The dial plan is one of the most important components of a Unified Communications system. Indeed, it is an integral component of all call processing agents. Generally, the dial plan is the decision maker and instructs the call processing agent on how to route the calls. Essentially, dial plan rules govern how user input is processed for making calls. Moreover, we can describe the dial plan with the following main functions:
Endpoint addressing
Firstly, all endpoints (such as IP phones, analog phones, and fax machines) and applications (such as voice-mail systems, auto attendants, and conferencing systems—all these through CTI ports) have their own directory numbers.
Path selection
Secondly, Depending on the calling device, one can select different paths to reach the same destination. For instance, this is a typical example when the primary path between two branches via the WAN is unavailable due to a failure. In that case, we can configure a backup route to route the call through the public PSTN network. Moreover, dialing patterns and user inputs are analyzed by call management systems, recognizing area codes and country codes to influence the routing of calls.
Calling privileges
Furthermore, by granting or denying access to certain destinations, we can assign different classes of service to the different groups of devices. As I have said, we should restrict the automatically configured phones to only handling emergency calls. Subsequently, we can have different types of employees with varying levels of access. For example, some employees can only initiate internal calls, while others can only initiate local calls. Finally, there are unrestricted users who have the ability to initiate even international calls. However, it is crucial to ensure that all users have unrestricted access to emergency services, such as 911 or 112, at all times.
Digit manipulation
Additionally, when we are initiating a call to the PSTN network, we have to convert our internal numbers to match the public numbering plan. Typically, our provider (Telco) gives us a range of numbers that we can use, and if we are initiating calls from our own network, we must present ourselves with these numbers. Otherwise, the provider is likely to reject the calls. In this case, it is necessary to manipulate the dialing string before routing the call. This often involves using the country code to reformat numbers for compatibility with local dialing formats. However, as you know, in most cases, we use a prefix to get access to the outgoing line. In this situation, we must modify the dialed number to remove the prefix.
Call coverage
Finally, endpoints or outgoing links can be classified into special groups. Given that these groups can handle the incoming calls for a certain service by following different rules: top-down, circular, longest idle, or broadcast. At this point, the digit analysis function determines which calls are appropriate for a user, an endpoint (IP Phone), a gateway, or a trunk. In this function, the implementation of call privileges takes place. We implement digit analysis using the following fundamental constructs:
- Patterns are numerical representations of telephone numbers that, when matched, trigger call routing. Specifically, for directory numbers, the patterns can match exactly, but for route patterns, they can also contain masked numbers. Furthermore, if the dial plan contains more than one match for a specific destination, it will use the most exact match.
- We use partitions to divide patterns into logical groups. Generally, to maintain control over your dial plan, assign all dialable patterns to a specific partition. This is for the same reason why carefully planning your dial plan is crucial.
- Calling search spaces—read it once again. As has been noted, the name is almost self-explanatory. The calling search spaces allow control over what groups of patterns can be accessed from a particular device. To put it another way, what are the dialed numbers? Alternatively, consider this: which gateways or trunks should a user utilize to initiate a call? For instance, all voice gateways in your branches use the same prefix to access them—0 or 9 in most cases. However, every phone in each branch uses a local gateway to reach the PSTN.
A call routing function controls the path selection for a call. For this purpose the function selects IP trunks or voice gateways with T1, E1, or ISDN interfaces to carry a specific call. Moreover, the call routing function also takes care of the automated failover when the primary path is not accessible, whether it is a problem with the media or a lack of resources (bandwidth).
Task 1: Configure Dial Plan Intrasite Routing
In this case, we will configure intrasite routing for San Jose and Chicago. Specifically, this involves setting up dial plans to manage call routing rules within the telecommunications system.
By the end of this task, you will understand the routing process, including the steps involved in directing calls through various nodes and applying rules to efficiently manage call routes.
Dial Plan Design for Intra-Site Routing
The following tables demonstrate the dial plan design for intra-site routing. Routing rules play a crucial role in this design, dictating the steps a call must follow during the routing process.
