music On Hold In Lync When AudioCodes M800 In Use

I was recently informed by one of the clients that i deployed Lync Server 2013, is having issues when calls put on hold. There were 2 issue. The first and major is that, when a call put on hold and retrieved, there’s no audio from caller end. It’s basically one-way audio. And the other issue is that Lync MoH no longer works. Meaning that the caller hears nothing but dead silence.

Given that the PSTN integration was done using a SIP Trunk, i suspected that the provider must have done a change on the trunk which cause the feature to break and cause one-way audio when calls put on hold.

Digging in to the M800 Sys Logs, it seems that when a call put on hold by Lync client, the hold method that Lync use is “Inactive”. Below is the Re-INVITE sent from Lync to M800.

INVITE sip:SD4tl71-vv9pmjn1vl07h0t6in0808cjov84opsv-7@;transport=tls SIP/2.0
FROM: <sip:+61732680000@uctect.com.au;user=phone>;epid=D273FA8C4C;tag=575613f4b
TO: <sip:0451984283@lyngw01.ac-onebox.com;user=phone>;tag=1c1714098312
CALL-ID: b01bc354-481a-4faa-aa5f-e4d14b46c1a7
VIA: SIP/2.0/TLS;branch=z9hG4bKb6b1af81
CONTACT: <sip:UC-FE.ac-onebox.com:5067;transport=Tls;ms-opaque=9928a17d8863ebef>
USER-AGENT: RTCC/ MediationServer
CONTENT-TYPE: application/sdp
o=- 34278 2 IN IP4
c=IN IP4
t=0 0
m=audio 51466 RTP/AVP 8 101
c=IN IP4
a=tcap:1 RTP/SAVP
a=pcfg:1 t=1
a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:Y8xM2t1C3q2zKVguMXQW3TPExRfQX8Dy6YPV+xVK|2^31|2:1
a=crypto:2 AES_CM_128_HMAC_SHA1_80 inline:35UmPksBksSuS3iCs+kjjTw2uruKKYS4ZRufvTYY|2^31
a=rtpmap:8 PCMA/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-16

The “Remote Hold Format” parameter in IP Profile configuration for both Lync and PSTN profiles are set to “Transparent”. Which means that the SBC will not do any modification and it will send the SIP traffic as-is to the PSTN.


As suspected, The M800 uses “inactive” method when call put on hold which pretty much grantee that there won’t be MoH.

SIP/2.0 200 OK
Via: SIP/2.0/UDP;branch=z9hG4bKac1164951996
From: “Support” <sip:0892000000@ipsystems.com.au;user=phone>;tag=1c1718935812;epid=D273FA8C4C
To: <sip:0451980000@ipsystems.com.au;user=phone>;tag=SDu8t2799-1701991312-1456809140654
Call-ID: 1718912646132016131218@
Supported: timer
Accept: application/media_control+xml,application/sdp
Contact: <sip:SD4tl71-vv9pmjn1vl07h0t6in0808cjov84opsv-7@;transport=udp>
Content-Type: application/sdp
Content-Disposition: session;handling=required
Content-Length: 240
o=BroadWorks 34676300 2 IN IP4
c=IN IP4
t=0 0
m=audio 16496 RTP/AVP 8 101
a=rtpmap:8 PCMA/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=bsoft: 1 image udptl t38

To fix this, set of message manipulation rules can be configured and assigned against both Lync and SIP Trunk IP Groups. These manipulation rules will change the hold method from “inactive” to “sendrecv” before sending it to PSTN. And it will change the hold method to “inactive” instead of “sendrecv”, before sending it to Lync Mediation Server. There should be both inbound and outbound manipulation sets. Manipulation rules should looks like below;


The Manipulation Set ID 2 should be configured in to SIP Trunk IP Group Table “Outbound Message Manipulation Set” and Manipulation Set ID 1 should be configured in to both Lync and SIP Trunk  IP Group Tables “Inbound Message Manipulation Set”.


Lync IP Group


SIP Trunk IP Group

Upon configuring, run a test call and put it on hold. The caller was able to hear the MoH and audio was there when the call was retrieved. When looking at the Sys log of the call, the message manipulation was clearly doing what was expected.

