in this (quite long) article I’ll explain how to configure Lync and Skype for Business to manage an SBA/SBS or an SBC outage in a Branch Office.
In this article we have a Lync/Skype for Business Enterprise Voice deployment with a Main Site (HQ) and a Branch Office Site, both with a local Sonus SBC Voice GW (1000/2000/SWe Lite), like the image below
How to manage SBA/SBS failure
If you do not configure anything else, this is what happens to Branch Office’s calls when SBA/SBS fail:
- SBA/SBS fail
- Branch Office users and IP-Phone registration fail
- Branch Office Users fail-over on Main Site Front-End
- Registration on FE is OK
- Branch Office User do not find any suitable Voice Route
So let’s fix the issue!
Set the parameter to reflect the configuration of the Branch Office Voice GW, take care of number of channels, encryption, Refer Support, Media Bypass and leave enabled the Outbound routing failover timer
Step 2: setup the Voice Gateway
This step will allow remote Voice Gateway to accept connection from Front-End server and use it as a secondary mediation server in case of failure of Branch Office SBA/SBS
In the same Signaling Group change the Load Balancing method to Priority.
This will instruct the SG to use the local SBA/SBS Mediation first (Priority 1) and the Main Site Front-End Mediation Server in case of SBA/SBS fault (Priority 2)
In SIP -> SIP Server Table open the name of the SfB Mediation Server.
Normally you will find one line of the SBA/SBS Server (sfbsbs01.uclab.local in this example).
We have to add the Front-End Server, so click on Create SIP Server -Z IP/FQDN and add server data as the example below, take care to set the Priority to 2
Step 3: setup the Voice Routing for SBA/SBS outage backup
Step 1 and 2 allow SBA/SBS, SBC and Front-End to speak each other.
In case of SBA/SBS fault, incoming calls are routed to Front-End (step 2 and Load Balancing Priority method), but without changes in Voice Routing no one could take advantage of these new settings for outgoing calls.
Call it as you like, respecting your name convention.
In this example I call it IT-Branch-Backup
Add Number Pattern that you want to allow during SBA/SBS outage (outbound calls). In this example we’ll allow European Emergency Numbers, Italy Landline Numbers and Italy Mobile Numbers.
Now we have to add the new route “IT-Branch-Backup” to PSTN Usage Policies used in Branch’s Voice Policies.
In this example I add “IT-Branch-Backup” route to PTN Usage into Branch Office Pool Voice Policy and to IT-Branch-All Voice Policy.
IT-Branch-Restricted do not gain this setting so users with this policy will not be able to make calls during SBA/SBS outage.
How to manage SBC failure
Step 4: setup the Voice Routing for SBC outage backup
Last but not least, we need to manage a fault on Branch Office SBC also (on SBA/SBS only is too easy!) 🙂
Our objective is described in this image: if the SBC on Branch Office goes down, Branch Office’s Users cannot place calls (point #5), so in this step we’ll setup a new route to intercept this situation and place calls on HQ’s Voice Gatway (point #6)
On Voice Routing -> Route panel create a new route, call it as your conventions, in this case I use IT-HQ-Backup.
Enter the Number Pattern you want to allow on this “emergency line” and chose the HW Voice GW (voicegw01.uclab.local) as Associated trunk.
In Voice Routing -> Voice Policy open a Branch Office policy and create a new PSTN Usage Record (I suggest to use a different PSTN Usage, or you can add the Route to the same PSTN Usage used in steps above).
Call it as you want, I call it as the Route I will add, IT-HQ-Backup
The newly created PSTN Usage need to be the last one, like the image below.
Add this PSTN Usage to every Voice Policies you want to give ability to call via HQ Voice GW in case of Branch Office SBC fault.
Commit All at the end.
Response Group Service fallback solution
If you route one or more Branch Office’s incoming calls to a Response Group on the Main Site Front-End, you need to read this article and use one of the two solutions presented.
As always, I hope this quite long article could help one of you.