Telephony Signaling

Document ID: 53049

Contents

Introduction
Prerequisites
      Requirements
      Components Used
      Conventions
E1 R2 Configuration Examples
      Mexico Telmex Modified
      Argentina Telecom
      Venezuela CANTV
      Brazil
      China
E1 R2 Caveats
E1 R2 Recent Commands
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Related Information

Introduction

R2 signaling is a channel associated signaling (CAS) system developed in the 1960s that is still in use today in Europe, Latin America, Australia, and Asia. R2 signaling exists in several country versions or variants, in an international version called Consultative Committee for International Telegraph and Telephone (CCITT-R2). The R2 signaling specifications are contained in ITU-T Recommendations Q.400 through Q.490.

E1 R2 signaling is an international signaling standard that is common to channelized E1 networks. E1 R2 signaling has been supported on the Cisco AS5200, 5300, and 5800 series access routers. E1 R2 signaling was introduced to the Cisco 2600/3600 series routers in Cisco IOS® Software Release 12.1.2XH and 12.1(3)T. E1 R2 is also supported on the E1 voice WAN interface cards (VWICs), which can be inserted into the WIC slot on the IAD2430s. Furthermore, Cisco AS5350, 5400, and 5850 also support this application.

Note: R2 signaling is not supported on the Cisco MC3810 router.

The purpose of this document is to offer some example configurations and important guidelines that will help customers set up an R2 interconnection. Troubleshooting is not covered as part of this document. For information on troubleshooting E1 R2, refer to E1 R2 Signaling Configuration and Troubleshooting.

Prerequisites

Requirements

There are no specific requirements for this document.

Components Used

This document is not restricted to specific hardware versions; however, some software recommendations are made. These recommendations are based on the fact that major software defects that are related to this technology have been identified and addressed by the respective versions. Nonetheless, extensive testing is required before you use the software in a production environment.

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.

E1 R2 Configuration Examples

This section provides a list of functional configuration examples that have been tested. These examples should be used as a reference when you provision E1 R2 in countries where the default settings do not apply.

Note: Only the commands under cas-custom are shown. The configuration of voice ports and dial peers is not covered. Cisco IOS Software Release 12.3(9) was used to test these configurations.

Mexico Telmex Modified

controller E1 0/0
 framing NO-CRC4
 ds0-group 1 timeslots 1-15,17-30 type r2-digital r2-compelled ani
 cas-custom 1
  country telmex
  category 2
  answer-signal group-b 1

Note: In some implementations, Telmex requires that Group A signals be used for automatic number identification (ANI) collection. If this is needed, add the command groupa-callerid-end under cas-custom. If this command is not configured, the router uses the country default (a Group C signal).

Argentina Telecom

controller E1 0/0
ds0-group 0 timeslots 1-15,17-31 type r2-digital r2-compelled ani
framing NO-CRC4
 cas-custom 0
  country argentina
  dnis-complete

Note: For most configurations, Telecom Argentina requires that an I-15 signal be sent after the last DNIS digit is dialed. If this is the case, configure dnis-complete. By default, an I-12 signal is used.

Venezuela CANTV

For incoming calls:

controller E1 0/0
 framing NO-CRC4
 ds0-group 0 timeslots 1-15,17-31 type r2-digital r2-compelled ani
 cas-custom 0
  country venezuela
  answer-signal group-a 6
  dnis-complete

Note: CANTV Venezuela uses A6 for answer signal.

For outgoing calls:

controller E1 0/2/0
 framing NO-CRC4
 ds0-group 1 timeslots 1-15 type r2-digital dtmf dnis

Brazil

controller E1 0/0
 framing NO-CRC4
 ds0-group 0 timeslots 1-15,17-31 type r2-digital r2-compelled ani
 cas-custom 0
  country brazil
  category 2
  answer-signal group-b 1

Note: Some Telefonica circuits require metering to be enabled. If needed, add the metering command under cas-custom.

China

controller E1 0/0
 framing NO-CRC4
 ds0-group 0 timeslots 1-15,17-31 type r2-digital r2-compelled ani
 cas-custom 0
  country china
  answer-signal group-b 1

E1 R2 Caveats

The following is a list of software caveats related to E1 R2. In order to follow these bug ID links and see detailed bug information, you must be a registered user and you must be logged in.

E1 R2 Recent Commands

Cisco has recently added new commands for E1 R2 implementations, to improve the flexibility of this application and to meet customer demands. These are the most important commands:

• alert-wait-time—Time to wait for alert indication for incoming R2 calls. Default is 15 seconds.

• call guard-timer—To set a guard timer to accept or reject a call, in the event that the RADIUS server fails to respond to a pre-authentication request.

• cause-on-congestion—Translates the R2 congestion signal to the ISDN cause value, in order to return this value to the originating voice gateway.

• disconnect-tone—Provides a tone to the calling party after the ending Group B register signal.

• signal-end-to-end—Transfer R2 Category and Answer signals end-to-end.

• trunk-group label —Configure interface to be in a trunk group.

  Note: Some of those commands are platform-specific. Refer to the Command Lookup Tool for details about every option.

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Related Information

• E1 R2 Signaling Configuration and Troubleshooting
• E1 R2 Signaling for the Cisco AS5300 and Cisco AS5200 Access Servers
• E1 R2 Signaling for the Cisco 3620 and 3640 Series Routers
• E1 R2 Signaling for the Cisco AS5800
• Voice Technology Support
• Voice and Unified Communications Product Support
• Recommended Reading: Troubleshooting Cisco IP Telephony
• Technical Support & Documentation - Cisco Systems