SIP/2.0 200 OK
Via: SIP/2.0/UDP;branch=z9hG4bKac25768176
From: “Support” <sip:0732684306@ipsystems.com.au;user=phone>;tag=1c1900081337;epid=D273FA8C4C
To: <sip:0451984283@ipsystems.com.au;user=phone>;tag=SDi988799-1512955841-1456808868261
Call-ID: 190005820313201613745@
Supported: timer
Accept: application/media_control+xml,application/sdp
Contact: <sip:SD4tl71-vv9pmjn1vl07h0t6in0808cjov84opsv-7@;transport=udp>
Content-Type: application/sdp
Content-Disposition: session;handling=required
Content-Length: 244
o=BroadWorks 34627140 1 IN IP4
c=IN IP4
t=0 0
m=audio 16670 RTP/AVP 8 101
a=rtpmap:8 PCMA/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=bsoft: 1 image udptl t38

If you have a similar  issue with a SIP Trunk with MoH, this could most probably be the solution.

Call Forwarding Configuration Between Skype for Business and Audiocodes Mediant 800

As you all know, in a PSTN call forwarding scenario, Skype for Business\Lync server always forward the original caller ID to PSTN. In an ISDN, this will be fine as PSTN provider will mask the calling number with the pilot number of the ISDN.

But, in a PSTN SIP Trunk scenario, this will be problematic as SIP Trunk provider will refuse to send any numbers that are unknown to the trunk. Basically, the calling number presentation must have a number that belongs to the SIP trunk.

This issue an be overcome by employing IP-to-IP Outbound number manipulation to manipulate the calling number and replace it with any number that belongs to the SIP Trunk. The downside of this method is that, when ever a call forward configured on Skype for Business\Lync client, the call will get forwarded to the configured destination with the number presentation of pre-configured number and not the original DID of the user. Some organizations accept this as it is but in my experience, most prefer to have the user DID be sent as the calling ID.

With Audiocodes, a SIP header manipulation rule can be configured to cater this requirement. Before doing that, there is a small configuration change need to be done on Skype for Business\Lync server voice routing. In the Skype for Business\Lync control panel, “Trunk Configuration”, enable “Enable forward call history” and save. Let it to replicate the changes. Capture










Once enabled, run a logging on SBC and see if the “Diversion” header appears. The Diversion header will contain the DID of the user that forwarding the call.
Contact: <sip:862712345;ext=12345@;ms-opaque=a30ebed1bacc5eac>
Supported: 100rel
Diversion: <sip:862712345;ext=12345@test.wa.gov.au;user=phone>;reason=unconditional;counter=1
User-Agent: Mediant 800B/v.7.00A.035.012
Privacy: none
P-Asserted-Identity: <sip:862712345@test.wa.gov.au;user=phone>
Content-Type: application/sdp
Content-Length: 382
o=- 1673518669 1456751675 IN IP4
c=IN IP4
t=0 0
m=audio 7760 RTP/AVP 8 0 97 18 13 101
c=IN IP4

Now the user DID number is appearing in Diversion SIP header, a message manipulation rule can be configured and assigned to SIP trunks IP Group against “Outbound Message Manipulation Set”

Go in to SBC Configuration and in “Msg policy & Manipulations”, create a Message Manipulation rule as below;


Once the header manipulation has been configured, the “FROM” header will get modified from the content that present in “Diversion” header.

13:37:42.094 : : NOTICE : [S=304817] [SID=8a25e1:12:26893] INVITE sip:0430912345@test.wa.gov.au;user=phone SIP/2.0
Via: SIP/2.0/UDP;branch=z9hG4bKac819203857
Max-Forwards: 10
From: <sip:862712345;ext=12345@test.wa.gov.au;user=phone>;tag=1c427358178;epid=DBF2EBCAFA
To: <sip:0430912345@test.wa.gov.au;user=phone>
Call-ID: 6326964502212016133741@
Contact: <sip:862793101;ext=3101@;ms-opaque=a30ebed1bacc5eac>
Supported: 100rel
Diversion: <sip:862712345;ext=12345@test.wa.gov.au;user=phone>;reason=unconditional;counter=1
Authorization: Digest username=”N9744″,realm=”test.wa.gov.au”,nc=00000001,nonce=”BroadWorksXijp9b5qgTla8pieBW”,Cnonce=”Default_Cnonce”,uri=”sip:0430912345@test.wa.gov.au”,qop=auth,algorithm=MD5,response=”0fa04b1d8cf108f8f48545baa53362cb”
User-Agent: Mediant 800B/v.7.00A.035.012
Privacy: none
P-Asserted-Identity: <sip:862712345@test.wa.gov.au;user=phone>
Content-Type: application/sdp
Content-Length: 382

At this point, the call must be ringing on the forwarded destination and it should be presenting with the forwarded user’s DID number instead of any fixed generic number.

