Dual Homed Conferencing Overview

Now let's take a look at a way to integrate on-premises Lync / Skype for Business with CMS via Expressway: the dual-home conference. This integration method provides the best end user experience because all participants, regardless of platform, will retain their native client experience. To Skype users, all participants will look like Skype users; and to users attending via the CMS meeting, everyone will appear as individual CMS meeting participants. A dual-homed conference is called such because for each meeting, a conference exists both in the Skype infrastructure side as well as on CMS. It is possible to integrate CMS directly with on-prem Skype for Business and the methods are similar, although that integration would only support audio/video. If you have an on-premises IM/P server, then you'll need to use Expressway.

Before you started, review the three domains in use:

• pod7.cms.lab - the Unified CM domain (i.e. all Jabber endpoints have this as their host portion)
• conf.pod7.cms.lab - the CMS domain, containing all user's CMS Spaces
• s4b.cms.lab - the Skype for Business domain

Certificate Requirements

Integrating either CMS or Expressway with Skype for Business Front End servers presents some additional certificate requirements. First, each Front End server must have the root CA that signed the Expressway-C and the CMS server certificates installed in its Local Machine Trusted Root Certification Authorities store. Having the same root CA certificate for all of these servers makes this step unnecessary.

Additionally, the Expressway-C's server certificate, when in a cluster, must be created such that there is a cluster FQDN as the Common Name and each cluster member as a SAN entry in the certificate. For non-clustered Expressways, the CN can simply be the FQDN of the server. Note that when integrating CMS directly to Skype for Business, this certificate requirement is the same, in that each CMS' cluster node would need to have a cluster FQDN as the CN and the cluster members in the SAN.

Skype for Business / Lync Server Configuration

For a complete dual-home experience, CMS needs to be able to resolve Lync meetings and to do that it needs to register as a real S4B client. For this we need to create one or more accounts for each CMS cluster node on the Skype for Business server. For this purpose, we have created nine accounts on the S4B server (3 accounts for each CMS node), pod7cms1aedge[1-3]@s4b.cms.lab, pod7cms1bedge[1-3]@s4b.cms.lab, and pod7cms1cedge[1-3]@s4b.cms.lab, which will be used for this purpose.

As mentioned, this has already been configured, so it's time to move on to the Expressway configuration.

Expressway Configuration

On Our Expressway-C, we need to identify how to handle the s4b.cms.lab domain. Any MSSIP variant matching that domain should be routed directly to the Microsoft Front End servers. Anything destined to that domain that is standards-based SIP must first go to CMS. And with that, we need to have three separate rules, one for each CMS cluster member zone.

First we will create the Search rule to route MSSIP calls to the S4B domain Front End.

1. Log in to the Expressway-C at https://expc1a.pod7.cms.lab (username: admin and password: c1sco123)
2. Navigate to Configuration > Dial plan > Search rules and click New
3. Configure the following to route MSSIP traffic to the S4B Zone:
   
   

   Parameter	Value
   Rule Name	S4B domain MSSIP to S4BFE
   Priority	100
   Protocol	SIP
   SIP Variant	Microsoft Variants
   Source	Any
   Mode	Alias pattern match
   Pattern type	Regex
   Pattern string	.*@s4b\.cms\.lab.*
   Pattern behavior	Leave
   On successful match	Stop
   Target	S4B Zone

   
4. Click Create search rule.

Now we can create the Search rule to route standards-based SIP calls for the S4B domain to CMS1a, CMS1b, and CMS1c in order to be transcoded. We will start with CMS1a.

1. Navigate to Configuration > Dial plan > Search rules on Expresssway-C. Click New
2. Configure the following:
   
   

   Parameter	Value
   Rule Name	S4B domain StdSIP to CMS1a
   Priority	100
   Protocol	SIP
   SIP Variant	Standards-based
   Source	Any
   Mode	Alias pattern match
   Pattern type	Regex
   Pattern string	.*@s4b\.cms\.lab.*
   Pattern behavior	Leave
   On successful match	Continue
   Target	CMS1a Zone

   
3. Click Create search rule.

NOTE: If you completed the Expressway Edge with Skype for Business Gateway calls section, then the following Search Rules, which route MSSIP-type calls for the UC domain to CMS, will already be present: UC domain MSSIP to CMS1a, UC domain MSSIP to CMS1b, and UC domain MSSIP to CMS1c. On the Expressway-C, navigate to Configuration > Dial Plan > Search rules and verify that you have these 3 rules. Otherwise, expand the MSSIP for UC domain to CMS button below and configure them.

CMS Configuration

In CMS, we will now receive calls to the S4B domain that are standards-based SIP. We need to accept the calls, forward them and route them back out as Lync-type trunks to Expressway. In doing so, we need to make sure the calls are handled properly such that S4B users can perform call backs and that the call signalling is properly routed to the CMS cluster node from where it originated.

