Cisco Unified Communications Manager (CallManager)

Document ID: 45704

Contents

Introduction
Prerequisites
      Requirements
      Components Used
      Conventions
Installation
UKNP Activation
      Route Filter for Basic Access
      Local Access
Partition Use
National Toll Bypass
      Extended National Toll Bypass
Number Blocking
Interdigit Timeouts
Troubleshoot
Appendix A - UK PSTN Numbering Overview
Appendix B - Filter Categories
      Tag Combinations
Appendix C - Digit Discard Instructions
Appendix D - Five-digit Subscriber Numbers
NetPro Discussion Forums - Featured Conversations
Related Information

Introduction

This document provides information about how to install and configure the United Kingdom Numbering Plan (UKNP).

Prerequisites

Requirements

Readers of this document should have knowledge of Cisco CallManager route patterns and dial plans.

Components Used

The information in this document is based on Cisco CallManager 3.3(4), 4.0(1), and later.

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Conventions

Refer to Cisco Technical Tips Conventions for more information on document conventions.

Installation

Follow these steps to install the UKNP on the Cisco CallManager Publisher and on all Subscribers:

1. Download the latest International Dial Plan for Great Britain from International Dial Plan Software Downloads.

2. Run the installation file on the Publisher Call Manager.

   Follow the instructions.

3. Restart the Cisco CallManager service.

   This allows the changes made by the installation file to take effect.

4. Run the installation on all Subscribers.

UKNP Activation

To activate the UK Numbering Plan, add a route pattern with the @ symbol in it. Make sure that you select UKNP (United Kingdom Numbering Plan) and not the NANP (North American Numbering Plan).

This allows full access the UK public switched telephone network (PSTN). All valid UK numbers can be dialed without restriction. However, restrictions can be applied using Route Filters, which is detailed in the next section (Route Filter for Basic Access).

Route Filter for Basic Access

In most systems, it is usually desirable to block calls to some numbers (premium rate, directory services, and so forth). Most categories of numbers can be blocked in a route filter. See Appendix B - Filter Categories for all categories.

1. Add a new route filter and select the United Kingdom Numbering Plan.

2. Enter a name for the filter.

3. Change the filter category settings to DOES-NOT-EXIST for categories to which you want to block access.

   Leave others at NOT-SELECTED.

   (PREMIUM-RATE-NUMBER DOES-NOT-EXIST AND
   DIRECTORY-SERVICE DOES-NOT-EXIST AND
   INTERNATIONAL-ACCESS DOES-NOT-EXIST)

   This example will block calls to numbers that start with 090 and 091, 118XXX directory services, and international numbers.

4. Apply the route filter to the route pattern.

   In this example, with a 9.@ route pattern, a user that dials 9091, 9118, or 900 hears a “number unobtainable” tone.

Local Access

In the UK, local subscriber numbers can be 5, 6, 7, or 8 digits long, which depends on the area code. The UKNP contains four route patterns that overlap, for local access:

LOCAL-5-DIGIT

LOCAL-6-DIGIT

LOCAL-7-DIGIT

LOCAL-8-DIGIT

You must modify the route filter so that only the required local subscriber route pattern or patterns are selected. If not, you might get interdigit timeouts when you dial local numbers and service codes.

For example, a gateway in a 2-digit area code with 8-digit subscribers has this filter:

(LOCAL-5-DIGIT DOES-NOT-EXIST AND
LOCAL-6-DIGIT DOES-NOT-EXIST AND
LOCAL-7-DIGIT DOES-NOT-EXIST)

If you have gateways in different area codes, then use a route pattern and appropriate filter for each gateway.

For areas with mixed 5-digit and 6-digit subscribers, a more complex filter is needed to avoid interdigit timeouts. For example, Bodmin has 5-digit subscribers in the range 72XXX to 79XXX, but the rest of the area is 6-digit. Therefore, it has this filter:

(LOCAL-6-DIGIT == [2-689]XXXXX) OR
(LOCAL-6-DIGIT == 7[01]XXXX) OR
(LOCAL-5-DIGIT == 7[2-9]XXX)

The OR statements appear when you add a new Clause to the filter. See Appendix D - Five-digit Subscriber Numbers for lists of area codes with 5-digit subscribers.

