UM server is the one that provides Voice Mail, Outlook Voice Access and other Exchange voice features. Integrating the UM functionality along with the existing telephony system or lync is one of the challenging role that admin would face. Planning should be done properly according to the enterprise voice plan which is used in the organization.
As we know from Exchange 2013 there is no separate role for UM. Their services are running in CAS server and Mailbox server and below are the list of services that are handling UM processes.
Microsoft Exchange Unified Messaging Call Router service
Routes the incoming SIP traffic from Lync server or any other IP-PBX or SBC which sends only SIP traffic. This traffic can come from a VoIP gateway, Session Border Controller (SBC), PBX or IP PBX. . Any media traffic sent to the Client Access servers would be redirected to a Mailbox server since the Client access servers are not capable of handling RTP and SRTP media traffics.
Microsoft Exchange Unified Messaging service
These servers will handle the initiating Session Initiation Protocol (SIP) traffic from the Lync server for voicemails are left over the Unified Messaging service. It accepts the connection either in port 5061 or 5060 (depends on your config secure or unsecure) and then redirects to Worker process in port 5065 or 5066 . This service does not do any media conversion.
Microsoft Exchange Unified Messaging Worker Process
Worker process receives the SIP requests only on port 5065 or 5066. Which means the actual media conversion takes place in this port. It does the following below thing
1) Does Registration of the process with Unified Communications Managed API 4.0 and converts all the required information for media processing for SRTP and RTP protocols.
2) Does the Initialization of Simple Mail Transfer Protocol (SMTP) message Submission and submits the voice message to the user’s mailbox who has UM enabled.
In this article we will have a look at the steps to configure UM and steps to integrating with Lync or existing telephone system in Exchange 2013.
Open EAC Click on Unified Messaging and select UM dial plans as shown below
Give it a name and provide the extension length that the users need for the subscriber access number to be used by Enterprise Voice users.
Select the Dial Plan type according to your Lync / IP-PBX or SBC settings you have.
Select the VoIP Security mode according to your enterprise voice plan settings that you have.
Select the appropriate country region and click save
Once finish click save and select configure the dial codes
Specify the codes according to your requirement.
Configure Outlook Voice Access as per requirement
Select settings and configure the options about searching the names when users are directed to the voice mailbox .
Configure the transfer and search options
Configure the transfer and search option according to the requirement and click save we are done.
Now we need to create a New UM IP gateway.
Things to consider before we create a new UM IP gateway
Run ExchUcUtil.ps1 and OcsUmUtil.exe only if you do not have any IP-PBX or SBC and if your are going to integrate your UM functionality with Lync or OCS pool. If you have multiple dial plans associated with different enterprise voice plan then you need to plan accordingly.
If you plan to integrate with Lync pool then run ExchUcUtil.ps1 on all Exchange Mailbox servers
Note : The ExchUcUtil.ps1 script creates one or more UM IP gateways for Lync integration. You must disable outgoing calls on all UM IP gateways except one gateway that the script created. This includes disabling outgoing calls on UM IP gateways that were created before you ran the script
Run OcsUmUtil.exe script on the Lync server
OcsUmUtil.exe Creates contact objects for each auto-attendant and subscriber access number to be used by Enterprise Voice users.
Verifies that the name of each Enterprise Voice dial plan matches its corresponding unified messaging (UM) dial plan phone context. This matching is necessary only if the UM dial plan is running on a version of Exchange earlier than Exchange 2010 Service Pack 1 (SP1).
If you are going to integrate UM with any IP-PBX or SBC directly then you can skip the above step.
Now we need to create a new UM IP gateway.
Open EAC click Unified Messaging and select New UM IP gateways
Give a name for the IP gateway
In the address tab give the FQDN or the IP address of the SBC or the IP-PBX that you have
Note: When you specify the FQDN on the IP-PBX or SBC then you need to create a Host A record for the same on DNS and map it to its IP.
Now select the associated dial plan that you need
Now enable the option the allow outgoing calls and allow message waiting indicator. Also set forwarding address if you wish to set forwarding address.
Click on save and we are done configuring UM dial plan and UM IP gateway in Exchange 2013.
Note: Unified Messaging requires enterprise CAL licensing.
There is no mandatory requirement for Public UM certificate.UM cert can be internal as you do not need to publish this service to the outside world, since you’ll connect via Lync to it and therefore the communicationss are all internal in that respect.