Partitions: Intra-Site Routing
| Partition | Description |
|---|---|
| SJC-Phones | Contains all San Jose phones. |
| CHI-Phones | Contains all Chicago phones. |
CSS: Intra-Site Routing
| CSS | Partition | Description |
|---|---|---|
| SJC-Everywhere-CSS | SJC-Phones | Contains all San Jose phones. |
| CHI-Everywhere-CSS | CHI-Phones | Contains all Chicago phones. |
Route Plan: Intra-Site Routing Summary
| Pattern | Partition | Type | Destination | Digit Manipulation | Description |
|---|---|---|---|---|---|
| 2001 | SJC-Phones | DN | SJC-Everywhere-CSS | NA | Phone1-1 |
| 2002 | SJC-Phones | DN | SJC-Everywhere-CSS | NA | Phone1-2 |
| 3001 | CHI-Phones | DN | CHI-Everywhere-CSS | NA | Phone2-1 |
| 3002 | CHI-Phones | DN | CHI-Everywhere-CSS | NA | Phone2-2 |
Activity Procedure
Complete these steps:
- First, Login with your credentials on the CUCM Administration page. From the menu, select Call Routing > Class of Control > Partitions.
- Then, click the Add new button.
- In the next step, type in all the partitions according to the first table above and click Save.
- To confirm the partition additions to the system, click Find.
- Now, on the Cisco Unified Communications Manager Administration page, select Call Routing > Class of Control > Calling Search Space from the menu.
- After that, Click the Add new button.
- For the Name field, type in the Calling search space’s name, and select the partitions that will be assigned to this Calling search space. Note that both Calling Search Spaces will only include the partition specific to their respective sites.
- Once done, Click Save.
- Now, Repeat steps 6–8 for all of the calling search spaces described in the table above.
- When configuring calling search spaces, consider how dial strings are used to translate various dialing formats to a standardized E.164 format for accurate call routing.
- Next, on the Cisco Unified Communications Manager Administration page, choose Device > Phone from the menu. Click Find to display all phones.
- Click Phone1-1 to modify it.
- Now Click on line 1.
- In the directory number configuration, assign the route partition according to the table.
- Next, assign the calling search space in accordance with the table.
- Finally, click Save.
- Remember to Click Reset the phone.
- Repeat steps 10–16 for all phones (use the configuration table as a reference).
Activity Verification
Once you achieve these results, you have successfully completed this task.
- SanJose phones (Phone 1-1 and Phone 1-2) can only call each other. Any attempt to call non SanJose phone will fail.
- Chicago phones (Phone2-1 and Phone2-2) can only call each other. Any attempt to call non Chicago phone will fail.
- Verify that the dialed string is correctly recognized and routed within Unified CM, ensuring calls follow the intended paths and rules.
Task 2: Configure Dial Plan On-Cluster Intersite Routing
In this task, you will configure on-cluster intersite routing between San Jose and Chicago. This involves managing remote call control to ensure accurate identification of call destinations, whether on-net or off-net, for efficient routing decisions.
You will also learn how to route calls by configuring route patterns, utilizing local gateways, and employing dial plans to control how outbound calls are directed to external networks.
Dial Plan Design for Intersite Routing
The tables that follow show the dial plan design for intersite routing.
Partitions: Intersite Routing
| Partition | Description |
|---|---|
| IntersiteRouting | Used for intersite routing. |
CSS: Intersite Routing
| Calling Search Space | Partition | Description |
|---|---|---|
| SJC-Everywhere-CSS | SJC-Phones IntersiteRouting |
Contains all San Jose phones. |
| CHI-Everywhere-CSS | CHI-Phones IntersiteRouting |
Contains all Chicago phones. |
Route Plan: Intersite Routing Summary
| Pattern | Partition | Type | Destination | Digit Manip. | Description |
|---|---|---|---|---|---|
| 802.3XXX | IntersiteRouting | TP | CHI-Everywhere-CSS | PreDot | Routes calls to Chicago |
| 801.2XXX | IntersiteRouting | TP | SJC-Everywhere-CSS | PreDot | Routes calls to San Jose |
Activity Procedure
Complete these steps:
- Firstly, add the IntersiteRouting partition.
- Next, add partition IntersiteRouting to Calling search space SJC-Everywhere-CSS and CHI-Everywhere-CSS. To accomplish this, follow the steps below: On the Cisco Unified Communications Manager administration page, from the menu, select Call Routing > Class of Control > Calling Search Space\
- click Find
- Next, click on calling search space CHI-Everywhere-CSS.
- On the Calling Search Space configuration page, highlight the partition IntersiteRouting, click the middle down arrow, and then select Save.
- Now, repeat steps 3–5 for calling the search space SJC-Everywhere-CSS. This step is crucial in the routing process as it ensures that calls are directed correctly between sites by configuring intersite routing.
- The next steps will include adding a translation pattern.
- On the Cisco Unified Communications Manager administration page, navigate to the Call Routing > Translation Pattern menu.
- Then, click Add New.