Partition Use

For more complicated systems, you can split the dial plan up into various partitions with the use of route patterns and route filters, as desired:

(LOCAL-6-DIGIT EXISTS)

(INTERNATIONAL-ACCESS EXISTS AND
COUNTRY-CODE EXISTS AND
NATIONAL-NUMBER EXISTS)

(NATIONAL-ACCESS EXISTS AND
PREMIUM-RATE EXISTS)

(NATIONAL-ACCESS EXISTS AND
AREA-CODE EXISTS AND
SUBSCRIBER EXISTS)

(NATIONAL-ACCESS EXISTS AND
MOBILE-ACCESS EXISTS AND
MOBILE-SUBSCRIBER EXISTS)

(SERVICE EXISTS AND
DIRECTORY-SERVICE EXISTS)

Partitions can then be assigned to Calling Search Spaces as normal. See Appendix B - Filter Categories for valid Tag Combinations.

National Toll Bypass

To use this numbering plan in a National Toll Bypass configuration, set up a route filter to filter desired area codes. For example, calls from the London office to the Reading area can be routed as local calls through a gateway in the Reading office:

(AREA-CODE == 118)

If you want, you can set the Digit Discard Instructions (DDIs) to one that specifies Nat->Local. This removes the leading 0 and the area code.

Extended National Toll Bypass

Suppose you want to take advantage of the fact that calls from one area to neighboring areas are charged at the local rate rather than the national rate. (British Telecom [BT] only, other operators might charge differently.)

For example, calls from Reading (118) to Nettlebed (1491), Maidenhead (1628), Ascot (1276), Bracknell (1344), Aldershot (1252), Basingstoke (1256) and Newbury (1635) are charged at the local rate. Therefore, you can route calls for all of these areas out of the Reading gateway and only be charged the local rate:

(AREA-CODE == 118) OR
(AREA-CODE ==1491) OR
(AREA-CODE ==1628) OR
(AREA-CODE ==1276) OR
(AREA-CODE ==1344) OR
(AREA-CODE ==1252) OR
(AREA-CODE ==1256) OR
(AREA-CODE ==1635)

The OR statements appear when you add a new Clause to the filter.

Tip: Refer to the BT site for details of neighboring areas.

Note: You can not remove the area code and leading 0 for these extra areas, so leave the Digit Discard Instructions as just Pre-Dot or none.

Number Blocking

You can use a route filter to block certain numbers.

Set up a route pattern and route filter that specifies a particular number, or use wildcards to block ranges of numbers:

(AREA-CODE == 20) AND
(SUBSCRIBER == 88244000)

(MOBILE-ACCESS == 7973) AND
(MOBILE-SUBSCRIBER == 83XXXX)

Click the Block this Pattern radio button on the Route Pattern page.

Interdigit Timeouts

Dial plans that overlap cause interdigit timeouts, which are the amount of time that CallManager waits for additional key presses before it decides that the user has finished dialing the number and routes the call. The default timeout is 15 seconds, which can be quite noticeable.

The UKNP tried to remove as many interdigit timeouts as possible.

• In the geographical numbering ranges, this has been programmed into the plan.

• For local access, a filter that specifies the local dialing length is needed (see the Local Access section).

• Some 0800 Freephone numbers are 10 digits and some are 11 digits. It is impractical to program so many variations into the dial plan, so interdigit timeouts exist in this range.

• On international calls, except to North America (country code 1), there will still be interdigit timeouts.

These are recommendations to reduce the impact of interdigit timeouts:

• Reduce Service Parameter T302 from 15 seconds to around 5 seconds.

• Train users to press # after they dial the number, because the plan allows for this and # immediately cancels the T302 timer.

Troubleshoot

You can use these tips to help troubleshoot route pattern and route filter issues with the UKNP:

• Turn Cisco CallManager tracing up to Detailed, so that Digit Analysis is visible.

• Use the Dialed Number Analyzer—which you must install from the Plug-ins menu—to show pattern matching.

Appendix A - UK PSTN Numbering Overview

The UK PSTN does not have a uniform structure like the NANP. Area codes can be 2, 3, 4, or 5 digits; subscriber numbers can be 5, 6, 7, or 8 digits; and service codes can be 3, 4, 5, or 6 digits. National numbers can be 10 or 11 digits (including the leading 0).

