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Monthly Archives: June 2010

How to configure a SIP trunk between Cisco Call Manager 5.x or 6.x or 7.x and OCS 2007 R1 or R2

If you want to ring from MOC to Cisco IP phone and back, then simple we will deal with it as if OCS is an IP PBX with its extensions 3xxx and you need to connect it with Cisco PBX with extensions 7xxx.

To do that we need a SIP trunk and for the SIP trunk to work fine we need to have some specific configuration on that trunk , remember any of these settings if they not configured right then you will not be able to make a stable calling between Cisco and OCS.

First we do the SIP trunk:







Now the SIP trunk which is acting like the bridge between the Cisco and the OCS is created, ok then we need now to create a criteria where this trunk is going to be used in. This is where is Pattern comes in where we will say if a Cisco phone set tries to dial extensions starting with 3xxx then you use the trunk which we have just created .

And from the way back from the OCS to Cisco, when the number is sent in the E164 format with the +, the Cisco will simply ignore all that and will take only the last 4 Digits which are the 7xxx.

Now you are ready to make the call and for the complete configurations from OCS side see this Guide.

Integration between OCS 2007 R2 and Tandberg server

1. Start the OCS interface by going to Start > Administrative Tools > Office Communications Server 2007.

2. OCS uses TLS by default; therefore TCP needs to be enabled in addition:

i. Right-click on the fully-qualified domain name (e.g., then select Properties > Front end properties.

ii. The Front End Server Properties dialog appears. Click Add.

iii. For IP Address, select All.

iv. For Port, enter 5060.

v. For Transport, select TCP.

vi. Click OK twice.

3. From software version 2.4(1) onwards, NTLM authentication is supported so the MCU can register to OCS by using a user account and password setup on the server. If you use that method, skip to step 5. To set the MCU as a trusted host, go to step 4.

4. Right-click on the server name (e.g. ocs-server) and select Properties > Front end properties. In the Host Authorisation tab click Add and enter the IP address of the MCU / IP VCR / IP GW that will register with OCS. Tick the Treat as Authenticated check box.

5. On the OCS server, set up a user for the MCU / IP VCR / IP GW:

i. Go to Start > Administrative Tools > Active Directory Users and Computers.

ii. Right-click on Users and select New > User.

iii. Enter a name for the MCU / IP VCR / IP GW (that will appear in people’s buddy lists) and give it a logon name of the form “”.

iv. Click Next.

v. Enter a password for the MCU / IP VCR / IP GW. Note that if you added the MCU as an authenticated host this is unused. Untick the check box that will prompt the user to change their password next time they log in, and tick the check box that display the message that the password never expires.

vi. Click Next, then click Finish.

6. In the list of users, double click on the MCU / IP VCR / IP GW that you just created and select Communications.

7. Select Enable user for Office Communications Server.

8. Enter the login name, now prefixed with “sip:”. In our example this would be “”.

9. Select the server name from the Server or Pool drop-down list and click OK.

10. Repeat steps 5 to 9 for any conferences and auto attendants that you wish to register. In step 8 the login that you choose should be the numeric ID of the conference/recording or auto attendant. Then:

– For each conference, select it from the Conference list on the MCU and click Configuration, then select SIP registrar. Then go to Settings > SIP and for SIP registration setting, select Allow Conference Registration.

– For each recording, select it from the Recording list on the IP VCR and select the SIP registrar. Then go to Settings > SIP and for SIP registration setting, select Allow Recording Registration.

11. On the MCU / IP VCR / IP GW, go to Network > Services and enable Incoming SIP (TCP) and SIP (UDP) for port A (and for port B, if it is enabled).

12. Go to Settings > Conferences and for Incoming call to unknown E.164 number select Default auto attendant.

13. Go to Settings > SIP.

14. If you did not register conferences, recordings or auto attendants individually in step 10, then for SIP registration setting select Register MCU, Register IP VCR or Register IP GW. Otherwise choose Allow conference registration or Allow Reordering registration, as appropriate.

15. Enter the address or host name of the OCS server into the SIP registrar address field.

16. For SIP registrar type, select Microsoft LCS.

17. Enter the username, e.g. If you are using NTML authentication, enter the password for the account that you configured in step 5. v.

18. For Audio codec, select G.723.1. This gives a better frame rate for OCS than using G.711u. The remaining fields can be left as their defaults.

19. Click Apply changes. The screen will refresh, including an indication that the unit is registered. (This may take a second or two to process: you may need to refresh the page again to see it).

20. The MCU / IP VCR / IP GW can now be entered into buddy lists in Office Communicator and called into video and audio calls.

21. To call from the MCU / IP VCR :

i. Go to the Add Participant page (MCU) or either the Call out and record or Call out and play recording page (IP VCR).

ii. For Address/Host name or IP Address, type the user name without the domain (i.e. “example name” not “”).

iii. For Call protocol, select SIP.

iv. Select Use SIP registrar.

v. Click Call endpoint.

22. To call from the IP GW, set up a dial plan rule whose action type is ‘SIP Registrar’ using the online help if necessary.