Microsoft’s Cloud PBX based on Office 365

Microsoft have announced bunch of new services to their Skype for Business Preview services that are based on O365. One of the services that was announced, was the preview availability of the cloud PBX with on-premises PSTN Connectivity.  With the cloud PBX service, organizations will now have the ability to leverage their existing on-premises PSTN lines such as ISDN or SIP Trunks to terminate calls to users that are enabled for O365.

What you need to have.

Before jumping on to preview Cloud PBX services, there’s a very important prerequisite that need to be fulfilled. That is having a Lync\Skype for Business Server hybrid setup already in place that configured with Enterprise Voice. Also, you would need to have Office 365 E4 licenses for the number of users that are enabled within Office 365.

This option is available for organizations that are having Lync 2010 servers that are running with CU no earlier than October 2012. But, the catch is that, they need to have Lync server 2013 or Skype for Business Server 2015 Edge servers to support the hybrid integration. So if you’re having Lync Server 2010 and considering Cloud PBX, it’s high time to move to Skype for Business Server 2015.

Features and Drawbacks.

With the Cloud PBX service, you now get to configure Enterprise Voice for O365 enabled users with desired Voice Policies and PSTN Usages. But, not all the features that available for on-premises users be available for Cloud PBX enabled users. Cloud enabled users will miss out on using call park, private line and several other features. Below are the list of Enterprise Voice features that are available for Cloud enabled users;Capture

Even though cloud enable users are losing some of features, most of important and critical features are still available for them which is really good.

How to Make it Better.

Microsoft have announced the availability of Azure Express Route to Office 365 several months ago. Organizations can leverage on this to enhance the connectivity to O365 with assuring a better bandwidth availability and control rather than using the standard internet services. This would also benefit in configuring Quality of Service (QoS) for media traffic that is essential to improve the media quality and overall cloud user experience. On side note, this would improve the user sign in time as well. Below is a sample diagram that illustrate the connectivity between corporate network and O365 over express route. Azure-ExpressRoute-1

Moving users to Cloud PBX and enabling for Enterprise Voice.

Once the Hybrid setup in place, you can move users to O365 and enabled Enterprise Voice for them. Before that, since the service are still in preview, you need to get a promotion code from Microsoft. The promo code can be retried by registering for service using https://www.skypepreview.com/Register URL. If you have the promo code already, follow the steps to enable uses;

  • Enable users for Enterprise Voice (performed while the users are homed on-premises).
  • Assign a voice routing policy (performed while the users are homed on-premises).
  • Obtain and activate a promo code, so that you can preview this feature.
  • Synchronize users to the cloud and assign licenses (performed using Office 365).
  • Move users to Skype for Business Online (performed using Windows PowerShell on-premises, but using your Office 365 administrator credentials).
  • Enable the users for Enterprise Voice and Cloud PBX Voicemail (performed using Remote PowerShell).

Migration of user accounts should be none intrusive and users will not lose any configuration that they made on their client.

As mentioned above, the service is still on it’s preview stage and it will become GA pretty soon and this would be a one step forward for the organizations that are looking forward to move in to Office 365.

Supported Survivable Branch Appliance (SBA) for Skype for Business

Since the Skype for Business server 2015 public release, one of the concerns that came up when upgrading existing Lync Server platforms to Skype for Business, is the support for SBAs. Microsoft issued a statement mentioning that the existing SBAs that are running with Lync server 2013 image, will be supported for Skype for Business till the hardware vendors come up with the Skype for Business image on their appliances.

Now, Sonus has announced that their newer software version V 5.0 for SBC 1000\2000 that supports Skype for Business Server, will be released on 28th of July 2015.

Audiocodes however, stated that their E-SBC (Enterprise SBC) appliance will fully support Skype for Business server 2015 since 07th of July 2015.

What’s new with Sonus Version 5.0 

Key Features in Release 5.0 in support of Skype for Business deployments include:

  • Presence: The new presence feature provides Skype for Business users with presence reporting when engaged in calls from non-Skype for Business endpoints.
  • Provisioning templates: The updated provisioning templates significantly reduce the complexity of configuring Skype for Business interworking. This feature is designed to enable an enterprise to deploy its Skype for Business application with greater speed-to-market, saving time and money.
  • Survivable Branch Appliance Support: Delivering continued market leading support for Survivable Branch Appliance (SBA) functions, this feature ensures that real-time communications are delivered even if the wide area network (WAN) goes down.

