Microsoft Lync 2010 + Polycom CX Handsets Configuration

It is becoming more common now for Microsoft Lync 2010 Enterprise Voice to replace traditional PBX Telephone Systems. IT Managers generally choose not to deploy Desktop Phones when doing this and provide employees with HD Grade Headsets but they appreciate that many employees / job roles require a desktop handset.

The Polycom CX Range are optimized for Microsoft Lync 2010 and for them to work with your Lync 2010 Deployment some small configuration changes are required.

The quickest way to setup Polycom CX phone requirements (CX500, CX600 & CX3000) in Lync Environments is by using the following steps



Step 1

Login to your DNS Management Server and create the following Entries:

Record Type Example Value Notes
A Record Enterprise Edition Server: Server1.YourDomain.LocalOr


Enterprise Pool Load Balancer:


An A Record matching your Enterprise pool’s FQDN in the internal DNS to the virtual IP address of the load balancer (or IP address of the Enterprise Edition Server if you have a single server pool)
A Record sip.YourDomain.Local Required for Device Connectivity
A Record Autodiscover.YourDomain.Local Required for Microsoft Exchange UM Functionality on devices.
A Record Ucupdates-r2.SIPDomain The CS Web Services portion of the Device Update Server URL. The device appends “:443/RequestHandler/ucdevice.upx”. Make sure the HLB translates external requests to use “:4443/RequestHandler/ucdevice.upx”, i.e. the external port is 4443
A Record Reverse Proxy FQDN:Server Name.SIPDomain Allows external devices to connect via TLS over HTTP to the update server.
SRV Record _sipinternal._tcp.SIPDomain_sipinternaltls._tcp.SIPDomain Two SIP FQDNs for internal routing one for communications over TCP, and one for TCP Communications secured by TLS.
SRV Record Edge Server:_sipexternal._tls.SIPDomain_sipexternaltls.SIPDomain Allows external devices to connect via SIP over TLS to the CS Enhanced Registrar internally.


Next, you need to setup the DHCP Options for the CX Phones

  • On the Microsoft Lync 2010 Server, copy the “DHCPUtil.exe” file and the “DHCPConfigScript.bat” file from your Lync Server 2010 “soft install media” path which will look like “…Lync2010-Media-SoftSupporti386”. Into a shared folder on the server (for example: DHCPTool)
  • Map the shared folder that you created and contains the files on the DHCP Server Host
  • Run the following command on the DHCP Server

Lync.Server.IPdhcptoolDHCPUtil.exe -SipServer <Lync Server Pool FQDN > -WebServer <Lync Server Internal Web FQDN> –RunConfigScript

This command should automatically create the DHCP Options for you which are as follows:

Option Value Usage
42 NTP Server IP Address Resolve time server address in an intranet only environment with Pin Authentication.Aries doesn’t know its domain and can’t do DNS.
43 VenderClassIDSub Options

  • UCIdentifier
  • URL Scheme
  • Web Server FQDN
  • Port
  • Relative Path for Cert Provisioning
Discover server during initial bootstrap.Aries doesn’t know its domain and can’t do DNS 

Used for branch scenarios

Ex. Complete DNS Failure

120 SIP Server FQDN Specify the pool FQDN of the pool that will be the first logon server for the device. Typically this is a directory pool, but if you do not deploy a director pool, this this is the front end pool FQDN. The Pool FQDN Suffix must match the users SIP URI.

Step 3

Once you have completed that step and confirmed that the DHCP Options appear, you need to setup some users and to do this you need to do the following:

  • Create a user within Active Directory
  • Enable the user in your Lync Environment
  • Setup the user for Enterprise Voice, assign them a Line URI Example: tel+1234, 1234 would be the phone extension.
  • Then you need to create the associated PIN using the Set-CSClientPin PowerShell command, running it twice which will get the PIN which will be active.

You can also do this via the GUI if you so wish, but I have seen it not work on occasions:

Login to your Lync Server 2010 CP, Ensure that the SIP User is enabled for ‘Enterprise Voice’; they have a Line URI Value and also a ‘PIN’ number generated.


Once you have completed the steps above, your Polycom Lync Desk Phones should find the Lync Server Infrastructure and you should be able to logon using your Pin. 🙂


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