- Now, use the following parameters for the new translation pattern:\
- Translation pattern : 802.3XXX\
- Partition : IntersiteRouting\
- Calling Search Space : CHI-Everywhere-CSS\
- Use Calling party’s External Phone number mask : Checked\
- Discard Digits: PreDot
- Click Save.
- To implement the new translation pattern, repeat steps 8–10 using the following parameters:\
- Translation pattern : 801.2XXX\
- Partition : IntersiteRouting\
- Calling Search Space : SJC-Everywhere-CSS\
- Use Calling party’s External Phone number mask : Checked\
- Discard Digits: PreDot
Activity Verification
Once you achieve these results, you have successfully completed this task.
- Now IP Phones in SanJose (Phone 1-1 and Phone 1-2) and Chicago (Phone 2-1 and Phone 2-2) can call each other. However, to initiate a call, a site code is required. In this case, SanJose’s site code is 801, and Chicago’s site code is 802.
- Ensure that the call routing configuration is verified to accurately manage each incoming call based on the site codes.
Task 3: Configure Dial Plan Intrasite PSTN Routing
In this task, you will configure intrasite and PSTN routing for San Jose and Chicago. The configuration will also consider the behavior and preferences familiar to users of mobile phones, especially in terms of call presentation and number formatting.
You will need to define routing rules that dictate the steps a call must follow during the routing process, including the configuration of nodes in a dial plan editor and the application of policies for advanced routing in systems like Cisco VCS.
| Partition | Description |
|---|---|
| SJC-PSTN | San Jose access to the PSTN lines. |
| CHI-PSTN | Chicago access to the PSTN lines. |
- CSS: PSTN Routing
| Calling Search Space | Partitions | Description |
|---|---|---|
| SJC-Local-CSS | SJC-Phones IntersiteRouting |
San Jose phones with local access only. |
| SJC-Everywhere-CSS | SJC-Phones IntersiteRouting SJC-PSTN |
San Jose phones with full access. |
| CHI-Local-CSS | CHI-Phones IntersiteRouting |
Chicago phones with local access only. |
| CHI-Everywhere-CSS | CHI-Phones IntersiteRouting CHI-PSTN |
Chicago phones with full access. |
- Route Plan: PSTN Routing Summary
| Pattern | Partition | Type | Destination |
|---|---|---|---|
| 9.! | SJC-PSTN | RP | 10.1.1.101 |
| 9.! | CHI-PSTN | RP | 10.1.1.102 |
Activity Procedure
Complete these steps:
- Add new Partitions and calling search spaces according to the tables above.
- Modify the existing Everywhere calling seaerch spaces to contain the newly added partitions.
- On Cisco Unified Communications Manager administration page, from the menu select Call Routing > Route/Hunt > Route Pattern.
- Click Add New.
- Use the following parameters for the new route pattern:
– Route pattern: 9.!
– Partition: SJC-PSTN
– Gateway/Route-list: 10.1.1.101 - Click Save.
- Click Ok.
- Repeat steps 3 – 6 for all route patterns in the table.
- For Phone1-1, Phone1-2, Phone2-1 and Phone2-2, assign to their lines the proper calling search space. On Cisco Unified Communications Manager administration page, from the menu select Device > Phone. Click Find to display all phones.
- Click Phone1-1 to modify it.
- Click on line 1.
- For the calling search space, assign the Calling Search Space according to the bullet list below:
– Assign Calling Search space SJC-Everywhere-CSS to the line of Phone1-1
– Assign Calling Search space SJC-Local-CSS to the line of Phone1-2
– Assign Calling Search space CHI-Everywhere-CSS to the line of Phone2-1
– Assign Calling Search space CHI-Local-CSS to the line of Phone2-2 - Click Save.
- Click Reset the phone.
- Repeat steps 9 – 13 for all phones.
- Modify the gateways configuration. On the CUCM Administration page, from the menu select Device > Gateway and click Find.
- Click 10.1.1.101 to modiofy it.
- On Call Routing Information – Inbound Calls, configure SJC-Local-CSS as a Calling Search Space.
- Click Save and Apply Config.
- Repeat steps 16 – 19 for the second gateway 10.1.1.102 and configure CHI-Local-CSS as a Calling Search Space for the Inbound calls.
Activity Verification
You have completed this task when you attain these results:
- Now Phone1-1 and Phone2-1 can call eachother by using their public (DID) numbers, going through the PSTN network.
- Now Phone1-2 and Phone2-2 can only call through the Inter-site codes, but NOT through the public network.