For more information about this software release, please visit;


Audiocodes Enterprise Session Border Controller (E-SBC)

Based on the statement that released on 07th of July, their E-SBC appliance is supported for the Skype for business Server. However, it’s not clear that the SBA image that been used within the SBA, is for Skype for Business Server or just the Lync Server 2013.


For more information about the Audiocodes E-SBC product range, Please visit;


So, if you have plans to upgrade existing Lync server platforms to Skype for Business Server, now you have the SBA component addressed by above product range. Plan the upgrade schedule with keep the software release days in mind.

In-place Upgrade Lync Server 2013 to Skype for Business Server 2015

It has been a while that the Skype for Business server 2015 released for public. I reckon it would be the time to upgrade the existing Lync server 2013 platform to Skype for Business Server 2015.

Before moving forward, there are concerns that need to be addressed upfront. The major one would be the overall downtime that occur because of the upgrade. If the existing deployment have multiple pools, then users can be moved to one of the pools and get the other one upgraded and have services running as usual. But, if there’s only one pool available, then the upgrade could be a potential risk and a lengthy downtime.

Also, it’s important to have an idea of what CU version that the existing Lync server 2013 platform is running. Make sure to upgrade the Lync server pool before moving forward with the Skype for Business upgrade and also plan adequate downtime that incorporate the existing pool CU upgrade as well as the in-place upgrade.

Moving forward with the Skype for Business 2015 upgrade, install the Skype for Business server Admin Tools on a domain joined machine (admin tools would not install on any Lync server 2013 front end servers). Download the topology from existing deployment, upon installing of the admin tools.Capture5

Once downloaded, drill down to the existing Lync server 2013 pool. Right click on the pool and select to “Upgrade to Skype for Business Server 2015”Capture6

Select “Yes” on the confirmation window. Capture7

As soon as selecting “Yes”, the Lync server 2013 pool will be moved to “Skype for Business Server 2015” section. This is as expected and should not be worried. Capture8

Now, publish the topology by selecting “Publish Topology” in “Action” menu.Capture9

The publishing process is as same as Lync Server 2013.  Do not change anything related to the Databases. Leave everything as it is.Capture11

Select “Next” and proceed with the topology publishing process.Capture12

Open up the “to-do list” to check that need to be done next. Capture13

Log in to Lync Server 2013 Front End server and run the Skype for Business Server 2014 set up from media. Capture3

Select to connect to the internet and check for updates. It will download the required windows patches and install. Capture4

Upon completing the download process, select next to proceed with the deployment. As for the first step, it will check the status of the existing pool. It will error out if the pool services are still running.Capture14

Open up the Lync server 2013 management shell and run Stop-CsWindowsServices to stop the Lync server services. This process need to be done on all front end servers. Capture15

Once all the services are down, retry the deployment process. It should continue through the process. It would take up to 45 – 60 minutes to complete the update. The upgrade process can be run on all Lync server 2013 front end servers simultaneously. No need to do it one by one.Capture1

select “Ok” to complete the upgrade process. Capture16

Now, the upgrade process is successfully completed. Wait till the process completed on all front end servers. Upon completion, run the command Start-CsPool -PoolFqdn <pool fqdn> . This is a new command that introduced in Skype for Business Server 2015. This command can be used to stop and start the pool without being worried about messing with the fabric and the quorum.Capture17


Confirm that all the windows services relate to Skype for Business server are up and running.Capture18

The Lync Server 2013 clients should get a prompt that the back end server is changed to Skype for Business and it require to restart the client.Capture20

Upon restarting the Lync 2013 client, the client will change the skin to Skype for Business 2015.


The upgrade process is now completed. Carry out the test plan to verify the features and functionality of the platform.

Integrate Lync Server 2013 with O365 Exchange for Unified Messaging

Lot of clients are now moving away from on premises Exchange and in to O365 these days. Exchange online came a long way and grown up a lot. In terms of Unified Communications, how should we get Voicemail out of O365 exchange?. And what will be the configuration that involves in?. To answer those questions, let’s have a look at what the prerequisites are and what the configuration should be.

Before moving forwards, there’s several critical points need to be addressed and understood;

  • On premises Lync Server 2013 deployment must have Edge servers installed and federation enabled
  • Edge server DNS resolution should be done via the External interface and not over the internal. It must have public DNS servers configured instead of internal DNS.
  • _sipfederationtls._tcp.domain.com SRV record must be configured in public DNS and resolve against the access edge FQDN (sip.domain.com)
  • The O365 Tennent domain must be set to “Authoritative” accepted domain

Form above mentioned 2 points, I cannot stress the importance of proper DNS configuration enough. If the DNS wasn’t properly configured, the whole partner federation component will get broken as a result and it will not be a pleasant experience.

