Integrating the existing Lync setup with PBX or SBC’s is always a complicated one. When we look as a overview things looks smaller and easy. We need to choose the right PSTN gateways, SBC’s that are compatible with Lync and SFB.
When the real time scenario of implementation kicks in there are several things , components and factors which needs to be configured properly.
If no proper planing and study on the existing setup is done ,then we will definitely run into multiple issues. Because we need to configure multiple things in PSTN gateways to create a proper channel route between these two medias.
If you aren’t voice expert its better to discuss this with VOIP engineer dealing with these PBX gateways or associated vendors so we will get best integration advice according to the setup.
In this article i’m going to explain few methods that we can follow to integrate Lync 2013 / SFB with Cisco Unified Call Manager in already existing Lync/SFB setup.
Speaking from my experience so far below are the possible ways of implementing this.
1. Cisco unified communication integration for lync (CUCI – Lync) :
You can follow this if you want to utilize the existing Cisco CUCM PSTN enterprise plan for all the end users without investing any other components.
Keep Lync/SFB only for IM & Presence and not having enterprise voice .
End users will get a Cisco Soft Phone agents in their desktops for making the calls.
End users have the option whether to use the soft phone or to use their desk-phone.
It is basically like Cisco integrating their PBX with Lync for IM and Presence without the need of Cisco IM and Presence server.
By reading through so many blogs and forums i can see this integration is more complicated.
End users might get confused to understand in how they need to make the call.
But the best thing is you can use your existing CUCM setup and the Lync does not require Lync Plus CAL for the voice functionality.
Less configuration on the Lync side . You can plan for this if you have a dedicated VOIP handling Cisco Team in your setup.
2. Remote Call Control or Call Via Work:
RCC enables users only to control their desk phones by using Lync on their desktop computers.
When a user signs in to the Microsoft Lync client, the Lync server sends instructions, through the IM and
Presence server of Cisco and then to the Cisco Unified Communications Manager maintains call features based on the end user action.
By enabling this it gives the end users to use the Lync 2013 user interface (UI) to control calls on their Cisco phones.
- Make an outgoing call
- Answer an incoming call
- Answer an incoming call with an instant message
- Transfer a call
- Forward an incoming call
Very IMP note: The Cisco Unified communications manager PBX should have the existing PSTN plan as such.
The Lync 2013 RCC feature only sends call control commands to PBX and the PBX will handle the call process . No mediation server is required in this scenario.
Unfortunately if you are implementing RCC in Lync 2010/2013 then end users will not be able to make enterprise voice calls when they are remotely connected.
Reason: It is not possible for a user to have both enterprise voice and RCC together in Lync. This is almost a legacy dying technology which we should not think for any new implementation. RCC is depreciated technology and not recommended by Microsoft as well.
It can be a good solution only during the transition period from CUCM to Lync or vice versa.
Call Via Work (SFB 2015) :
People might think Microsoft has replaced CWV in SFB 2015 and why we need to implement this thinking the negative impacts from RCC.
This is an amazing hybrid type of solution from Microsoft. The end user can set their ring back number in their SFB client.
The function of call via work is, the SFB mediation server will make a call to the configured phone number by end user and a second call to the destination number and connect both calls. The destination number calls will be handled by your PBX gateway. The connectivity from the mediation server to the PBX will be direct SIP. In turn this will have a configuration of Dialplan, Voicepolicy, Pstnusage,and a Route to a sip trunk or gateway users.
This is very useful when you are in a poor internet connectivity on your trip and you can set your mobile number as callback in your SFB client and we will have a great calling experience.
The prerequisite for CVW is similar to RCC but we require mediation server in additional.
No need to buy additional hard IP phones for end users if the voice plan stays with your PBX. SFB client perfectly routes and call to the destination with CWV feature.
This type is very good in leveraging and using the existing Cisco’s CUCM PSTN plans for end users.
This enables enterprise voice features for the end users without having the head ache of deploying additional components SBC’s etc..,
We need to have a direct SIP trunk configured between the both systems CUCM and your mediation server. We need to have mediation server configured in this case. A dedicated mediation server without collocated is recommended for this setup by Microsoft.
This can be used during transitions as well as a permanent solution.
You need to create a SIP trunk and a route pattern between Mediation server and CUCM.
There is an excellent document from Cisco for the same .
If you want to plan for the rest of the above as well there are documents from Cisco as well as Microsoft .
Note : It is very important to have a detailed study and discussion on your existing PBX setup , PSTN plan , Network layout and Lync Setup with all the required teams and vendors before planning for integration.
Thanks & Regards
MVP – Exchange Server