Unified CM Call Routing

Unified CM Call Routing Configuration

Configure Unified CM SIP Trunk to Expressway-C

Now that you CMS Spaces created via the LDAP configuration and the inbound call settings set up to allow calls into CMS, you need to configure the call control devices to route the calls to CMS. The two most common integration options for CMS are either directly to the Unified CM cluster or directly to Expressway-C. While there are many reasons for doing one or the other or both, for this lab you will integrate CMS initially with Expressway, and Expressway will have a SIP trunk to the Unified CM cluster. This is the best option to support Microsoft interoperability via CMS because Expressway has the capability to identify and route calls based on the variant of SIP (either Microsoft or standards-based). For this design, you will initially have only one SIP trunk from the Unified CM to the Expressway-C. This would be used for all Business to Business calling as well as CMS traffic. Later we will consider the ad-hoc conferencing use case for Unified CM endpoints, which will require additional trunks from the Unified CM to CMS.

Begin by configuring the Unified CM SIP Trunk to the Expressway-C, including SIP Trunk Security Profile, followed by the necessary dial-plan components. In short, we will configure the following:

  1. SIP Trunk Security Profile is needed because we want all calls between the Unified CM and Expressway to be secure and encrypted.
  2. Secure SIP Trunk between the Unified CM and Expressway, utilizing a default SIP Profile for Expressway/VCS and normalization script.
  3. Route Group that includes this SIP Trunk.
  4. Route List that points to the Route Group.
  5. SIP Route Pattern to route any domain ( *.* ) to Expressway.
  6. SIP Route Pattern that blocks anything for the local UCM domain (pod2.cms.lab), so that calls to the local UCM domain are never extended to Expressway, thereby avoiding a potential routing loop.

If you would like to configure the Security Profile, SIP Trunk, Route Group, and Route List, continue with the following steps. If you would like to have this configuration created automatically for you, click HERE. You should see another window pop up with the results. If the addition is successful, you can skip the next few sections and move on to the Configure Dial Plan on Unified CM configuration.

SIP Trunk Security Profile

  1. Open the browser to the CUCM1a at https://cucm1a.pod2.cms.lab
  2. Log in with username admin and password c1sco123.
  3. Navigate to System > Security > SIP Trunk Security Profile.
  4. Click Add New
  5. Enter Encrypted SIP Trunk Profile for Expc1a in the Name field.
  6. For Device Security Mode choose Encrypted
  7. In the X.509 Subject Name field enter expc1a.pod2.cms.lab
  8. Click Save

SIP Trunk to Expressway-C

  1. Now navigate to Device > Trunk
  2. Click Add New
  3. Chooose SIP Trunk as the Trunk Type
  4. Click Next
  5. Configure the following parameters:

    Parameter Value
    Device Name EXPC1A-SIP-TRUNK
    Device Pool Default
    SRTP Allowed Checked
    Run On All Active Unified CM Nodes Checked
    Calling Search Space CSS_INBOUND_EDGE
    Calling and Connected Party Info Format Deliver URI and DN in connected party, if available
    Destination expc1a.pod2.cms.lab
    Destination Port 5061
    SIP Trunk Security Profile Encrypted SIP Trunk Profile for Expc1a
    SIP Profile Standard SIP Profile for Cisco VCS
    Normalization Script vcs-interop
  6. Click Save
  7. Click OK on the popup
  8. Click Reset
  9. On the Device Reset popup click Reset
  10. Click Close

 
 
 

The SIP trunk should be put into a Route Group, which needs to then be placed in a Route List. These should already be configured for you (called RG-EXPRESSWAY1 and RL-EXPRESSWAY1), however if you need a refresher, expand the following steps.

Route Group

  1. In the Unified CM navigate to Call Routing > Route/Hunt > Route Group
  2. Click Add New
  3. For the Route Group Name enter RG-EXPRESSWAY1
  4. Select the EXPC1A-SIP-TRUNK device from the Available Devices and click Add to Route Group
  5. Click OK if you get a popup
  6. Click Save

Route List

Now configure the Route List.

  1. In the Unified CM navigate to Call Routing > Route/Hunt > Route List
  2. Click Add New
  3. For the Name enter RL-EXPRESSWAY1
  4. For the Cisco Unified Communications Manager Group, choose Default.
  5. Click Save
  6. In the Route List Member Information box, click Add Route Group
  7. Select RG-EXPRESSWAY1 as the Route Group
  8. Click Save
  9. Click Ok in the pop-up
  10. Check Run On All Active Unified CM Nodes
  11. Click Save, to save the Route List configuration.

Configure Dial Plan on Unified CM

Configure Route Patterns on Unified CM

From the LDAP import, we created Spaces for all of our users with a 7XXXXXXX pattern. Unified CM needs to have a Route Pattern to be able to call those Spaces.

From the LDAP import, we created Spaces for all of our users with a 7XXXXXXX pattern. Unified CM needs to have a Route Pattern to be able to call those Spaces.

  1. Log in to the CUCM1a at https://cucm1a.pod2.cms.lab (username: admin and password: c1sco123)
  2. Navigate to Call Routing > Route/Hunt > Route Pattern
  3. Click Add New
  4. In the Route Pattern field, enter 7XXXXXXX
  5. For Route Partition, select PT_EXPRESSWAY
  6. For Gateway/Route List, select RL-EXPRESSWAY1
  7. In the Call Classification box, select OnNet
  8. Uncheck the Provide Outside Dial Tone selection
  9. Click Save

This will allow calls to that numeric range (7XXXXXXX) to be extended to Expressway.

Configure SIP Route Patterns on Unified CM

With CMS primarily integrated to Expressway, the Unified CM dial-plan is essentially a Business-to-Business type of dial plan. Since we want to allow users to call any remote domain, we will use wildcards. We will be careful not to allow anything that matches the local Unified CM/Jabber domain, otherwise you could potentially create a loop, since the Expressway is configured to route that domain right back to the Unified CM. You will configure a wildcard pointing to Expressway and a block pattern for the local domain.

  1. Log in to the CUCM1a at https://cucm1a.pod2.cms.lab (username: admin and password: c1sco123)
  2. Go to Call Routing > SIP Route Pattern
  3. Click Add New
  4. Configure the following parameters:

    Parameter Value
    IPv4 Pattern *.*
    Route Partition PT_EXPRESSWAY
    SIP Trunk/Route List RL-EXPRESSWAY1
  5. Click Save

Now that you are routing all domain calls that do not match a local URI to the Expressway-C, you must take into account that some URIs that match the local domain pod2.cms.lab, but no user exists for that URI, will also match. You want this traffic to be dropped. Perform the following steps to configure the SIP Route String so that calls to invalid local URIs will not be routed to the Expressway-C.

  1. Go to Call Routing > SIP Route Pattern
  2. Click Add New
  3. Configure the following parameters:

    Parameter Value
    IPv4 Pattern pod2.cms.lab
    Route Partition PT_EXPRESSWAY
    SIP Trunk/Route List RL-EXPRESSWAY1
    Block Pattern Checked
  4. Click Save