Note: The leading 0 is not considered part of the area code, although it is commonly written that way.

These are the rules for geographic numbers:

• 2-digit area codes have 8-digit subscribers.

• 3-digit area codes have 7-digit subscribers.

• 4-digit area codes have 6-digit subscribers.

• Some 4-digit area codes have both 5- and 6-digit subscribers.

• 5-digit area codes have 5-digit subscribers.

• Some 5-digit area codes overlap with 4-digit area codes.

As previously stated, national numbers have either 10 or 11 digits (including the leading 0); they are in the format 0SABCXXXXXX.

There are also two 8-digit short numbers:

• Childline—08001111 (Freephone)

• NHS Direct—08454647 (local rate)

Appendix B - Filter Categories

NATIONAL-ACCESS

AREA-CODE

SUBSCRIBER

INTERNATIONAL-ACCESS

COUNTRY-CODE

NATIONAL-NUMBER

SERVICE

DIRECTORY-SERVICE

FREEPHONE-NUMBER

CORPORATE-NUMBER

MOBILE-ACCESS

MOBILE-SUBSCRIBER

PAGING-ACCESS

PAGING-SUBSCRIBER

PERSONAL-ACCESS

PERSONAL-SUBSCRIBER

LOCAL-RATE-ACCESS

LOCAL-RATE-SUBSCRIBER

NATIONAL-RATE-ACCESS

NATIONAL-RATE-SUBSCRIBER

PREMIUM-RATE-NUMBER

BROADBAND-SERVICE

SPECIAL-RATE-ACCESS

SPECIAL-RATE-SUBSCRIBER

LOCAL-5-DIGIT

VOIP-NUMBER

LOCAL-6-DIGIT

LOCAL-7-DIGIT

LOCAL-8-DIGIT

* Number lengths do not include the leading 0 for national numbers.

Tag Combinations

INTERNATIONAL-ACCESS:COUNTRY-CODE:NATIONAL-NUMBER
INTERNATIONAL-ACCESS:COUNTRY-CODE:NATIONAL-NUMBER:END-OF-DIALING
NATIONAL-ACCESS:AREA-CODE:SUBSCRIBER
NATIONAL-ACCESS:MOBILE-ACCESS:MOBILE-SUBSCRIBER
NATIONAL-ACCESS:FREEPHONE-NUMBER
NATIONAL-ACCESS:FREEPHONE-NUMBER:END-OF-DIALING
NATIONAL-ACCESS:LOCAL-RATE-ACCESS:LOCAL-RATE-SUBSCRIBER
NATIONAL-ACCESS:CORPORATE-NUMBER
NATIONAL-ACCESS:BROADBAND-SERVICE
NATIONAL-ACCESS:PAGING-ACCESS:PAGING-SUBSCRIBER
NATIONAL-ACCESS:PREMIUM-RATE-NUMBER
NATIONAL-ACCESS:NATIONAL-RATE-ACCESS:NATIONAL-RATE-SUBSCRIBER
NATIONAL-ACCESS:SPECIAL-RATE-ACCESS:SPECIAL-RATE-SUBSCRIBER
NATIONAL-ACCESS:PERSONAL-ACCESS:PERSONAL-SUBSCRIBER
NATIONAL-ACCESS:VOIP-NUMBER
SERVICE
DIRECTORY-SERVICE
LOCAL-5-DIGIT
LOCAL-6-DIGIT
LOCAL-7-DIGIT
LOCAL-8-DIGIT

Appendix C - Digit Discard Instructions

Nat->Local

Nat->Internat

Internat->Nat

Mobile->Internat

InternatDirectDial

Note: When you apply an inappropriate DDI, called numbers are truncated. For example, when you apply Nat->Local to a Freephone number.

Appendix D - Five-digit Subscriber Numbers

NetPro Discussion Forums - Featured Conversations

Related Information

• Ofcom , the UK Media regulator
• UK Phone Information
• Cisco CallManager International Dial Plan Deployment Guide
• International Dial Plan Software Downloads
• Route Filter Configuration
• Voice Technology Support
• Voice and IP Communications Product Support
• Recommended Reading: Troubleshooting Cisco IP Telephony
• Technical Support & Documentation - Cisco Systems