CMS Forwarding Rules

You have CMS rules for accepting calls inbound as well as routing calls outbound. The one piece that is needed to allow CMS to accept a call inbound and immediately send it back out to an outbound destination is a forwarding rule. At a minimum, you need to allow CMS to forward calls to the Unified CM domain (pod7.cms.lab) as well as to the Skype for Business domain (s4b.cms.lab). You could configure these individually, but for now we'll show how to set this up to allow all calls to be forwarded unchanged.

1. Access CMS admin for CMS1a: https://cms1a.pod7.cms.lab:8443/incoming_calls.html.
2. Navigate to Configuration > Incoming calls
3. Add a rule for the local UC domain. This rule may already be present if you configured the Expressway Edge section:
1. Under Call forwarding, in the first blank row, under Domain matching pattern, enter pod7.cms.lab
2. Set the Priority to 1
3. Change the Forward setting to forward
4. Set the Caller ID setting to pass through, because we want these to be completely unchanged for anything that's not a Microsoft destination.
5. Click Add New
4. Add a default rule for the Skype for business domain:
1. Under Domain matching pattern, enter s4b.cms.lab
2. Set the Priority to 1
3. Change the Forward setting to forward
4. Set the Caller ID setting to pass through
5. Click Add New

Note: Depending on the sections you completed, you may see additional routes to these added.

Our CMS deployment already has an outbound route to the CUCM domain, but in order for calls to be routed to the Skype for Business domain, s4b.cms.lab, another route is required. Then a rule is required in order for calls to target that domain and allow for conference resolution.

Now you can configure the required outbound rules and inbound rules as follows.

CMS Outbound Rules for Skype for Business

You have previously configured inbound and outbound CMS routing rules before using the GUI. Do the same via the API as follows (and we will note the equivalent GUI and API parameters):

1. Launch Postman
2. Specify the POST verb, in order to add a new rule.
3. Change the URL to https://cms1a.pod7.cms.lab:8443/api/v1/OutboundDialPlanRules
4. Click on the Body tab below the URL.
5. If not already selected, select the x-www-form-urlencoded radio button.
6. If necessary, click on the Bulk Edit selection at the right of the Key/Value headers, then get rid of any old data.
7. The following parameters need to be configured, listed here as shown in the GUI as well as the corresponding API parameter:
   
   

   GUI Parameter	API Parameter	Value
   Domain	domain	s4b.cms.lab Our Skype for Business domain.
   SIP proxy to use	sipProxy	expc1a.pod7.cms.lab
   Local contact domain	localContactDomain	cms1a.pod7.cms.lab The CMS1a FQDN.
   Trunk type	trunkType	Lync
   Behavior	failureAction	Stop
   Priority	priority	90
   Encryption	sipControlEncryption	Encrypted
   Call Bridge Scope	scope	callBridge
   Call Bridge Scope	callbridge	###_CB_cms1a_callBridge_ID_###

   In Postman, the following parameter pairs can be pasted in to the bulk entry window:
   

   domain:s4b.cms.lab sipProxy:expc1a.pod7.cms.lab localContactDomain:cms1a.pod7.cms.lab trunkType:lync failureAction:Stop priority:90 sipControlEncryption:encrypted scope:callBridge callbridge:###_CB_cms1a_callBridge_ID_###
8. Click Send
   
   
   NOTE: Be careful to only press the Send button once. There is nothing to prevent you from adding multiple rules that are exactly the same. This may not cause issues initially, but certainly will cause confusion.
9. You only need to repeat this for cms1b and cms1c, changing only the localContactDomain parameter. For cms1b paste the following into the Postman bulk edit window and click Send:
   domain:s4b.cms.lab sipProxy:expc1a.pod7.cms.lab localContactDomain:cms1b.pod7.cms.lab trunkType:lync failureAction:Stop priority:90 sipControlEncryption:encrypted scope:callBridge callbridge:###_CB_cms1b_callBridge_ID_###
10. Lastly, for cms1c paste this into the bulk edit window of Postman and click Send:
    domain:s4b.cms.lab sipProxy:expc1a.pod7.cms.lab localContactDomain:cms1c.pod7.cms.lab trunkType:lync failureAction:Stop priority:90 sipControlEncryption:encrypted scope:callBridge callbridge:###_CB_cms1c_callBridge_ID_###
11. Examine the Outbound rules from the CMS GUI. Log in to https://cms1a.pod7.cms.lab:8443/outbound_calls.html (Username: admin, Password: c1sco123)
12. You should see the three new rules that have been created in addition to the first two you already had. Make sure the Local contact domain entry is for the same server specified in the Call Bridge Scope
    

CMS Inbound Rules for Skype for Business

1. Navigate to Configuration > Incoming Calls, or https://cms1a.pod7.cms.lab:8443/incoming_calls.html.
2. Add a domain with the following parameters in the Call matching section:
   
   
   GUI Parameter	API Parameter	Value
   Domain name	domain	s4b.cms.lab
   Priority	priority	40
   Targets spaces	resolveTocoSpaces	No
   Targets users	resolveToUsers	No
   Targets IVRs	resolveToIvrs	No
   Targets Lync	resolveToLyncConferences	Yes

   As performed earlier, you could have sent a POST to the /inboundDialPlanRules node.
3. Click Add New

If you also required numeric dialing of Skype for Business meetings from Unified CM you could have also set Targets Lync to Yes on each of the three existing rules that map to the CMS FQDNs for calls matching the CMS domain. In this lab, you won't use that so we will skip that optional step.