To check if the domain is accepted and authoritative within O365, below command can be used

Get-AcceptedDomain  | Format-List

So, to begin with the configuration within Lync Server, verify the configuration of the Access Edge. It should be as mentioned below;Capture4

Next, a Hosting Provider needs to be configured. To configure this, run the command; New-CsHostingProvider -Identity “Exchange Online” -Enabled $True -EnabledSharedAddressSpace $True -HostsOCSUsers $False -ProxyFQDN “exap.um.outlook.com” -IsLocal $False -VereficationLevel UseSourceVerificationCapture1

Now, create a Hosted Voicemail Policy. This is the policy that get assigned to a user who needs to be enabled for O365 Unified Messaging. To configure the policy, run the command; New-CsHostedVoicemailPolicy -Identity “CloudUMPolicy” -Destination exap.um.outlook.com -Description “Hosted Voicemail Policy for Lync Users” -Organization “contosoltd.onmicrosoft.com”Capture8

In above command, the Organization parameter must be specified as the tenant name and not the shared name space. Ex, contoso.com (shared name space), contosoltd.conmicrosoft.com (Tenant Name). Then run; Invoke-CsmanagementStoreReplication to replicate the changes.

Now to create UM contact object for Subscriber access and Voicemail. Usually for on-premises Exchange, we use OCSUMUtil.exe tool to create these objects. But in O365 UM scenario, we have to use Lync Server management Shell to create these objects. In order to create the contact object for Subscriber Access, the command; New-CsExUmContact -SipAddress sip:exumaa1@domain.com -RegistrarPool lyncPool.domain.com -OU “OU=ExUmContacts,DC=domain,DC=com” -DisplayNumber -AutoAttendant $False -IsSubscriberAccess $True can be used. Capture

Now we are done with Lycn server bits and move on to O365 portal to configure the UM Dial Plan. Log in to the O365 portal using https://portal.office.com and go to the Admin Centre. Capture2

Go to “Exchange” and select “UM Dial Plans”. Select “+” to create a new dial plan. Configure the dial plan name, number of digits of an extension. Select “SIP URI” from the drop down for “Dial plan type”. Set the language, the country code and save the configuration.Capture2













Open the newly configured Dial plan and select “Configure” to configure the rest of the parameters of the dial plan.Capture3












Move to “Outlook Voice Access” tab and configure the DID number for the Subscriber Access in E.164 format as shown below. If you want to use a custom greeting, the audio file can be uploaded in to the “Default Greeting” configuration.Capture











Then go to “Settings and configure the operator extension. This will help to transfer the calls to the operator, if the caller couldn’t be served by the subscriber access component. Capture5











Next to configure the “Dialling Rules”. Dialling rules are configured to dictate which number or number patterns can be routed via the subscriber access as well as the auto attendant. Usually, the dialling rules are configured to route all digits without any restriction, unless if there’s a special requirement that need to configure specific numbers. Configure the dialling rules as mentioned below. This dialling rule will be later on assigned to the Um Mailbox policy as well.Capture6

Now to assigned the dialling rule to the dialling authorization table. Configuring this will allow users who are coming in to the Subscriber Access and Auto Attendant to reach out to internal user extensions. Assign the dialling rule to the authorization table and check “Calls in the same dial plan” and “Allow calls to any extension” components.Capture7

In Transfer and Search tab, verify that the “Transfer to Users are selected. The rest of the parameters can be left alone.Capture8

Now, go back and open up the configured Dial Plan and double click on the default UM Mailbox Policy. This policy get created automatically upon completion of the UM dial plan creation.Capture2

In “General” we usually leave the parameters as it is. If required, some of the UM functionalities can be controlled within this section.Capture15

In The “Pin Policy” tab, you can change the number of digits that are required for the PIN and whether to allow the common patterns for the PIN. Usually, the PIN would be set to 4 digits length and allow common patterns. Capture16

The  “Dialling Authorization” is the most important part within the UM Mailbox policy. If not configured with a number policy, it will not allow calls to be routed to internal extensions from the subscriber access or auto attendant. Assign the previously configured number policy to allow all digits and “Calls within the same UM dial plan” and “Call to any Extension” should be checked.Capture17

This is all that is to the Subscriber Access component of the Exchange UM in O365. The same steps can be followed to configure the Auto Attendant. It will require to configure a UM Object for the Auto Attendant in Lync Server and then need to configure the Auto Attendant within O365.