CMS Lync Edge Service Accounts

In order for CMS to join Dual Home meetings via the PSTN Dialin number or use Skype for Business Edge TURN services, each CMS node must be configured with one or more service accounts. Lync allows up to 12 TURN allocations per login, so we may need more than one per server. This configuration should be done via the GUI of each meeting server.

1. First, CMS1a:
1. Navigate to Configuration > General, or https://cms1a.pod7.cms.lab:8443/config.html (Username: admin, Password: c1sco123)
2. In the Lync Edge settings section, for Server address, enter s4b-fe.cms.lab
3. Below that line, for Username, enter pod1cms7aedge@s4b.cms.lab
4. For Number of registrations, enter 3
5. At the bottom of the page, click Submit
6. Now check to see if things are properly registered. Navigate to Status > General and observe that the Lync Edge registrations should show "3 configured, 3 completed successfully", instead of just in progress or another status.
   
2. Next, we'll repeat for CMS1b:
1. Navigate to Configuration > General, or https://cms1b.pod7.cms.lab:8443/config.html (Username: admin, Password: c1sco123)
2. In the Lync Edge settings section, for Server address, enter s4b-fe.cms.lab
3. Below that line, for Username, enter pod1cms7bedge@s4b.cms.lab
4. For Number of registrations, enter 3
5. At the bottom of the page, click Submit
6. Check to see if things are properly registered. Navigate to Status > General and observe that the Lync Edge registrations should show "3 configured, 3 completed successfully"
3. And finally for CMS1c:
1. Navigate to Configuration > General, or https://cms1c.pod7.cms.lab:8443/config.html (Username: admin, Password: c1sco123)
2. In the Lync Edge settings section, for Server address, enter s4b-fe.cms.lab
3. Below that line, for Username, enter pod1cms7cedge@s4b.cms.lab
4. For Number of registrations, enter 3
5. At the bottom of the page, click Submit
6. Check to see if things are properly registered. Navigate to Status > General and observe that the Lync Edge registrations should show "3 configured, 3 completed successfully"

Testing Dual Home Conferences

In Dual Home Conferences, the key is for CMS to be able to resolve Skype for Business meeting information.

Normally you would have Outlook to schedule a new meeting. To speed things up, we have set up a conference already and will test joining it to illustrate the process of CMS lookup up and joining a Skype for Business meeting.

Here is the meeting information:

We see there is a meeting URL, which Skype for Business clients would click, and a conference ID, which is not the what CMS will need to resolve to a URI in order to join the meeting. To the standards-based SIP users, they will simply need to dial the conferenceID@skypedomain and CMS will handle the rest.

1. Access PC1
2. From the Desktop, double-click on the S4B Dual Home Conf icon. This opens up the URL to https://meet.s4b.cms.lab/s4b1pod31/CLJ753MV, which will trigger the Skype for Business client to dial into the meeting.
   Alternatively, open Chrome and paste the following URL in the address bar: https://meet.s4b.cms.lab/s4b1pod31/CLJ753MV (the meeting URL from the invite above).
3. The browser may require confirmation to open Skype (Open URL:lync15 Protocol). Click Open
4. You may also be asked to confirm that you'd like to Use Skype for Business (full audio and video experience). Simply click Ok
5. You are now in the meeting. There will likely be at least one other participant in this meeting already. Click the Video Camera icon and then Start My Video.
6. Now join this conference from Jabber. Place a call to the URI 29905@s4b.cms.lab. This will force CMS to look up the URI for the Skype for Business meeting with conference ID 29905 on the Front End server before setting up a CMS meeting and joining.
7. When finished please disconnect the call from PC1 and the laptop.

This concludes the on-prem Skype for Business integration example. If you are interested in external Edge connectivity for WebRTC clients or the Cisco Meeting Management (CMM) product and have not yet completed those sections, feel free to work on them now.

 

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SECTION COMPLETE!

You've finished this portion of the lab. We have multiple other optional lab sections, depending on your time and interest, to continue on.

• Understand other CMS features, such as:
  • Spaces, to understand more about how Spaces are organized and configured.
  • Ad-hoc conferencing and integration with the Unified CM
  • CallBridge Groups for load balancing calls
  • Branding, for a more customized deployment.
• Explore Cisco Single Edge with Cisco Expressway and CMS:
  • Learn about deploying external WebRTC Web App using Cisco Expressway, to provide external users the same Web Bridge capability.
  • Configure advanced Business-to-business calling with Skype for Business gateway calling.
• Experience Cisco Meeting Management (CMM), our free product to allow video conference administrators to provide white-glove conferencing services.